503 service temporarily unavailable 503 service temporarily unavailable nginx/1.14.1 503 service temporarily unavailable 503 service temporarily unavailable nginx/1.14.1 503 service temporarily unavailable 503 service temporarily unavailable nginx/1.14.1 503 service temporarily unavailable 503 service temporarily unavailable nginx/1.14.1 503 service temporarily unavailable 503 service temporarily unavailable nginx/1.14.1 503 service temporarily unavailable 503 service temporarily unavailable nginx/1.14.1 503 service temporarily unavailable 503 service temporarily unavailable nginx/1.14.1 welcome to studies in digital heritage    1: i welcome to the first issue of studies in digital heritage (sdh)! sdh offers professionals active in the field of digital heritage the opportunity to publish their work, at no cost, in an online, peer-reviewed open access journal with three issues per year. topics appropriate for the journal cover the entire workflow of cultural heritage studies, from discovery and documentation of monuments to analysis, interpretation, and public outreach. articles should highlight the role of digital technology in facilitating cultural heritage research and applications. sdh is especially eager to publish work that is innovative and creative in one of two ways: articles whose importance depends on the value of the cultural object studied; and those presenting innovations in digital technologies. for example, an article presenting a new insight or discovery about a key monument such as the temple of zeus at olympia would be appropriate for the journal, as long as that insight arose from the application of digital technology. equally of interest to sdh are articles about purely technical advances of direct application in one of the fields of cultural heritage. in addition to articles, sdh also publishes mediated blogs; reviews of books, software, and hardware; and review articles summarizing the state of the technology or art regarding any digital heritage topic or discussing the advantages and disadvantages of different approaches to a given task the content of blogs can vary widely, including, e.g., a comment (whether critical or constructive) about an article we have published, the announcement of an upcoming conference with related call for papers, etc. articles may be as long as 10,000 words, or, with special permission, even longer. in addition to text and images, sdh supports the following embedded media: audio, video, and interactive 3d models using a webgl solution such as 3dhop, sketchfab, or unity. once an article has been submitted, it is assigned to an editor, who, in turn, recruits a minimum of two and, ideally, three referees. identifying suitable readers can sometimes take a month or more. referees are generally given one month to write their reports. our goal is to act on submissions within two or, at most, three months of submission. as with most journals, submissions can be accepted, accepted subject to revision, or rejected. if an article is accepted subject to revision, the original referee requesting changes is consulted before the new version is accepted and published. welcome to studies in digital heritage    1: ii sdh encourages authors to team up to propose special issues for the consideration of our editorial board. we also encourage authors to volunteer to serve as reviewers and members of the editorial board. articles are published in two formats: online and a downloadable pdf. editors of special issues can arrange for printed versions to be generated through the print-on-demand service of the indiana university press. as a publication of the indiana university press (iu press), sdh offers authors free professional services including copy-editing and help with layout and design. iu press also handles advertising, publicity, and submission of the applications for obtaining an impact factor. in short, sdh is here to serve the needs of the international community of digital heritage professionals and to do so with open access, no article processing charge (apc), and no sacrifice in standards with respect to style, layout, and scientific substance. sincerely yours, bernard frischer, indiana university, co-editor-in-chief gabriele guidi, politecnico di milano, co-editor-in-chief and the following members of the editorial board: willem beex, beex, netherlands wolfgang börner, museen der stadt wien stadtarchaeologie jane w. crawford, university of virginia, usa nicoló dell’unto, lunds universitet, lund, sweden livio de luca, centre national de la recherche scientifique, marseille, france john fillwalk, idia lab ball state university, united states philippe fleury, university of caen normandy, france irmela herzog, rhineland commission for archaeological monuments and sites, bonn, germany welcome to studies in digital heritage    1: ii paolo liverani, university of florence, italy giulio magli, politecnico di milano, italy andrás patay-horváth, university eotvos lorand (elte), hungary laia pujol-tost, pompeu fabra university, spain guillaume robin, university of edinburgh, united kingdom maria roussou, assistant professor, national and kapodistrian university of athens apostolos sarris, foundation for research and technology, hellas (forth), greece rebeka vital, shenkar. design. engineering. arts, israel georg zotti, ludwig boltzmann institute for archaeological prospection and virtual archaeology, austria information integration in a mining landscape gerald hiebel, klaus hanke, gert goldenberg, caroline o. grutsch, markus staudt university of innsbruck, austria the integration of information sources is a fundamental step to advance research and knowledge about the ancient mining landscape of schwaz/brixlegg in the tyrol / austria. the approach is applied for the location, identification and interpretation of mining structures within the area. our goal is to illustrate the use of the cidoc crm ontology with extensions in combination with a thesaurus to integrate data on a conceptual level. to implement this integration, we applied semantic web technologies to create a knowledge graph in rdf (resource description framework) that currently represents the available information of seven different sources in a network structure. more sources will eventually be integrated using the same methodology. these include geochemical analysis of artifacts, onomastic research on names related to mining and archaeological information on other mining areas, to research the spread of prehistoric mining activities and technologies. the rdf network can be queried for research, cultural or emergency response questions, and the results can be displayed using geoinformation systems. an example of an archaeological research question is the location of mining, settlement and burial sites in the bronze age, differentiating between ore extraction, ore processing and smelting activities. for emergency services, the names and exact locations of mines are essential in case of an accident within an old mine. different questions require different subsets of the created knowledge graph. the results of queries to retrieve specific information can be visualized using appropriate tools. key words: information integration, mining archaeology, ontology, semantic technologies, geoinformation sdh reference: gerald hiebel, et al. 2017. information integration in a mining landscape. sdh, 1, 2, 8 pages. doi: 10.14434/sdh.v1i2.23231 1. information sources the himat research center of the university of innsbruck (http://himat.uibk.ac.at) investigates the mining history of the eastern alps from prehistory to modern times. various projects of the research center in the area of schwaz/brixlegg target the location, identification and interpretation of mining structures. geological prospections are a fundamental source of information about structures originating from mining activities. herwig pirkl [pirkl 1961] thoroughly investigated the schwaz/brixlegg mining area. the result was a publication describing the geologic and surface author's address: gerald hiebel,unit for surveying and geoinformation, university of innsbruck, technikerstrasse 13, 6020, innsbruck, austria; email: gerald.hiebel@uibk.ac.at permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal structures of the area and containing three geological maps at the scale 1:10000. two of these maps have been digitized in the course of the work done in the himat research center. structuresidentified by pirkl as underground mining and surface mining have been registered together with their names and coordinates. in addition, information on mining structures provided by the geological survey austria [gba 2014] has been integrated (figure 1). figure 1. mining structures identified by pirkl and the geological survey austria (source: gba, 2014). to better locate structures, the high-resolution elevation model of the province of tyrol was examined for concave and convex surface structures that are in proximity to the structures identified by pirkl (figure 2). information about the archaeological sites has been extracted from archaeological literature and from project reports of archaeological prospections and excavations conducted by the himat research center (figure 3). the most recent project, “prehistoric copper production in the eastern and central alps,” contributed significantly to our knowledge of the archaeological sites related to prehistoric mining activities. to document the research in the area, we used the himat database [hiebel et al. 2013], which records the research activities conducted in the years from 2007 to 2011. figure 2. surface structures identified in the high-resolution elevation model of the province of tyrol (source: land tirol 2009). figure 3. archaeological sites in the area of schwaz/brixlegg (source: himat 2016). 2. information integration to integrate the heterogeneous information described in the previous section, we first needed a conceptual model that has the ability to represent the concepts coming from the different himat research domains such as geology, surveying, archaeology, linguistics or metallurgy. the cidoc crm ontology [le boeuf et al. 2016] was chosen because it is an event-centric data model, and we identified past mining activities and contemporary research activities (which are subclasses of events) as the essential nodes that relate research objects to the documentation and hypothesis created in archaeological research (figure 4). extensions of the cidoc crm [cidoc crm 2016 ] were used to model observations (crmsci), interpretations (crminf), geometric information (crmgeo) and digital provenance (crmdig). the classes of the model had to be refined with a thesaurus (figure 5) in order to represent the detailed information in the available documentation and to answer research questions relevant to the domain. the integration of vocabularies originating from different sources has been a serious challenge [doerr 2006]. within the dariah infrastructure (http://www.dariah.eu), an approach was developed to integrate terms within a backbone thesaurus and thus create the ability to query upper levels without the need to reach consensus on lower level terms, which is often an almost impossible task to accomplish [dariah eu 2016]. figure 4. conceptualizations used for the approach that are represented with cidoccrm classes. we used karma [isi 2016], a tool of the semantic web community, to map the information sources to the data model. figure 6 shows how the original data of the documentation, which must be provided in a structured format (either tabular or hierarchical), was mapped to the formal definitions of the cidoc crm ontology. a knowledge graph was created to represent the information, which can be exported in rdf (resource description framework), a data format that is able to relate logical statements within a network [w3c 2014]. rdf is the foundation of the linked open data (lod) cloud, where data sets are linked to each other on a global level (http://www.linkedopendata.org). in the continuation of the project, we plan to link the created resources to datasets of the lod cloud such as geonames and wikidata (the human and machine-readable representation of wikipedia). the thesaurus was created with the karma tool as well and represented in skos (simple knowledge organization system), a data model of the semantic web community for sharing and linking knowledge organization systems, such as thesauri, taxonomies, classification schemes and subject heading systems [w3c 2009]. figure 5. thesaurus examples to refine the conceptualizations. figure 6. using karma to map structured data to the formal definitions of the cidoc crm. after mapping the different information sources and the thesaurus to the common data model, the created rdf structure is placed in a triple store, which is a database to store rdf data. in the triple store, the linking of resources (single information source elements such as a specific underground mine or a concept like the early bronze age) takes place, realizing the actual integration. resources are either linked on a class level (because they belong to the same cidoc crm class, e.g., observation), on the skos concept level (because the same thesaurus term was attributed to them, e.g. , “early bronze age”) or on an individual level (because they describe the same material structure object or observation, e.g., “barbarastollen”). linking on an individual level is also known as coreference or entity matching and may involve additional processes to assess the identity of individuals, if no common identifier is available in the different data sources, which is often the case. 3. information retrieval examples the rdf network of the triple store can be queried using the sparql [w3c 2013] query language. to test the integration, we used a model archaeological research question concerning the location of mining, settlement and burial sites in the bronze age, differentiating between ore extraction, ore processing and smelting activities. the results of the query were loaded into a geoinformation system, and a map of known bronze age sites related to mining, settlement and burial activities was created (figure 7). for emergency services, names and exact locations of mines are essential in case of an accident within an old mine. a list of mines containing this information was created from the triple store and given to the emergency services. figure 8 shows the mines and their names on a map. these two application scenarios show how, for different questions, a subset of the created knowledge graph is of interest and that the relevant information can be retrieved and if necessary visualized using appropriate tools. figure 7. map of known bronze age sites related to mining, settlement and burial activities. figure 8. names and locations of mines retrieved for emergency services. 4. conclusion and outlook an approach to integrate information available within a mining landscape coming from various sources was developed. a common data model with tools and specifications of the semantic web community was used to perform the actual integration. with specific information retrieval examples, it could be shown that the integration process works and that the triple store can be used to answer specific research questions. in the current implementation, seven data sources from geology, surveying and archaeology are integrated within the himat database. further research will apply the methodology to more sources. in the near future, museum exhibition data, a linguistic dissertation about toponyms related to mining and geochemical metal analysis of prehistoric artifacts are targeted. the integrated data will be used to identify material structures or places in lod sources like geonames or wikidata through string matching processes and semantic queries. 5. acknowledgements the research presented here was financed by the austrian science fund in the course of an erwin schrödinger scholarship (j 3646-n15) and by the university of innsbruck in the course of a graduate scholarship (240346). 6. references dariah eu. 2016. dariah backbone thesaurus (bbt) -definition of a model for sustainable interoperable thesauri maintenance. thesaurus maintenance working group, vcc3, dariah eu. http://83.212.168.219/dariahcrete/sites/default/files/dariah_bbt_v_1.2_draft_v4.pdf (4.1.2017) m. doerr. 2006. semantic problems of thesaurus mapping. journal of digital information 1 (8): retrieved from https://journals.tdl.org/jodi/index.php/jodi/article/view/31/32 (3.11.2016) gba. 2014. digitale datensätze des bergbau/haldenkatasters betreffend ausgewählter bergbaugebiete im raum schwaz-brixlegg und kitzbühel-jochberg. fachabteilung rohstoffgeologie der geologischen bundesanstalt. g. hiebel, k. hanke, and i. hayek. 2013. methodology for cidoc crm based data integration with spatial data. f. contreras, m. farjas, and f. j. melero. in caa 2010: fusion of cultures. proceedings of the 38th annual conference on computer applications and quantitative methods in archaeology, granada, spain, april 2010. uk, bar international. 547-554. isi. 2016. karma: a data integration tool. , http://www.isi.edu/integration/karma/ (3.11.2016) cidoc crm. 2016. cidoc crm compatible models & collaborations. http://www.cidoc-crm.org/collaborations (9.1.2017) p. le boeuf, m. doerr, c. e. ore, and s. stead. 2016. definition of the cidoc conceptual reference model. http://www.cidoc-crm.org/official_release_cidoc.html (6.4.2016) h. pirkl. 1961. geologie des trias-streifens und des schwazer dolomits südlich des inn zwischen schwaz und wörgl (tirol), jahrbuch geol. b. a. (1961), bd. 104. 1. heft, (wien 1961). w3c. 2009. skos simple knowledge organization system reference. https://www.w3.org/tr/2009/rec-skos-reference-20090818/ (19.6.2016) w3c. 2013. sparql 1.1 overview. https://www.w3.org/tr/sparql11-overview/ (9.1.2017) w3c. 2014. resource description framework (rdf). http://www.w3.org/rdf/ (19.6.2016) maxentius 3d project lucia marsicano, saverio giulio malatesta, francesco lella, emanuela d'ignazio, eleonora massacci, and simone onofri sapienza university, italy the aim of the project is to propose a full 3d model of the circus of maxentius in rome encompassing all the aspects of the environment, as well as the architectural system. the circus is part of a complex built by maxentius at the beginning of the iv century ad. the maxentian complex is situated on the via appia between the second and the third mile; today this area is part of the parco regionale dell'appia antica, where the need to preserve the ecosystem makes it impossible to remove the vegetation. for this reason a large part of the circus is covered by the vegetation, making the survey of the entire structure impossible for researchers. the starting point was a study of the archaeological data, and then the team carried out a targeted field survey to integrate the published data with new information useful for creating a metrically correct reconstruction of the monument. to model both the landscape and the architectural structures, blender, an open source software, was utilized, and to model the statues zbrush, a proprietary software package, was used. each element was modeled using scientific evidence or, lacking that, by employing analogies. the result is a metrically and scientifically correct 3d model of the circus of maxentius useful for studying the monument from a new point of view. by integrating archaeological data and using 3d graphics, it was possible to verify the hypothesis of reconstruction of the monument. key words: archaeology, 3d reconstruction, blender, zbrush sdh reference: lucia marsicano, et al., maxentius 3d project, 2017. sdh, 1, 2, 14 pages. doi: 10.14434/sdh.v1i2.23199 1. introduction the maxentian complex, composed of the palace, the mausoleum of romulus and the circus of maxentius, is situated along the via appia between the second and the third milestones. the area is part of the regional park of the appia antica, comprised of 3500 hectares. the park includes eleven miles of the via appia, the caffarella valley (200 ha.), the archaeological area of the ancient via latina, the aqueducts park (240 ha.), the tormarancia estate (220 ha.) and the farnesina estate (180 ha.). the main purpose of the park is to preserve the ecosystem, protecting its flora and fauna. for this reason, the structure of the circus is covered by dense vegetation, and it is not possible to see the monument in its entirety. the state of preservation of the circus, its historical importance and questions about the arrangement of the monument are the reasons why our team decided to make a 3d model of the circus of maxentius (fig. 1). figure 1. circus of maxentius we began with the study of the archaeological data, especially cartography, axonometric drawings and plans. then the team carried out a limited field survey to collect more data. unfortunately, because the vegetation covers such a large part of the monument, it was not possible to significantly integrate the published data. while the plans and axonometric drawings were the starting point for gaining an understanding of the structural features of the monument, historical illustrations were also useful in proposing a likely reconstruction. also useful were a large number of drawings which show the state of preservation of the monument during the past as well as a hypothetical reconstruction. to complete the 3d model of the circus, other details were included. it was possible to insert detailed elements, like the machine used to count the laps, and some statues, thanks to fragments found during the excavations [luschi 1999]. furthermore, there are several illustrations from the roman period, such as mosaics and reliefs, which were useful for adding more details. once all the data had been collected that were useful for making an accurate reconstruction, the team went ahead with the 3d modeling using the open source software blender. zbrush, a proprietary software package that allows us to model detailed objects easily and quickly, was used to model the statues (fig. 2). figure 2. statue of venus 2. the circus of maxentius the emperor maxentius commissioned two major building programs during his brief reign: the first in the center of rome, along the via sacra, and the second just south of the city, along the via appia. since he did not have official endorsement, maxentius used these works to take advantage of his close connection with the traditional capital of the empire and to align himself with earlier emperors in order to demonstrate the legitimacy of his reign (306–312 ad) [pisani sartorio 1999]. it is revealing to focus on maxentius’ decision to construct a personal complex with a residential villa, a circus, and a mausoleum on the via appia, three kilometers outside of the city walls. maxentius’ desire to compete with the tetrarchs and their personal palaces must have impelled him to chose an extramural location so that he could design his own palace free of the spatial and ritual constraints imposed by the older imperial residences on the palatine hill. the three maxentian monuments were strongly interconnected not only in sharing the same building technique of opus vittatum, but also physically. to integrate the three elements of the complex, passageways connected the precinct of the mausoleum to both the residence on the hill above and to the circus that lay in the valley to its east. a long, covered corridor stretched diagonally across the terraced slope to connect the imperial box on the north wall of the circus to the center of the maxentian palace. two main factors influenced the composition of the complex: the topography of the area, which determined the location and orientation of the circus, and the pre-existing architectural features. the circus, built in 310–311 ad, is the site’s best known feature and is one of the best preserved examples of a roman hippodrome. the structure is oriented east-west within a natural valley between the hill of the late republican tomb of caecilia metella and the hill where the maxentian villa is sited. the circus spans a length of 520 meters, and at its widest, it measures 92 meters across. the long sides of the track are not parallel, in order to leave the racing chariots just enough space while placing the spectators as close as possible [ioppolo 1999]. the track is 36.90 meters wide on one leg and 29.60 meters on the other; the radius of curvature of the staircases flanking the triumphal gate is about 30 meters [ioppolo 1999]. from an architectural point of view, the circus is essentially the dirt track and the central spine, a 296-meter-long narrow masonry construction. this structure includes at its ends the masonry foundations of the metae, with three marble cones above, the obelisk, and the ten basins of water of the euripus. the obelisk is now situated on the top of the fountain of the four rivers designed by bernini and located in piazza navona. the track was surrounded by steps, or stands, on which the spectators sat to watch the race; the steps are interrupted by the judges’ tribunal situated on the southern side. on the northern side is the pulvinar imperatoris, connected to the villa by a passageway. it was possible to enter the circus through three gates: the porta pompae, the porta triumphalis and the porta libitinensis. the last was used as exit for horses and riders injured during the race [ioppolo 1999]. because of the presence of vegetation, it is not possible to discern the entire shape of the circus. the majority of the functional components are still visible, however, despite their ruinous condition, so it was possible to make some hypotheses and to proceed with the 3d modeling. 3. 3d modeling 3.1 the towers the two towers of the oppidum were modeled one at a time because of the differences between the two objects. archaeological plans and historical illustrations of this part of the circus were chosen as references; thanks to the archaeological data it was possible to create a metrically correct model of the plan. once this part of the tower was finished, the object was extruded to produce the elevation, taking into account the archaeological remains, the reconstruction proposed in the historical illustrations, and the studies conducted on the masonry. the northern tower is proposed as a three story building. the ground floor, covered by a vault, has two gates; the first is the entrance door, the second leads to the carceres, while the second floor has no door but two windows. according to the available data, the model proposes a stairwell on the northern side of the tower [ioppolo 1999]. the southern tower is, as the northern one, a three story building, in which every level is covered by a vault. this tower has an entrance at the ground floor and a second one from the terrace on the first floor. because of the absence of archaeological remains of stairs or steps, the model of the southern tower is proposed without a stairwell. in both cases, the reconstruction shows a terraced roof, even if no archaeological remains can confirm this hypothesis (fig. 3). figure 3. the towers (northern tower on the left; southern tower on the right) 3.2 the carceres the archaeological remains of the carceres are too scanty to make a detailed hypothesis of restoration. the presence of some remains allows us only to recognize ten pillars that could have supported a series of arches and cross vaults. the resulting spaces were used to hold the chariots before the start of the race. the widest arch, in the middle of the structure, is hypothesized to be the porta pompae. in proposing this hypothesis, it was necessary to integrate archaeological data with some illustrations from the eighteenth century and to make comparisons with the hippodrome in leptis magna [ioppolo 1999]. the choice to cover the structure with a series of vaults was made for statical reasons (fig. 4). figure 4. carceres 3.3 the stands the external perimeter of the circus is delineated by a long wall supporting the stands from which the spectators could watch the race. this architectural element is largely damaged but it is possible to understand its organization, thanks to studies conducted on a portion on the southern side where the state of preservation allows us to recognize all the features. the stands consist of a series of twelve steps divided into two levels by a wall in opus latericium. each step is 39 cm high and 30 cm deep, so the stands could host around 10,000 spectators [ioppolo 1999]. access to the stands was provided by twin staircases flanking the doors located along the inner wall. taking into account the measurements of the steps and the width of the surviving walls it is possible to estimate the total height of the stands at around 8 meters. in the upper part of the external wall, amphoras were embedded in the masonry core in order to lighten the structure. even though the stands are in extremely poor condition and largely covered by vegetation, the remaining visible parts provided enough detail to model this important part of the circus. starting from the archaeological plans and the axonometric drawings created by ioppolo, it was possible to produce an accurate 3d model that includes the twin staircases and the embedded amphoras as well (fig. 5). figure 5. the stands 3.4 the tribunal the tribunal was modeled using as references the available archaeological plan and historical illustrations. in this case, there were many open questions about the hypothesis of restoration. the first was the presence of stairs by which to approach the terrace of the tribunal. this architectonic element is not well known, but in the model it is proposed as stairs that connect directly to the ground floor. the tribunal in its central part; the staircase is covered by a barrel vault. other unknown elements are the three doors located at the level of the exedra. the one on the left leads to a small wedge-shaped room interpreted as closet between the octagonal structure and the portico. the central door has been interpreted as passageway that connects the exedra and the quadrangular room. the third one was probably a window used to give symmetry at the façade of the tribunal (fig. 6). the last unknown part is the roof; there are no extant elements or useful comparisons enabling us to propose an accurate hypothesis, but we decided to show a roof composed of four distinct elements that cover the four different rooms. figure 6. the tribunal. 3.5 the pulvinar along the northern side of the circus, close to the second meta, is situated the pulvinar, where the emperor used to watch the race. this feature was directly connected with the palace by means of a passageway. unfortunately, the archaeological remains are too badly damaged to allow us to make a detailed hypothesis of their reconstruction. moreover, this part of the circus was largely modified during the middle ages, and as a result it is not easy to recognize the maxentian walls [ioppolo 1999]. for this reason, the 3d model here presented is largely hypothetical and is based on the historical illustrations from the sixteenth century that show the state of preservation in that period. the resulting model, according to the reconstruction proposed by bianconi fea [ioppolo 1999], presents a rectangular room covered by a terrace and preceded by the stands, with columns on the façade (fig. 7). figure 7. the pulvinar. 3.6 the spina the spina was modeled using the archaeological plan and the data collected during the survey. this element is one of the best preserved and most recognizable, so it was also possible to integrate the archaeological data with mosaics and scenes represented on reliefs from the roman period. figure 8. arrangement of the spina. 3.7 porta libitinensis the porta libitinensis is situated along the stands, close to the second meta. this gate, used as an exit for removing injured or dead horses and riders, consists of two arches connected by a vault. it is 4.44 meters wide and 6.89 meters long [ioppolo 1999]. the porta libitinensis is still visible so it was quite simple to propose a 3d model by integrating the archaeological plan with new photos and direct studies (fig. 9). figure 9. porta libitinensis 3.8 porta triumphalis the porta triumphalis is located in the middle of the eastern side and consists of two walls surmounted by a barrel vault and an attic. the structure still exists, so we could proceed with our model with confidence in the details. today the visible remains include the walls, the vault, the two stairs connecting the ground floor with the stands, and the steps leveling the slope between the track and the external ground. the only missing part is the attic but, thanks to comparison with contemporary arches, it was possible to hypnotize its likely appearance (fig. 10). figure 10. porta triumphalis. 3.9 the terrain to complete the model of the circus it was necessary to elaborate a 3d model of the landscape in which the monument stood. starting from altimetry data provided by igm (istituto geografico militare) cartography, it was possible to produce a metrically correct model of the terrain. after having imported into blender the contour lines, previously extracted from the maps, it was first necessary to convert the curves into a mesh. then, using the add-on delaunay triangulation and voronoi diagram, it was possible to generate a 3d model. to make the object more manageable, the shrinkwrap modifier was applied. this modifier works by putting on the mode a lan that automatically covers the geometry while keeping the shapes and measurements. the result is an accurate, detailed and topologically correct model of the terrain (fig. 11). figure 11. 3d model of the terrain. 4. texturing last step of the project was texturing the 3d model. because of the poor state of preservation, detailed data were not available but, thanks to previous studies, it was possible to make some hypotheses of restoration. in considering the spina, pulvinar, tribunal and porta triumphalis, we propose a marble facing. this hypothesis seems to be confirmed by comparisons with others monuments and by the finding of marble fragments. the situation of the carceres is more complicated; due to the lack of significant remains it is impossible to know for certain if there was a facing or not. nibby asserted that this feature was covered by marble, basing his hypothesis on the quantity of marble found close to the pillars [luschi 1999]. it is also possible that the only part covered by marble was the central arch, the so-called porta pompae. thus we propose two solutions: the first presents a complete marble covering (fig. 12) and the second shows the masonry exposed and only the porta pompae with a marble facing (fig. 13). figure 12. carceres completely covered. figure 13. carceres with masonry exposed. to obtain a photorealistic result, the model was textured in blender using the node editor in cycles render. this tool allows us to produce a detailed texture easily and quickly, through the use of nodes reproducing the physical effects related to the behavior of light. the same editor was used to realize the water of the euripus (fig. 14) and to texture the terrain. figure 14. euripus and statue of venus. 5. conclusion the result of this project is a metrically correct 3d model of the circus of maxentius useful in two ways. on the one hand, the model could stimulate wider reflections on other archaeological topics, such as structural aspects and decoration systems for this type of roman monument. on the other hand, this model presents a full reconstruction of the monument to a contemporary public audience. the production of a 3d model is a good opportunity to deepen the knowledge of the monument and to verify the hypotheses of restoration. moreover, the study of an accurate 3d allows us to pose new questions concerning the circus of maxentius and the entire complex. the same methodology could be applied to many projects, in order to propose new hypotheses and to improve the knowledge of the monuments under investigation. 3d models also represent a good dissemination tool. for example, our model could be used to show to the public how the monument looked during the fourth century ad. in this regard, details of the model parts have been included in an augmented app in order to provide a simple and involving way to enjoy the monument (fig. 15). figure 15. augmented reality app. 6. acknowledgements we gratefully acknowledge dr. ersila maria loreti (sovrintendenza capitolina ai beni culturali) for supporting the research. we also give special thanks to michele camicioli for his precious work on the statue’s model and to francesco iaia for creating the augmented reality app. 7. references giuseppe ioppolo. 1999. la struttura architettonica. in la villa di massenzio sulla via appia. il circo. roma: istituto nazionale di studi romani, 103-195. licia luschi. 1999. gli scavi di nibby e la decorazione dell’euripus. in la villa di massenzio sulla via appia. il circo. roma: istituto nazionale di studi romani, 197-217. giuseppina pisani sartorio. 1999. inquadramento storico. in la villa di massenzio sulla via appia. il circo. roma: istituto nazionale di studi romani, 89-100. received march 2017; revised july 2017; accepted august 2017. lessons from lidar data use in the netherlands willem beex, amsterdam, the netherlands lidar provides data from which accurate models of the natural land surface completely stripped of buildings and vegetation can be derived. interestingly for cultural heritage and archaeology, most of the data is already freely available for research. this is certainly the case in the netherlands, with the actueel hoogtemodel nederland 2, or ahn2. the density of the measured points is at least 50 centimeters, which means that the remains of structures larger than one by one meter can be detected. as a result, many unknown structures have been discovered with it. however, these excellent results have blinded many cultural heritage and archaeology practitioners to obvious mistakes when interpreting lidar data. this paper is intended to highlight best practices for the use of lidar data by cultural heritage professionals. keywords: lidar, dem, new archaeological finds sdh reference: willem beex. 2017. lessons from lidar data use in the netherlands. sdh, 1, 2, 10 pages. doi: 10.14434/sdh.v1i2.23270 1. introduction lidar is an acronym for light detection and ranging or, alternatively, laser imaging detection and ranging. modern lidar data sets are often freely available via the internet. for instance, in the netherlands the actueel hoogtemodel nederland (ahn) website makes available the most recent digital elevation model (dem) of the country (ahn.arcgisonline.nl/ahnviewer/). many other european countries have similar services. modern lidar data offer a unique opportunity to detect previously undocumented surface cultural heritage (hesse 2010.]. these data are often presented using excellent software applications, which are capable of creating beautiful images very easily. in particular, the possibility to “see beneath the vegetation” is highly appreciated. its use has produced several important and interesting woodland discoveries in recent years [creemers et al. 2011; bazelmans 2016; van der schriek 2016; meylemans et al. 2016]. however, there are several important caveats that must be considered: most lidar data are not as uniformly distributed as expected; automatic and semi-automatic classification of point data is never 100% perfect; the maximum guaranteed density of measured points determines the minimum size of features that can be detected; author's address: willem beex, beex, blankenstraat 172, 1018 sg amsterdam, the netherlands; email: info@beex.nl permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal gridding algorithms have limitations; and the results are often presented in such a beautiful way by modern applications that the need for field validation of the results is sometimes neglected. the aim of this paper is not only to consider these problems, but also to provide a checklist that scholars can use in applying lidar data to their research. 2. gaps in the data it can be useful to consider radar when studying lidar, as the two work in a similar manner. as with radar, a lidar beam will reflect off the first object in its path. this object is what gives a “return” and it also leaves a “shadow” behind it. it is very important to understand this, as it means that lidar can only create a dense and smooth model of the actual surface if enough laser beams can reach the ground level [gatziolis and andersen 2008]. in order to optimise the results, all lidar flights in the netherlands take place during the winter months, december 1 through march 31 [heerd et al. 2000; van der zon 2015]. this is the best period of the year for “seeing through the forest” as deciduous trees have shed their leaves and not yet grown new ones. taking advantage of the winter period will obviously not work for coniferous forests. so, what is visible from the air will entirely depend on the number of viewpoints and the density of the canopy. thus, a uniform distribution will rarely occur, as parts of the surface will not be reached by the laser [van der zon 2015]. for this reason, it is very important to investigate the actual point-cloud provided by the organization that took the measurements. all competent organizations will have this data available for research. for example, on the dutch ahn2 website all point-clouds are available for download. it is even possible to download special geotiff images that mask the areas with a substandard number of observations [van der zon 2015]. however, for a detailed analysis it is often better to visualize the point-cloud projected onto a map of the research area. several applications exist, both commercial and freeware, which are capable of this operation. usually it is best to get the program, or additional module, that can be incorporated into the existing workflow. when choosing software, it is wise to remember that lidar point-clouds contain huge numbers of individual measurements. it can therefore be worthwhile augmenting the internal memory (ram) of the computer and it is wise to test the applications with the available hardware and operating system configuration. an example from the lidar point-cloud of the dutch coniferous forest near wolfheze, shows exactly what should be considered before any further analysis (fig. 1). the points on the surface, indicated by yellow spheres for better visibility, are clearly not uniformly distributed. the vegetation, shown by the green dots, obstructed the laser in many places. this means that only larger features, like ditches and trenches, will consistently appear in the 3dmodels of an area, while smaller objects, like barrows, may not be detected. more deceptively, the untrained observer of a fully processed visualization based on lidar data may get the impression that the area has been disturbed. knowledge of the actual point-cloud should help avoid this kind of misinterpretation. figure 1. coniferous forest near wolfheze. point-cloud of the ground in yellow and of the vegetation in green. the gaps on the ground, created by the trees, are clearly visible. 3. classification of the data most modern lidar data are available in one or more files representing a classification [van der zon 2015]. this classification is mainly based on “laser returns.” this principle is based on the fact that a pulse (or “laser return”) will receive the reflection from the top of a tree or a building slightly earlier than from halfway down a tree or a building, or from the actual ground surface. other variables, like the intensity of the reflection of different kinds of materials, are also detectable [berendsen and volleberg 2007; english heritage 2010]. using a (semi-)automatic method, it is possible to classify each measurement based on all those tiny differences. in its most elaborate configuration, a lidar file can have points classified with one of up to 31 definitions [gatziolis and andersen 2008]. however, usually only eight such classes will be used, mainly to differentiate between levels in vegetation, buildings, water, ground, and unclassified data. the dutch ahn2 uses a slightly different approach. here the main division is between surfaceand other measurements. this is because it is primarily intended for water management [van der zon 2015]. in general, lidar classification is an excellent approach. however, it is important to remember that lidar classification is never 100% perfect [van der zon 2015]. it is still a semi-automatic process. this means that the software will not detect all the differences, so manual editing may be necessary. the definition of features, certainly in cultural heritage, can also be problematic. for instance, what should be done about the remains of earthworks; are they part of the ground, or are they part of a structure? a very good example can be given from the kempen region in the dutch province of noord-brabant. for undocumented reasons, two similar restored bronze age barrows have been classified in different ways. figure 2 clearly shows that one barrow (on the left) with its ring-shaped wall, has been removed from the surface-data. it was identified as a man-made addition, even though the adjacent barrow was left in the surface data. in addition, another similar structure five kilometers away (on the right) was also left as part of the surface-data. in these cases it was easy for researchers to spot these differences. however, it illustrates the danger of blindly accepting lidar classification without any further checks. figure 2. three similar bronze age barrows in the kempen region, dutch province of north-brabant. for some undocumented reason the barrow and the ring-wall on the left have been removed in the classified lidar data, but the other two remain. the site on the left is toterfout – halve mijl, zand-oerle. the barrow on the right is den zwartenberg in hoogeloon. the co-ordinates follow the dutch new amersfoort rd projection. 4. density of the data versus detected features while modern lidar sources like ahn2 have improved sampling density over earlier surveys, there is still a minimum size of feature that can be detected. it is wise to remember that even this improved sampling density can be effectively degraded by vegetation cover, like coniferous forests. the nyquist-shannon sampling theorem can be used to determine the size of feature that can be detected with any specific sampling spacing. the feature size detection threshold is an area twice the sampling distance in each direction, and a recognizable shape can only be found when the area of the feature is five times the sampling distance in each dimension [beex 2003]. this means that if your lidar data-set has a point every meter, only features with a minimum size of two by two meters will be reliably detected and only features with a minimum size of five by five meters will have the correct shape. a comparison between the older dutch ahn1 data and the new ahn2 measurements clearly shows this. ahn1 guaranteed a five-meter resolution and ahn2 a 50-centimeter resolution. figure 3 shows part of the maas-ruhr-stellung (the meuse-ruhr defence line), the german defences on the east bank of the river meuse, dating from late 1944 and early 1945 [seltmann 2006; van der schriek and beex 2017]. this elaborate trench-system is barely discernible on the ahn1 image but much finer detail is visible on the ahn2 derived image. figure 3. differences in quality between the older dutch ahn1 on the left, and the newer dutch ahn2 on the right. the red arrowsindicate the remains of the german “maas-ruhr-stellung” (the meuse-ruhr defence line). in the higher blue area,the remains of a ‘celtic field’ system are also visible. the co-ordinates follow the dutch new amersfoort rd projection. the obvious conclusion is that lidar-data should not be used to visualise anything smaller than the detection threshold. however, with powerful modern computers it can be tempting to use lower detection thresholds. indeed, it is often the case that students try a lower detection threshold value, as it gives a ‘sharper look’ to the visualization. such behavior will not only create false algorithmic artefacts but also gives a deceptive illusion of precision. this in turn may deceive other researchers, who may then draw incorrect conclusions. thus, despite the temptation, this practice should be avoided. 5. algorithms it is often forgotten that any lidar-map or 3d-model is in fact the output of an algorithm. even with a dense network of measurement points, translation into a mesh or a contour map must still occur. this is a sophisticated operation for which many alternative mathematical solutions are available. figure 4. two very different images of the same lidar data. both images show the same earthwork representing a model of a british wwii convoy ship. but in the top left picture, the algorithm especially searched for small ditches running nw-se. used in this way, it almost looks as if the site has been recently ploughed. in this case, the bottom-right image with a basic search gives a more accurate representation of the earthwork. the co-ordinates follow the dutch new amersfoort rd projection. two very different results from the same area near westelbeers, the netherlands, clearly show the implications of using different algorithms (fig. 4). the images show an earthwork built to represent a british wwii convoy ship. the site was used for target practice by german stuka dive bombers [beex 2009; van der schriek 2016]. both images were created with the same lidar data-points. in fact, even the basic algorithm used was the same; kriging with a 5 by 5 metre search-radius [cressie 1990; abramowitz and stegun 1972; surfer 13 2016]. however, in the top left image, the algorithm was configured to look for elongated structures running nw-se. as a result, the same data is processed in a different manner, and the resulting image looks as if the site has been ploughed. this example clearly shows that the operator must be careful. the computer does not know the difference, so the researcher must use his/her expertise to select the appropriate method. for instance, some algorithms are particularly adept at finding specific shapes in the landscape, such as linear features like ditches or walls, but can also produce distorted images or 3d-models with false structures in them. first, the researcher needs to have an understanding of the distribution of the original measurements, the actual landscape, and the physical nature (size and shape) of the features that are under investigation. second, proper knowledge of the limitations of the available algorithms is required [beex 2003]. if these conditions are not met, any result is in fact doubtful. 6. always check the results in the field an actual inspection of the research area may seem obvious, but cannot be emphasized too often. for example, only a survey of the terrain of the earthworks near westelbeers clearly showed why the four structures could be detected by lidar, whereas the fifth had completely vanished (fig. 5) [beex 2009; van der schriek 2016]. the fifth ship was built on a heath that has since become arable land. its location was outside the area designated as a nature reserve during the 1950’s. it was subsequently removed, along with the topsoil, as part of agricultural development. this meant there was no elevation remaining to be measured. the fourth model, while located on the heath and within the nature reserve, was in an area of fastgrowing vegetation (fig. 5/4). therefore, it was not detected when the other three earthworks were restored a decade ago. of course, there were also other contributing factors. conflict archaeology was still in its infancy [van der schriek and van der schriek 2014], so no proper archaeological survey was conducted at the time of restoration. the area was a restricted military complex during the war and so not many people knew about the structures. in any case, this example clearly shows the need for background information and actual inspection of the terrain. without this knowledge, conclusions could have been very wrong indeed. figure 5. location of earthworks (1-4) representing a british wwii convoy near westelbeers (province of noord-brabant, the netherlands.) used for target-practice by german stukabombers. the red circle indicates the spot where a fifth earthwork used to be. the co-ordinates follow the dutch new amersfoort rd projection. 7. conclusion if taken for granted, even the most beautiful lidar-images can become a source of incorrect interpretations and future mistakes. there are five important aspects of lidar-data that should always be checked and validated, before further analysis is undertaken. perhaps the best solution would be to add an additional map with each lidar-image, showing the quality of the individual fields in the documented area. but at least metadata, or a very good description of the entire process, must be available, even if the maps and models are prepared by another institution. 8. a helpful checklist researchers working with lidar-data should consider these five points: always check for the presence of gaps in the data. always check the classification of the data. always check the density of the data versus the size of the detected features. always check which algorithms and variables were used. always ground-truth the results in the field. 9. acknowledgements the author would like to thank max van der schriek, phd researcher at the vrije universiteit, for the dutch wwii examples, and bert brouwenstijn, vrije universiteit, for the poster design. 10. references m. abramowitz and i. stegun. 1972. handbook of mathematical functions. dover publications. j. bazelmans. 2016. het ahn2 en het raadsel van het toponiem bussum-fransche kamp. in archeologica naerdincklant. archeologisch tijdschrift voor het gooi en omstreken1. 11-23. https://independent.academia.edu/naerdincklant b. beex. 2009. oefenbommen op een zee van heide. vitruvius 9: 18-21. w. beex. 2003. use and abuse of digital terrain/elevation models. enter the past. the e-way into the four dimensions of cultural heritage. caa 2003. computer applications and quantitative methods in archaeology. bar international series, 1227. h. j. a. berendsen and k. p. volleberg. 2007. new prospects in geomorphological and geological mapping of the rhine-meuse delta – application of detailed digital elevation maps based on laser altimetry. netherlands journal of geosciences. geologie en mijnbouw 86 (1): 15-22. g. creemers et al. 2011. laseraltimetrie en de kartering van celtic fields in de belgische kempen: mogelijkheden en toekomstperspectieven. relicta 7: 11-36. a. c. cressie. 1990. the origins of kriging. mathematical geology 22: 239-252. english heritage. 2010. the light fantastic. using airborne lidar in archaeological survey. swindon. d. gatziolis and h. e. andersen. 2008. a guide to lidar data acquisition and processing for the forests of the pacific northwest. united states department of agriculture. http://www.fs.fed.us/pnw/pubs/pnw_gtr768.pdf r. m. van heerd et al. 2000. productspecificatie ahn 2000. rijkswaterstaat: rapportnummer: mdtgm 2000.13 r. hesse. lidar-derived local relief models – a new tool for archaeological prospection. archaeological prospection 17: 67-72. e. meylemans et al. 2016. revealing extensive protohistoric field systems through high resolution lidar data in the northern part of belgium. archäologisches korrespondenzblatt 45(2): 1-17. m. van der schriek. 2016. dutch military landscapes. heritage and archaeology on wwii conflict sites. 20th conference on cultural heritage and new technologies, vienna (chnt20). http://www.chnt.at/wp-content/uploads/ebook_chnt20_vanderschriek_2015.pdf j. van der schriekand m. van der schriek. 2014. metal detecting: friend or foe of conflict archaeology? investigation, preservation and destruction on wwii sites in the netherlands. journal of community archaeology and heritage 1(3): 228-244. m. van der schriekand and w.f.m. beex. 2017. the application of lidar-based dems on wwii conflict sites in the netherlands. accepted for publication on the journal of conflict archaeology. m. van der schriek. 2017. archaeological research and heritage management on second world war conflict sites in the netherlands. accepted for publication on the journal of conflict archaeology. march 2017; revised july 2017; accepted august 2017. data curation: how and why. a showcase with re-use scenario philipp gerth, anne sieverling and martina trognitz german archaeological institute, berlin, germany the ianus project, funded by the german research foundation (dfg), is building a digital archive and portal for archaeology and ancient studies in germany. following a 3-year phase of conceptual work, the archive and portal are now being implemented and the data center is beginning its operational work. data curation is essential for preservation of digital data and helps to detect errors, aggregate documentation, and ensure the reusability of data; in some cases, it can also add useful additional files and functionality. this paper presents the workflow of data curation based on a data collection about european vertebrate fauna. it exemplifies the different stages of processing a dataset at ianus according to the oais model from its initial submission until its final presentation on the data portal. data access and reusability can be enhanced by enrichment, in the case of the vertebrate fauna dataset, by gis integration of geographic information and reutilization of bibliography. furthermore, a data re-use scenario is presented in which the dataset has been integrated with one from another repository by using semantic web technologies. key words: data curation, data enrichment, long term preservation, data re-use, semantic web sdh reference: philipp gerth et al. 2017. data curation: how and why.a showcase with re-use scenario. sdh, 1, 2, 12pages. doi: 10.14434/sdh.v1i2.23235 1. introduction ianus is a research data center for archaeology and ancient studies in germany that provides a digital archive and a portal for data dissemination. the project is funded by the german research foundation (dfg) and is divided into two phases. the first was a three-year phase of conceptual work; in the current second part, the concepts are being implemented and the data center is beginning its operational work. the aim is to establish a reliable and sustainable data center where archaeologists as well as ancient studies researchers in general can archive their research data, and start new research projects with the data they will find in the ianus data portal [schäfer et al. 2015, pp. 131-134] the work for this article has been carried out in the project ianus, which is funded by the dfg under grant agreement no.903456 and in the ariadne project, which is funded by the european commission under the community's seventh frameworkprogramme, contract no. fp7-infra-2012-1-313193. author's address: philipp gerth, anne sieverling and martina trognitz, it department, german archaeological institute, podbielskiallee 69-71, 14195 berlin, germany; email: (philipp.gerth, anne.sieverling,martina.trognitz)@dainst.de permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal recently the data portal was launched to present the first datasets from the digital archive (available at http://www.ianus-fdz.de/datenportal/). the homepage of the portal gives an overview of the available datasets, showing a preview picture and a snippet of the project description. each of the actual datasets has its own homepage, providing the project overview, and two subpages with rich metadata and the files available for download. figure 1. screenshot of the data portal with the homepage of a dataset. information about the data provider(s), a map, the associated institution holding the copyright, the license conditions (e.g. cc-by or cc-by-sa), the digital object identifier doi [trognitz 2013] and a recommended citation can be found on the left sidebar of the dataset pages (fig. 1). the homepage of a dataset displays the abstract of the project, the description of the dataset, selected publications, a statement of the data provider and relevant keywords. the subpage metadata presents the keywords concerning subject, content, localization, chronology and method, related publications, and statistical information about the files. before viewing the data page, the terms of use have to be accepted. this page displays all available files of the project, which are organized in directories. by clicking on the folders on the left side in the box named project structure, a detailed overview of the files is shown and the files can be previewed or downloaded. before the download starts, a window with the license conditions informs the user about the terms of re-use. in some datasets, an additional zip file is provided to allow downloading the whole dataset at once. before a dataset can be presented on the portal data curation is needed. the curation process begins with a systematic review of the dataset. the review provides the basis for converting files into appropriate formats for long-term preservation, preparing documentation and metadata, detecting possible errors, and other measures to ensure the preservation and reusability of digital data. in some cases, further functionality and additional files can be created to enrich the dataset during the process of data curation. we present the workflow of data curation based on a data collection about european vertebrate fauna (available at http://dx.doi.org/10.13149/001.mcus7z-2), as well as its enrichment, and showcase a possible re-use scenario of this dataset. 2. project and dataset description the dataset "european vertebrate fauna" was produced in a project in the 1990s by three scientists at different german institutions: norbert benecke (german archaeological institute), angela von den driesch (university munich) and dirk heinrich (university of kiel). in the project, information about european vertebrate fauna was collected and its development from the late pleistocene until the middle ages analyzed, covering a time span of more than 10,000 years. no new animal bones were gathered and analyzed, but the data about all already published animal remains across europe were entered into a dbase-database. in 4500 publications, over 8200 find spots and 100 different species were documented. on the basis of this huge compilation of data the researchers investigated changes in skeletons, habitat, human-animal relations and many other aspects. see for example [crees et al. 2016; sommer et al. 2014] among other project publications. all parts of the project, including the produced data, were excellently documented and even the structure of the database was published [benecke 1999, pp. 152-154]. but subsequently, after later examination of the data by different scientists, the database was not used anymore. instead, the data was exported into tables, which were used and subsequently changed. this is the reason why the database does not represent the actual state of progress any longer. therefore, ianus did not receive a database, but a dataset containing the different exported and updated tables and files. these files comprise the largest part of the dataset, and their organization is based on the original structure of the database, consisting of the topics catalogue, species, measurements and literature. the structure of the data sheets, their connection and content as well as the abbreviations, are explained in a detailed readme file that helps in understanding the dataset and curating it in a proper way [benecke et al. 2016]. 3. data curation the curatorial work was carried out and documented according to the open archival information system oais https://public.ccsds.org/pubs/650x0m2.pdf [ccsds 2012]. the submission information package (sip) of the data provider was transformed into a valid archival information package (aip) and for the data portal into a dissemination information package (dip) (fig. 2). figure 2. workflow of data submission, curation and dissemination according to the oais model. 3.1 file renaming and conversions to generate the aip and dip a curation strategy based on ianus' it-recommendations [ianus 2016] was defined and the following file conversions were executed: some of the files and folders had umlauts and space characters that were changed with bulk rename utility (available at http://www.bulkrenameutility.co.uk/main_intro.php). for the aip, doc-files were converted to docx. this was done with the tool doc2docx (available at http://www.er-ef.net/doc2docx.html). for digital preservation and especially for dissemination, docx-files were also saved as pdf/a-1, using adobe acrobat x. format validation of the pdf/a-1 files was additionally executed with verapdf (available at http://verapdf.org/). the tables had to be converted from xls to xlsx for the aip as well as for the dip. additionally, a conversion from xlsx to csv was carried out. for the batch-processing from xlsx to csv bytescout spreadsheet was used (available at https://bytescout.com/). all xml-based files were validated with the open xml sdk 2.0 productivity tool of microsoft (available at https://www.microsoft.com/en-us/download/details.aspx?id=5124). for future validation, it is planned to test other, non-proprietary tools and integrate them into the data curation workflow. 3.2 3.2 file reorganization the main data provider, prof. dr. norbert benecke, allowed us to change the structure of the folders and files as well as their names; therefore, we could restructure the file tree. the folder containing all readme files was deleted and the files were moved to the respective other folders to keep them with the contents they describe (fig. 3). in the sip, the folder "publications" contained a single file in docx format with a list of 13 publications that were published during the lifespan of the european vertebrate fauna project. this list was included in the project metadata and the file was converted to pdf/a. for the resulting aip and dip the folder was deleted and the file moved to the uppermost level of the whole dataset [benecke et al. 2016]. since the dataset does not contain a database, as explained above, the names of the folders were changed manually from 'database' to 'files' so as to not confuse future users. for example, the folder 'database countries' was renamed to 'catalogue files' and 'database species' to 'fauna files' (fig. 3). figure 3. changes and enrichmentof the dataset from sip to aip. 4. enrichment of the data while restructuring and converting the dataset, ideas came up to enrich the dataset in order to facilitate re-use. two additional means for an easier access were generated: one for gis and one for reference management. 4.1 4.1 gis integration to prepare gis integration, a single file containing all geographic information from the 35 files of the folder "catalogue files" was created [benecke et al. 2016]. this file was then imported into the open source desktop geographic information system q-gis (available at http://www.qgis.org/de/site/). import and display of the find-spots data revealed that the coordinates in the tables needed revision. the coordinates were expressed in degrees, minutes, and seconds (dms) but used the notation of decimal degrees (e.g. "15,59" instead of 15° 59'). therefore, the coordinates were converted [linoff 2015 , 148] into proper decimal degrees (e.g. 15° 59 to 15,9833) for use in q-gis (fig. 4). errors in some coordinates were corrected manually and documented in a supplementary readme file. all resulting files (cpg, dbf, geojson, prj, qpi, shp, shx) generated from q-gis were also stored and are provided together with the original data for re-use [benecke et al. 2016 ]. figure 4. distribution map of the european vertebrate fauna find-spots. 4.2 bibliographic information in addition to converting the original doc-files containing bibliographic references from the folder "literature" into its respective archival formats (docx and pdf/a), it was decided to add further functionality by aggregating the references dispersed across 22 files into one single bibliographic file in bibtex format. this allows for integration of the information into reference management software. for this purpose, the documents were saved manually as plain text encoded in utf-8. with a python script, the text files were scanned for information about author, year, and title, and converted into a bib-file. the original reference was kept and added into the note field. during this process missing information, wrong punctuation and similar errors were manually corrected in the text files. in the resulting bib-file parts where data providers had marked missing information with question marks or 'xxx' were revised and completed when possible; duplicates were also removed. a single file containing the whole bibliography of the dataset in a standardized format increases the re-use potential of this information [benecke et al. 2016 ]. 5. data re-use on the european level in order to demonstrate the potential of integrating different scientific datasets in the domain of archaeological science, two heterogeneous zooarchaeology datasets, one hosted by ianus and one by the archaeological data service in york/uk, were combined by using semantic web technologies. researchers of zooarchaeology have a long tradition of sharing their datasets and articles in community portals like bone commons http://alexandriaarchive.org/bonecommons/, the zooarchaeology social network, the zooarch email discussion list https://www.jiscmail.ac.uk/cgibin/webadmin?a0=zooarch and other platforms [kansa and deblauw 2011]. this discipline serves as a useful case study, as the terminology used is highly standardized, its materials and methodologies are global in scope and many research questions are only answerable by taking into account multiple datasets. the integration of the two datasets was undertaken as part of the eu project ariadne, which brings together and integrates existing archaeological data infrastructures with the goal of offering researchers unified search and discovery facilities over a wide range of distributed datasets [ariadne 2016]. besides the already described european vertebrate fauna, a second dataset was chosen from the project "a review of animal bone evidence from southern england," funded by english heritage and aimed at reviewing animal bone evidence from the late bronze age throughout late iron age in southern england. the regional review report [hambleton 2008], for which this database serves as an open accessible online appendix, provides a synthetic review of published faunal assemblages. consequently, analyses (e.g. ageing, butchery, biometric data) focus on the exploitation and deposition of sheep, cattle, pig, horse and dog. other taxa (e.g. wild mammals, birds, fish and amphibians) are also discussed. the information in the database, published by the archaeological data service [hambleton 2009], is based on 108 site reports, which correspond to excavations at 101 separate monument locations and 154 distinct 'assemblage' records for faunal assemblages. additionally, bibliographic references for all zooarchaeological reports reviewed are listed in the database. the two datasets were mapped to the common super-classes and relationships of the ontology cidoc-crm to relate both relational data models to a common standard. to guide these mappings, the tool 3m mapping memory manager (available at www.ics.forth.gr/isl/3m/) was used. the knowledge graph derived from the mapping and alignment of the two datasets is depicted in fig. 5. to overcome the language barrier between the german and english datasets a common standard was introduced, by using the encyclopedia of life (eol, available at http://eol.org/), which provides biological definitions of species in a classification tree. as the thesaurus is not available in semantic web formats, the terms used were described with rdf/xml. figure 5. graphic representation of the cidoc-crm mapped datasets in the "animal remains" scenario the integration of the two zooarchaeology datasets leads to an environment where users are able to specify queries that run on a common aggregated repository and combine the results coming from the different datasets (fig. 6). the first example in the figure is a species-centric query, where all sites with horse remains are shown with their bone assemblages. for a researcher who is interested in the distribution of a specific species the literature references could be a welcome starting point. the second example illustrates possible basic statistical analyses with the help of the query language sparql over a common mapped dataset. a frequency distribution of selected species in the archaeological contexts is depicted in the bar chart. this approach highlights the high potential of re-using datasets and how new results can be gained without having to invest in the costly acquisition of new research data. figure 6. queries on the two integrated zooarchaeology datasets: a sparql query on the left side and visualization of the result on the right side 6. discussion this paper presented the data portal of the ianus project and addressed some details of the data curation workflow according to the oais standard. a zooarchaeological dataset was used to exemplify the steps involved in the creation of a dataset suited for long-term preservation. two cases of enriching the data were presented, to allow for gis and reference management integration. during this process, some errors in the dataset were detected, corrected and documented. this led to a significant improvement of data reusability without violating the archiving principles of the immutability and authenticity of data, as new datasets were created while still preserving the original ones. finally, we have shown a solution for the integration of heterogeneous datasets using semantic web technologies. these aggregation activities point to a very promising direction and could incorporate all archaeological datasets stored in different data centers into an integrated knowledge graph to provide access to a huge amount of comparable data. this could enable users to answer research questions across heterogeneous resources through gaining statistically more reliable results without the acquisition of new data. but to use this potential, willingness of the researchers to make their data openly available in open and standardized formats is necessary. 7. references ariadne advanced research infrastructure for archaeological dataset networking in europe. 2016. building a research infrastructure for digital archaeology in europe. ariadne booklet. http://www.ariadne-infrastructure.eu/about n. benecke. 1999. the project "the holocene history of the european vertebrate fauna." in n. benecke, ed. 1999. the holocene history of the european vertebrate fauna. archã¤ologie in eurasien 6, rahden/westfalen: marie leidorf verlag, 151-161. n. benecke et al. 2016. holozã¤ngeschichte der tierwelt europas [data-set], berlin: ianus. http://dx.doi.org/10.13149/001.mcus7z-2. bone commons, http://alexandriaarchive.org/bonecommons/ ccsds consultative committee for space data systems. 2012. reference model for an open archival information system (oais). recommended practice ccsds 650.0-m-2. magenta book, washington, dc: ccsds secretariat. https://public.ccsds.org/pubs/650x0m2.pdf j. j. crees et al. 2016. millennial-scale faunal record reveals differential resilience of european large mammals to human impacts across the holocene. proceedings of the royal society b, 283: 20152152. http://dx.doi.org/10.1098/rspb.2015.2152 e. hambleton. 2008. review of middle bronze age late iron age faunal assemblages from southern britain. research department report series number 71-2008. english heritage. e. hambleton. 2009. a review of animal bone evidence from southern england [data-set]. york: archaeology data service [distributor]. http://dx.doi.org/10.5284/1000102 ianus, ed. 2016. it-empfehlungen fuìˆr den nachhaltigen umgang mit digitalen daten in den altertumswissenschaften [version 1.0]. http://dx.doi.org/10.13149/000.y47clt-t s. w. kansa and f. deblauwe. 2011. user-generated content in zooarchaeology exploring the "middle space" of scholarly communication. in e. kansa et al., eds. archaeology 2.0 new approaches to communication and collaboration. los angeles: cotson institute of archaeology press, 185-206. g. linoff. 2015. data analysis using sql and excel. new york: wiley. f. schã¤fer et al. 2015. forschungsrohdaten fuìˆr die altertumswissenschaften – eine kurze bilanz der aktuellen situation von open data in deutschland. archã¤ologische informationen, 38, 125-136. http://dx.doi.org/10.11588/ai.2015.1.26156 r. s. sommer et al. 2014. range dynamics of the reindeer in europe during the last 25,000 years. journal of biogeography 41, 298-306. http://dx.doi.org/doi:10.1111/jbi.12193. m. trognitz. 2013. abschlussbericht testbed "persistent identifiers." http://www.ianus-fdz.de/projects/ergebnisse/wiki zooarch. email discussion list. https://www.jiscmail.ac.uk/cgi-bin/webadmin?a0=zooarch received march 2017; revised july 2017; accepted august 2017. reconstructing vindonissa as a living document: a case-study of digital reconstruction for output to pre-rendered and real-time applications jonas christen, ikonaut gmbh, switzerland / zurich university of the arts, switzerland the legion camp "vindonissa" in switzerland is considered one of the most important roman excavation sites north of the alps. research there has been conducted for over a century and reconstructive drawings have always been a way to showcase scientific progress. the earliest of these drawings date back to 1909. in 2015, the local archaeological service decided that a new series of illustrations should be produced. topographical data, archaeological plans, as well as building profiles provided by experts were the basis for these illustrations. future uses of the same model could include animations or real-time applications for augmented and virtual reality. in order to avoid remodeling for these uses, the whole camp and its surrounding settlements had to be constructed as adaptive and flexible 3d models. the requirements on a model for still rendering are very different from those on real-time renderings in game engines. also, the reasonable level of detail for images on eye level is very different from the level of detail for bird's-eye panorama. therefore, the main challenge was to develop an efficient workflow for multiple output media and different points of view. while some of the proposed methods proved to facilitate the process without adding time needed for modeling, there still remain a lot of open questions. a "living document" should allow all stakeholders (excavators, archaeologists, historians, and illustrators) to access and change information in all stages of the process. this still has to be considered a long-term goal and is a problem far from being solved. key words: computer-visualization, 3d reconstruction, 3d modeling, virtual reality, roman legion camp sdh reference: jonas christen 2017. reconstructing vindonissa as a living document: a case-study of digital reconstruction for output to pre-rendered and real-time applications. sdh, 1, 2, 396-408. doi: 10.14434/sdh.v1i2.23280 1. introduction the company ikonaut gmbh works closely with experts in order to accurately communicate scientific content either to other experts or to a broader public. its members are trained scientific illustrators, aware of the trade-offs and dangers that are implicated by a visual reduction in complexity of content or the depiction of details that have no adequate scientific justification. in the case of the new digital visualizations of the roman legion camp of vindonissa, the client author"s address: jonas christen, zurich university of the arts, department of design, pfingstweidstrasse 96 ch-8005 zürich, switzerland; email: jonas.christen@zhdk.ch permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal (the archaeological service of the canton of aargau in switzerland) decided deliberately to move away from the graphic style of previous visualizations and asked for three more detailed, photorealistic images. the leader of the vindonissa excavations, dr. jürgen trumm, very closely oversaw the process of the reconstruction and was responsible for the scientific accuracy of the buildings and the environment depicted. early in the process, the client and the company decided that they would attach importance to the reusability of the emerging model. it should not only be usable for this specific use-case but adaptable for future known and unknown uses with manageable investment of time and money. 2. earlier visualizations of vindonissa to understand the need for easily adaptable models, a short overview of the camp"s history and previous visualizations reconstructing it are desirable. inscriptions and coins were discovered in the area as far back as the 14th century, but excavations only started toward the end of the 19th century [trumm 2015]. the earliest reconstruction drawings of vindonissa date to 1909 [trumm 2016] but they are limited to individual buildings whose remains give a clear indication to their original use (e.g. the amphitheater). the first attempt at a partial reconstruction of the camp dates to 1939 and was done by w. eichenberger (fig. 1a). thanks to grey areas around the reconstructed part it clearly separates the better-known parts from areas that had not been excavated at that time. in 1945, architect h. herzig drew the first full reconstruction of the camp (fig. 1b). while the general layout and placement of the structures hold up to today"s scientific findings, various detailed buildings are now thought to have looked very different, an obvious example being the factory-like houses with chimneys. around a decade later, a colorful illustration with legionnaires in the foreground was made. it supposedly was published in a school book in the 1950s although no references of the author or the publication could be found (fig. 2a). figure 1. early visualizations of the roman legion camp a) only known structures are depicted [eichenberger 1939]; b) the first attempt at reconstructing the whole camp [herzig 1945] it was not until 2001 that a new attempt at reconstructing the settlement was made by a. haltinner (fig. 2b). it left a lot of interpretation open to the viewer and did not go into detail where the underlying information was not clear enough. quite contrary to that image, the next reconstruction from 2006 is very detailed and lively (fig. 3). it attempts to capture the hustle and bustle that a citylike settlement with around 10,000 inhabitants must have had. five years later, a 3d-model was printed and installed as a central piece of the permanent exhibition at the site"s museum (fig. 4). it has almost the same scientific basis as the previous image, but instead of focusing on the inhabitants of the camp, it depicts the buildings with a much higher level of detail. figure 2. more than fifty years apart but not so different: a) northern view by an unknown artist in the 1950s [trumm 2016]; b) graphic approach at the start of the 21st century [haltinner 2001] figure 3. showing a lively interpretation of the camp and its surroundings [atelier bunter hund 2006] figure 4. new media allowing for new forms of representations: 3d-printed model in the local museum [flück 2011] 3. challenges of producing for multiple formats the model mentioned above was available at the start of this project in a converted format, but it had originally been constructed for 3d printing. this meant that some details were missing and that, because of its polygon structure, it could not be included it in the texturing workflow. instead of adapting the existing models to new needs, the decision was made to start again from scratch. in order to avoid remodeling for future uses, the model should be easily adaptable. the following section is an overview of present and future challenges and proposed solutions. while some of these solutions are already common place in the workflow, others are more difficult to integrate or even mutually exclusive. due to time and budget constraints, it was not possible to adhere to the proposed ideal solution. as a compromise, individual buildings were produced with a relatively low polygon count but with high quality textures. as the textures had to be painted for every building, these textures could be produced in a high resolution almost without any additional work. the number of template buildings was to be kept as low as possible to allow them to be replaced easily. the archaeological service of the canton aargau has a general plan which combines all excavation findings of the site. but the purpose of this plan was to give a general overview and visual summary, so it has been generated manually in adobe illustrator and does not include geodata. in 2017, work has started to generate a complete plan for cad/gis environments within a few years. this would facilitate the inclusion of georeferenced data in 3d models as well as the exchange between scientists and 3d artists. in the project discussed in this paper however, it was not possible to georeference the archaeological findings because of the lack of a general plan. that and other limitations mean that the "living document" is still a long-term goal and not something that has already been achieved. nevertheless, this document will shed a light on some considerations that should help working towards a real "living" version of vindonissa. table 1. overview of the challenges faced in this project. 4. a workflow for long-term effectiveness the basic information for the modeling (approximate number and size of windows, inclination of the roofs etc.) could be obtained from the model done in 2011. the appearance of the buildings inside the legion camp was therefore already set and only needed minor updates according to scientific findings. the discussion between the modeler and the expert was focused much more on the number and positioning of houses in the vici: results of recent excavations indicate that the settlements around the legion camp were much smaller than previously thought. windows and doors were inserted into the basic models as boolean objects using cinema4d"s mograph module. this allows one to change the number and positioning for each model while including a certain degree of randomness to make the model appear livelier. the roofs were modeled as separate objects so that they could be easily transferred between the template models. it would have been possible to use only as few as 16 polygons per roof, but they were instead cut into pieces of around 1 meter, as shown in fig. 5. figure 5. buildings are cut into polygons of approximately even size for deformation. that allowed us to use a deformer which changes the location of each point by a few centimeters according to a black and white image, again with the goal of making the model look more life-like by avoiding totally straight forms. all models are constructed so that they extend around one meter into the ground. this way their instances can be placed on uneven ground without risking that parts of the building appear to hover over the ground. figure 6. the painted texture as it looks after exporting from 3d-coat. figure 7. variations can be obtained by turning layers on and off: a) recently built version; b) weathered and damaged version of the same building the texturing workflow required working back and forth between applications. after a review of the suggested textures by the scientific expert, the models were exported from cinema4d in obj format. from there, they were imported into 3d-coat, which has very flexible uv-mesh and painting tools. the color information was applied in multiple layers, starting with the basic roof tiling and plaster before filling in a weathered and damaged look. these layers could be exported as separate images or combined in an editable photoshop file like fig. 6, including a normal map. color correction and variation according to different ages of buildings can be applied easily as shown in fig. 7. the textures were created in a resolution of 4096x4096 pixels, much higher than needed in the first set of renderings but again with the goal of using them in future close-ups. to keep the modeling and texturing process as fast as possible, it was necessary to identify a group of base models that could be used multiple times within the legion camp. the 23 models in fig. 8 were repeatedly used in around 95% of the buildings in the scene. the other 5 % are special buildings such as the surrounding wall, the aqueduct, the amphitheater, etc. the base models could even be used for some special buildings like the baths in fig. 9, with the reservation that for a closer look the model would have to be redone, as it lacks the detail of manually-made models. each porticus in the scene uses the same original section of a porticus shown in fig. 10 which is modeled with only 32 polygons and therefore saves much-needed computing power. albeit these considerations, it is still necessary to convert the whole scene with a few manual steps before exporting it to real-time engines like unity. figure 8. a repository of base models makes up most of the camp. figure 9. even complex buildings can be composed of the base models as long as they are not viewed up close. figure 10. the original simple porticus is used throughout the whole scene. the terrain is an area that required many compromises in this project owing to the different characteristics of working in the 3d modeling software cinema4d and in the real-time engine unity. in the modeling tool, the whole area is viewed from above and does not require a high polygon count or image resolution. in the real-time software on the other hand, the user will be standing on the ground and expect the terrain to simulate realistic bumps in elevation as well as high resolution textures. for the scope of this project, it was necessary to limit the resolution of the polygon mesh and the textures and work with a proven re-projection method shown in fig. 11. a raw rendering of the terrain was imported to photoshop and painted there according to details provided by the scientific expert. the resulting flat image was then camera-projected onto the terrain mesh which resulted in a highly variable look that allowed to change lighting settings dynamically. another obvious difference between pre-rendered images and real-time renderings is that, in the first, it is possible to apply color correction, fix mistakes and even apply atmospheric details such as smoke and clouds. for the application in a game engine all these effects need to be processed in realtime, which uses a lot of computing power and is therefore sparsely used in low-budget simulations. figure 11. the landscaping process: a) the visualized terrain data; b) painted texture in photoshop without lighting or shadows; c) texture is reapplied onto the terrain through camera mapping figure 12. the raw rendering out of cinema4d before applying atmospheric details in photoshop. 5. challenges and lessons learned working efficiently for one primary output medium while keeping another in mind led to considerable challenges. the base models of houses, for example, had one initial size that had to be adapted for multiple uses in and around the legion camp. in extreme cases, the models changed from 0.5 up to 2 times of their original size. in the pre-rendered situation with a bird"s eye view the resulting changes in texture and window size are not visible but if viewed from eye height these errors are noticeable and very distracting. more models would therefore have to be made if the whole camp should be made accessible in a close-up. some of the decisions taken at the start of the project were later considered obsolete and should not be repeated in future projects. the windows, for example, are just one polygon, which was then extruded to keep the polygon count low. their appearance is not satisfactory in close-up and it would not have made a big difference in work or polygon count to include a bevel (curvature) to the window frames. 6. current status and outlook the still renderings shown in figs. 13, 14, and 15 were first published in the annual report of "gesellschaft pro vindonissa" [trumm 2016]. as there is currently no mandate or planned use for the real-time application, the execution of a proof of concept was pursued as an internal project at ikonaut. further development of specific questions regarding movement and narrative interaction were posted as a student project at the university of applied sciences and arts northwestern switzerland fhnw. a team of two students then created a framework shown in fig. 16 that allows objects to be easily imported into an environment that has built-in functionality for a common form of teleportation locomotion as well as audio guide stations that are activated by the user. the next step will be to import the model of the whole legion camp into the real-time application and decide on one or multiple points of interest where a story can be told and where accessories and environmental effects will be added. figure 13. final image, overview of the camp and its surrounding landscape in the 1st century ad figure 14. final image, close-up of the camp in the 1st century ad figure 15. final image, close-up of the settlement post military use in the 2nd century ad in the process of transferring models from cinema4d to unity it was noted that there is still a lot of manual labor involved for every object. even when including the lessons learnt, the process is not satisfactory, and there is still a long way to go until it can be called a true "living document". in an idealized version of such a document, everyone involved in the production of knowledge in the project would enter additional data in the same file. all programs would draw their information from this file, from cad to 3d and real-time applications. such a solution would decrease the time needed for exchange and help to keep everyone aligned, from excavation personnel to archaeologists to 3dartists and even the public. academic work has been done previously on different aspects of this bigger end-goal. working group 5 of cosch project exemplifies an international multidisciplinary approach to reach solutions for some of these issues [cosch action 2009]. while it will not be realistic for any one institution or company to solve the whole problem, it will make sense to achieve the long-term goal via small steps. an example for such a small step is the plan to post another student project at fhnw outlining a solution for the automatization of the model exchange process. so-called "instances" from cinema4d should be automatically transferred to "prefabs" in unity4d. while their function is the same (have one original model cloned in order to safe processing power and allow for easy updatability) their practical application and the way the program handles them is different in both applications. also, during the process the instances from cinema4d will have to retain their name, which is given by the archaeologist"s naming convention. another goal is to include documentation of background information and the way decisions were taken in the project in order to comply with principle 4 of the london charter [london charter group 2009]. one of the solutions proposed at chnt in earlier years, e.g. [apollonio 2016] or [hauck and kuroczynski 2015] could be applied. for a private company, it would be preferable to have a minimalistic documentation standard that could be expanded upon later. as the documentation process is (not yet) a part of the project outline and therefore not paid, it would only be feasible to include documentation if the workflow needed is not too time consuming. figure 16. first look at the virtual reality implementation in unity. a navigation menu with available locations is displayed. the user teleports to new locations using hand controllers. 7. conclusion this paper presented a method for the 3d-modeling of a roman legion camp, planning for output in multiple formats from pre-rendered to real-time rendering. some of the ideas put forward could be applied universally when working on a large-scale 3d model of a settlement where a lot of buildings can be classified into types thanks to their repetitive nature. some challenges inherent to the goal of producing for pre-rendered and real-time renderings at the same time were mentioned. most notably, these challenges include the level of detail for modeling the buildings and the terrain. in pre-rendered scenarios from a bird"s eye view, the buildings can be modelled with few polygons and low-resolution textures while the terrain can be painted in an external software. including 3d vegetation is computationally expensive and not necessary. on the contrary, in real-time renderings from an eye-level perspective, house models need more detail in modeling and textures. the terrain must include 3d vegetation, if a realistic look is desired. combining these elements is only possible when extra time and budget are available, though small preventive measures, some of them outlined in this paper, can help to keep later development time down. 8. references atelier bunter hund. 2006. leben im aargau. andrea john & felix boller. inbeat gutshause. buchs lehrmittelverlag des kantons aargau, 36f. cosch action. 2017. working group 3: algorithms and procedures. http://cosch.info/wg3. fabrizio apollonio. 2016. classification schemes and model validation of 3d digital reconstruction process. in international conference on cultural heritage and new technologies, vienna, 2015 – proceedings. http://www.chnt.at/wp-content/uploads/ebook_chnt20_apollonio_2015.pdf. hans herzig. 1946/1947. versuch einer rekonstruktion der tore, türme und umwallung von vindonissa. in gesellschaft pro vindonissa, ed. jubiläumsbericht 1946/47. brugg: vindonissamuseum, 68. jürgen trumm & ikonaut. 2016. vindonissa aus der vogelschau neue und alte blicke auf das römische windisch. in gesellschaft pro vindonissa, ed. jahresbericht 2015. brugg: vindonissa-museum, 11. jürgen trumm. 2015. vindonissa. in historisches lexikon der schweiz (hls). http://www.hls-dhs-dss.ch/textes/d/d12287.php karin meier-riva. 2001. unter der erde. vom leben und sterben in vindonissa. 7. london charter group. 2009. the london charter for the computer-based visualization of cultural heritage. http://www.londoncharter.org/fileadmin/templates/main/docs/london_charter_2_1_en.pdf matthias flück. 2011. the printed legionary camp of vindonissa – the development of a new digital and physical model of vindonissa. in international conference on cultural heritage and new technologies, vienna, 2010. http://www.chnt.at/wp-content/uploads/ebook_ws15_part3_sessions1.pdf oliver hauck, piotr kuroczynski. 2015. cultural heritage markup language – how to record and preserve 3d assets of digital reconstruction. in international conference on cultural heritage and new technologies, vienna, 2014. http://www.chnt.at/wp-content/uploads/ebook_chnt20_hauck_kuroczynski_2015.pdf walter eichenberger. 1938/39. frontispiece. in gesellschaft pro vindonissa, ed. jahresbericht 1938/39. brugg: buchdruckerei effingerhof ag, frontispiece. received january 2017; revised july 2017; accepted august 2017. archaeological excavation and documentation of kafir kala fortress tomoyuki usami, graduate university for advanced studies, japan alisher begmatov, kyoto university, japan takao uno, tezukayama university, japan amridin berdimurodov, the institute of archaeology of the academy of sciences of the republic of uzbekistan, uzbekistan gennadiy bogomolov, the institute of archaeology of the academy of sciences of the republic of uzbekistan, uzbekistan the site of kafir kala is located in the south-east of modern samarkand city, uzbekistan, and well-known for its unique seals and other artifacts. since 2013, the japanese-uzbek joint archaeological expedition has been carrying out excavations and digital surveys on this site, mainly focusing on the fortress area. this paper is a preliminary presentation of newly excavated pre-islamic structures and 3d models, contributing to a better understanding of the urban settlement history of pre-islamic samarkand, as well as other regions of central asia. key words: kafir kala, fortress, fire layer,laser scanning technology, 3d models sdh reference: tomoyuki usami et al. 2017. archaeological excavation and documentation of kafir kala fortress. sdh, 1, 2, 12 pages. doi: 10.14434/sdh.v1i2.23267 1. introduction central asia is generally characterized by its vast expanse of steppes and deserts with an arid climate. the oasis of samarkand, however, is rich in water, and has fertile lands suitable for agriculture and pasturage, owing to the zarafshan river that flows through the region. it is perhaps one of the main reasons that several important and populous urban settlements along the silk road emerged in this oasis. only a few of these urban settlements have been thoroughly studied. the site of kafir kala, however, was only sporadically excavated and studied until the early 2000s. author's address: tomoyuki usami, department of japanese studies, the graduate university for advanced studies, japan; email: usami.tm@gmail.com;alisher begmatov, dept. of letters, kyoto university, japan; email: alisher.begmatov@gmail.com; takao uno, department of culture and creativity, tezukayama university, japan; email: tsuno@tezukayama-u.ac.jp; amridin berdimurodov, the institute of archaeology of the academy of sciences of the republic of uzbekistan, uzbekistan; gennadiy bogomolov, the institute of archaeology of the academy of sciences of the republic of uzbekistan, uzbekistan. permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal between 2001 and 2008, the italo-uzbek expedition carried out excavations mainly on the citadel of kafir kala, a lofty and well-arranged fortress located in the south-east of samarkand. during the excavations, the expedition unearthed various artifacts of islamic and pre-islamic periods. the expedition also identified the presence of the layer where a severe fire occurred. the fire presumably broke out during the conquest of central asia by the arabs. from the fire layer, numerous seals were discovered. this indicated that the citadel of kafir kala may have functioned as an important administrative center. the italouzbek expedition identified the structure and main functions of the citadel after the occupation of the site. however, the structure and function of the citadel before the occupation remained unclear due to the discontinuation of the excavations. only a small part of the fire layer in the south of the citadel was excavated. in 2013, the japanese-uzbek1 expedition launched its archaeological research mainly to disclose the structure of the citadel below the fire layer, and to identify the function of the citadel before the fire occurred. along with excavations, the expedition also carried out digital documentation. the present paper aims at presenting the results of excavations on kafir kala conducted in recent years, as well as the production of 3d modeling of newly unearthed structures below the fire layer of the fortress. 1the japanese-uzbek expedition began its collaborative research in the oasis of samarkand in 2005. in 2007-2012, the expedition carried out a number of excavations on the citadel, inner city and suburb of the archaeological site dabusia; this is a large urban site (approx. 80 ha) situated halfway between samarkand and bukhara, two core cities along the silk road. the expedition revealed details about the emergence of the settlement and its later development as a major economic center (uno and berdimurodov 2013). the members of the uzbek part of the japanese-uzbek expedition were mostly the same as in the italo-uzbek expedition. it was at the initiation of the uzbek part that the archaeological research on kafir-kala was organized. the research backgound the site of kafir kala is located approximately 12 km south-east of the famous site afrasiab (old samarkand) along the dargom river, which branches off from the upper-middle zarafshan river (figure 1). its location perhaps played a strategic role in connecting samarkand with the eastern areas, such as penjikent, and the southern part, which includes the key cities of the modern kashkadarya region, as well as the cities in the modern surkhandarya region or even further south. this site consists of three main parts: citadel, inner city (shakhristan) and suburb (rabad). the citadel, which occupies the central area of the kafir-kala complex, is a considerably high square fortress (about 20m high and 75 × 75m at the base) surrounded by three towers in the northeast and southwest (figure 2). kafir-kala (arabic: كافِرkāfir "unbeliever", ﺔﻌﻠﻗqal'a "fortress") meaning "fortress of unbelievers" is a toponym which replaced the original name of the site sometime after central asia shifted to islam. this kind of replacement of site names is observed elsewhere in central asia, thus causing serious difficulties for researchers in identifying the site from written sources. nevertheless, grenet and de la vaissière (2002) proposed that kafir kala may as well be identified as rewdat2 which was noted by ibn-hawqal, a medieval historian, as the residence of the king of fergana, located one farsākh (i.e., ca. 6 km) south of samarkand. this was convincing because kafir kala is the biggest archaeological site in the southern vicinity of samarkand. however, coin finds unearthed from the fire layer of the site indicate that kafir kala had already been occupied once, a few years earlier than the arrival of the king of fergana to form an alliance with the ikhshid (king) of sogd against the arabs. thus, we cannot precisely identify the site from the written sources. 2rewdat was traditionally identified as tali barzu, located about 6 km south of samarkand. this site was systematically excavated by grigorjev. figure 1. location map of kafir kala on a landsat tm satellite image. prior studies on the site kafir kala go back to the late 1920s, and they provide valuable primary information about this site. the first topographical map of this site was made by masson (1928). the first systematic excavations were carried out by grigorjev (grigorjev 1941, 1946), an who mainly focused on the suburb area of kafir kala and unearthed craft materials, including a pottery kiln. it was followed by obel'chenko and shishkina after over a decade. obel'chenko identified two main periods for the settlement in the city and shishkina excavated a necropolis in the suburb (shishkina 1961, 1969); this necropolis was reconstructed by nil'sen (nil'sen 1965, 1966). at the end of the soviet era and right after uzbekistan became an independent republic, the institute of archaeology of the academy of sciences of uzbekistan launched a few test trenches in the citadel (berdimurodov and samibaev 1995). a decade later an italo-uzbek expedition (university of bologna and the institute of archaeology of the academy of sciences of the republic of uzbekistan) carried out large scale and systematic excavation campaigns focusing on the fortress/citadel between 2001 and 2008. the outcomes of this joint research significantly enriched our knowledge about kafir-kala. in the early years, the expedition discovered a part of the fire layer, which yielded nearly 500 specimens of seals. the fire layer is presumably one of the clear traces that reflects a tragic event which occurred during the arab conquests of the region (see mantelini and berdimurodov 2005; cazzoli and cereti 2005). figure 2. the view of the fortress: a) from the north-west, b) from the south-west (photo by tomoyuki usami) as mentioned earlier, the investigations by the japanese-uzbek expedition on the fortress/citadel began in 2013. the actual function of kafir kala before the occupation remained obscure after three seasons of excavations. there were some assumptions that the fortress may have functioned as a zoroastrian temple, as its structure four corner towers, a courtyard in the center and long benches (sufa) along the inner walls was similar to the structure of jar-tepa (berdimurodov and samibaev 1999). this site was a zoroastrian temple situated about 30 km east of kafir kala which was also presumably destroyed during the arab occupation of the region (see figure 1). however, the results of recent excavations on kafir kala shed some light on this issue. new findings such as fragments of wall paintings discovered in the citadel indicate that the site may have functioned as a fortress. nevertheless, we will have to excavate the last remaining small part in the north of the citadel in order to adequately explain its structure and function. 2. outline of the results of the investigations following the work done by the italo-uzbek expedition, the japanese-uzbek expedition has continued further investigations on this key site, mainly focusing on the fortress area. as mentioned above, nearly 500 specimens of seals were discovered by the italo-uzbek expedition on kafir kala. furthermore, during the japanese-uzbek excavations, over 200 specimens of seals have additionally been unearthed from the same fire layer. the finds of 700 seals in total from a single site is, thus far, the largest number ever found in central asia. the seals bear impressions of various divine, human and animal figures, as well as geometric shapes, and some have sogdian and bactrian inscriptions depicted on them (figure 3). the seal finds show a clear evidence that kafir-kala played a vital role in the region (see also cazzoli and cereti 2005; begmatov et al. 2016). figure 3. examples of sealsunearthed from kafir-kala (photo by alisher begmatov). a few dozen bronze and silver coins of the pre-islamic period were also found in the same fire layer, and these allow us to identify the date of this layer. the fact that the latest coins discovered from this layer are known to have been issued during the tarhun reign (ad 700-710) has reinforced our view that the fire at the citadel occurred in the beginning of eighth century. apart from coin and seal finds, various artifacts, metal and pottery and were unearthed. the preislamic pottery finds especially represent unique examples of the area. throughout the regular excavation work, the japanese-uzbek expedition has identified the whole structure of the fortress in the fire layer – discoveries of sufa (a bench made of rammed earth or bricks) along the eastern and western walls in 2013-2014; a courtyard in the center in 2014; corner towers in 2013-2016 remains of a large building with several square holes for wooden pillars, and finally fragments of wall painting in 2015-2016. additionally, the expedition discovered that the fire layer spread almost all over the inner ground surface of the fortress. this fact convinces us again that a huge fire must have occurred in the citadel. between 2013 and 2014, the japanese-uzbek expedition identified two sufas along the east and west walls. the sufa along the eastern wall is preserved in a relatively good shape ( figure 4). its length is about 22 m and its width about 130 cm. six square holes for wooden pillars at intervals of approximately 170 cm were found 280 cm west along the sufa. in 2014, the courtyard of the fortress was excavated and on the eastern side of the courtyard center a tree root was found, which may suggest that a tree might have existed inside the fortress. and from nearby, to the west of the tree root, there was a slope gently rising towards the remains of the large buildings that were excavated later in 2015. figure 4. the sufa along the eastern wall (by photo alisher begmatov). during the campaigns of 2013-2015, we excavated four corner towers of the fortress. the shapes of the towers were oval, but slightly different from one another, perhaps due to damage. in the fire layer of the south-eastern tower, a horde of sogdian coins was found. the discovery of a large building (trenches 6 and 7 mentioned below) with wall paintings from the fire layer is one of the most significant finds. the building, as well as other structures and materials in the fire layer are quite well preserved. although the wall paintings are damaged due to the fire, they provide us with valuable information about colors and decorative ornaments, and may also assist us to understand the principle governing the construction of the inner fortress. the building consists of a platform with evenly distributed wooden pillars; some of the square burned wooden bases of approximately 90 cm each side remained. during 2015-2016, the japaneseuzbek expedition excavated trenches 6 and 7 and identified 12 square holes in total. since we had noticed a few square holes in earlier excavations in the western part of the big building, we estimated that 18 wooden pillars were built to support the roof of the building. the size of this large building is 22 m in length and about 11 m in width. we also noted the presence of two entrances (altogether three entrances, including the one excavated in 2013) to rooms on the north-eastern side. the central room stands directly opposite the entrance into the fortress and is reached by a gently rising slope approximately 180 cm from where the courtyard begins. this central room perhaps is the key to completely understanding the function of the citadel; it will be excavated in the season. 3. digital survey of kafir kala fortress as previously mentioned, the japanese-uzbek expedition has so far made efforts toward the digital documentation of kafir kala fortress. we have employed different technologies to obtain the most accurate data. we first conducted a topographical survey of 5the fortress and its surrounding areas with the use of total station and gps, and generated a digital elevation model from the topographic data (fig. 5). it clearly shows the characteristics of the shape of the fortress. we scanned all the excavated areas (trenches) and structures on the fortress with the 3d laser scanner. a faro focus 3d scanner was mainly used in this work (fig. 6). this 3d laser scanner is nowadays widely used in archaeology and cultural heritage; it enabled us to efficiently create accurate 3d models of the objects. this scanner are lightweight and small and its portability is a great advantage in conducting surveys on the upper parts of the fortress, where we need to climb a steep hill every time we work. using the software "faro scene," we processed the scans and generated 3d models. at this step, the ortho-images were also derived and brought into a gis environment. all the models of the investigated area were overlapped and visualized in the gis environment (fig. 7). clearly, the use of gis is also quite significant in terms of the data management. along with the 3d laser scanning documentation, we have recorded x, y, and z coordinates of all the excavated objects with total station since we began the excavations on the site kafir kala, and taken numerous photographs in the survey process. figure 5. digital elevation model of the fortress. (a): top view (b): bird's eye view. figure 6. faro focus 3d laser scanner (photo by tomoyuki usami). one of the most important issues is, therefore, how we should manage such a huge quantity of data. we have tackled this with the use of gis: we put all the data obtained during the fieldwork into gisdatabase with a single coordinate system and organized them. particular attention is here drawn to the digital survey process of trenches 6 and 7 (fig. 7), where the large building with paintings was discovered during 2015-2016. the first step is planning the positions of the 3d laser scanner. as stated above, the building consists of a platform with evenly distributed wooden pillars, with some of the square burned wooden bases, approximately 90 cm on each side, remaining. the presence of entrances was also identified. we carefully made a decision on the placement of the scanner in order to fully and accurately scan such complex structures (fig. 8). then we acquired 12 scans and 8 scans in trench no. 6 and no. 7 respectively. next, processing of the scans was performed with the faro scene software (figure 9), and finally the models were made. ortho-images were at the same time derived and imported into the gis environment (fig. 10). in short, the productions were positive: for instance, a platform of building with evenly distributed wooden pillars and the square burned wooden bases, as well as the fire layer, were clearly described. this survey process no doubt has helped to develop our understanding on the construction principal of the fortress. figure 7. view of the citadel with ortho-images. a. from the north-east. b. from the top figure 8. trenches 6 and 7 with the positions of scanners. (a): trench 6 (from the south). (b) trench 7 (from the south-west). figure 9. screenshot of the point cloud (trench 7 as an example). figure 10. the imageof trench 7. 4. results of the investigations and future work this article demonstrates the results of the excavations by the japanese-uzbek expedition at kafir kala and the efforts of the digital survey, with a special focus on the large building with paintings discovered at the fortress area. kafir kala, which is well known for the discovery of unique seals, has been continually excavated and accurately documented with the use of 3d laser scanning technology. 3d measurement techniques are quite helpful to capture the complexity of the building and other structures that are difficult to describe in detail using the traditional survey method. although the investigations of our project are still in progress, we have gradually developed our discussion on the planning and arrangement of the inner fortress before the fire occurred. we have identified the gate, the sufas along the east and west walls, the courtyard in the center, the slope that leads to the entrance with burned brick-tiles, square holes with carbonized wooden bases of pillars, and walls and corridors surrounding the fortress as well as corner towers on four corners of the fortress. the building with paintings, which occupies the north-eastern part of the fortress, is no doubt a key point. it is difficult to infer the exact function of the fortress at this point. however, as a future work, we will continue the excavations and documentation on the remaining part of the citadel, and that will allow us to develop our understanding. we assume that the room with entrances connected to trench 7 possibly keeps an important secret of the fortress, which may lead us to discover the actual function a castle or a temple. 5. acknowledgements the excavation work was supported by the sasakawa scientific research grant from the japan science society. the authors are particularly grateful to m. tosi and s. mantellini for scientific support. 6. references a. begmatov et al. 2016. excavations of the uzbek-japanese expedition on the site of kafirkala. in international conference on archaeology of uzbekistan during the years of independence: progress and perspectives. samarkand. 116-118. a. e. berdimuradov and m. k. samibaev. 1999. khram dzhartepa-ii: k problemam kul'turnoj zhizni sogda v iv-viii vv. (the temple of jartepa-ii: on the problems of cultural life of sogd in the 4th-8th centuries). tashkent. a. berdimurodov et al. 2016. bully s buddijskim sjuzhetom s gorodischa kafirkala. arkheologija uzbekistana 2 (13): 51-60. s. cazzoli and c. g. cereti. 2005. sealings from kafir kala: preliminary report. inancient civilizations from scythia to syberia, vol. 11. 1-2, 133-164. r. dimartino. 2011. studio analitico della cultura materiale fra vii e ix secolo d.c. nella regione di samarcanda (uzbekistan): analisi morfo-tipologica, produzione e commercio della ceramica di kafir kala. dottorato di ricerca in bisanzio ed eurasia. universita di bologna. f. grenet and e. de la vaissière. 2002. the last days of panjikent. silk road art and archaeology 8, 155-96. g. v. grigorjev. 1941. tali-barzu kak pamyatnik domusul'manskogo sogda. t. petersburg) archive of the institute of history of material culture, russian academy of sciences fond 35, opis' 2, delo 92. g. v. grigorjev. k voprosu o khudozhestvennom remesle domusulmanskogo sogda. ksiimk, xii, m.l. ibn ḥawqal. 1976. kitāb şūrat al-arḍ. j. kramers in bibliotheca geographorum arabicorum ii, 3rd ed. leyden. s. mantellini and a. berdimuradov a. 2005. archaeological explorations in the sogdian fortress of kafir kala. in ancient civilizations from scythia to syberia, 11 (1-2): 107-132. m. e. masson. 1928. o mestonakhozhdenii sada timura davlet-abad. izvestija sredneaziatskogo komiteta. tashkent. 43-48. v. a. nil'sen. 1965. k voprosu o naznachenii sogdiiskogo zdanija okolo kafir-kala pod samarkandom. imku 6, 116-123. g. a. pugachenkova. 1983. ishtikhanskie drevnosti (nekotorye itogi issledovanii 1979). sovetskaja arkheologija, 259-270. g. v. shishkina. 1961. rannesrednevekovaja sel'skaja usad'ba pod samarkandom. imku 2, 192-222. t. uno and a. berdimurodov. 2013. the site of kala-i dabusia: sogdian city along the silk road. shinyosha. archaeological research of city centers of central asia received march 2017; revised july 2017; accepted august 2017. amphitheater of volterra: case study for the representation of excavation data carlo battini, university of genoa, italy elena sorge, soprintendenza archeologia della toscana, italy the present paper aims to describe how different surveying techniques can be used together for a better understanding of the artefact under investigation. digital surveying employing tools such as terrestrial laser scanning (tls) and structure-from-motion (sfm) software can be used together and made to interact with one another in order to compile an exhaustive database, rich in colorimetric and metric information. the case study examined in the present research is the discovery of the amphitheater of volterra. it was discovered in july 2015 during the clearance operation of a local stream, and it is located near porta diana, a few hundred meters from the roman theater, which was discovered in the last century. the excavation campaign occurred between october and november 2015, and it revealed the ridges of the structure's support walls. this structure is constituted by three levels, which together are nearly ten meters deep. in the post-processing phase, three-dimensional models were used to create the metric images necessary to study the stratigraphic units. moreover, during this phase, it was possible to test the ability of mobile applications to visualize and manage 3d models and excavation information. key words: mobile app, virtual, amphitheater, 3d models, digital survey sdh reference: carlo battini and elena sorgel. 2017. amphitheater of volterra: case study for the representation of the excavation data, sdh, 1, 2, 13 pages. doi: 10.14434/sdh.v1i2.23242 1. introduction the present paper aims to describe an experimental method to organize the data gathered during an archaeological excavation. using different surveying techniques simultaneously can contribute to a better understanding of the studied artefact on variable levels of detail. after having been validated, the gathered data were inserted into a database managed by mobile systems. the present paper studies a prototype of a mobile application, which is currently being implemented, to organize information with virtual visualizations. features of the project include adding textual information, saving graphic notes, executing linear measurements, and taking photographs localized in the virtual three-dimensional space. author's address: carlo battini, dicca department of civil, chemical and environmental engineering, university of genoa, 16145, via montallegro 1, genoa, italy; email: carlo.battini@unige.it; elena sorge, soprintendenza archeologia della toscana – florence, italy.; email: elena.sorge@beniculturali.it permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal 2. the discovery of the amphitheater the amphitheatre of volterra was rediscovered on the 8th july 2015, with the uncovering of a 40meter-long curved wall (fig. 1, fig. 2). thanks to the funding from the bank of volterra, it was possible to start the first excavation campaign, which confirmed the hypothesis that this structure was actually a forgotten roman amphitheater consisting of three floors (fig. 3). 1:270 c. battini figure 1. the discovery of the first stretch of roman masonry. figure 2. the curved line of the wall is visible. at this stage of the work, the presence of a roman amphitheater was hypothesized. amphitheater of volterra 1:271 figure 3. after just one day of excavation, archaeologists found the first confirmation of the presence of a structure hidden in the ground. the aim of our first season, which lasted six weeks, was primarily to confirm the existence of the monument itself, as well as to plan the subsequent excavation campaigns, which were postponed as winter was drawing near. for this reason, only the first layers, were removed, thus revealing the actual dimensions of the amphitheater. this sample provided the concrete evidence that the structure discovered was, in fact, an amphitheater composed of three floors, built with steps, which, however, were not found in this section. the cavea was vast and structured on three levels, prima, secunda, and summa cavea (or maenianum primum, secundum, and summum), separated by the praecinctiones, which can be described as thick concentric support walls. the arena is located at a height that we imagine to be two metres below where we reached at the end of the excavation; therefore, it should be circa 6 meters from the height of the current excavation level (fig. 4). architecturally, the amphitheater could likely have had a mixed structure, with strong similarities to the vallebuona theatre, i.e., inserted (where possible) into the slope of a hill, with other parts built on substructures, as research carried out in one of its carceres (chariot pit) seemed to prove. during the first survey, it was not possible to examine the ruins; therefore, currently nothing can be said about the actual state of conservation of the structure. the non-invasive geo-diagnostic surveys, carried out during winter in the area by soing, a company based in livorno, italy and a project 1:272 c. battini partner of the italian superintendency of cultural heritage, showed that the structure was even larger than previously suspected (fig 5). figure 4. the portion of the cavea of the amphitheater with the carceres of the first two orders delimited by the first and second praecinctio. figure 5. image of the non-invasive geo-diagnostic surveys carried out during winter in the area by soing (livorno, italy). amphitheater of volterra 1:273 thanks to a collaboration with the department of civil, chemical and environmental engineering (dicca) in genoa, it was possible to carry out digital surveys to study the samples taken. the reconstruction of the monument showed that its dimensions are around 82 m x 64 m, with three stone step floors, as demonstrated in the last excavated area (fig. 6). figure 6. location of archaeological assays performed. the total dimensions of the monument are wider than previously hypothesized – they seem to be around 82 m x 64 m. 3. excavation and recording information the excavation procedures were implemented using modern techniques of three-dimensional surveying, which can acquire a vast amount of data to then create a rich database for investigating the finds. nowadays, these methods are essential for data interpretation, conservation, and storage, as well as the appreciation of the finds, thanks to interacting systems of visualization [russo et al. 2011]. as usually happens, the techniques of digital surveying, i.e., terrestrial laser scanning (tls), topography and the structure-from-motion (sfm) technique [bertocci 2014] can be used together to 1:274 c. battini acquire the most information possible, depending on the peculiarities of the utilized technique. these surveying techniques have different levels of definition and errors. however, they can be compared and used simultaneously to enrich the database with new information. in the survey of the amphitheater of volterra, the three techniques were implemented in accordance with a project of precise survey, which was fundamental for analyzing the quality of the data collected as well as for defining an operative procedure for the campaign of data acquisition. in the first phase, a topographic support network was built to record the data coming from the tls (fig. 7) and sfm surveying techniques [russo et al. 2011]. figure 7. the first laser scanner survey campaign: a) scanner z + f imager 5006h; b) point cloud displayed within the leica cyclone 9.1 software. several scientific contributions have studied these two methods, which today are consolidated in the discipline of surveying, with the aim of determining the potential strengths and limitations of using them in alternation or at the same time [beraldin 2004; boehler and marbs 2004]. the application of these methods in the field of cultural heritage [boehler and marbs 2004; grussenmeyer et al. 2008] highlights how some parameters are fundamental to a successful survey. dimension, geometric complexity, and coloration can be pivotal factors in increasing or diminishing measurement errors at the moment of the three-dimensional acquisition. therefore, particular attention was given to the definition of a maximum admissible error. owing to the presence of sandy soil and ashlar walls and because of the dimension of the structures to be surveyed, the maximum allowable error was set at 1.5 cm. with this value, it was possible to store all the information on the collected stratigraphic units as well as to operate with an expeditious approach during the stage of survey. the processes leading to the evaluation of this error included the comparison of the databases acquired with the two different surveying techniques. for the comparative test, the decision was made to analyze the result of the first excavation campaign, which was characterized by extreme geometrical complexity as well as by the presence of areas with soil and well-preserved wall structures. using the z+f imager 5006h phase-shift laser, which can scan structures within a range of 79 metres with an accuracy of 2 mm, it was possible to record the geometrical structures of the archaeological site with the reflectance value of the material. the point clouds, which were needed to create a amphitheater of volterra 1:275 threedimensional model of the sample, were acquired using 14 laser locations. the point clouds were converted into a 3d-mesh model by simplifying data with a distance of 1 cm between all points (a value below the acceptable error defined in the preliminary stage). subsequently, the resulting threedimensional model underwent a process of cleaning and elimination of all imperfections. the final result was a model of 12,058,625 triangles (fig. 8). at the same time, the 3d data of this excavation area were captured using the sfm technique. the surveying process was carried out with a nikon d5000 reflex camera using an 18-105 mm lens. by maintaining the same focal aperture, it was possible to acquire a great number of shots, which were subsequently elaborated using photoscan (version 1.2.2; fig. 9). figure 8. three-dimensional model composed of approximately 6 million polygons deriving from the points cloud acquired with laser scanner. figure 9. the acquired images (all shot with the same focal length) were used to reconstruct the threedimensional model with the sfm technique. 1:276 c. battini after the processes of image alignment, and the construction of a sparse cloud, a dense cloud, a 3d model and texture, it was possible to create a 3d model with the same orientation and dimensions as the result obtained with the tls technique. the two three-dimensional models were compared using the cloudcompare 2.6.2 software, in order to evaluate the differences between the two surveying techniques. the values acquired were a mean-distance value of 0.002917 m and the standard-deviation value of 0.012793 m, which are both below the limit defined during the preliminary phase (fig. 10). based on this comparison, for the following three-dimensional surveys the research team decided to adopt the sfm technique (with topographic support) as the main tool to acquire metrical information. this technique proved to be less expensive in the phase of data elaboration and could also be used by less experienced staff, which avoided excessive interruption of the excavation processes. figure 10. the comparison of the two three-dimensional models (tls and sfm) within the open-source software cloudcompare 2.6.2. 4. mobile application for data management the collection of information is only the first step in the understanding an archaeological object. data must be catalogued and made available to several experts of various disciplines for interpreting the historical evolution of the site. the archaeological excavation is the moment in which all information not collected and catalogued will be definitively lost, disrupting the process of understanding of the object investigated [bezzi et al. 2011]. collecting and recording the information at regular intervals is, therefore, the first step to scientifically validate the information collected [grabner et al. 2003]. amphitheater of volterra 1:277 new research projects can be developed with the use of commercial platforms and open source tools, such as three-dimensional models, images, texts, and sounds to view and interact with the collected data. many studies, such as the archeoguide [vlahakis et al. 2002], were able to create guided tours in augmented reality with head-mounted displays. other projects, such as virtual rome, reconstructed the landscape of modern day rome and that of rome in the second century a.d. using common web browsers with three-dimensional online reproduction, including multimedia insights [pescarin et al. 2009]. currently, the 3d heritage online presenter (3dhop) platform, developed by the visual computing laboratory of the department isti-cnr of pisa, proves to be a promising project for visualizing digitized media assets on the web [potenziani et al. 2015]. the use of multiresolution encoding efficiently streams high-resolution 3d models, such as the sampled models usually employed in cultural heritage applications. in addition, it provides a series of ready-to-use templates and examples tailored to the presentation of ch objects, and it interconnects the 3d visualization with the rest of the dom webpage, making it possible to create integrated presentation schemes (3d and multimedia). the present research aims to determine how a mobile application can aid the understanding and the study of an archaeological object. in particular, the use of virtual reality can be an essential tool to understand the spatial morphology of the artefact, allowing the user to use and add information pivotal to the understanding of the object’s evolution. the aim is to create an application able to: three-dimensionally browse within the 3d models of the collected samples; take measurements from one point to the other; record textual and graphical notes located in the 3d space, in order to facilitate the study of the object; take photos using the camera of the mobile system, and locate these images in specific points of the 3d model. the present project was realized using unity 3d, a programming software usually adopted to develop videogames and able to provide all the necessary utilities to create a 3d environment. the development of the proposed application started by defining the features necessary to support user interaction. the application should visualize three-dimensional models, enable virtual browsing, and organize text and images. data can already be in the application, or it can be inserted during runtime by the user while browsing. in order to promote potential developments of this application and to give it greater versatility, the decision was made to create an sql database which can be updated within the server to exchange and save the collected information (fig. 11). figure 11. data are not stored locally but are sent through the appropriate script for connection to a central server in a mysql database 1:278 c. battini interactions with the designed application, for example virtual browsing, data addition, and connection with the database, are obtained through specific scripts written in c# (fig. 12) that manage the variables necessary to implement each action. for example, the script for graphic notes was created using a sequence of specific actions: acquiring the screenshot of the user’s viewpoint; creating a plane perpendicular to the visual axis, with the same dimension as the screen of the mobile support; applying the screenshot as plane texture; creating the graphic note defined by the user with the touchscreen of the mobile support, using the raycast function. in particular, with this function, it is possible to send invisible rays, parallel to visual axis, in correspondence to the point touched by the user on the touchscreen. the intersection of these rays with the plane, created previously, identifies a series of spatial points to which a red circle is then associated. because of the proximity of these circles with respect to their dimension, a continuous line can be simulated, which then leads to the creation of the graphic note; acquiring the mobile-support screenshot and its saving in the sql database. other scripts use the raycast function to identify the spatial coordinates of the points (essential to associate the information in the virtual space or to measure distances) or to identify the name of a gameobject (gameobjects are the fundamental objects in unity that represent characters, props and scenery), which is useful to retrieve specific information in the database (fig. 13). three-dimensional browsing requires the use of two pointers located at the corners of the screen, allowing both the movement (left sticker) and the rotation (right sticker) of the user’s viewpoint. lastly, the three-dimensional models used in the present study derive from the three-dimensional surveying procedures, which were simplified with retopology and advanced texturing techniques. to avoid increasing the dimension of the installation starter pack, the three-dimensional models are downloaded the moment the user chooses the sample to be visualised, by then saving it in a specific folder of the mobile support, making it available to be subsequently visualised. figure 12. use of unity 3d to develop the mobile app. on the right: the programming window of the scripts in the c# language amphitheater of volterra 1:279 figure 13. some screenshots of the application: a) list of the excavations on the server side; b) pop-up menu with programmed features; c) vr view of the excavation; d) drawing on the snapshot; e) window to enter a title and description; f) snapshot stored server side; g) visualization of information entered; h) window with storage of a photo and title. 1:280 c. battini 5. conclusion the technology of representation is constantly developing, offering the user increasingly higher interactivity. refined virtual-reality techniques and increasingly powerful technological tools are the fundamental requirements to create useful applications in the field of cultural heritage, which can help researchers to share and spread information. technological tools and applications should not be regarded as distant from the discipline of cultural heritage. on the contrary, they facilitate researching and sharing operations and are much more efficient than traditional means. technologies for representation are today in continuous development and allow an ever-greater interactivity by the end user. techniques of virtual reality increasingly refined and technological tools ever more powerful are the essential ingredients for making useful applications in the field of cultural heritage. the possibility of using these state-of-the-art tools can be of great interest to help researchers to share and disseminate information. these tools and technological applications should be seen as tools to facilitate the operations of research and sharing in a much more effective way than can be done with traditional methods. 6. acknowledgements the authors wish to thank: valeria d’aquino, giacomo baldini, giano snc, paolo nannini, giovanni roncaglia, stefano sarri, pasquino pallecchi, domenico zaccaria, the municipality of volterra, stokholm university, cassa di risparmio di volterra, fondazione cassa di risparmio di volterra and franca taddei. the author would also acknowledge that paragraph 2 was written by e. sorge, while c. battini wrote the remaining paragraphs. 7. references elsevier bv. 58 (jul), ex1, https://doi.org/10.1016%2fs0924-2716%2804%2900027-9 lorenzo còveri. il genovese del quattrocento, lingua della repubblica. in italia settentrionale: crocevia di idiomi romanzi. de gruyter, https://doi.org/10.1515%2f9783110910346.261 giuliano de felice, and maria giuseppina sibilano. 2010. strategie di documentazione per la ricerca e la comunicazione archeologica. il caso di faragola (foggia, italia). virtual archaeology review. 1 (may): 95. https://doi.org/10.4995%2fvar.2010.4696 fabio remondino. 2011. heritage recording and 3d modeling with photogrammetry and 3d scanning. remote sensing. 3 (may): 1104--1138. https://doi.org/10.3390%2frs3061104 stefan hynst, michael gervautz, markus grabner, and konrad schindler. 2001. a work-flow and data model for reconstruction, management, and visualization of archaeological sites. in proceedings of the 2001 conference on virtual reality, archeology, and cultural heritage vast '01.. acm press. https://doi.org/10.1145%2f584993.585000 p. grussenmeyer, e. alby, t. landes, m. koehl, s. guillemin, j. f. hullo, p. assali, and e. smigiel. 2012. recording approach of heritage sites based on merging point clouds from high resolution photogrammetry and terrestrial laser scanning. isprs international archives of the photogrammetry, remote sensing and spatial information sciences. xxxix-b5 (jul): 553--558. https://doi.org/10.5194%2fisprsarchives-xxxix-b5-553-2012 lanier, jaron. 1994. a virtual reality-based simulation of abdominal surgery. defense technical information center. luigi calori, carlo camporesi, and sofia pescarin. 2009. virtual rome. in proceedings of the 14th international conference on 3d web technology web3d '09. acm press. https://doi.org/10.1145%2f1559764.1559792 marco potenziani, marco callieri, matteo dellepiane, massimiliano corsini, federico ponchio, and roberto scopigno. 2015. 3dhop: 3d heritage online presenter. computers & graphics. 52 (nov): 129--141. https://doi.org/10.1016%2fj.cag.2015.07.001 michele russo, giorgia morlando, and gabriele guidi. 2007. low-cost characterization of 3d laser scanners. in videometrics ix. j.-angelo beraldin, fabio remondino and mark r. shortis (eds.). spie. https://doi.org/10.1117%2f12.705712 v. vlahakis, m. ioannidis, j. karigiannis, m. tsotros, m. gounaris, d. stricker, t. gleue, p. daehne, and l. almeida. 2002. archeoguide: an augmented reality guide for archaeological sites. ieee computer graphics and applications. 22 (sep), 52--60. https://doi.org/10.1109%2fmcg.2002.1028726 received october 2016; revised september 2017; accepted november 2017. archiving the past while keeping up with the times valentijn gilissen and hella hollander data archiving, networked services (dans), the netherlands the e-depot for dutch archaeology started as a project at data archiving and networked services (dans) in 2004 and developed into a successful service, which has ever since been part of the national archaeological data workflow of the netherlands. while continuously processing archaeological datasets and publications and developing expertise regarding data preservation, various developments are taking place in the data landscape and direct involvement is necessary to ensure that the needs of the designated community are best met. standard protocols must be defined for the processing of data with the best guarantees for long-term preservation and accessibility. monitoring the actual use of file formats and the use of their significant characteristics within specific scientific disciplines is needed to keep strategies upto-date. national developments include the definition of a national metadata exchange protocol, its accommodation in the dans easy self-deposit archive and its role in the central channelling of information submission. in an international context, projects such as ariadne and parthenos enable further developments regarding data preservation and dissemination. the opportunities provided by such international projects enriched the data by improving options for data reuse, including the implementation of a map-based search facility on dans easy. the projects also provide a platform for sharing of expertise via international collaboration. this paper details the positioning of the data archive in the research data cycle and presents examples of the data enrichment enabled by collaboration within international projects. key words: data archiving, preservation, standards, collaboration, access, portals sdh reference: valentijn gilissen and hella hollander. 2017. archiving the past while keeping up with the times, sdh, 1, 2, 12 pages. doi: 10.14434/sdh.v1i2.23238 1. dans and the research data cycle data archiving and networked services (dans) is the dutch research data archive. predecessors in data archiving in the netherlands date back to 1964; dans was established in 2005 following revisions of the existing initiatives by the royal netherlands academy of arts and sciences (knaw) and the netherlands organization for scientific research (nwo) [dans 2017]. dans has a notable role within both of its founding organizations. the knaw is a branch research organization of fifteen internationally renowned dutch research institutes, including dans. dans promotes sustained access to digital research data and carries out research on this topic; its data author's address: valentijn gilissen and hella hollander, data archiving and networked services (dans), anna van saksenlaan 51, 2593 hw den haag, the netherlands; email: valentijn.gilissen@dans.knaw.nl; hella.hollander@dans.knaw.nl permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal archiving services additionally serve as essential support to all other research institutes. nwo is the organization which funds scientific research at public research institutions in the netherlands. research which is funded by nwo should ensure that the resulting data is archived in a sustained form, which dans enables through the use of its online archive, the electronic archiving system: easy [dans easy 2017]. the research data cycle can be summarized as follows: a researcher produces research data; another researcher needs to be able to find, access and re-use the data for new research; the initial research should be referenced; the new research results in its own dataset, and so on. the policies of dans aim to ensure the sustainability of the research data cycle in the long term: to ensure preservation of data, dans states that data should be archived in a repository which complies with international standards and guidelines of trustworthiness: a certified "trusted digital repository" (tdr). to support the use of trusted digital repositories, funding organizations should oblige researchers to deposit their research data in a tdr. in order to make data accessible, dans promotes open access, but understands that for reasons such as privacy sensitivity of certain data files it is not always possible to make data available without restrictions. the position of dans is "open if possible, protected if necessary." to accommodate re-use of data as well as to attribute credit to researchers, persistent identifiers, unique hyperlinks following a specific manner of resolving in order to remain valid over the long time should be used for referencing data sources in scientific publications. a dataset should have the same scientific value as a research article; the persistent identifier could be likened to the isbn code of a publication. archives use the open archival information systems (oais) reference model [ccsds 2012] to identify all sorts of aspects which need to be taken into account when managing data between submission by a data producer and dissemination to a data consumer. while the oais is not a set of instructions on "how to build your own archive," the functions and concepts defined within the oais allow an internationally shared view of what an archive should encompass. the reference model supports the methods for certifying an archive as a trusted digital repository according to international standards. there are three degrees of certification for tdrs: the basic/essential certification of the data seal of approval (dsa); the extended certification of the nestor seal (din 31644); the formal certification as an iso standard (iso16363). the dans archiving system easy was awarded with the nestor seal in early 2016 and was the first digital archive in the world to obtain this certificate. the oais reference model is presented as a schematic process of "management" situated between the producer and the consumer. merely having an archive that is oais-compliant would not fully meet the aims dans has as a digital archiving organization for research data. if the archive takes its proper place within the research data cycle, the flow of data should continue with the data consumer becoming a new data producer, using persistent identifier citation for referencing the source data. 2. inside dans easy figure 1 shows the homepage of dans easy with its direct features highlighted in text boxes. a central search bar can be used to search through all metadata of all datasets. information provided with “search help" informs the user of search options such as the use of and/or booleans and wildcard characters. alternatively, the links to advanced search and browse options can be followed for performing more specific searches. a prominent button for submitting a new dataset deposit is presented in the center of the screen. for proceeding with a deposit or for accessing certain data files, users need to be logged in to the system; the options for registering or logging in remain present in the top of the screen until the user does so. it is not necessary to log in in order to search and browse through datasets, or to view their metadata restricted access only pertains to downloading or opening data files. the bottom of the screen holds a number of links to background information on the use of data, including full instructions for citing data. additionally, the trusted digital repository certificates which were obtained for easy are presented here by their seals, with links to detailed information on the subject. figure 1. an overview of the homepage of easy, dans' electronic archiving system. datasets in easy are described with metadata following the international standard (qualified) dublin core. the advanced search options enable searches within specific dublin core metadata fields: title; creator; description; subject; coverage; identifier. a good example to show the benefit of using advanced search is a researcher who wants to find archaeological research projects conducted in the center of the dutch city of houten. "houten" is also the dutch word for "wooden." to avoid searching for houten and additionally getting all the results of datasets that mention wooden objects in their metadata, it is recommended that the user perform an advanced search on houten within the metadata field "coverage" (temporal and spatial coverage). alternatively, if a researcher wants information on wooden artefacts but wants to avoid results which are only about the city of houten, a search for "houten" should be done within the metadata field "subject". browse options include means to refine search and browse results by audience, access category or by additional search queries. if, following on the above example, the researcher gets many results for a search for "houten" in "coverage," it could be that the dutch word for "wooden" is part of a street name in a different city. a follow-up search could be another advanced search for "coverage": "utrecht", which is the name of the province wherein the city is located. when a dataset is viewed, the user will see it presented in three tabs: overview: a highlighting of the dataset title and (abstract) description from the metadata, which can be accompanied by pictures, illustrations, logos to represent the dataset. the overview also displays the correct way to cite the dataset in literature, by use of the "digital object identifier" (doi) persistent identifier. description: all of the (qualified) dublin core metadata provided for the dataset. data files: the data files published with the dataset, with options for showing additional details if available, and for downloading if accessible. if not accessible, the page explains what conditions need to be met in order to download the data. datasets are described and deposited by researchers themselves. a deposit module takes researchers through the dublin core metadata fields as well as a page where they can upload the data files. few fields are mandatory but a depositor is encouraged to fill in as much metadata as possible to make a dataset findable as well as understandable to anyone. if a research project was done in the city of houten but houten is only part of the title and not specifically entered as "spatial coverage," the dataset would not be found in the use-case scenario given above. when a dataset is being deposited, a data manager of dans checks the incoming dataset for completeness and understandability. the manager may make minor changes or additions to the metadata or may provide migrations of file formats if this benefits the long-term preservation and accessibility of the data. the dataset will only be published after the data manager has performed all of the relevant quality assessments and preservation actions. at the beginning of 2017, easy contains over 33,000 published datasets from various scientific disciplines; it continues to receive new datasets on a daily basis. dans especially accommodates the scientific disciplines classified under the humanities, social sciences and behavioral sciences; the dutch technical universities manage exact mathematical science data themselves, in co-operation with dans, to ensure sustainable storage. the vast majority of datasets in easy are datasets from the discipline of archaeology, totalling over 27,000 datasets and continuously growing (figure 2). the relatively large number of archaeological datasets can be attributed to the successes of the e-depot for dutch archaeology (edna), which started as a project at dans in 2004 and is now embedded as a service within easy [edna 2017]. edna raised awareness of the necessity of data archiving within the archaeological scientific community, digitized many gray literature reports for publication in easy, and enabled all of the archaeological project bureaus, municipalities and universities to use easy to store and disclose their larger datasets. figure 2. a collage for a poster, showcasing the archaeological content of easy. while a number of archaeological datasets in easy contain only a single pdf of a publication, described with dublin core metadata, there are many larger datasets available, and dans especially aims to archive and publish such sets, which generally contain data tables, photographs, digital drawings and specialist reports alongside the final publication (figure 2). a dataset should contain the final data of a research project and the size of the dataset generally matches the extent of the fieldwork conducted. the dataset of a non-intrusive survey will contain only a single publication; the dataset of an intrusive survey may contain more files such as data tables. the dataset of a full excavation may contain a large set of photographs taken in the field, digital drawings and scans of drawings of pits and profiles, daily reports, a database with registration tables and specialist determination tables for the different material types of the finds. 3. dans participation in international projects by participating in (inter)national projects and infrastructures, dans contributes to sustainable access to research data. dans is involved with a large number of projects; three projects will be highlighted here which are of special interest to archaeologists. 3.1 carare from 2010 to 2013, 29 european organizations worked together in the european carare project [carare 2017] to make two million archaeological and architectural objects accessible via the europeana website. this target has been exceeded by 5 million objects. dans contributed the archaeological publications that are published in easy (figure 3). in the process, dans gained valuable experience with metadata mapping, harvesting of selected metadata records from easy, having the resource displayed on a map through translation of the national dutch coordinate system and having the resource link back to the content via the persistent identifier. figure 3. the first version of the carare map portal, which was available until december 2016. the portal is now incorporated in europeana collections [europeana 2017] 3.2 ariadne ariadne stands for advanced research infrastructure for archaeological dataset networking in europe. 23 partners from 16 european countries collaborated in the ariadne project from february 2013 to january 2017 with the overall goal to establish a european research infrastructure for the integration of archaeological datasets. in addition, tools were developed that provide researchers access to this data [ariadne 2016]. dans contributed data from the archaeological e-depot edna and the digital collaboratory for cultural dendrochronology (dccd), making the data in easy more visible internationally via the ariadne portal. dans collaborated closely with leiden university in data mining and linked data activities, which allowed the mapping and translation of dutch concepts from the national archaeological vocabulary to international vocabularies within the european infrastructure. additionally, data mining was performed on the content of pdf publications from datasets that were lacking information in their metadata on coordinates. this enabled the addition of correct coordinates to the metadata of about 3500 datasets, a result of clear mutual benefit to dans (elaboration of metadata) and the ariadne project (adding of content). on the ariadne portal (figure 4) thousands of resources can be found via a map, a timeline search and a keyword search, all with various options for filtering results. the mapping of keywords from national vocabularies allows comprehensive cross-searching the resources from all partners. figure 4. the ariadne portal [ariadne 2017]. collaboration within ariadne led to the publication of new guides to good practice, including a guide on dendrochronology [brewer and jansma 2016] and a guide on 3d data [trognitz et al. 2016]. the activities performed and the experience gained in order to have the easy content displayed on the ariadne portal additionally enabled dans to develop a map display feature in easy, a feature which was implemented at the beginning of 2016. search and browse results are initially shown in a list, as has always been the case, but the display can now be switched from "list" to "map" (figure 5a). all of the search/browse results which include coordinates are then displayed on openstreetmap in agglomerations of results. zooming in will result in the agglomerations to spread out, to the point that single results are found. figure 5a. the map display feature for browse results in easy. figure 5b. a zoom on search results for houten in the map display feature. figure 5b shows a zoom on an advanced search for "houten" in "coverage," following on from the example presented in section 2. with several dozen hits, showing the search results in list display would not be very helpful for a researcher who is only interested in archaeological research carried out in the center of the city. switching to map display allows zooming to the location and selecting single results in the target area. apart from the invaluable contributions to the development on the map display feature, dans was also able to make use of the work done on mapping of metadata within the ariadne project to contribute to the national development of an xml standard for archaeological data tables. this xml standard was developed by the dutch archaeological sector as a national exchange protocol [sikb 2016]. the protocol serves to provide more and better metadata for archaeological projects and to have terminology standardized according to the national archaeological vocabulary. it allows for a complete export of archaeological database tables to standardized xml, which means that every archaeological company can use their own database system but still provide an export to make the data interoperable. dans implemented the protocol in easy to the effect that data depositors can now upload the xml with new deposits and have metadata from the xml extracted in the easy dublin core metadata fields. this has proved to be a very efficient means to provide full and correct metadata with a data deposit, saving time and effort for depositors as well as for data managers. 3.3 parthenos parthenos stands for pooling activities, resources and tools for e-heritage research networking optimization and synergies. whereas carare and ariadne focused on archaeology, parthenos empowers digital research across all fields of the (digital) humanities, including history, language studies, cultural heritage and related fields. the interdisciplinary four-year project, which began in may 2015, provides a thematic cluster of european research infrastructures (e-infrastructures and other world-class infrastructures), carries out integrating initiatives, and builds bridges between different but interrelated fields of research. [parthenos 2017] central topics are the implementation of common aaa (authentication, authorization, access) and data curation policies within the framework of the data lifecycle, including long term preservation, certification and intellectual property rights (ipr). expected key results of the project are: guidelines on data management: to produce a coherent, authoritative, well accepted set of policies/guidelines/tools concerning the management of data lifecycle and related issues such as ipr, quality and so on. standardization and semantics: to produce a wide set of standards and semantics, originated from community needs and tailored to the methodology and intended use by researchers. services and tools: to produce a coherent set of tools for carrying out research using and reusing data. dans is working on the harmonization of research data management within the various disciplines and the certification of their repositories. dans contributes its guidelines and experiences on data management to the parthenos resources. in return, the international collaboration on data policies and protocols allows enhancing dans' own guidelines. one of the topics covered by such guidelines is the topic of preferred formats, the best choices for file formats over the long term. dans published its preferred formats guide in september 2015 [dans 2015], which details the best options for long-term preservation per file type (figure 6). the guidelines aim to make data available in file formats which are, as far as possible: open formats; frequently used; independent of specific software, developers or vendors. a working group within dans is responsible for maintaining the guidelines, which can be subject to revision based on issues such as new file formats occurring in dataset deposits, or new software developments. parthenos functions as a platform for international discussions on the subject, which also contribute to updates of the preferred formats guidelines. figure 6. the overview table of the dans preferred formats guidelines. 4. conclusion this paper explained the role of dans as a trusted digital repository within the research data cycle and described the easy electronic archiving system and its archaeological content. furthermore, it gave examples of results from dans' involvement within three international projects and the mutual benefits from dans bringing content to those projects and enriching its own output in return. the paper has different objectives, depending on the background of the readers. researchers are encouraged to use the described services. the search and browse options of dans easy allow finding datasets from dutch scientific research including a large number of archaeological records; the portals of europeana/carare and ariadne assist in finding datasets of sources from all over europe which can be useful for further research. when creating data, recommendations and guidelines coming from the parthenos project should help in keeping the data findable, accessible, interoperable and re-usable. when re-using data, researchers are strongly encouraged to keep the research data cycle alive by citing the data source and by depositing their own datasets. storing data in a trusted digital repository will give the best guarantees for sustainability in the long term. organizations with a tdr like dans will continue to provide content to existing portals and to participate in projects to disclose data. therefore, new datasets deposited in a tdr such as easy will also be enriched by making them findable through innovations such as the ariadne portal. readers working in other parts of the research data cycle such as data management are encouraged to participate as much as possible in (inter)national projects and to work together to promote sustained access to research data. the examples given in this paper show that international collaboration can generate great mutual benefits. there is much to gain in connecting data across borders and disciplines, for anyone involved – and there is no reason not to work together; we should all be friends. 5. references ariadne advanced research infrastructure for archaeological dataset networking in europe. 2016. building a research infrastructure for digital archaeology in europe. ariadne booklet, december 2016. retrieved april 13, 2017 from http://www.ariadne-infrastructure.eu/about ariadne advanced research infrastructure for archaeological dataset networking in europe. ariadne portal. retrieved april 13, 2017 from http://portal.ariadne-infrastructure.eu brewer, peter and esther jansma. 2016. dendrochronological data in archaeology: a guide to good practice. archaeology data service / digital antiquity. guides to good practice. retrieved april 13, 2017 from http://guides.archaeologydataservice.ac.uk/g2gp/dendro_toc carare connecting archaeology and architecture in europeana. retrieved april 13, 2017 from http://www.carare.eu ccsds consultative committee for space data systems. 2012. reference model for an open archival information system (oais). recommended practice ccsds 650.0-m-2. magenta book, washington, dc: ccsds secretariat. retrieved april 13, 2017 from https://public.ccsds.org/pubs/650x0m2.pdf dans data archiving and networked services. retrieved april 13, 2017 from https://dans.knaw.nl/en dans data archiving and networked services. 2015. file formats, preferred formats and accepted formats. preferred formats. version 3.0, september 2015. retrieved april 13, 2017 from https://dans.knaw.nl/en/deposit/information-about-depositing-data dans easy data archiving and networked services electronic archiving system. retrieved april 13, 2017 from https://easy.dans.knaw.nl/ui/home edna e-depot for dutch archaeology. retrieved april 13, 2017 from https://dans.knaw.nl/nl/over/diensten/data-archiveren-en-hergebruiken/easy/edna europeana. europeana collections. retrieved april 13, 2017 from http://www.europeana.eu/portal/en parthenos pooling activities, resources and tools for e-heritage research networking optimization and synergies. retrieved april 13, 2017 from http://www.parthenos-project.eu sikb – stichting infrastructuur en kwaliteitsborging en bodembeheer. 2016. sikb0102 archeologie, xml exchange standard. retrieved april 13, 2017 from http://www.sikb.nl/datastandaarden/richtlijnen/sikb0102 trognitz, martina, kieron niven, and valentijn gilissen. 2016. 3d models in archaeology: a guide to good practice. archaeology data service / digital antiquity. guides to good practice. retrieved april 13, 2017 from http://guides.archaeologydataservice.ac.uk/g2gp/3d_toc received march 2017; revised july 2017; accepted august 2017. digital 3d reconstructed models: using semantic technologies for recommendations in visualization applications steffanie wefers, ashish karmacharya, and frank boochs, mainz university of applied sciences, germany mieke pfarr-harfst, technische universität darmstadt it is common for cultural heritage applications to use spatial and/or spectral data for documentation, analysis and visualization. knowledge of data requirements coming from the cultural heritage application and technical alternatives to generate the required data, based on object characteristics and other influential factors, pave the way for the optimal selection of a recording technology. it is a collaborative process, requiring the knowledge of experts both from cultural heritage domains and from technical domains. currently, this knowledge is structured and stored in an ontology (so-called coschkr). its purpose is to support ch experts who are not familiar with technologies by prescribing an optimal spatial or spectral recording strategy adapted to the physical characteristics of the cultural heritage object and the data requirements of the targeted ch application. the creation of digital 3d reconstructed models for analysis and visualization purposes is becoming more and more common in humanities disciplines. therefore, an implementation of the mechanisms involved in visualization applications into this ontology would have huge benefits in creating a powerful recommendation solution. illustrating the overall structure of coschkr, this paper addresses and discusses challenges in structuring the processes of cultural heritage visualization and implementing these into the ontology. key words: ontology, facts and hypothesis, inference, cultural heritage, data processing sdh reference: stefanie wefers et al. 2017. digital 3d reconstructed models: using semantic technologies for recommendations in visualization applications. sdh, 1, 2, 537-546. doi: 10.14434/sdh.v1i2.23327 1. introduction visualization and 3d reconstructed models have become more and more an established feature of research in the field of cultural heritage (ch). since the 1980s, 3d handmade models have developed a strong tradition as a medium of communication in knowledge transfer. the most popular author's address: stefanie wefers, ashish karmacharya and frank boochs, i3mainz, institute for spatial information and surveying technology, hochschule mainz, university of applied sciences, lucy-hillebrand-straße 2, d-55128 mainz, germany; email: stefanie.wefers@hs-mainz.de; ashish.karmacharya@hs-mainz.de; frank.boochs@hs-mainz.de; mieke pfarr-harfst, technische universität darmstadt, el-lissitzky-straße 1, 64287 darmstadt, germany; email: pfarr@dg.tu-darmstadt.de permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh.© 2017 sdh open access journal application is displaying these digital 3d reconstructed models in a video, especially in the context of an exhibition. one of the reasons for this application is that the 3d models transfer a message through images that are understood as a universal language requiring no further encoding [pfarrharfst 2016]. three-dimensionality within these models makes it possible for a broad public to get an idea of complex spatial interrelation and to contextualize ch objects within a 3d setting. therefore, digital 3d reconstructed models are understood (in addition to written text and spoken words) as a further medium for storing and transferring knowledge [pfarr-harfst 2016]. creating scholarly digital 3d reconstructed models of ch objects is a multidisciplinary task [pfarrharfst and wefers 2016]. the knowledge about the details of the object that is to be reconstructed comes from ch experts such as archaeologists, art historians, or historians. in a first step, the basis for the modeling has to be set through (1) a compilation of relevant available publications, 3d data, spectral data, images, descriptions, drawings, paintings etc. and, if necessary, (2) a digitization of non-digital information. relevant information is compiled by ch experts; however, the data acquisition is done by technical experts capable of properly applying technologies such as 3d recording or spectral recording. afterwards, modelers begin to create the digital 3d reconstruction, working with the compiled information and data. they regularly discuss interim reconstruction results with the ch experts, allowing for adjustments and clarification of (so far) neglected details, until the digital 3d representation reflects the vision of the ch expert. how detailed this information needs to be is very often underestimated by ch experts who, both as information recipients and providers, are used to two-dimensional visualizations within their domain. in contrast to 3d reconstructed models, such 2d visualizations easily allow missing information to be hidden. for digital 3d reconstructed models, however, detailed three-dimensional descriptions of the ch object and its constructive parts are needed; if it has been visualized in its context, its spatial position and context are also required. many decisions have to be made by the ch expert: for some of these, no scholarly evidence might exist; for other decisions further reconstruction options, which are still under scholarly discussion and might not be concluded at all, have to be neglected. supporting such visualization applications could be achieved by implementation of application requirements in a machine-readable ontology-based knowledge representation. through semantic web technologies, knowledge can be inferred from ontology-based knowledge representations. the overall idea is to create a recommendation platform for ch experts that highlights emerging challenges during 3d reconstruction projects while taking individual input interactively into account. 1.1 knowledge representation with the overall intention of prescribing the optimal selection of spatial and spectral recording technologies and the technical strategy or strategies for fulfilling the data-specific demands of ch applications, an ontology-based knowledge representation is currently under development. it is called coschkr, and acronym for color and space in cultural heritage knowledge representation [karmacharya et al. 2016; wefers et al. 2016]. cosch is the acronym of the european cost action td1201: color and space in cultural heritage (cosch), during which the foundation of the knowledge representation was developed (http://www.cosch.info). cultural application defines the requirements and demands that are necessary for successful completion of the application. these requirements and demands are related to the nature and quality of data, while the technologies and the underlying components are able to generate required quality data. therefore, coschkr is driven through the primary axis of ch applications → data ← technologies. this axis is represented through the top-level classes, ch applications, data and technologies, and is defined through their interrelationships. the classes are further defined through rules, which describe their semantic constructs. in addition to these three classes defining the primary axis of the ontology, the ontology includes classes representing the physical (ch) objects through the top-level class physical thing, as well as other external impacts through the top-level class external influences. both classes represent restraining/supporting constraints to the technologies. these constraints are semantically constructed through rules inside these two classes. physical objects represented in physical thing provide restraining/supporting constraints on technologies, e.g., through their size and/or shape. likewise, specifications of the project, such as available budget, which are encoded inside external influences, may have an impact on the recommendation of an optimal recording device, e.g., due to higher costs than are available in the project budget. the structure, relationships, and rules are logic-based constructs encoded into the ontology through machine interpretable language (owl). this enables machines to participate and assist in interpreting and concluding, through reasoning, the logic-based facts. the top-level classes and relations of coschkr are illustrated in fig. 1 [for details see karmacharya; wefers et al. 2016]. figure 1. top-level classes and relationships of the ontology coschkr. the rules binding ch applications and technologies through data initiate navigation through the ontology that requires knowledge assertions from the user. in many cases, these assertions reflect the actual discussion between a humanities expert, who would like to record a physical ch asset, and a technical expert, who is actually recording the asset. this assertive mechanism feeds the facts into the ontology, and these facts provide the basis for the rules to be inferred inside the ontology. 2. state-of-the-art the word "semantic" implies "meaning" or "understanding". the technologies implementing semantics aim at explicitly describing the meaning of content; they do not aim at the content itself. the evolution of the semantic web framework in the late 20th century has given a boost to technologies such as artificial intelligence, which exploit the semantics of content to reason onto the conclusions [berners-lee 2006]. in this context, ontologies play a major role: they are traditionally used to structure knowledge by defining terms and relationships describing a specific knowledge domain [heflin 2004] and were first used in philosophy dealing with the theory of existence [hofweber 2011]. they define the descriptive semantics of the various entities related to a specific knowledge domain. the semantic web considers ontologies as the main medium to express and represent structured knowledge. it uses a standardized web ontology language (owl) (https://www.w3.org/owl/) bringing expressive and reasoning power to the semantic web. so far, ontologies have been rarely used for implementing and representing 3d visualization because: few studies have been carried out to evaluate and classify 3d visualization techniques; they mainly focus on the interaction techniques [v-must 2013] and/or software/hardware configurations [potter and wright 2006] used in specific applications; and different classifications, terminologies, and taxonomies have been defined, each for specific aims and applications [shu et al. 2008]; due to the huge variety they cannot be considered for a heuristic view, which is needed to develop an ontology with the above described purpose. even when such kinds of ontologies are developed, they are used to define problems in designing visualization techniques and/or their preferred application areas, without giving details on the specifications of these techniques and where and how they are intended to be used. for example, the top level visualization ontology (tlvo) provides a common vocabulary to describe visualization data, processes, and products [brodie et al. 2004]. more recent research analyzes visualization taxonomies and proposes modifications of tlvo [pérez et al. 2010]. other examples are: a visualization ontology that adds semantics for the discovery of visualization services [shuet al. 2008]; "unifying ontology" for visualization systems that allows reasoning on the optimal use/reuse/synthesis of graphical representation for a special situation [voigt and polowinski 2011]. for our purpose, the ontology lacks many basic concepts, e.g., there is no representation of 3d visualizations or the targeted applications, and last but not least, the ontology is no longer accessible; and a query based selection of relevant visualization techniques [metral et al. 2012]. the work on visualization ontologies primarily focuses on either classifying hardware/software and their configurations or selecting specific representations. they primarily work on querying asserted knowledge for the answers. however, the selection of visualization techniques and workflows, based on the demand(s) of the required data for a specific purpose, requires the following essential components to be listed in an ontology: (1) visualization techniques/workflows, (2) technologies dictating the data generation, (3) the content and quality required for the visualization, and (4) the accessibilities of information/data that will generate the required content. moreover, such a kind of an ontology would need to bind these components together through proper relationships and rules. if these preconditions were met, the ontology could be used to develop optimal visualization techniques and workflows adapted to the needs of the targeted application. 3. essentials of coschkr currently, coschkr relies on facts, which are either given by the existential physical facts of the ch asset or through proven technical capabilities of technologies, which are needed for the entire process of an optimal data acquisition and processing adapted to the requirements of the targeted application. in both cases, the ontology infers from the facts, which are logically encoded as rules, in various related classes. the ontology requires asserted knowledge of these facts before inferring them. an illustration of such an assertive process is presented through the example of an already implemented typical ch application, which focuses on the "analysis of geometric alteration". an example for such an application is a project focusing on archaeological waterlogged wooden samples, which were 3d documented before and after conservation treatment in order to be able to evaluate geometric alterations caused by the conservation treatment through comparison of the data sets [e.g., mazzola 2009] (http://www.rgzm.de/kur/index.cfm?layout=holz&content=start). as an example, we present the first basic semantic rules for this ch application geometric alteration (which is a subclass of the top-level class ch applicationsm; for more details, see karmacharya, wefers, boochs 2016; wefers, karmacharya, boochs 2016). it requires high quality 3d data representing the object for at least two instances. the class is semantically constructed through the rule that states this requirement. the rules are defined through description logic statements (dl) [baader 2003], but for simple explanations, we use equivalent lexical statements. equation 1 states that the class geometric alteration requires at least two 3d data of the object, and equation 2 states that these data need to be of high quality. geometric alteration has requirement on data minimum 3d data has representation of one physical thing (eq. 1) geometric alteration has requirement on data minimum 3d data has quality high quality (eq. 2) the equations 3 to 5 illustrate the rules inside the ontology, which semantically define different components of the technology, while equation 6 displays the inference result of those rules. structured light 3d scanning hashas main operating instrument structured light 3d scanners (eq. 3) structured light 3d scanners has measurement principles triangulations (eq. 4) triangulations has generation of data 3d data has quality high quality or medium quality or low quality(eq. 5) this permits the inference: structured light 3d scanning has generation of data 3d data has quality high quality or medium quality or low quality(eq. 6) the above-described first selection of technologies is afterwards iteratively inferred for their optimal suitability against the restraining/supporting constraints of the characteristics of physical objects (inside physical thing) or other external impacting factors (inside external influences). for example, the size of the object, in this case the archaeological waterlogged wooden samples, plays a major role in filtering out technologies. the size of these wooden samples is on average 10 x 6 x 6 cubic cm and is asserted as "small". through this classification, instruments and their subsequent technical processes suitable for recording only large physical objects such as laser scanners and laser scanning are filtered out. these assertions are the facts that the ontology requires and they are put forward to the user (in most cases ch experts). they are formulated through predefined knowledge inside the ontology describing its individual components. the system asks for further assertions about the knowledge of the object and other environmental or project-oriented issues in order to give a recommendation as to which technology should be considered due to its optimal suitability. fig. 2 displays a user interface simulation that recommends structured light 3d scanning for recording waterlogged wooden samples with the purpose of evaluating possible geometric alterations. as mentioned above, however, ch applications encompass not only analysis of spectral or spatial data but also very often focus on visualization of data. a wide variety of visualization types (interactive, animation, graphical etc.) exist for 3d and/or spectral data representing existing physical ch objects, reconstructions of only partly preserved ch objects, and 3d reconstructed models. whether coschkr should also address these manifold visualization types, especially the implementation of visualization applications for digital 3d reconstructed models [pfarr-harfst and wefers 2016], is a challenge (see below). figure 2. simulated user interface for knowledge assertion of waterlogged wooden samples. 4. discussion and conclusions as regards ch applications which focus on visualization, the big difference from other ch applications so far implemented in coschkr (see geometric alteration case study described above) is that non-existing or only partly existing physical things are digitally visualized in their complete and/or former condition. an example is a project focused on the scholarly digital 3d reconstruction of the byzantine city of ephesos [grellert et al. 2010]. this visualization is characterized by the fact that the entire city, including its location in the landscape, its city-walls, streets, squares, buildings and monuments, is reconstructed based on the outcomes of archaeological excavations (foundations of buildings and monuments with associated but isolated building blocks and other construction parts, small finds found within the buildings, etc.) and their scholarly interpretation [e.g.,mangartz 2010; pülz 2010; wefers 2015]. all physically existing finds and features of the excavations are real evidence; their spatial and spectral information can be used for modeling without contradiction. however, the interpretation of these finds and features, which means putting them into a context, such as a room or object and ascribing them to a specific spatial position within a room or object, is a hypothesis. the validity of such hypotheses differs depending on the preservation condition and/or completeness of the physical object and the level of information provided by other sources. based on this, hypotheses can be classified by a number of levels and implemented into coschkr. however, the granularity of these levels still needs to be determined and cross-checked with other approaches. for in stance, kuroczyński et al. [2015] set-up nine levels of hypotheses to be able to classify the scholarly content of a digital 3d reconstructed model. for this purpose, they define a hypothesis as a combination of the level of information provided by the source and the level of detail displayed in the digital model. due to the purpose of coschkr and as described above, the level of hypothesis has to be defined differently. however, to allow a linkage of both concepts it might be of benefit to either have the same granularity or at least reflect the granularity of kuroczyński et al. [2015] in a possiblyhigher or lower granularity of coschkr. implementing such kinds of levels of hypotheses into coschkr would allow us to give recommendations for the required involvement of a ch expert during the 3d modeling process. the level of hypothesis has impact on the 3d modeling workflow: that is, a higher level of hypothesis requires more and frequent involvement of the ch expert during the 3d modeling process. for example, in the project focusing on the scholarly digital 3d reconstruction of the byzantine city of ephesos, a water-powered stone sawing machine was included. evidence for the stone-sawing machine was found within one room of terrace house 2, but actually not a single construction part of the machine itself is preserved. only supports, postholes, chutes, the waterwheel raceway, and stones with cut-marks are preserved. this evidence, together with the expert's knowledge about stone-sawing machines and further contextual information, such as time of application, gave reason to set up the hypothesis that a water-powered stone-sawing machine was constructed in this room of terrace house 2 [mangartz 2010]. together with ground plots and sections of the preserved tangible ch 2d reconstruction, drawings were prepared as a basis for the digital 3d reconstruction. especially during the digital 3d reconstruction of the machine, more detailed descriptions were requested by the 3d modelers (e.g., concerning the construction of the push rod suspension, extender wheel, frame saws, suspension of the frame saws, water wheel, mounting of the water wheel, etc.). it would have been advantageous for the whole reconstruction project if this verification process could have been planned at the very beginning. besides the above-described implementation of the level of hypotheses, further information about the object to be modeled and the targeted application would be required from the user as input, in order to be able to give more detailed support. however, the biggest challenge related to ch applications of visualization is that they are very different from each other and rarely share similarities. each case needs to be planned, implemented and applied independently. this is because ch visualizations depend on hypotheses provided by ch experts' interpretations. these hypotheses affect data processing steps in varying degrees. every hypothetical interpretation needs to be independently and carefully handled during the data processing, which is in this case the digital 3d reconstruction or modeling. this is not the same as in the case described above (geometric alteration), which deals with facts and evidence. data processing activities form a workflow and are used to create a digital 3d reconstruction, which is used for a visualization application. these activities are listed as relevant subclasses of the top-level class data processing. they are related through rules that link them together and determine their workflow. these rules are created on facts and thus can fail to comply when asserted through hypothetical interpretations, especially when there are individual hypotheses for individual visualization cases. such lapses can/will alter/break the sequence in the workflow. one of the greatest challenges within coschkr is including hypotheses and linking them to data processing tasks without interfering with the inference mechanism. we have suggested the classification of hypotheses based on their correspondence with the proven evidence. this, however, requires humanities experts' involvement in data processing steps. the balance between such involvement and their influence on adjusting parameters of the defined semantic rules within data processing activities (defined through subclasses of the top-level class technologies) is a challenge that requires further clarification through future discussion and activities. 5. acknowledgement the authors would like to thank meng. guido heinz (rgzm) for his essential input regarding the development of the technologies classes. part of this work was supported by the cost action td1201 "color and space in cultural heritage" (www.cosch.info). 6. references f. baader. 2003. the description logic handbook: theory, implementation and applications. cambridge: cambridge university press. t. berners-lee. 2006. artificial intelligence and the semantic web, 14. http://www.w3.org/2006/talks/0718-aaai-tbl/overview.html k. w. brodie et al. 2004. visualization ontologies: report of a workshop held at the nationale science centre. report e-science institute j. heflin. 2004. owl web ontology language use cases and requirements. https://www.w3.org/tr/2004/rec-webont-req-20040210 t. hofweber. 2011. logic and ontology. stanford encyclopedia of philosophy. https://plato.stanford.edu/entries/logic-ontology a. karmacharya et al. 2016. knowledge based recommendation on optimal spectral and spatial recording strategy of physical cultural heritage objects. in proceedings of the 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approach to visualization resource management. in international workshop on design, specification, and verification of interactive systems. berlin, heidelberg: springer-verlag gmbh, 151-156. a. pülz. 2010. das sog. lukasgrab von ephesos: eine fallstudie zur adaption antiker monumente in byzantinischer zeit. forschungen in ephesos 4, 4. wien: verl. der österr. akad. der wiss. g. shu et al. 2008. bringing semantics to visualization services. advances in engineering software, 39, 6, 514–520. v-must. 2013. virtual museums by interaction technology. http://www.v-must.net/virtual-museums/categories/interaction-technology m. voigt and j. polowinski. 2011. towards a unifying visualisation ontology. technische berichte technische universität dresden, fakultät informatik 2011, 01. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-67559. s. wefers. 2015. die mühlenkaskade von ephesos. technikgeschichtliche studien zur versorgung einer spätantiken bis frühbyzantinischen stadt. monographien des rgzm 118. mainz: verlag des rgzm. s. wefers et al. 2016. development of a platform recommending 3d and spectral digitisation strategies. virtual archaeology review 7, 15, 18–27. received october 2016; revised september 2017; accepted november 2017. musint ii: a complex project on a virtual and interactive museum involving institutions in florence, rome and heraklion anna margherita jasink, cristian faralli, and panaiotis kruklidis, university of florence, italy musint ii is part of a more general project on a series of virtual and interactive museums, using traditional and new technologies with the aim of reaching a wider audience. an interdisciplinary methodology provided by the participation of archaeologists, architects/designers and computer scientists makes the project rich in attractive solutions for visitors of different levels. musint ii uses a sophisticated structure, a series of 3-dimensional models produced with both photogrammetry and laser scanning. a complex database with many interconnected queries was implemented to make the study of a large number of objects more efficient and to offer truly innovative research responses with effortless data processing. new hyper-realistic techniques are used to best illustrate the reconstruction of buildings, objects and scenes of life. a specific educational section is addressed to young people, with all these new techniques applied in a winning way. the main object of musint ii is a specific category of small objects, sealings and seals, coming from the excavations at haghia triada carried out by the italian archaeological expedition in crete at the beginning of 1900. our purpose is to offer a new analytic and, at the same time, synthetic vision, addressed to a wide audience, of the historical and archaeological representation of one of the most important sites of minoan crete. key words: interactive museum, aegean civilizations, technological methodologies sdh reference: anna margherita jasink et al., musint ii: a complex project on a virtual and interactive museum involving institutions in florence, rome and heraklion, 2017. sdh, 1, 2, 1 pages. doi: 10.14434/sdh.v1i2.23192 1. introduction the development of new technologies and their application in the general field of cultural heritage has opened new perspectives also in museology [economou 2006; hermon and nicolucci 2007; oberländer-târnoveanu 2008; epoch project at http://epoch-net.org/site/] to such an extent that the very idea of the museum has evolved from a traditional static form, conceived for the direct observation of artifacts to a more dynamic and interactive concept that goes beyond the single site exhibition. the individual traditional museum has been digitally duplicated to make it accessible online. exploiting advanced digital communication tools, it is possible to go beyond the simple "replica" of the museum to show the intrinsic properties of the artifacts, hidden aspects not visible at first sight, such as the original geographical or historical location of their creation and other information accessible through dedicated databases, in some cases with recorded interviews with curators. these important advances are still confined in the domain of a static vision of the museum, although with a delocalized access; the main function of the interaction is to offer the possibility of browsing through collections and choosing which item to view. the best examples are obviously those of the british museum and of the louvre, with huge collections and various databases available online, educational content for children and special focus on selected items. the virtual museum [djindjan 2007; mancini 2008; antoniou et al. 2016] author's address: a. m.jasink, university of florence, via san gallo 10, florence, italy; email: jasink@unifi.it; c. faralli email: cristianfaralli@gmail.com; p. kruklidis email: panaiotiskruklidis@gmail.com permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal can arise as an autonomous digital entity ensuring on the one hand general free access on the web and on the other hand enhancing the traditional museum experience through personalization, interactivity and richness of content. this has been accomplished by full recourse to new technologies [stanney & hale 2014]. it is quite evident that the virtual museum is particularly suited for applications in archaeology [moscati 2007; artusi et al. 2010]. new imaging methods [remondino 2011] allow for an augmented and more significant representation of the artifacts. in addition, the virtual museum provides the audience with extended and integrated information on the site of the finds, their history and their cultural context. finally, it allows the simultaneous exhibition of finds stored in different museums or locations, resulting in a more complete understanding of materials. to explore these and other applications for archaeology is the aim of the virtual museum transnational network vmust (2011-2015) (http://www.v-must.net/). this paper deals with musint, the first application of the virtual museum to aegean archaeology (bronze age greece). so far, this sector of studies has been variously illustrated through augmented reality techniques: see, e.g., the reconstruction of hall 64 of the pylos palace, messenia (http://classics.uc.edu/prap/hall64.html). the most important bronze age findings from the largest museum collections of greece are now available online, thanks to the latsis foundation museum cycle (http://www.latsis-foundation.org/eng/education-science-culture/culture/themuseums-cycle). however, this is simply the online transposition of actual printed catalogues, without any possibility of interaction. no aegean site or project figures in the v-must network, though various examples from classical greece are represented. actually, a proper virtual museum is still missing and musint is the first attempt in this direction. this is why, in recent years, we developed a research project (musint) on virtual and interactive museums of aegean civilizations with the goal of reaching a wide audience, combining traditional methods and new technologies [jasink, tucci and bombardieri 2011]. the virtual museum is accessible on www.aegean-museum.it or www.dbas.sciant.unifi.it website (www.aegean-museum.it/musint2/it for musint ii). the project includes the joint contribution of archaeologists and historians, to define the subject-matter and to write accurate texts; of architects/designers, to ensure enhanced standards of pictorial and graphic representation; and of computer scientists, to guarantee a smooth and effective connection between content and display. the intrinsic multi-disciplinary approach made the project attractive to different visitors due to the variety of available pathways. in a previous chnt meeting, an application of musint to the teaching of ancient history in primary schools was discussed [dionisio and jasink 2016]. in the present paper, musint ii, a major addition to the general project, is described. technological methods and interactive devices have been more extensively exploited to present specific historical and archaeological topics at a high scientific level on the one hand and for a non-specialized audience on the other. musint ii is accessible on the websites given above. the core of the new project is the collection of small clay objects from the neopalatial villa of haghia triada, one of the main cretan sites, which flourished in the middle of the 2nd millennium bc. this is the period of full development of the minoan civilization. while the topic of the new project is more limited, the potential audience is definitely wider. in fact, the new museum is structured in two sections, the first addressed to scientists and curious adults and the second with explicit educational aims. the cretulae or nodules we are dealing with represent, together with the tablets, the administrative documents of the period and may bear both sealings and signs carved in linear a script. these small objects were discovered at the beginning of the 1900s during excavations by the italian archaeological expedition in crete, specifically devoted to the phaistos and haghia triada sites. the majority of these finds remained in crete, in the heraklion archaeological museum, while others were taken to italy and are presently stored in the national archaeological museum of florence and in the prehistoric-ethnographic pigorini museum in rome, the latter named after its founder luigi pigorini (see fig. 1). figure 1. home page of musint ii these documents have been repeatedly analyzed since their discovery. the novelty of the present project is to make the items from the three locations simultaneously available in the single virtual museum of musint ii while retaining their individuality. this is not only a useful and simplified tool for researchers but it is also a unique opportunity for other visitors to get a full idea of the minoan administrative system. all web pages are characterized by a common graphics with rich and attractive details. the page layout is designed with a full colored background, with communicative images and animations. the color palette is decided in advance and an independent style for each page is obtained with appropriate colors. photographs, drawings and reconstructions recall the style of the general musint project and move on two parallel but different tracks, as required by appropriate approaches to scientific and educational sections. 2. haghia triada the haghia triada webpage, from which five different items can be explored, is shown in figure 2. fig. 2. home page of the "haghia triada" website haghia triada history. various phases of the archaeological site, which developed throughout the bronze age (prepalatial, protopalatial, final/monopalatial, postpalatial periods), can be explored, with particular attention to the neopalatial period, to which the sealed documents refer. excavations. this page is concerned with italian archaeological missions in crete and the story of the protagonists of this adventure is also briefly described. reading the information provided has been improved and made easier by using the so-called "popup windows" written in javascript. this programming language is considered one of the most powerful tools for improving a website with dynamic and interactive applications. javascript code is perfectly embedded in htlm-php languages normally used to build websites. javascript popup windows are successfully used in the musint ii website to open pages containing biographies with pictures and other images, without compromising the understanding of the text [faralli 2016]. documents. administrative documents are described, including tablets and sealed brief inscriptions. the latter documents, in particular the florentine and roman pieces, are the core of musint ii, as will be seen in the following. they are small clay pieces with an impressed seal on one side and, often, a symbol in linear a script on another face, as shown in figure 3. database. this database is one of the most innovative aspects of musint ii. the relational database management system used is mysql. this system is very useful for managing dynamic websites. mysql is fully supported by most of the programming languages, such as php. the interaction between the database and the web pages is achieved by using the sql language to construct the queries and to recover the data. this architecture has been successfully used in a well-known application in the aegean field [arachne: http://arachne.uni-koeln.de/], which concerns the whole corpus of minoan and mycenaean seals. along the same lines we have already been able to enter into an extremely more elaborate analysis of a specific sector of the seals [dbas chs cretan hieroglyphic seals: http://www.sagas.unifi.it/vp-394-dbas-chs-cretan-hieroglyphic-seals.html], to sort out useful statistical information. gallery. photos, maps and drawings complete the haghia triada section. figure 3. typologies of the administrative sealed documents from haghia triada (modified from hallagher 1996) the present database improves considerably the study of the haghia triada sealed documents. first of all, it gathers in a unified digital catalogue the information on the seals and on written signs, which have been separately published in the basic volumes cms ii 6 and gorila 2, respectively. in addition, it allows extensive and overlapping crosscorrelations that can lead to new interpretations of both seals and written signs. dedicated files to single cretulae with a stamped seal and, very often, with carved script signs, constitute the starting point for entering into new and diversified routes by means of distinct but connected queries, which try to answer as many questions as possible. this relational database allows users to consult the information about shape, motifs, inscriptions and so on of single objects and to make queries to correlate such information; it also provides statistical data (percentages, recurrences, and so on). a more detailed discussion of the structure of this database will appear in a forthcoming paper by alberti, faralli and jasink. this specific project on materials that have already been widely analyzed has been conceived not as a mere instrument but as a scientific study capable of contributing to our knowledge of the administrative system, of the figurative arts and of the daily life of the minoan neopalatial society, at least in haghia triada. 3. the italian museums in the present section, we consider the web pages (shown in figure 4) of the museums in florence and rome that have been worked out with equal criteria but show some differences in two of the three sub-sections. a significant difference is found in the "collections." the roman one consists solely of materials from crete, while the florentine collection includes the whole aegean world crete, greece, cyclades, rhodes and, in addition, cyprus including neolithic and bronze age objects as well. the pigorini museum of rome received many more objects from the italian mission in crete than the florentine museum. but in florence, the director of the archaeological museum, luigi adriano milani, in the years between the end of the 19th century and 1910, was in contact with various merchants and archaeological institutions, and bought or traded objects which enriched the florentine "aegean collection." in florence, therefore, materials from haghia triada are not as abundant as in rome [jasink and bombardieri 2009; jasink, tucci and bombardieri 2011; musint website]. figure 4. web pages of the two italian museums with minoan collections this explains the difference of the third item introducing the web pages on the two museums: "more documents from haghia triada"for rome and "seals from crete"for florence. the first includes documents (three tablets and one pithos), which differ from cretulae, but still come from haghia triada and may be considered as administrative and written sources. the second is made up of a series of seals that came to the florentine museum through different routes and range from the minoan prepalatial to the last mycenaean period (figure 5). these have been included in musint ii to complete the italian collection of aegean seals, theseals are presented in musint ii as 3d models, in the same way as the sealings. a more detailed discussion about 3d structure and the photogrammetry methodologies is dealt with in another paper in this same volume [marziali and dionisio 2017] and in other articles [pitzalis et al. 2007; sotoodeh et al. 2008]. figure 5. examples of seals of the aegean collection in florence as discussed above, the core of musint ii is represented by the files made available in the sub-section "sealed documents from haghia triada," which has the same structure for the two museums. a dedicated file, containing a descriptive table with detailed information and, whenever possible, a 3d image, has been uploaded for each object (figure 6). for the descriptive tables, reference can also be made to the general haghia triada database. figure 6. example of a file concerning a "hanging nodule" from haghia triada the 3d images, created either with photogrammetry methodologies (florentine seals) or with laser scanning acquisition (florentine and roman sealings) [remondino 2011] and uploaded on the sketchfab platform, have been transferred in musint ii. to this purpose, a pro account has been created on the sketchfab platform in order to make a profile page available with the necessary space to implement and visualize the realized 3d models. for each 3d model, three files have been uploaded (a jpg texture file, an obj model file and a mtl material file) to compose a single compressed folder. this reduces the overall dimensions, thus facilitating the uploading in the website. the web pages related to the 3d models have been customized in order to obtain a better interaction between the sketchfab service and the musint ii website. html/php code has been embedded to recover information from the remote archives. at the same time, a series of tailored database tables have been constructed to manage the amount of data coming from sketchfab. finally, sql code has been written to allow these data to be read and shown in the website [dionisio et al. 2016]. tools for processing and editing of 3d meshes as meshlab can be also found in the epoch project results, together with a number of documents and publications about technological strategies to improve the cultural heritage sector [mcloughlin 2007]. 4. educational section in the educational section (figure 7), initially in italian, images and contents play a basic role, with the goal of raising an immediate interest in the younger audience. charming hand-made drawings have been created with traditional techniques and with the support of computer graphics. six different webpages may be opened in this section. videos, games and storytelling are proposed to the audience, in a mix that has been variously experienced by other projects [danks et al. 2007; ripanti 2015; antoniou et al. 2016; mcloughlin et al. 2007; the chess project at http://www.chessexperience.eu/; the emotive project at http://emotiveproject.eu/]. figure 7. home page of the educational section videos. five videos have been inserted here. the files are directly uploaded in the server where the website is running in order to avoid banners or advertising from third-party services. despite the small amount of disc space, the videos are well balanced, with good resolution and lag-free streaming through the internet. the <video> tag has been used to embed the files in the html source code. it allows easy control of some useful properties, such as the file type and the dimension of the window shown on the website. while the first video is a simplified introduction to explain the meaning of cretulae, seals, sealings, script-signs and their function in the minoan administration, the second and third ones are brief representations of the photogrammetric technique applied to the 3d digitalization of one of the florentine seals and of a florentine sealing. the fourth video shows the lessons for the montelupo fiorentino's pupils. the last one is an application of the hdm (head mounted display) technology to popularization; it deals with a multimedia animation on the minoan haghia triada villa. total immersion is obtained by stereoscopy and a very large fov (field of view). however, hdm (in particular oculus rift dk2) has many other types of sensors, such as gyroscopes, accelerometers and positional tracking systems, which allow for a precise localization and orientation of the user within the virtual environment. hdm affords a visualization able to display more deeply the dynamics of the virtual and actual reality of both the structure of the villa and the internal environments and the objects of interest. the attention is particularly on sealings. from the point of view of the visualization by a non-specialized audience, this approach makes the available data accessible in a simple, more immediate and lively way [albertini and baldini 2016a]. for an actual immersive application and a full display of the video one needs to use tools presently available at the dreams-lab of the scuola normale superiore in pisa [albertini and baldini 2016b]. nevertheless, the video in musint ii gives a precise idea of the potential of the immersive reconstruction. download and color the sealings. on the opening webpage the images of the sealing of the two italian museums appear at once. each one of them may be downloaded on a4 size paper and colored according to the taste of the pupil. this section is clearly conceived for the primary school pupils who can create a series of posters. paint new images. this sub-section allows the visitor to work directly on the computer, in addition to the possibilities described above. the webpage contains images of sealings that are only in the heraklion museum. each of them can excite the imagination of the young visitor who, once the seal is chosen, has an empty page available with only a small icon of the selected seal in the top margin. the visitor may draw his own new image of the seal without leaving musint ii. a 2d-painting tablet has been implemented and is hosted in the musint ii website for the graphic elaboration of the images. it includes drawing tools and color palettes that the visitor may use in order to create and color his own seal. this interactive whiteboard has been made by embedding a drawing application in the webpage html source code. learn and play. the importance of games and gamification is increasingly appreciated by scholars and museum specialists, so a series of activities, using even elaborated games, has been planned to turn museums into interactive places with learning purposes [barandoni 2016]. games, either in a pdf format or in interactive environments, can help students to appreciate difficult contents and to learn a scientific lexicon. on the other hand, they can also allow teachers to fill the gaps between what can actually be found in school textbooks (normally not updated with recent research) and on the web. in line with these premises, this section contains a series of games (figure 8), created by cristiana barandoni and revised by isabella valinoti, which assume an acquaintance with information derived from musint ii and, as a consequence, represent an effective and good test on basic knowledge of minoan crete. these games are, at the moment, only downloadable in pdf format, but shortly will be transformed into games that users can play online. discover curiosities from texts and colored drawings. in the images of this sub-section some aspects of minoan life are illustrated. the colored drawings are created with photo editing and digital painting (figure 9), which we may call the "hyper-realistic current." the hyper-realism in archaeology may be taken as a provocation, but it is a well-suited pathway for a type of communication that is able to overcome the distance between experts and non-specialist observers. the most current techniques, mixed photo editing and digital painting, allow quality effects in the production of historical reconstructions, while being plausible and attractive. specifically in the interactive museum content, reconstructions in realistic style offer a modern vision of minoan life. starting from the limited information available, the archaeological illustrator goes on to reconstruct the scenes of life and the ancient crafts in the minoan aegean world. they may also serve as a guide to explore sub-section c. construct your own path for this tale. the short tale, la mattina di zuzã¹, created by maria emanuela alberti, includes valuable information on daily life in minoan haghia triada and develops as a sort of thriller [see alberti 2016 for a commentary]. during the whole path, a lot of questions are asked to the young visitor, even about alternative endings of the story. many new drawings (figure 10) have been designed by alberti and kruklidis for this tale, which represents a useful and amusing conclusion for the didactic section of musint ii. fig. 8. home page of "games" figure 9. from minoan sealsand frescoes to a modern representation of craftsmen at work. figure 10. drawings by e. alberti and p. kruklidis from the tale la mattina di zuzã¹ 5. conclusions the purpose of this project is to offer a new analytic and, at the same time, a synthetic vision open to a wide audience, from researchers to young students, of one of the most important sites of minoan crete, haghia triada, and its administrative documents. the project has been developed in the form of a museum that includes the presentation of the whole collections of sealed documents stored in heraklion and in the two italian museums, the latter also as 3-d models. in addition to the timely analysis of the individual documents and of the relationships between them, the purpose of the project is to offer to the visitor a wider perspective on the archaeological discoveries and historical context. the database about the whole corpus of cretulae of haghia triada represents an important achievement and may be a starting point for new research. the educational section has been implemented with games, drawings, questions and a story. for four years (2014 – 2017), musint has been the basis of workshops held at the primary school of montelupo fiorentino with pupils and teachers. pupils have been thoroughly exploring the materials of the virtual museum and have been using them as source of inspiration for a number of creative re-elaborations, including drawings, puzzles, games, short oral presentations and short acting scenes. a final celebration of the success of these musint workshops took place in the school last may, and saw the participation of more than 200 pupils, with their teachers and parents, both from the higher classes that have been involved in the workshops, and from lower classes, that will start the experiment next year. everybody considered these workshops an important educational opportunity, to improve pupils' knowledge of antiquities, and their creative and critical skills, and to offer a valuable occasion for social interaction among them. through these workshops, we learned that interaction with the contents of the virtual museum and creative activities were the most successful among pupils and the most effective in building their historical knowledge. so we decided to implement the games section and the illustrations of musint. the next step we plan for musint is indeed focused on storytelling, with fixed characters exploring various myths of ancient greece in comparison with the archaeology of bronze age. as reported above, musint ii is accessible both from dbas (data bases about aegean subjects): dbas.sciant.unifi.it (website included in the home page of sagas department of the university of florence as www.sagas.unifi.it/cmpro-v-p-376.html) and from www.aegean-museum.it/ (a website linked to the first one and containing the whole corpus of databases visible from dbas). moreover, musint ii may be accessed directly from www.aegean-museum.it/musint2/it/. more detailed information on musint ii, including extended references on the various scientific and technical aspects of the project, can be found in jasink and dionisio, eds., 2016. 6. references cms ii 6 = corpus der minoischen und mykenischen siegel, band ii, 6. die siegelabdrã¼che von aj. triada und anderen zentral und ostkretischen fundorten. berlin: gebr. mann verlag, 1999. full references to be added received march 2017; revised july 2017; accepted august 2017. 3d gis for building archaeology. combining old and new data in a three-dimensional information system in the case study of lund cathedral martina polig, lund university, and sweden traditionally, building archaeology is conducted by creating and interpreting 2d documentation, even though the spatial properties of a building are not fully expressed in 2d. the third dimension has been mostly neglected, due to technical limitations that can be overcome through the rapid progress in 3d technology. this study shows how a 3d gis can be applied from the outset of a building archaeological study to create a three-dimensional information system connected to a geometrically accurate 3d model of a structure. the building under investigation was lund cathedral (sweden), whose long and complex history has been studied for two centuries. gaining an understanding of all interventions, as well as managing the heterogonous datasets, is a challenge. in order to overcome these difficulties, various datasets and their relevant metadata were imported into the arcgis software and linked to a geometrically accurate 3d model of the church, placing all pieces of information in their correct spatial position. thus, data that was previously impossible to view simultaneously and in the same space can be displayed together, creating a unique holistic oversight of the available material. through the flexibility and versatility of the system, information can be displayed and queried at will, as well as updated continuously, greatly facilitating interpretation and making it an important resource throughout the entire building archaeological study. keywords: 3d gis, building archaeology, 3d model, information system sdh reference: martina polig 2017. 3d gis for building archaeology. combining old and new data in a threedimensional information system in the case study of lund cathedral. sdh, 1, 2, 14 pages. doi: 10.14434/sdh.v1i2.23253 the work for this article was funded by the c. m. lerici foundation in stockholm and was carried out in collaboration with dark-lab at lund university and the "lund cathedral 2023" project. author's address: martina polig, science and technology in archaeology research center (starc), athalassa campus, 1545 nicosia, cyprus; email: martina.polig@gmail.com permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal 1. introduction for decades, gis has been an integral part of archaeological practice and its many advantages and uses in visualizing and managing archaeological data have been discussed as well as examined from a critical and theoretical perspective [lock 2001; wheatley and gillings 2002; conolly and lake 2004; frischer 2008; hac!güzeller 2012]. the potential for using a three-dimensional environment and 3d data in a gis has also been part of this discussion. the first attempts in using a 3d gis on an intrasite level was through the characterization of archaeological features with polylines, polygons, points or volumes, visualized in a three-dimensional environment of a gis [doneus and neubauer 2005; losier et al. 2007; katsianis et al. 2008]. even though accurate three-dimensional models through laser scanning or photogrammetry were available, it was difficult to implement them in a gis due to the limited visualization capacities of geometrically-complex 3d models; even so, some attempts have been made to combine 3d models with gis [allen et al. 2004; doneus and neubauer 2005]. many of the 3d models generated within building archaeology, be they reconstructions with cad or mesh from photogrammetry or laser scanning, were not implemented in information systems but used for other purposes, for example, to generate 2d documentation [e.g., jones 2011]. nevertheless, the potential of linking 3d models of buildings to additional information was recognized, but, owing to the difficulties in implementing such models into a gis, other ways of realizing this were found with game engines and web applications [de luca et al. 2011; kurdy et al. 2011; agugiaro and remondino 2014]. thanks to recent technical developments, the implementation of complex texturized three-dimensional geometries in a gis software is now possible; several case studies have explored the new possibilities that this advance has brought to archaeological research [forte] et al. 2015; dell'unto et al. 2016; landeschi et al. 2016]. the present study will contribute to this line of research by investigating how heterogeneous datasets connected to a building archaeological study can be implemented directly into one geographical information system, while also exploiting the three dimensionality of the work space and the object of study fully. this has been accomplished by linking multi-resolution models of the building under investigation, lund cathedral, with heterogeneous data, using the models as "containers" and context without resorting to hyperlinks. 1.1 the case study: introducing lund cathedral lund cathedral is situated in the heart of the city lund in the south of sweden. the romanesque church dates back to the twelfth or thirteenth century and soon became the ecclesiastical center of scandinavia. during its history, it has been modified and renovated multiple times as well as investigated from an architectural and archaeological point of view [rydén and lovén 1995]. the large amount of data created in these studies is now being expanded by the interdisciplinary research project "lund cathedral 2023", which has been initiated in light of the upcoming 900th anniversary of the church in 2023. the aim of this project is to collect, revise and update the knowledge that has been gathered around lund cathedral. managing and gaining an understanding of such large datasets, comprising also point clouds from a recent laser scanning and photogrammetry acquisition campaign, constitute a challenge. the availability of the 3d documentation of the entire structure made lund cathedral an ideal case study for testing the implementation of 3d models of an entire building into a gis, making it the center of a three-dimensional information system containing heterogeneous datasets. 2. creating a three-dimensional information system for the development of the three-dimensional information system we chose to use arcgis pro from esri, which offers a good performance for visualization and manipulation of data in a 3d environment. the different datasets that were incorporated into the system comprised 3d models, 2d data generated from the 3d models, excavation maps and sections, archaeological drawings, text information and photographs (fig. 1). the heart of the system is the 3d models that functioned as "containers" and as context for the rest of the data. due to the size of the cathedral and the dataset and the limited timeframe of the study, it was necessary to restrict the area of research to the crypt in the eastern part of the cathedral. the crypt was chosen because it constitutes a closed environment in itself and its size is manageable for the time period of the project. figure 1. the heterogeneous datasets implemented in the system: 3d models, 2d data generated from the 3d models, excavation maps and sections, archaeological drawings, text information and photographs. 2.1 3d models three different resolutions of 3d models from three different acquisition campaigns were imported into the system and georeferenced. the first model (fig. 2), which serves as a visual and contextual reference for the others, was received from the lund cathedral 2023 project. it is a low-resolution model of the entire cathedral that was created through image-based modeling and from pictures taken by a drone. it was georeferenced by aligning it to a partial model of the cathedral, created by the author also through image-based modeling and georeferenced in photoscan with gps points. all the other models were aligned to this model, and thus georeferenced as well, in the open source software cloudcompare, which can visualize georeferenced models and save the correct coordinates without shortening them. figure 2. low-resolution 3d model of the entire cathedral. on the next level of resolution is a 3d model of the entire crypt that is quite accurate in its detail and is based on laser scan point clouds from an acquisition by lund university (fig. 3). the point clouds were cleaned and meshed in the open source software meshlab. in order to be able to import such a detailed mesh to the gis it was necessary to divide it into four models, each with around five million faces. figure 3. 3d model of the crypt, divided in four smaller parts with each one around 5 million faces. the models with the highest level of detail are the walls of the crypt, divided into smaller sections with each one having about 2 million faces (fig. 4). these models were made from the high-density point clouds from a laser scan acquisition by the company sweco, which was commissioned by the lund cathedral 2023 project to scan the entire cathedral. they were cleaned and meshed in the software cloudcompare, which is more adapted to very large point clouds compared to meshlab. a very high resolution was necessary for these models in order to allow users to distinguish single stones in the walls. this makes it possible to make a wall analysis directly on the 3d model by identifying and characterizing with polygons different phases in the wall (see fig. 4). these polygons are linked to an attribute table that can be customized and contains additional information about a specific wall part, such as the dating, the level of degradation, etc. figure 4. high-resolution models of the walls in the crypt that allow users to distinguish single stones in the walls. polygons (in purple) were drawn directly on the 3d model, characterizing repair works from the nineteenth century. 2.2 2d data from 3d models 3d models of structures and buildings are often used to create traditional documentation like plans and sections. these can be integrated as well into the gis, visualizing them together with the 3d models. as an example, for this study, sections of the crypt at regular intervals of 50cm were created in cloudcompare. they were imported into the gis as raster, georeferenced and then moved on the z-axis to the height at which they were taken (fig. 5). figure 5. section generated by a cut through the 3d models of the cathedral and visualized with the 3d models at the height at which it was taken. 2.3 excavation maps studies of buildings often also include excavation documentation. in case of lund cathedral, there were several excavations conducted within and outside the church over the last century. a cumulative excavation plan that shows all the excavation trenches of the twentieth century was imported as a raster and georeferenced in the gis (fig. 6). trenches of more interest were vectorized by drawing polygons and then connected with additional information through the attribute table (year, findings, etc.). in this way, the original cumulative excavation map has become much more easily readable and clearer, with single excavations represented as layers, which can be visualized and queried at will. if more detail is necessary, the individual trenches can easily be integrated with further related excavation material in form of maps, sections or finds. figure 6. cumulative excavation map imported into the gis and visualized with the 3d model of the entire cathedral in transparency and the crypt. trenches of interest were redrawn with polygons and connected to an attribute table. the different colors of the trenches symbolize different years of excavations. 2.4 sections even though sections are part of traditional excavation documentation, they have been treated separately from the maps in this study because they constitute vertical and not horizontal information. the possibility of working in a three-dimensional environment is of particular importance with sections, because it allows us to visualize them with their true orientation and in relation to horizontal information. as an example, a section of an excavation trench in the corner between the northern side aisle and the northern transept of the cathedral was chosen (fig. 7a). the scanned drawing of the section was imported, scaled and vectorized in the gis. additional information, e.g. about the material, was added in the attribute table. the drawing was then exported into autocad to perform the necessary rotation to put it in a vertical position, an operation that is unfortunately not yet possible in arcgis pro. after being reimported in the gis it was put in its correct position. unfortunately, there was no exact information about the position of this section available other than a description of its location on the drawing itself (fig. 7c). nevertheless, it was possible to place the drawing accurately thanks to an alignment with a 3d model of the cathedral. in fact, the drawing shows also part of the wall of the cathedral above ground that was acquired through laser scanning. a highly detailed mesh of the relevant part was created and aligned to the low resolution overall model of the entire church. the stones visible in the mesh and on the drawing were then used as references for placing the drawing correctly in the space. figure 7. (a) the original drawing of a section at the northern transept with the area above ground visible also on the 3 d model highlighted in pink. (b) the section visualized together with the overall 3d model of the church, encircled with red. (c) a close up of the section and the high-resolution model used to position the section. it was decided to visualize the different materials of the stones (information stored in the attribute table) with different colors. 2.5 archaeological drawings archaeological drawings are part of the traditional documentation material available on the cathedral, and it was necessary to find a way to incorporate them directly into the gis. this can be achieved by applying the drawings as textures on the 3d models. a drawing of the southern niche in the northern chapel of the crypt was chosen; it was created in the first half of the twentieth century. it depicts decorations in and around the niche that are now only partially visible and only in certain light conditions. a low-resolution model of the niche and the surrounding wall was created in meshlab. the drawing was added to the scene in meshlab and draped over the model as texture. the texturized model could then be imported into the gis, where the drawing can be visualized and placed in the context of the rest of the crypt (fig. 8). figure 8. archaeological drawing of a niche in the northern part of the crypt imported into the system by using it as a texture on a 3d model of the niche. 2.6 text information the literature about a structure may also contain information about things or elements that have a specific position in relation to the structure (burials, specific decorative elements, inscriptions and graffiti, etc.) but have for one reason or another never been visualized in a drawing. in the case of the cathedral in lund there are several researchers [e.g. rydbeck 1953; cinthio 1957] who discuss the stonemason signs in the cathedral, sometimes with detailed descriptions of the location of some of the signs. however, only a few archaeological drawings of other architectonic elements exist on which the signs have also been represented and no map or drawing is available that shows all the signs. this is most likely due to the difficulty of representing with traditional means the hundreds of signs that are distributed over the entire church and at various heights. in the gis system, each stonemason sign can easily be represented by a point on its exact position on the 3d model. information about the dating and type of sign can be stored in the attribute table (fig. 9). figure 9. stonemason signs mapped directly onto the 3d models as points, along with the corresponding attribute table, which contains information about the dating and a picture of the type of sign for each point. 2.7 photographs photographs were also incorporated into the system, by implementing them directly into the attribute table. in this way, each feature can have one raster associated with it. it is of particular use in cases where a feature is not or only poorly represented as a 3d model and it is thus not possible to have an immediate visual understanding of what it looks like. this can be the case when a mesh is not detailed enough to properly represent a certain element, for example, the decoration on some of the capitals in the crypt (fig. 10). if something that is not present anymore in the buildings is signed in with a polygon or a point (e.g. finds), or if it is too small to show on a 3d model, for example, the stonemason signs in this case study, adding a photograph serves as an aid to immediatelyunderstand what is referred to (fig. 9). figure 10. capitals and column shafts characterized with simplified geometries of respectively rectangles in yellow and cylinders in red. the only capital with a decoration of acanthus leaves in the crypt is selected (light blue rectangle) and its attributes made visible, including also an image. 3. discussion the aim of this study to test how different kinds of datasets typically associated with building archaeology can be implemented in a 3d gis linking them directly with 3d models of a building was successfully achieved. all datasets could be inserted into the system, benefitting directly from its three-dimensionality. the only exceptions are the excavation maps and the photographs, which could also be inserted in the same way in a 2d space and would only profit from the third dimension by being visualized in relation to the rest of the data. once all the data was imported it could be manipulated and investigated to promote interpretation and understanding through queries and measurements and by creating new data. however, the implementation of certain datasets has already created an additional value impossible to achieve without 3d. a part of the 3d models themselves and the archaeological drawings which were attached to the 3d models as textures; this is the case for sections taken from the 3d models which can be added at the exact position at which they were taken, showing how the thickness of the walls varies at different heights (fig. 5). in this category also belong the excavation sections, which can be imported vertically and could, coordinated with maps of the trench in question, restore a three-dimensional view of the excavation. likewise, the stonemason signs have to be mentioned, which could be visualized for the first time and whose distribution pattern within the crypt can be easily understood in this way. the imported data can be explored further by querying the attribute table connected to it or changing the visualization of specific attributes within a layer in order to recognize patterns. in the case of stonemason signs, only the sign associated with one stone mason could be highlighted, so as to visualize the areas of construction in which he was active. an example of the recognition of patterns by changing the visualization of a specific attribute is a different representation of the material of the stones in the foundation wall visible in a section (fig. 7). the available datasets can also be used to create new quantitative or interpretational information. the former can be produced, for example, from the vectorized section drawings of the previous examples. more specifically, the stones, which are now represented as polygons, have been automatically stored in the attribute table, along with their size. this data, if extended to larger parts of the church, can then be used to generate and compare the average size of building stones in different areas or time periods of the structure. new interpretational data can be created by structuring elements of interest (architectonic, decorative, etc.) into different layers, associating them again with more information through their attribute tables (e.g., fig. 10). furthermore, wall analysis can be performed directly by drawing on the 3d models (fig. 4), which constitutes a powerful tool for understanding the building process when it is combined with the visualization and query tools already described. visualization is playing a key role in the above described uses of a 3d gis. in fact, archaeological research depends heavily on discovering patterns and identifying and defining relationships and connections, all of which is heavily influenced by how the available information is visualized. for llobera, it is surprising that there has not been given much more attention to visualization in archaeology and he argues that its importance and capacities have not been fully acknowledged and explored [llobera 2011]. frischer [2008] also emphasized the significance of visualization, citing the information specialist colin ware [2004: 3], who describes five ways in which visualization can facilitate understanding and interpretation: it may facilitate the cognition of large amounts of data it can promote the perception of unanticipated emergent properties it sometimes highlights problems in data quality it makes clear the relationship of large-and small-scale features it helps us to formulate hypotheses thus, being able to visualize all the available data on a case study in one environment constitutes a great advantage in interpretation. if and how all the above five points can be addressed in practice by 3d gis, as presented in this study, has still to be investigated when the system is put to a test and used by archaeologists to answer specific research questions. in order for the system to be fully functional, it has to be expanded and data concerning the entire building has to be integrated. of crucial importance is also the development and formulation of an adequate ontology. in fact, according to niccolucci et al., who advocate the importance of ontologies for an efficient and meaningful interpretation, "…data cannot be compared, if the data structures have no clear semantics (identity of concepts employed for data structures), and the provenance of knowledge is not transparent" [2015: 3]. 4. conclusions this study has shown how old and new datasets related to building archaeology, acquired with different methods and over a time period of a century, can be integrated into one three-dimensional platform. the implemented data can be visualized, queried and manipulated in novel ways that would not be possible without the use of a 3d gis. of crucial importance is the simultaneous development of an ontology and an appropriate data structure for the system in order to exploit its full potential. the goal of such a platform is to facilitate interpretation and understanding of the information and material concerning a building for researchers. thanks to the flexibility of the software and its independence of scale, it is possible to create information systems in a wide range of level of detail, from data regarding entire building sections, to single stones or even marks on stones. consequently, the amount of data as well as the amount of time and work spent in creating the system will vary substantially. incorporating all the available datasets on a structure might not be necessary or even desirable, depending on the questions asked. it is thus up to the researcher to decide the level of detail for a project and which combination of datasets are interesting to explore and to integrate into the system. 5. acknowledgements i would like to thank the c. m. lerici foundation in stockholm for funding this project as well as dark lab at lund university for giving me access to their equipment and facility and its members for their support and help in the project. furthermore, i want to express my gratitude to the "lund cathedral 2023" project for their collaboration and for giving me access to their scan data acquired by the company sweco. each photograph and illustration is either my intellectual property or i have received permission from the copyright holder to use it. 6. references giorgio agugiaro and fabio remondino. 2014. 3d gis for cultural heritage sites: the queryarch3d prototype. in stefano campana and fabio remondino, eds. 3d modeling in archaeology and cultural heritage – theory and best practices. bar international series 2598. oxford: archaeopress. peter allen et al. 2004. seeing into the past: creating a 3d modeling pipeline for archaeological visualization. in proceedings 3d data processing, visualization & transmission (3dpvt '04), thessaloniki, greece, sept. 6–9, 751–758. erik cinthio. 1957. lunds domkyrka under romansk tid. in acta archaeologica lundensia: series in 8o 1. lund. james conolly and mark lake. 2004. geographical information systems in archaeology. cambridge: cambridge university press. livio de luca et al. 2011. a semantic-based platform for the digital analysis of architectural heritage. computers & graphics 35, 2, 227–41. doi:10.1016/j.cag.2010.11.009. nicoló dell'unto et al. 2016. experiencing ancient buildings from a 3d gis perspective: a case drawn from the swedish pompeii project. journal of archaeological method and theory 23, 1, 73–94. doi:10.1007/s10816-014-9226-7. michael doneus and wolfgang neubauer. 2005. 3d laser scanners on archaeological excavations. in proceedings of the xxth international 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doi:10.1016/j.jas.2007.06.002. micheline kurdy et al. 2011. 3d virtual anastylosis and reconstruction of several buildings in the site of saint-simeon, syria. in the 4th international workshop 3d-arch 2011 "3d virtual reconstruction and visualization of complex architectures" 2-4 march, trento, italy, 45-52. giacomo landeschi et al. 2016. 3d-gis as a platform for visual analysis: investigating a pompeian house. journal of archaeological science 65, 1, 103–13. doi:10.1016/j.jas.2015.11.002 marcos llobera. 2011. archaeological visualization: towards an archaeological information science (aisc). journal of archaeological method and theory 18, 193–223. doi:10.1007/s10816-010-9098-4. gary lock. 2001. theorising the practice or practicing the theory: archaeology and gis. archaeologia polona 39, 153–64. l. m. losier et al. 2007. 3d geometrical modeling of excavation units at the archaeological site of tell'acharneh (syria). journal of archaeological science 34, 2, 272–88. doi:10.1016/j.jas.2006.05.008. franco niccolucci et al. 2015. the formal logical foundations of archaeological ontologies. in mathematics and archaeology. boca ratan [fl]: crc press 86–99. otto rydbeck. 1953. lundensiska stenhuggarmärken. lund. thomas rydén and björn lovén. 1995. domkyrkan i lund. malmé: corona. colin ware. 2004. information visualization: perception and design. 2nd ed. amsterdam: elsevier science & technology books. david wheatley and mark gillings. 2002. spatial technology and archaeology: the archeaological applications of gis. new york: taylor & francis. received march 2017; revised july 2017; accepted august 2017. the tower of torrenostra in torreblanca, spain: studies and documentation for a landscapearchaeology reconstruction fabrizia giannotti, andrea leonardi, andrea pasquali, university of florence, italy during the survey campaign of the toviva research project, "torres de vigĺa y defensa del litoral valenciano. generación de metadatos y modelos 3d para su interpretación y efectiva puesta en valor," many of these towers were digitally surveyed using a 3d laser scanner and terrestrial and aerial photogrammetry. the survey campaign took place in april 2015 and after gathering the data, a phase of elaboration successfully produced the architectural drawings of plans, elevations and sections. a part of this documentation was presented on the poster "when an isolated building becomes a guideline for the urban pattern. the case of 'torrenostra' in torreblanca, castellón, spain," by t. g. piqueras, s. giraudeau and a. leonardi in 2015. in this paper, we want to present the next stage of the work, aimed at reconstructing the original landscape around it. although today the tower is surrounded by other buildings, the situation was different in the past, when the tower was isolated on the coast. rediscovering the original landscape of the city could be a topic of interest and discussion in the museum of the territory of torreblanca. this presentation could take place inside the tower and explain to visitors the history of the territory and its evolution, involving the structure of the tower itself, its changing shape and its value. the 3d reconstruction, both digital and tangible, is also a good way to involve children and adults alike, adding a special value to the historical building. key words: 3d laser scanner, terrestrial and aerial photogrammetry, original landscape, museum, 3d reconstruction. sdh reference: fabrizia giannotti, andrea leonardi, andrea pasquali. the tower of torrenostra in torreblanca, spain: studies and documentation for a landscape archaeology reconstruction. sdh, 1, 2, 735-749. doi: 10.14434/sdh.v1i2.23244 1. introduction the tower of torrenostra is one example of military architecture of the sixteenth and seventeenth centuries, developed on the east coast of spain in the presence of a particular socio-political context and technological progress. in 1557, when philip ii ascended the throne, he began to support the author's address: fabrizia giannotti, andrea leonardi, andrea pasquali, dept. of architecture, university of florence, florence, italy; email: f.rizia@hotmail.it, leonardi.andrea93@gmail.com, pasqualiandrea@yahoo.it permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal ambitious project undertaken by bernardino de cardenas, duke of maqueda, for his father. the project involved the creation of a network of watchtowers to defend the coast, to spot pirates in advance and to create a first line of defense against them (fig. 1). an important figure of this period was giovanni battista antonelli, a military engineer who designed many towers, whose work was continued by other members of his family throughout the sixteenth and seventeenth centuries. nowadays, these military structures form an important architectural heritage that has lost its main characteristic: unity. the toviva project aims to conduct studies useful to the improvement of these towers that were once part of a single defense system, but which, today, are mainly abandoned. figure 1. the system of towers of the valencian coast. 2. characteristics of defensive system the system of towers on the valencian coast, in use since ancient times and widely used by the muslims, was passive and preventive. built mainly for sighting and for the organization of the defense, it was made up of elements resistant to cannonade by pirates. their primary function was to ensure a flow of constant information on sightings to neighboring towns and towers, allowing for the possibility of setting getaways or entrenchment. the location of the towers was fundamental to the control of the surrounding territory, guaranteeing the surveillance of headlands, coves, ravines and fresh water springs. these sighting sites were strategically built on hills, from which it was possible to enjoy a broad view of the surrounding territory. the points to be monitored were not only those where the pirates might land, such as bays or protected places near the villages, but also the river mouths, where they could penetrate the territory, and areas where they could stop and take on supplies, for example near sources of fresh water. therefore, it was crucial to ensure visibility between adjacent towers, which were generally built at a distance of a league, a measure that halved in the case of mountainous terrain and could double if it were flat. 2.1 almenaras the towers communicated through warning systems (almenaras) that included the passage of information through the guards, who moved from one tower to another, spreading the news. this was in addition to signals in the visually connected towers in the case of the presence of enemy vessels. when a suspected ship got too close to the coast, soldier on horseback (atajador) who sighted it fired a warning shot in the air to ask the boat to get closer to be identified. figure 2. warning system: signal fires, acoustic signals with a horn and the seguro signal. in the event that the ship tried to escape, a warning of a possible attack was given. as soon as the ship was identified as a pirate, the defenders lit signal fires with smoke blown in the direction of the origin of danger. at the same time, the atajadores moved to the contiguous towers and into the towns to sound the alarm. in addition to visual warnings, it was also possible to use acoustic signals, especially in case of low visibility. horns and bells were used, and a pre-established code allowed the passage of detailed information about the enemy. in the case that no danger was present, a flag was raised on the towers to allow the local population to return to everyday activities, such as hunting and fishing: this was the seguro (safe) signal (fig. 2). 3. site the tower of torrenostra, built between the xvi and xvii centuries, is located in the city of torreblanca, spain. it is one of the towers on the valencian coast, built by ing. g. b. antonelli, that still stands. torreblanca is a municipality located on the coast of the province of castellón and bathed by the mediterranean sea. just three kilometers from the village is the sandy torrenostra beach where the tower is situated. thanks to the construction of this coastal defense tower on the beach at the end of the xvi century and beginning of the xvii, the fishing village of torrenostra was able to grow. over the centuries, the tower and its surroundings have undergone profound changes, as a result of human settlement. in fact, throughout the xix century, when the ottoman threat ceased, aixoplucs, occasional shelters for families who were dedicated to fishing activity in these waters, were built on the formerly uninhabited seafront (fig. 3). figure 3. historical image of the waterfront and ancient fishing village. at the beginning of the xx century, the typical "houses of a ground floor and one or two spans" were built next to each other and aligned with the eastern front of the tower, which overlooks the sea. later, the tower became private property and its original appearance underwent several changes. in subsequent years, the denial of permission to build the pier dashed the hopes of a growing population and led to the migration to more prosperous neighboring areas, such as peñĺscola, with major piers. since the 1960s, when the development of tourism caused an interest in this place, the emergence of apartment blocks and new housing replaced the old fishermen's houses and the old retaining wall was transformed, thanks to the construction of breakwaters, into a wide sandy beach. the urban development that took place in torrenostra was spontaneous because of the lack of urban planning and land use regulations (fig. 4). this led to the annexation of more housing units on the structure of the tower, which is now integrated into the block of buildings located along the coast. figure 4. aerial views of the urban development of torrenostra. in 1984, spatial planning of torreblanca to regulate the growth and urban development of torrenostra was finally approved, and in february 2002, the tower was declared to be of cultural interest in the area of the architectural and environmental heritage of education, culture, research and local government sport generalitat valenciana. figure 5. the tower today surrounded by other buildings. between 2005 and 2006 it was restored and, since its restoration, can be visited both during the summer and winter seasons. 4. formal description and restoration the torrenostra tower is a typical example of a coastal square tower. however, it is now incorporated into new building and it is part of the strip of buildings that are on the city's waterfront (fig. 5). it is thought that the tower was built in the late seventeenth century (the first documented reference known coincides with the ordinances of 1673), as an intermediate tower between cap i corb and torre de la sal, to protect the coastal area and the pier of torreblanca. it was one of the watchtowers in the defense system of the coast of castellón (fig. 6). its orientation is toward the sea, which is located in the southeast. its square floorplan measures externally about 9 m and internally 4.45 m, while the walls are about 2.30 m thick. these dimensions may be put in relation with the measurement unit of that time: the wall thickness is 10 palms, while the inside is 20, thus obtaining a total of 40 external palms. the overall height, between the ends of the inclined base and the frame, is 9 m: so, this facade is a 40 palms square. even if the actual access level is well above the original, the presence of a clearly visible base with a very marked inclination means that we cannot be sure that it matches the original. figure 6. watchtowers of the coast of castellón. all levels of the tower are connected by a spiral staircase with a central pillar, with a total of 6 internal diameter palms, located in a corner inside the wall thickness. the steps consist of carved stone blocks, an original and exceptional element (fig. 7). figure 7. spiral staircase with a central pillar. in all levels there are small apertures, loopholes, made of stone and brick, and at the second floor, above the original entrance door, there is a window with an architrave, now walled-up. the rooms of the three levels are covered by three barrel vaults. those of the first and second levels develop in a parallel direction with respect to that of the coast, while that of the third level has a development perpendicular to the previous. the tower ends at the top with a stone molding, and a terrace surmounted by four cylindrical angular towers. a rectangular matacan, a projecting parapet with a hole in the floor, is placed above the original access door (fig. 8). figure 8. east elevation and section of the tower it is one of the best-preserved examples of a costal tower. in 2006, a restoration was completed that allowed us to recover its original state, which had been greatly altered over the years. fortunately, even before the restoration began, the tower did not present serious problems in its construction or structural integrity, although the existence of certain pathologies required several restoration interventions (fig. 9). in fact, having completed the cleaning and removal all the improper elements that had no historic/architectural value, we immediately started to consolidate the structure and above all to rebuild all the missing elements of which visible traces were left or whose existence was known from documentary sources. the most important interventions were the reconstruction of the scarp in the basement (with probably an inclination not similar to the original one), the restoration of the facade openings, the reconstruction of the parapet, the four corner towers (with respective loopholes) and the matacan above the original entrance (fig. 10). the restoration performed is very different from the "minimum intervention" typical of critical restoration, which involves only the steps needed to remove improper additions and to consolidate the structure to ensure its conservation. figure 9. pictures of the roof restoration. figure 10. comparison of the elevations before and after restauration. thanks to this intervention, the original and unified image of the tower has been restored, keeping its essence as a watchtower, not precluding uses for purposes other than the control and coastal defense (not necessary nowadays), but especially ensuring its stability and its preservation over time. 5. survey methods, equipment and software in april 2015, a group of professors and researchers of the heritage restoration institute of the polytechnic university of valencia and the department of architecture of the university of florence conducted a survey campaign of eleven days duration, aimed at architectural survey of several towers with similar characteristics, including torrenostra. an entire day was dedicated to surveying this tower. it was digitally surveyed using a 3d laser scanner (of the type z + f 3d laser scanner imager 5006h), and then terrestrial and aerial photogrammetry was done (with a quadcopter dronequad). this was very useful for the survey of the exterior, because through it was possible to obtain otherwise unobtainable images from different viewpoints. the objective of the survey was the digitization of internal and external surfaces of the tower and its graphic representation, which allowed us to locate and read the construction system, its elements and materials, so that we could see any structural or functional issues arising from changes that had occurred over the centuries. through this work, it was possible to highlight the potential and the peculiarities of the tower and to understand its evolution. this was characterized by the presence of new elements found in the restoration of 2006, and other original and still visible structures, such as the original spiral staircase. in addition, structures such as the old entrance, that had been hidden by buildings juxtaposed to the tower, were "uncovered" by the restoration. after the data gathering, a phase of elaboration produced architectural drawings of plans, elevations and sections. the data obtained from the 51 scans were imported into the leica geosystems cyclone 9.1 software in order to combine the individual point clouds from various scans and to get to a single final cloud (fig. 11). figure 11. individual point clouds from various scans. the final three-dimensional point cloud was subsequently imported into the software bentley pointools edit pro 1.5, which allows selecting, editing and segmentation of the cloud. in this software, the cloud of points through the "plane shader" function can be displayed with a range of shading options and in different chromatic scales that allow an easier interpretation of the data and the production of more detailed images (fig. 12). figure 12. plane shader function. through the clipbox function, it was possible to incorporate the object in a box, whose limits allowed us to "cut" a specific part to obtain planes and sections in the desired points. finally, it is possible to generate snapshots at high resolution (300 dpi), in scale and in the desired format (in this case a scale of 1:50 and .tiff format), which are useful for the actual digital reconstruction of the tower. these snapshots were then placed on autodesk autocad 2015 to create the two-dimensional drawing. as the last step, all this was drawn on adobe photoshop cs6 to get to a better end-result graph that would allow a simpler reading of the tower. 6. 3d reconstruction the work involved the production of two 3d reconstructions to reproduce the current state and the hypothetical initial state of the tower (fig. 13) is useful for understanding better the differences between them. in effect, if today the tower is presented surrounded by other buildings on the two lateral sides, the situation was very different in the past, when the tower was totally isolated on the coast. the current condition, therefore, must be understood as the result of several interventions over centuries, prompting a need for a proper interpretation of the definition of the original features. the hypothetical 3d reconstruction is based on the study of the main defensive elements of the tower, on the analysis of the types with which these elements appear in the other towers of the defensive system of the valencian coast and, of course, on the historical documentary sources. figure 13. 3d reconstruction reproducing the current state and the hypothetical initial state of the tower. in our hypothetical reconstruction: the angular towers, useful for spotting the enemy and for attacking him from above, have been imagined without the covering bricks added during the restoration because this feature does not appear in any other tower; the matacan, a projecting parapet with a hole in the floor placed above the door and useful for defence from above, has been maintained as it was built during the restoration, on the southwest side of the tower, where the original entrance was; the loopholes (long and narrow openings in the wall) have been restored in all elevations of the tower; the parapet has been retained as it was built during the restoration, with the upper part inclined to prevent the enemy from finding points to anchor; the original entrance, which today is walled, has been re-opened on the west side of the tower; as for the scarp wall, which today is on the southeast and northwest sides of the tower, we preferred not to make risky and unfounded assumptions because we had no certainty, neither regarding the actual presence nor about the type. 7. the museum in order to give completeness to the studies of the toviva project, aimed at the survey and knowledge of the spanish coastal towers, we wanted to provide our tower with a project proposal that would complete the path of knowledge undertaken. in addition, we want to provide useful operational ideas in order to solve the problems and support the observations found during the survey and the subsequent processing of the data. the rediscovery of the original landscape of the city could be an interesting topic to explain in a museum of the territory of torreblanca. this could take place inside the tower and could explain to the visitor what the the territory was like in the past and how it has evolved over time, in particular the changing shape and value of structure of the tower itself. the proposal of the museum was born from the desire to tell and enhance the history and the essence of torrenostra tower. our aim is to emphasize and bring out the identity of the tower, now blurred by the context in which it is inserted, creating an incentive to keep active this wonderful example of fortified architecture, too little appreciated and known only superficially. the intention is to create inside the tower itself a dynamic space that can tell the story not only of the tower and the territory in which it is located, but will also present the historical context that, in fact, has determined its existence. the tower and its history will be connected to the other towers, in order to recreate, at least in memory, the old unitary system of towers. in the tower, we want to create a combination between the rigidity and the "story" of the stone, compared with the "modernity" of steel and glass, in order to create an attractive environment without changing the essence of the towerthat will be enjoyed by tourists and local visitors. the tower, which until now has not yet found its rightful "place" inside torrenostra, will perform several functions from the exhibition hall to the projection room, in order to create a stimulating and attractive space capable of rekindling interest in this architecture that perhaps many residents now take for granted, without knowing its history and understanding its true value (fig. 14). the museum concept, born with the goal of coexistence, has the following objectives: to tell and show, through exhibition panels and videos made with the help of the drone, the history of the site where the tower stands, the ancient desert coast, from the first settlements of fishermen until today; to tell the story of the kingdom of spain and the birth of the defensive system of towers, describing its characteristics and dynamics; to show and explain, through exhibition panels and through a three-dimensional model, the structure of the tower, from the materials to the typical characteristic elements of the fortifications, highlighting the evolution undergone by the same during the course of the centuries; to create aggregation environments, reinterpreting the original function of the tower in relation to our times, setting it as an element of identity not only of the landscape but also of its inhabitants and their culture. figure 14. internal views of the torrenostra museum. these objectives of our design proposal will be accomplished by the layout of the tower environments; the designer's intervention will make the spaces useful, creating a setup able to correlate the problems identified with the space for the achievement of the historical and cultural essence inherent in the architecture of the tower. we will try to realize everything without compromising the rigid architecture of the tower, trying instead to interact with it with the maximum respect, promoting its spatial and functional versatility, creating within it a path to guide the visitor through the characteristic elements of the tower, and the different spaces that facilitate the aggregation and collective aspects. in this way, the 3d reconstruction visible in the tower, both digital and tangible, is also a good way to involve children and adults at the same time, adding a special value to an historical building. the choice of materials and colors of the supports and of the theca was made, on the one hand, favoring a "rough" material, iron, as the stone of the tower, and on the other hand, we have chosen to use the glass to leave visible transparency in the wall system. the panel sections and profiles, slightly oversized, were chosen to respond to the massive character of a fortified place. because of the low level of natural light and the point lighting system, created during the restoration by placing four corner spots at each level of the tower, we chose to provide for each panel led lights incorporated into the upper section of the structure, so as to illuminate each work exhibited in a complete and uniform way. regarding the theca, placed at the center of the last level of the tower and consisting of a square base with an aluminum frame and an upper glass cube, the illumination was placed below, to emphasize its presence at the center of the room as if it were suspended in space and time. the abovementioned lighting systems, not anchored to any part of the structure, implement the aspect of reversibility of the panels (adjustable and removable) and the entire design intervention. 8. conclusion the 3d reconstruction, both digital and tangible, adds a special value to a historical building, reestablishing the tower in a circuit of fruition, military in the past and cultural now. virtual and material models will allow users to understand the state of the landscape of the past, imagining the situation and relationship of our tower with its place. the museum proposal is aimed at increasing the use and the functional reinterpretation of the tower, which is thus related to our contemporaneity. along with it, the survey of the tower provides a data archive for future reflection and comparison between its previous state and the subsequent restoration; this is useful for assessment and eventually for the evolution of restoration methods, restructuring and rebuilding of the iberian school. all this helps to provide a comprehensive view of the historical evolution of the tower, archiving with scientific methods all the steps of the structural evolution of the tower, but also of its restoration work. the goal is to configure the tower not only as a symbol and a testimony of the past that characterizes the coastal landscape, but also as an element of identity of the local culture and inhabitants who interact with it, continuing to bring it to life in our time. the desire is therefore to create a new hub in a community trying to create an evolutionary input targeted mainly to an increase in cultural tourism, and the consequent increase of the territorial possibilities aimed at seeking new users and visitors. 9. references r. atzeni and v. naldini. 2014. guardando il tempo da una torre sul mare. firenze: università degli studi di firenze, tesi di laurea in architettura. s. bertocci and m. bini. 2012. manuale di rilievo architettonico e urbano. novara: città studi edizioni. m. j. v. boira. 2007. las torres del litoral valenciano. valencia: generalitat valenciana. v. c. cerdàn. 2012. torres de vigĺa y defensa del litoral valenciano (iii): de la torre de burriana a la torre de el puig, proyecto final de grado. taller 12, conservaciòn del patrimonio. estudios previos escuela técnica superior de ingenierìa de edificaciòn. valencia: upv. a. frascari et al. 2015. digital construction for analysis: the scalambri defensive system in sicily. p. r. navarro, in , defensive architecture of the mediterranean. xv to xviii centuries, vol. i. valencia. 307-314. t. gil piqueras et al. 2015. when an isolated building becomes a guideline for the urban pattern. the case of "torrenostra" in torreblanca, castellòn, spain. in proceeding of the 20th conference on heritage and new technologies. vienna: ed. museen der stadt wien – stadtarchäologie. a. j. latorre. 2012. torres de vigĺa y defensa del litoral valenciano (ii) : de la torre de la sal a la torre de mijares, proyecto final de grado. taller 12, conservaciòn del patrimonio. estudios previos escuela técnica superior de ingenierìa de edificaciòn. valencia: upv. r. o. lerma traver. 2012. torres de vigìa y defensa del litoral valenciano (ix). de la torre de agua amarga a la torre de la horadada, proyecto final de grado. > taller 12, conservaciòn del patrimonio. estudios previos escuela técnica superior de ingenierìa de edificaciòn. valencia: upv. b. prades and juan emilio. 2013. gentes, costumbres, tradiciones, historias, y paisajes de tierras castellonenses: trazos de la historia marinera de torrenostra-torreblanca. http://torrenostra.blogspot.com.es/2013/02/torrenostra-historia.html a. f. requena. 1997. la denfensas de las costas valencianas en la época de los austrias. alicante. p. rodriguez navarro. 2015. defensive architecture of the mediterranean, xv to xviii centuries.vols. i and ii. valencia. p. rodrĺguez navarro et al. 2015. metodologĺa integral para la documentación de las torres de defensa de la costa valenciana. in defensive architecture of the mediterranean xv to xviii centuries, vol. 1. valencia: editorial universitat politècnica de valència, 312-328. m. j. sànchez mora. 2013. torres de vigìa y defensa del litoral valenciano (vi). de la torre del gerro a la torre del descubridor, proyecto final de grado. taller 12, conservaciòn del patrimonio. estudios previos escuela técnica superior de ingenierìa de edificaciòn. valencia: upv. a. e. soler. 2015. las torres de defensa del litoral: sant vicent (benicàssim) y torrenostra (torreblanca). estudio arquitectónico y constructivo. p. rodrĺguez-navarro, in defensive architecture of the mediterranean. xv to xviii centuries, vol i. castellón, spain: editorial universitat politècnica de valència, 167-174. b. r. vila. 2013. tutor: pablo rodriguez. torres de vigĺa y defensa del litoral valenciano (i): de la torre de sol de riu a la torrenostra. proyecto fin de grado. universidad politécnica de valencia. received march 2017; revised july 2017; accepted august 2017 the mausoleum of giuseppe tonietti on elba island. from a masterpiece of adolfo coppedè to a compromising state of decay. angela mancuso, andrea pasquali, giorgio verdiani university of florence, italy this study shows the results of the digital and photographic surveys carried out on an architectural work of great importance: the mausoleum of the tonietti family, designed by adolfo coppedè, built on the island of elba in tuscany at the beginning of the 20th century. the current alarming conditions of the building invite us to reflect on the unpleasant but common fate of many buildings of the liberty and eclectic periods in italy. with the evolution of rationalism of the architectural form and thus the gradual elimination of decorative elements from architectural objects, architectural research, and with it the observation and conservation of cultural heritage, has increasingly focused on the new rational style, omitting many examples of floral style equally deserving of attention. the alarming state of preservation of the tonietti mausoleum, combined with the total absence of conservation projects by local authorities, set the conditions for the dissolution of the work and the consequent loss of the cultural and territorial connotation that it created. processing of the survey data and the collection of documentation are intended to create the basis for the comparison of the work's original state and its current form, determining the current conditions of decay. one may hope that this work can lead to a practical impulse to conservation of this cultural property designed by the youngest of the coppedè brothers, while giving it due recognition for its inherent qualities and position in the history of architecture. key words: digital survey, mausoleum, liberty and eclectic architecture, coppedè, tuscany sdh reference: angela mancuso et al. 2017. the mausoleum of giuseppe tonietti on elba island. from a masterpiece of adolfo coppedè to a compromising state of decay. sdh, 1, 2, 16 pages. doi: 10.14434/sdh.v1i2.23247 1. historical introduction to the monument at the end of the nineteenth century, the island of elba was the italian center of iron mining. one of the most important mines was located in rio marina. the first concessionaire of this mine was giuseppe tonietti, a man of great capacities and moral integrity. starting as a naval captain, tonietti became a very rich man in rio marina and also an influential one, serving as a city counsellor and a "labor knight." in 1896 he died, leaving all his fortune to his wife and his son ugo ubaldo tonietti. after his temporary burial in a niche of the town cemetery [a.s.c.r.m.], his son decided to build a monumental chapel as a family tomb, in the place where his father used to walk and stare at the sea, on the peak of the lentisco mount. at that time, the italian architect adolfo coppedè was working at elba for the businessman pilade del buono, a long-standing friend of tonietti's father. ugo tonietti commissioned coppedè to design and the construct the chapel, which today is considered one of the best examples of the eclectic work of adolfo coppedè. from the second half of the 20th century, with the extinction of the tonietti family, the chapel was abandoned. today it appears in an advanced and dangerous state of deterioration that will be object of discussion in this work. 1.1 the architect adolfo coppedè adolfo coppedè was born in florence on april 29, 1871, the third son of mariano coppedè and antonietta bizzarri. he attended the professional school of decorative and industrial arts in florence, and was a prize-winning student. in 1892 he enrolled at the accademia di belle arti in florence, but he only occasionally attended it, since he started working with his father and brothers as a wood sculptor. in 1898 and 1899, adolfo coppedè participated in the competitions for the artistic pensioner of rome, winning the first contest and finishing second in the final one. on this occasion, he was noticed by the hon. pilade del buono, who led him to elba, where del buono commissioned several works. in 1901 he married anita burchi, daughter of augusto burchi, a professor at the academy of fine arts in florence, and in 1902 he obtained the license for teaching architectural design. during his career, he was in charge of many projects, including important palaces in florence, for which he won the premio martelli three times (an award established by the florentine architect giuseppe martelli, 1792-1876); several buildings in milan; and the very important project for the salons of borsa in genoa. between 1937 and 1950 he devoted himself to the administration of the parugiano farm, in montemurlo, near florence. on august 15th, 1951, he died in parugiano and is buried in the chapel of the villa. 1.2 coppedès' style important for our study is the position of coppedè and his brother gino in the italian artistic and architectural milieu of the beginning of the last century. the coppedè brothers are often framed as exponents of modernism and of the italian liberty style. however, their version of modernism stood in direct and open conflict with eclecticism and historicism, which extended to the coherent development of the idea of a building and its continuous formal architecture, which refused to proceed by successive additions, which promulgated the identification between function and decoration and which required forgetting the distinction between construction and architecture. a quick examination of the coppedès' style shows that no characteristics of their works correspond to the features just mentioned. this is probably due to their different culture and the environment, as compared with other contemporary architects in italy. this clear separation can be read in the total absence of the works of the coppedès in all the textbooks about liberty and italian modernism. this is unfortunate: it would have been appropriate to mention the coppedès' contributions and to give students a general picture of these eclectic architects who, in their own way, made a significant contribution to the architecture of the 1900s in italy, especially in the cities of genoa, florence and milan. 1.3 works on elba and in italy the elba projects were quickly commissioned from adolfo coppedè. the first of these to be finished was the del buono chapel in the cemetery of portoferraio. in this work, there is still a strong element of the neo-gothic style that distinguishes his early works and which would be the basis for his future developments. the other building that today is a symbol of coppedè on elba is the palazzo dei merli, unfortunately destroyed by bombing in 1943, but of which there are many photographs. this, too, was characterized by a neo-gothic style. the true coppedè style is first attested in the tonietti chapel. other work done on elba include the san martino house and farm, the property of pilade del buono, and the palazzo for the administrative offices of an iron mill. at the end of his stay on elba, adolfo coppedè returned to italy, bringing back useful experiences in architectural design that resulted in further commissions, first in the florence area and later in genoa and milan. overall, his work as an architect was limited in comparison to the professional activity of his brother gino, whom adolfo had always seen as an inspiration and reference, always trying to outdo him [bossaglia and cozzi 1982]. in florence in 1906 he built the villa pagani-nefetti, for which he won for the first time the hammer award, and the antonini house, with an elevation marked by two turrets and balconies supported by large talamoni; it was originally decorated with painted panels by galileo chini. the peak of adolfo coppedè's architectural career was reached between 1909 and 1912 with the design of the interior of the halls of the new exchange of genoa. to the important achievements of this period are added several unrealized projects at an urban level, such as the project for the reordering of piazza colonna in rome (1908), two reordering projects in florence (1909-1910; 19101915) and the project for a monumental bridge over the tiber river in rome (1909-1912). another important creation that, after genoa, marks the passage of coppedeian style from florence to the northern italy is the palazzo viviani-cova (1910-1915) in milan. also in milan are located the palace in via elba (1912-1919) and the most important building in via broletto, setting of the national fund for accidents at work (1913). the palace decorations are characterized by a mix of eclectic, baroque and secessionist references, with elements both floral and geometric. in florence coppedè also designed the villino sequi-bopp (1913-1914), the renovation of the palazzo pazzi-quaratesi, headquarters of the bank of florence, for which he was the subject of numerous polemics, and the interior of the agricultural credit bank in piazza della signoria, for which was appointed grand officer of the crown of italy. between 1918 and 1919 he carried out the restoration of the palazzo del canto alle rondini and the ancient pharmacy of marco palmieri. between 1919 and 1925, he designed and built the house of cellini, executed the renovation of the theatre-garden alhambra in piazza beccaria (both of which no longer exist), the renovation of the villa il bargellino, he built the castle mezzaratta in settignano and the villa bartolini salimbeni, still existing even if with some changes. dating to 1926 are the unrealized project for the "mussolini gallery" in florence and the façade of the parish church with accommodation of the square outside and the war memorial and fountain in radda in chianti [bossaglia and cozzi 1982]. 2. the tonietti mausoleum 2.1 historical notes as mentioned above, at the end of 1800, adolfo coppedè went to elba with pilade del buono. through him he knew and met giuseppe tonietti, the first tenant of the mines of rio marina and one of the city councilors, who died at the age of sixty years, leaving his son an immense fortune to manage. ugo ubaldo tonietti decided to build a funerary chapel to honor his father. the area he chose was the top of the mount lentisco, the place where his father used to go for a walk and admire the sea (figs. 1 and 2). figure 1 (above). skyline with tonietti's mausoleum near the port of cavo. figure 2 (below). the façade of the mausoleum. the tonietti chapel is considered the major work of adolfo coppedè, both on the island and among all his works. it is a witness to the climate of those years, the ambitions of the clients as well as the high quality of the designer [bossaglia and cozzi 1982]. the family chapel for the tonietti is configured almost like a lighthouse that marks the route between piombino and portoferraio, rising majestically in the verdant forest. the association to the shape of the lighthouse, as well as its location, makes much more sense if there is a link to the beginning of giuseppe tonietti as owner and highly experienced navigator. according to some sources, the chapel is built of elban granite, white marble and stone of the boulder of fiesole. moreover, the internal iron parts probably come from officine michelucci in pistoia, tuscany, and finally the painting that served as the altar backdrop, are probably the work of carlo coppedè, adolfo's brother [formenti and magnani 1905]. for these features, it has been difficult to find confirmation now that most of the coppedè files are difficult to access or have gone missing. the only exception is the front door: a picture is present in the book containing some photos of the officine michelucci, which also lacks an archive [dezzi bardeschi 1980]. 2.2 architectural description the mausoleum is composed of a large and impressive staircase (fig. 2) that leads the visitor to the decorated entrance gate of the main room ot the first level. this room is characterized by a ribbed cross-vault and a polygonal apse, covered with a ribbed half-dome, where an altar was located (fig. 3). the tombs were both positioned under the flooring and on the two sides of the chapel, where the signs of the presence of two big coffins are still clearly visible. according to some authors, these coffins were made of white carrara marble. the interior part of the chapel was painted by carlo coppedè. still visible are some traces of a starry sky and of other decorations on the vault and the half-dome [formenti and magnani 1905, brancaccio 2011]. figure 3. interior of ground floor and the vault. the door at the left of the altar leads to a steep and narrow staircase that goes to an upper leve where there is a very small room with an iron helicoidal staircase (fig. 5) arriving at the lantern. from this room, going up a couple of steps, it is possible to see a breathtaking view of elba (fig. 4). figure 4. views on landscape by the oculi at the first floor of mausoleum. unfortunately, at the time of the construction of the chapel, these four oculi were closed with windows, which have now totally disappeared: the salty air entering through these openings has caused the rusting of the staircase, which is now in a state of collapse and impossible to use. figure 5. view on interior of first floor – the four oculi and the iron staircase. 2.3 reflection on the actual state of preservation the mausoleum is located on the top of a hill called monte lentisco, its location is characterized by a flourishing vegetation that in years have grown more and more, surrounding more closely the monument, invading the staircase with the roots and causing the collapse. some shrubs are also visible on the façades. an historical photograph [a.s.f.] of the mausoleum makes it possible to define the differences between the original and current condition of the interior of the building (fig. 7). what is most evident is the lack of some important parts of the balustrade, of the entrance gate and of some sculptural pieces. it is also evident, after a first visit to the chapel, that many of these items were intentionally removed. we may also observe several phenomena of decay: the presence of lichens and moisture, the collapsed staircase at the entrance, and the degradation of the interior. this is one of the most dangerous conditions of the current state of the chapel: as the access is open to everyone, it is not inconceivable that a visitor might fall down while trying to reach the entrance. over the study surfaces of the chapel, is possible to see much damage caused by humans. the two heads on the beaks of the side ships are no longer present in the area, so it makes sense to think of a theft. the same is true for some parts of the balustrade. the columns grouped at the side of the door have been engraved, and graffiti are visible on the left one. 3. the workflow on the tonietti mausoleum the work on the tonietti chapel was carried out with an initial bibliographic and archival search that produced the results shown in fig. 6. figure 6. diagram of workflow. after this, the work continued with the digital survey and its data elaboration. it is important to highlight that what is covered in this paper is just the initial part of a more exhaustive research project that will probably be the subject of future publications. this initial search is of utmost importance for continuing the mausoleum studies with a precise analysis of the state of degradation and a hypothesis of restoration, conservation and musealization. 3.1 a preventive site inspection for a survey the first inspection of the tonietti chapel was done in may 2016. this first approach had the function of understanding exactly what might have been the advantages and disadvantages of a digital survey campaign of the structure. from this first inspection we noticed the presence of a long gravel road, with many curves and a significant height. the second observation regarded the state of the chapel: it was surrounded by a dense network of medium and tall trees, which on two sides come very close to the structure, not allowing the viewer to take pictures moving away from its exterior perimeter. to solve this problem, at least partially, we removed a portion of the surrounding vegetation, and some branches were bent back, thereby increasing visibility. finally, some we noted the considerable height of the building and on the inability of reaching the second level, owing to the unsafe conditions of the iron stairs. 3.2 the digital survey campaign the survey campaign using 3d laser scanner has been carried out over two days. starting from the access door, we covered first the interior and then the exterior, for a total of 65 stations. the instrument used is a phase-shift ls -imager 5006hby zoller+fröhlich. this tool works in a range from 0.4 meters to 79 meters, although the best data are obtained in the range between 1 and 50 meters. it scans the points for 360° on the horizontal and for 310° on the vertical axis, where it excludes the portion of the points below the scanner tripod. the device can calculate the scans in different modes: starting from the "preview" mode, very quick and with a low number of points, it can work in "middle," "high," "super-high," and "ultra-high," with each jump in quality increasing the time of the scan and the number of resulting points. in our case the scan type was changed according to our requirements: in the interior, where the walls were fairly close to the scanner's station points, we used the "preview" and "medium" mode. the external scans were always made in "high" and once even in "super-high" mode, to reach the lantern. the issues mentioned above caused a partial final point cloud, and these results were also affected by the presence of different projections highlighted by the truncated-pyramid shape of the chapel. 3.2.1 processing the processing work was performed by means of specific software to manage the point cloud. the obtained 65 scans, in original .zfs format, were registered with the automatic procedure on autodesk recap 360 pro. this software automatically registered all the external scans and most of the internal ones, the only cases where manual intervention was necessary was in the case of the narrow and windy stone staircase. later, the complete point cloud was exported to .pts format so that we could switch to bentley pointools v8i. this was used because it is very convenient to manage and edit the point cloud with a special clip-box, which allows one to obtain snapshots useful for the preparation of traditional two-dimensional products. it allowed us to obtain plans at different levels, sections and elevations, with a good level of detail and precision. this software also allows one to view the cloud in false color (hue) or grayscale (grayscale) and to use a plane shader to display different color planes along the axes or a vector. re-drawing was performed with autodesk autocad 2016. 3.2.2 results finally, from the ls survey campaign two plans were re-drafted (one for the first level and one for the second), four vertical sections (passing through the key brick of the first floor vault) and the four façades, all with a high level of precision, even despite all the issues explained above. these 2d drawings were rendered at a scale of 1:50. the drawings were used for the basis of the subsequent material and degradation studies. figure 7. comparison of first photo and actual state of conservation and diagram of degradation (image courtesy of ministero dei beni e delle attivitá culturali, drawings by the authors. it is strictly forbidden to reproduce or duplicate the image if not in low resolution and for personal purposes). 3.3 the photogrammetric survey campaign during the ls survey campaign, a photographic survey with professional equipment was carried out in parallel. this gave us a complete photographic coverage of the building, mapping its environment and the building materials and state of degradation of its facades. although this work affected the entire structure, here we report a single but relevant application. 3.3.1 application on the most important piece of the balustrade: the griffon. the mausoleum was characterized by a balustrade that ran all the way around the first level of the structure and opened at the entrance. figure 8. view of the griffon and the mausoleum. as one can note from the historical picture on our left and from the numerous fragment and pieces around the chapel, it was composed of four angular pieces of quadrangular shape, cylindrical lateral pieces and two special pieces at the entrance: two symmetrical winged lions. today no piece of balustrade is still standing: many of them have been stolen and reused, and some others are scattered around the site. two lions probably remain in situ thanks to their great weight. one of them is lying on its side (fig. 8). with a preliminary clearing of the shrubs, it was possible to photograph and reconstruct the geometry via a photogrammetric process and a mirroring of the resultant texturized mesh. figure 9. photogrammetry steps of griffon. the photogrammetry was carried out with the software agisoft photoscan release 1.2. the final model in .psx extension has been exported in .obj with his own combined material file .mtl (fig. 9). the texturized mesh in .obj format has been cleaned, edited and mirrored in maxon cinema 4d (fig. 10). figure 10. color map and rendering of griffon model. the resulting model seems very precise and accurate, preserving both the geometry of the animaland its material definition. signs of the deterioration of the stone are clearly visible in the original part of the lion: moisture, lichens and missing parts sadly characterized this piece like the entire structure. 4. discussion 4.1 the precarious actual state of preservation of the biggest pieces of eclectic and art nouveau architecture in italy the relatively brief period in which eclectic architecture and art nouveau style were dominant in italy and europe was soon followed by a rationalist movement that threw the floral style into oblivion [cresti 1991]. for this reason and because of the strong contradictions and differences between the two movements, the products of the liberty style were soon abandoned, with the result that one can observe today: the only liberty buildings still restored and usable are the privateon es which have been maintained from one owner to the next with the same economic means. contrariwise, when this did not happen, liberty houses, palaces, monuments or tombs often found themselves abandoned only a few years after their construction, or, if they survived at all, they were in a very precarious condition. many examples of this adverse fate can be found in monumental cemeteries of the late nineteenth century in the most important cities, which were the centers of the liberty architectural production (e.g., milan, turin, florence, viareggio, montecatini, livorno, rome, and palermo). sometimes the same thing happened to public buildings: if their use remained constant over the years, their structure and their decorative elements have been maintained until now. however this positive outcome is not encountered in the greater part of the buildings, often abandoned just a few years after their construction owing to a change in architectural taste, of location or due to an improvement of technological needs of people or society. this is the case, for example, of the terme del corallo in livorno, of the glasshouse of montecatini—both beautiful buildings now abandoned, whose condition now is only the faded sign of a past and glorious time. moreover, it must be said that, unlike liberty, eclectic architecture suffers not only from a lack of maintenance, but also from a much more serious and dangerous lack of documentation. this problem was encountered in the case study of the tonietti chapel in cavo: for this monument it is still difficult to find the exact date of construction, the original drawings or copies, notices by the architect or by other people who visited the chapel in the first years of twentieth century. this lack of evidence, owing, as said before, to an important loss of interest by people of the period and afterwards, has made research a very difficult matter. as a matter of fact, very little information has been reported over the years, and there has been no confirmation that only a detailed study of the monument can give. for this reason, the present research project is but the first step in a much larger effort to recuperate this important, but sadly neglected, chapter of italy's modern architectural history. 5. conclusions along with the inspection work, survey, and documentation of the current state of the building, the first stage of this research project on tonietti chapel included a quick comparison between its current state and its condition when new. this was possible thanks to some photos found in the archivio di stato of florence. this work of comparison also helped us to find elements that no longer exist, whose existence would otherwise have been impossible to imagine. this was the case of the heads over the lateral ship bows, which have completely disappeared from the outer perimeter of the building, where a large part of the balustrade is still preserved. additionally, the comparison between the pictures shot immediately after the end of the construction work and the current state highlights an important issue that the buildings produced in the early 1900s have faced throughout the twentieth century and beyond: the complete lack of interest on the part of the scholarly community and of the territorial governments. undoubtedly the main factor responsible for this neglect is the ideology of the mechanistic rationalist movement, which helped create indifference, if not outright hostility, to this "old-fashinoned" style of architecture. in particular, in the case of the mausoleum tonietti, the neglect was probably intensified by the relationship between the family and the local community. the aim of this work, still in its initial phase, will be of a comprehensive understanding of this important building by adolfo coppedè, continuing the study with an in-depth analysis of its building material and their degradation phenomena and with a final restoration proposal that can give a new life to this fascinating monument, symbol of the eastern area of the elba island. this will confer on the mausoleum tonietti the importance it deserves: through a possible future restoration project we can expand the monument's current purely ornamental function in the elban landscape and make it once again an active component of the island's cultural tourist route. above all, we will situate this building, its architectural movement, and analogous contemporary works in the evolution of italian architectural history, providing the necessary clarifications and corrections, in order to create a meaningful picture useful for the formation of future architects and architectural historians. 6. references bossaglia rossana. 1987. archivi del liberty italiano: architettura. milano: franco angeli. bossaglia rossana and cozzi mauro. 1982. i coppedè. genova: sagep editrice. brancaccio loredana. 2011. adolfo coppedè agli esordi dell'elba contemporanea. livorno: sillabe. cresti carlo. 1991. firenze 1896-1915 : la stagione del liberty. firenze: alinea. dezzi bardeschi marco. 1980. le officine micheluccie l'industria artistica del ferro in toscana (1834-1918). pistoia: cassa di risparmio di pistoia e pescia. docci mario and fiorucci tiziana. 2005. metodologie innovative integrate per il rilevamento dell'architettura e dell'ambiente. roma: gangemi editore. fantini valentina. 2014. abandoned art nouveau in italy. in proceeding of the 18th international conference on cultural heritage and new technologies 2013. vienna: museenderstadtwien –stadtarchäologie. formenti carlo and magnani francesco. 1905. cappella gentilizia della famiglia tonietti all'isola d'elba, architetto adolfo copped. in l'edilizia moderna, periodico mensile di architettura pratica e costruzione, anno xiv -fasc. 1. milano: modiano. giusti maria adriana. 1996. le età del liberty in toscana. proceedings of the conference in viareggio, 29-30 september 1995. firenze: octavo franco cantini editore. guidi gabriele, russo michele and beraldin jean-angelo. 2010. acquisizione 3d e modellazione poligonale. milano: mcgraw-hill companies. insabato elisabetta and ghelli cecilia. 2007. guida agli archivi di architetti e ingegneri del novecento in toscana. firenze: edifir. lambardi sebastiano. 1966. memorie antiche e moderne dell'isola d'elba. bologna: forni. ninci giuseppe. 1988. storia dell'isola d'elba. sala bolognese: forni. targioni tozzetti giovanni. 1768. relazioni di alcuni viaggi fatti in diverse parti della toscana. firenze. vanagolli gianfranco. 2012. miniere e ferro dell'isola d'elba. tempo spazio lavoro tecnologia immagini. livorno: le opere e i giorni. verdiani giorgio and fantini valentina. 2012. the "terme del corallo" in livorno, italy, a contribution to try going beyond the abandon. international journal of heritage in the digital era 1 (1): 15-19. verdiani giorgio, parretti lorenzo, fantini valentina, de paola jacopo and giraudeau stéphane. 2013. ad impossibilia nemo tenetur: three case studies on built heritage elements at risk. in built heritage 2013 monitoring conservation and management, milano, 18-20/11/2013, vol. 1. 574-581. zecchini michelangelo. 1971. l'elba dei tempi mitici. pisa: pacini mariotti ed. a.s.f. archivio di stato di firenze a.s.c.r.m. archivio storico comunale rio marina received march 2017; revised july 2017; accepted august 2017. the medieval bishop's palace in milicz. 3d reconstruction as a method of a research hypotheses presentation justyna kolenda and małgorzata markiewicz polish academy of science, poland as a result of the intensive development of multimedia, 3d visualizations of various kinds of historically, artistically or scientifically valuable objects became standard at the beginning of the 21st century. what triggered the construction of three-dimensional visualizations was the will to protect cultural heritage especially historical monuments which are in ruins and exposed to further destruction as well as the need to disseminate information about such objects beyond a small group of specialists. another catalyst for this was the need to verify the existing proposals for reconstructions or research hypotheses. the bishop's palace in milicz (poland) was probably built in the late thirteenth or early fourteenth century. it was a brick building whose layout was typical of ducal buildings known in silesia. the erection of the building in milicz was connected with the creation of the church castellany in this area. the visualization of the oldest phase of the bishop's palace in milicz is part of the project regni custodiam et clavem santok and clavis regni poloniae milicz as an example of two border towns, implemented by the institute of archaeology and ethnology of the polish academy of sciences and financed with the funds of the national program for the development of humanities for the years 2011-2017 (number 11h 11 0184 80). virtual reconstructions were based on the analysis and interpretation of source materials, in accordance with the guidelines contained in the london charter. the purpose of the visualization is to present the history of the building to the residents of milicz and tourists and, in the long run, to allow local authorities to take steps towards the preservation and revitalization of the bishop's palace. key words: 3d visualization, reconstruction, the bishop's palace in milicz, the london charter sdh reference: justyna kolenda and małgorzata markiewicz. 2017. the medieval bishop's palace in milicz. 3d reconstruction as a method of a research hypotheses presentation. sdh, 1, 2, 428-443. doi: 10.14434/sdh.v1i2.23458 1. introduction over the last few years there has been a very intensive development of digital media, such as computer visualization techniques, which have significantly extended research possibilities in the field of humanities, including the disciplines researching the past [sylaiou and patias 2004; hermon and kalisperis 2011]. authors' address: justyna kolenda and małgorzata markiewicz, institute of archaeology and ethnology polish academy of sciences centre for late antique and early medieval studies, ul. więzienna 6, 50-118 wrocław, poland; email: jko@arch.pan.wroc.pl; mma@arch.pan.wroc.pl permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal digital technologies provide contemporary researchers with set of tools and methods enabling them, apart from verifying the existing research hypotheses and putting forward new ones, to create knowledge about the past by the development and presentation of spatial images of historic architecture [johnson 2007; riedel and bauer 2008]. one of the consequences of the use of these new media is the great popularity of three-dimensional visualizations of the buildings of historic value which are part of local cultural heritage. 2. research objectives we present in this article the method and tools that were applied to develop a 3d visualization of the medieval palace in milicz (poland). this is a multi-stage historic object which was extended and modernized many times over its seven-hundred-year-long history (fig. 1). figure 1. the bishop's palace in milicz: above – west side; below – south side (photo by m. markiewicz). the palace was originally constructed at the end of the 13th century or the beginning of the 14t century and presumably it was connected with the investment made by the bishop of wrocław. in 1358, it was sold to duke kondrat i of oleśnica, who remodeled it. from 1494 it was the seat of the kurzbach family and at the end of the 18th of the maltzan family, who later moved to a newly built residence [chorowska and kudła 2005]. the building began to serve a secondary role and this is when the process of its slow deterioration started, which significantly intensified in 1945 because of wwii. the decision to develop a visualization of the oldest stage of the palace resulted from the fact that numerous and often inconsistent proposals for the reconstruction of the specific chronological stages of this building were in the literature on the subject. j. gottschalk, for instance, noted that the masonry castle was built by the dukes of oleśnica after the invasion of the hussites in 1432 [gottschalk 1939, 43], whereas b. guerquin indicated that the middle of the 14th century was the time when the castle was constructed on an irregular plan, with residential buildings located in the southern part of the yard and an enclosure wall with the entrance from the eastern side. the building with a great hall was supposedly constructed after the fire in 1536. [guerquin 1957, 59]. less than twenty years later, the same researcher reconstructed the oldest design featuring the residential tower on a rectangular plan with two outside buttresses from the southern side and with three open space floors [guerquin 1974, 198]. the proposal by j. pilch is also in line with the layout described above. in his opinion, a castle was supposedly built in this place according to an irregular plan surrounded by a wall with an entrance on the eastern side and a residential building in its southern part. just like his predecessors, he also claims that after the fire in 1536 a new building was constructed there with a great hall whose ceiling was supported by a single pillar [pilch 1978, 167]. the spatial layout, the size, and the chronology suggested by the researchers mentioned above were verified during the archeological and architectural research conducted in the 1980s [rozpędowski and kudła 1987; kudła 1988]. the findings of this research were discussed in two articles by m. chorowska and a. kudła [2005] as well as m. chorowska [2008]. according to those researchers, the object was built much earlier, in the 13th century or at the beginning of the 14th century, as a long free-standing house that functioned as a palace of the bishop of wrocław [chorowska, kudła 2005, 86-87]. this short outline of the history of that palace is confirmed by numerous remodelings, which each time changed its layout, size, and form in compliance with the architectural program which was popular in each period, while at the same time eliminating older elements. the stages mentioned above refer to remodeling as well as the disappearance of the older elements of architecture. unfortunately, during the development of the visualization it was quite difficult to identify the oldest elements, which survived only partially. the objectives of the three-dimensional visualization were: to present the oldest stage – the bishop’s palace (currently completely invisible in the ruins and inaccessible to the potential viewers) – one of this type of structure built in the middle ages in europe [chorowska 2008]; to present the reconstruction of this building according to the plan that is popular in the literature on this subject and to begin an academic discussion of its correctness; to present to the viewers the value of the object, to provide information about it by popularizing its three-dimensional reconstruction. 3. procedure the issues connected with the 3d visualization of architecture have many aspects which should be considered at several research levels. these include: the choice of a historic site and the evaluation of the feasibility of the development of a spatial image based on it, its documentation method (traditional methods, photogrammetry, scanning), and also the selection of tools and assumed principles of building databases, which often provide the basis for the evaluation of the reliability of the whole process of visualization development. the final effect of this sort of project, namely the spatial model, is usually one of many possible proposals for the visual presentation of the past affecting the imagination of modern society. in each case, the right procedure should be selected, which must be suitable for the conditions of the original elements of the object and the expectations of the contemporary viewers. this problem is especially evident when you compare the methods applied when developing 3d models of objects with poorly preserved original fragments, such as the ruins in milicz, to those applied in the visualizations of well-preserved structures. in the first case, the use of older architectural documentation developed with the use of traditional methods determines the correctness and consequently the reliability of the visualization. it includes information that has been irretrievably lost over the last 60 years as a result of continuous deterioration. this situation requires the assumption of specific procedures and tools to combine qualitatively varied sources: the older, often graphic and descriptive documentation, with the newer, digital data collected for still existing parts of the objects. obviously, this procedure is different from that used when developing visualizations of well-preserved structures for which digital data are available and which allow for new documentation as well as higher research quality. thus, there is a clear discrepancy regarding the quality of sources between, on the one hand, the archival documentation developed with traditional methods whose processing requires the use of adequate procedures and, on the other hand, the documentation developed nowadays with the use of the latest research methods (e.g. laser scanning). it should be kept in mind that any visualization of seriously damaged historic structures is only one kind of proposal for the reconstruction of such an object, developed on the basis of its original fragments and known analogies, as well as the experience and knowledge of the persons involved in the development of a spatial image. the use of 3d visualization to reconstruct the historic structure in milicz had several purposes, the most important of which was the possibility of better rendering and consequently better understanding of the form and function of the palace. the computer-generated virtual space provides at present an important research environment for experiments. it is possible to create and analyze alternative model designs that provide the basis for the research process. through the application of this method of reconstruction of a historic site, it is possible to generate any number of images of the palace and individual rooms (general views, details, close-ups, any layout images or scale). it is also possible to use this method to reconstruct the poorly preserved elements of architecture in several variants and critically analyze the spatial images developed in this way. another benefit in favor of the use of 3d visualization in the process of reconstruction of the palace in milicz was the great popularity and the high degree of acceptability of the images generated in the form of computer graphics by non-academic audiences. posting them on internet portals contributes to the broadening of the knowledge of the past with no need for those interested to visit the actual site. citizens who are not history lovers or do not care about the past in general but do like computer graphics also find them interesting. furthermore, this type of reconstruction also affects people who are fascinated by new technological developments, including the developers of computer games. it can then be claimed that the use of this method of reconstruction of the bishop's palace increases the possibilities for research on this very historic object and the 3d model promotes interest from contemporary society. 4. the reconstructive process the different dating, form, and function of the oldest stage of the structure identified with the bishop's palace presented by m. chorowska and a. kud"a prompted the work on its visualization. as mentioned above, the palace was remodeled a number of times, which is why the oldest elements of the building are often invisible under the walls from later stages. the research work began with the question: which parts of the presently existing main body of the building and which elements of the furnishings can be considered to be the remains of the oldest stage of the structure? the question forced the researchers to chronologically divide the original walls, assume specific research procedures, and apply an adequate conceptual framework. the problem was well presented in the article titled visualizing knowledge about virtual reconstructions of ancient architecture, whose authors stated the following in its introduction: “photorealistic images tend to leave their viewers with the impression that the objects depicted actually exist. in the case that the viewer knows that the objects do not really exist – either because they have not yet been built or because they were destroyed – a photorealistic image nonetheless suggests that detailed information has been amassed about the objects being shown” [strothotte et al. 1999]. the issue was then discussed in the london charter, whose main objective is to draw the attention of the groups of specialists who apply computer graphics when developing spatial images of cultural heritage to the necessity of developing and applying reliable methods that would guarantee the historical accuracy of 3d models of historical sites. the virtual reconstruction of the bishop's palace in milicz was developed as a result of analysis and interpretation of source materials in compliance with the guidelines of the london charter, drafted in 2009 by the international team of researchers from the department of digital humanities of king's college, london, and the science and technology in archaeology research centre of the cyprus institute. that document presents the methods which guarantee the highest quality of 3d reconstructions and control mechanisms confirming the historical reliability of 3d models [beacham et al. 2008; bentkowska-kafel 2008; denard 2012]. 5. stages of development 5.1 survey of sources and data archiving the answer to the question asked above regarding the original remains of the oldest stage of the structure depended on a survey of the sources. this survey included the architectural documentation made in the 1960s when the condition of the building was much better and some parts of the basement were still accessible, the findings of archeological and architectural studies conducted in the 1980s, which determined the depth of the foundation, the structure of embankments and the presence of cobblestones in the yard.1 figure 2. process of reconstruction of the bishop's palace in milicz (by m. markiewicz). the available images from the early modern period were analyzed and they provided the basis for determining the extent of the palace remodeling and consequently the degree of intervention into the oldest stage. the survey also covered the written documents indicating the successive changes of ownership, which each time resulted in a remodeling or extension of the object in line with the architectural style popular at specific historical periods. these data were complemented with additional measurements and the photographic documentation made for the purposes of the model. at that stage, it was also important to consult specialists and to search for iconographic analogies available in the subject literature and publications presenting various kinds of reconstructions of medieval structures, both in traditional and digital form. during that stage of the work, the available plans, drawings and photos of the main body of the palace, its rooms and architectural details, especially the parts of the object that do not exist anymore, were digitalized. 1the studies were conducted by the institute of history of architecture, art and technology at wrocław university of technology in 1986-1988. the plans that were available during the reconstruction were traditional and digital to the scale 1:100. the documentation collected during the survey guaranteed the historical reliability indicated and strongly emphasized in the london charter. the database which was developed included all collected information in catalogs (photos, drawings, descriptions). the paradata gathered in this way, i.e. the knowledge gained during the virtual reconstruction through analysis and interpretation of source material as well as through the analysis of missing data, has become the basis for further research on 3d reconstruction [bentkowska-kafel 2008, 44]. 5.2 preparation of vector drawings and textures the reconstruction of the main body of the palace was based on the vector plan and the measurements conducted in the actual ruins. the documentation of the original external face of the walls above the foundation of the oldest stage and the face of the stone foundation was the basis for the textures, namely photos developed with the raster graphics software. the reconstruction was based on the original photos of the palace surfaces, i.e. the face of the first-floor stone wall as well as the brick bond at the second and third levels. 5.3 modeling and texturing this stage of the reconstruction work included modeling with the use of 3d graphics software – autodesk 3ds max (fig. 3). the process was divided into three stages. the first stage focused on the modeling of the landscape where the palace was built. the island with the moat around it, which does not exist anymore, was reconstructed. the next stage included the reconstruction of the palace, the cobblestone yard with a stone well, and an embankment with a gate. some of these elements from around the palace were found during the archaeological studies conducted in the 20th century. the third stage was connected with the modeling of individual rooms, their furnishings, and architectural details. the models were developed by transforming parametric (basic) and editable objects. the first ones were modified with the use of the parameters, which resulted in changing their geometry. that method provides a lot of flexibility. the editable objects do not provide such flexibility in the scope of parameter editing, but they can be edited by modifying sub-objects and using special editing features. the editable objects have a lot of editing features (modifiers) which are specific to individual types of objects. after the completion of the modeling process the previously developed textures were laid over specific elements of architecture. figure 3. a three-dimensional model of the palace in milicz: above – model 3d without textures; below – 3d model – orthogonal view (by m. markiewicz). 5.4 lighting and cameras after the textures were laid over individual 3d models, the virtual cameras were set. this way the socalled points of observation were selected, which affect the future perception of the whole visualization by the viewers. the adequate models of lighting, light reflection and refraction, corresponding to the lighting conditions outside and inside the building, were selected. the main body of the palace was illuminated with sunlight, whereas its individual rooms on the second and third floors were illuminated with sunlight streaming through the windows and illuminating the interiors. this way the lighting resembled that in the medieval interiors. the spaces in the basement had lights illuminating the rooms as well as spotlights, whose source was the candles placed in the corners of the rooms. this resulted in the effect of semi-darkness, typical of this type of room. 5.5 rendering and recording the last stage of the digital reconstruction of the palace was the rendering and recording of the completed digital images with the use of autodesk 3ds max, consisting of the analysis of the relationship between matter and light. the objective of the application of this procedure was to present the model as realistically as possible. v-ray (chaos group) rendering engine was used to develop the visualization of the palace. this produced a more realistic image, as the lighting effects were rendered realistically. it is often stressed in the literature on the subject that the photorealistic visualizations convey false impressions that the object presented really exists, or that the data used as a basis for the reconstruction provide a lot of reliability [strothotte et al. 1999, 16-17]. that is why it is necessary to provide a description of the reconstruction process and show all hypothetical elements so that the viewers can interpret the image presented to them correctly. in order to avoid the problems with the loss of data, the individual stages of visualization were recorded according to the principles of the london charter. 6. results the critical analysis of the collected sources resulted in differentiating their reliability (fig. 4). for this purpose the collected data were divided into three groups, including: original elements of the oldest stage of the structure of the highest informative value, elements confirming the presence of various types of facilities which were reconstructed on the basis of original traces (50% probability of existence in the object), hypothetical elements whose presence was implied on the basis of general knowledge of such architectural structures which existed in the middle ages (10% probability). the division which was applied is substantially justified by the guidelines of the london charter [bentkowska-kafel 2008; markiewicz 2014]. figure 4. the bishop's palace in milicz. "a reliability meter" (by m. markiewicz). figure 5. 3d visualization of the bishop's palace in milicz: 1 – residential room; 2 – utility room; 3 – latrine; 4 – basement; 5 – basement; 6 – kitchen; 7 – representative room (by m. markiewicz). the original sources included the data regarding the size, form, and layout of the whole structure. it is assumed that the bishop's palace (fig. 5) was constructed as a two-winged building with three floors on a rectangular plan with its longer axis oriented north-south (32-33x14 m). its north and south parts (gable walls) had buttresses. the lowest level, the basement, was built of cobbles; the other two floors were built of brick in flemish bond. the southern part of the building, which was used for residential and utility purposes, has original windows on the first floor, whereas its northern, representative part had a large, single room called the great hall (14.25x11 m) on the third floor (fig. 6). the whole structure was surrounded by a wood and earth embankment and the area between the embankment and the palace from the west was paved with cobbles. in the northern part of the court, under the defensive embankment, there was an oval well made of cobbles. the reliable sources include the remains of one of the palace's rooms, namely a latrine (fig. 6). it was located in the south-east buttress with an entrance from the room on the second floor and a corridor hidden inside the buttress with a small recess for candles leading to it. the reliable sources also indicate the layout and the size of individual rooms used for residential and utility purposes (5.76.7m x 11.2 m) as well as the presence and location of chimney flue inlets, which confirms the presence of heating appliances in individual rooms of the palace. however, their form and size were reconstructed on the basis of iconographic sources. there were hooded fireplaces located in the north-east corner of the room on the second floor and in the south-west corner of the room on the third floor. there was a similar situation in regard to the fireplace located in the middle of the west wall in the representative room. consequently, all heating appliances should be included in the secondary category data, whose existence was confirmed by sources; however, their form and size were visualized by analogy to this type of appliance known from other buildings with the same chronology. the hypothetical elements, whose existence is confirmed on the basis of general knowledge of the architecture of a given period, include an external staircase (its layout, size, and form), roofing, and the location of windows in the east facade. it proved impossible to unequivocally establish the original location of the gate in the enclosure embankment wall. it was assumed that the location of the gate, built later in the second half of the 14th century, was connected with the existing layout of the complex and the even older system of roads, especially those of transportation and trade routes. it was established on the basis of this assumption that the gate was located in the east section of the embankment. the whole complex was surrounded by a moat, whose water most probably came from one of the side channels of the barycz river (fig. 7). the reconstruction of the kitchen stove in the form of an open, rectangular hearth made of brick and clay is totally hypothetical. a similar level of license was taken regarding the visualization of the kitchen and the basement rooms located on the first floor; at present it is completely filled with debris. figure 6. the bishop's palace in milicz. 3d reconstruction of the latrine and the representative room (by m. markiewicz). figure 7. 3d visualization of the bishop's palace in milicz (by m. markiewicz). 7. conclusions the process of presenting and popularizing the past in modern society is dominated by images. we experience the past through our discernment or perception [barceló 2014]. the way in which we experience and analyze historical knowledge is determined by how it is presented visually. so far, the information about the bishop's palace in milicz (the oldest stage of its architecture) has been completely unavailable in the form of 3d visualization and the existing descriptions have not provided a clear picture of its form or function. the presented reconstruction is the first depiction of this type. it is very useful that we can present the findings of research conducted on that structure to the public with the use of a visual message. the choice of the reconstruction in the form of a spatial image resulted from the fact that the software to develop 3d graphics is today an invaluable and increasingly popular tool for visualizing cultural heritage [barceló 2000; apollonio 2016]. to see means also to learn, so the digital image is designed for a large group of viewers and it provides added value to the analysis of the past. it also significantly improves the process of remembering new pictorial information and associating it with known information that already exists in the viewer's memory. another advantage is that the developed model can get critical feedback and it can be corrected in accordance with newly gathered data or technical possibilities [markiewicz 2014]. in poland this research method has been applied to verify numerous reconstructions proposed for the architectural design in ostrów lednicki [siewczyński 2004]. the analysis of the existing reconstructions of the palace with the use of three-dimensional modeling resulted in the exclusion of spatial solutions which could not have existed for technical reasons. the digital image of the palace in milicz, its selected rooms and facilities presents the original form of the historic building, which is at present seriously damaged and as such difficult to see among the ruins. we are aware that the three-dimensional method of modeling which we used is not a breakthrough in the application of this technique in architectural and archeological studies. however, its use is significant because even if that historical object is secured and converted into socalled permanent ruins, it will never assume the form or the layout of the oldest stage. it will only conserve the best-preserved elements from individual stages of the times when the building was used. that is why the visualization of the oldest stage of the building (bishop's palace) is the only way to present it to the academic community and to the public. the church in the town of bezławki is a good example of this type of popularization of historical heritage. just like the palace in milicz, the church was also remodeled a number of times; first it served as a castle of the teutonic knights, then as a residence of a noble family and finally as a protestant church.2 it is only through a visualization of individual stages that the whole history of the palace can be followed. the presentation of a threedimensional model of the bishop's palace in milicz to the public will trigger a discussion about this historic site. a lot of questions were asked during the visualization process which could be answered only during the reconstruction of the ruins. it can be claimed on the basis of research experience gained during the reconstruction process that multi-stage buildings which are in ruins and whose process of destruction continues require an individual research approach. the development of a proper research approach depends then on the number of remodeling stages and their extent (e.g. changes to the older walls, demolition of individual parts, change of function of specific rooms, changes in the furnishings) and the possibility of precise dating of those changes. 8. references fabrizio i. apollonio. 2016. classification schemes and model validation of 3d digital reconstruction process. proceedings of the 20th international conference on cultural heritage and new technologies 2015 (chnt 20, 2015). vienna. 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http://www.ime.gr/publications/print/imeros/en/04/article01.html received march 2017; revised july 2017; accepted august 2017. the bogliaco bartolani chapel in the holy gates cemetery, florence. survey and analysis for restoration. olimpia barbieri gentili calcagnini, gabriella goretti, angela mancuso, and milena roccabruna university of florence, italy the holy gates cemetery in florence is located on the hill of san miniato al monte. the cemetery was built in 1854 and it has always been characterized by its monumental nature, with highly decorated burials and chapels designed by the most famous architects of the time. today the cemetery is not well preserved; many tombs are abandoned and there is a general need for restoration. many studies on the major chapels of the cemetery have been carried out by the diagnostics laboratory of the specialization school of the university of florence. this paper presents the survey and the analysis of the state of degradation of the bogliaco bartolani chapel, built in 1913 by the architect enrico dante fantappiè, an italian master of eclecticism. this chapel is a very interesting example of the characteristic style of the cemetery, which is notable for the juxtaposition and contrast of different materials and crafts employed. the studies on the chapel follow a line that goes from an initial photographic and metric survey, to bibliographic and archival research, and finally to an examination of the decay on the exterior façades. the final phase will be a comparison between this tomb and another example of a chapel by fantappiè, located in the same cemetery, where similar construction design has led to similar degradation phenomena. moreover, the workflow presented provides an interesting example of how studies can be carried out quickly and economically in a context where money and human resources are lacking. key words: burial architecture, italian eclecticism, metrical survey, degradation analysis, comparison. sdh reference: olimpia barbieri gentili calcagnini, et al. 2017. the bogliaco bartolani chapel in the cemetery of porte sante, florence. survey and analysis for restoration. sdh, 1, 2, 19 pages. doi: 10.14434/sdh.v1i2.23188 1. historical and geographical introduction florence is an italian city of over 380,000 inhabitants, located in tuscany and famous all over the world for its cultural heritage and culture. a romanfoundation, during the middle ages florence was a very important cultural, commercial, economic and financial center. thecity was also the centerof the italian renaissance and later, the capital of the grand duchy of tuscany. author's address: olimpia barbieri gentili calcagnini, gabriella goretti, angela mancuso and milena roccabruna, dept. of architecture, specialization school in architecture and landscape, university of florence, italy. permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal from 1865-1871, florence served as the capital of italy. in these years numerous interventions involving new designs and new adaptations were made under the direction of the architect giuseppe poggi. one of the most important was the creation of avenues on the old circuit of the city walls and the consequent redesign of the spaces adjacent the ancient walls. among these was the design of a monumental staircase that gave access to the basilica of san miniato al monte and the fortress connected to it; this work presented the opportunity to create a new monumental cemetery [cirri 2003, capaccioli lazzareschi 1999]. 2. florence and its first burial complex during the eighteenth-century florence boasted that it was very avant-garde in theorizing about modern burial structures. unfortunately, a brilliant theory is not always followed by good practice, and the existing cemetery of trespiano was considered an indecorous graveyard for decades [cirri 2003]. 2.1 the monumental cemetery of the holy gates in 1837 the fortress of s. miniato was developed as a majestic graveyard. the cemetery of the holy gates, as it was called, was designed by the architect niccolò matas and opened in 1848. it was expanded using the area of the fortress around the magnificent church of s. miniato al monte, one of the finest examples of florentine romanesque architecture. this church and fortress were located on a hill overlooking the city (fig. 1). at first, the access to the church was from the romantic country paths around florence. it is depicted in many old prints, and drawings and is described in quotations in contemporary literature. a magnificent entrance was built in the 1830s and during the following years. thanks to the talent of many florentine architects such as mariano falcini and tito bellini, the monumental cemetery served to welcome important florentine and italian personages. originally there were only graves in the central part of the cemetery and chapels along the ramparts. in the 1870s, graves began to be embellished with crosses, vases and statues and many new chapels and funerary monuments were erected in the central and south-eastern portions of the cemetery. in contrast to the earlier cemetery of trespiano, there were permanent graves in s. miniato, and these were provided with white marble coverings, so that the burial ground looked like the floor of a medieval church. today the cemetery appears to visitors like a “complex mass of many different styles, marbles and ornamental designs,” seemingly chaotic but with the feeling of “a piranesian monumental density” [cirri 2003]. figure 1. view from the cemetery of the holy gates -florence the tendency towards appearance for the sake of appearance is typical of the middle class, and it is characteristic of this cemetery. it was a way to express social rank by using universal codes: gothic or medieval style displayed great integrity and piety; a renaissance decoration expressed authority and confidence; a 16th century-style grave symbolized a capital surplus; and a greek style represented elegance. often all these were blended together. the question of the style of the cemetery of s. miniato reflects the debate about the urban renewal of florence as the capital of italy. there was a great controversy about the style of florence at that time, and not all the architects agreed with poggi's urban planning scheme. s. miniato cemetery became a neutral zone where people could give vent to their passions and to their personal style; it became an open space for formal research and a privileged place for architectural experimentations. [salvagnini 2001] 3. architect enrico dante fantappiè 3.1 one of the contributors to the actual structure of the monumental cemetery enrico dante fantappiè was born in florence on 28th september 1869. as a young man, he worked as an apprentice carpenter in the family business. his father was a cabinet maker, and starting in 1870 he created “incredible and artistic illuminations and torches,” receiving orders for many parties. most of time, the orders included not only fantastic illuminations but also furniture as well as special architectural installations such as triumphal arches, towers, chinese pavilions and scale models. in addition to working in the family business, fantappiè attended the school of fine arts in florence and, in the 1890s, he took part in seminars by vincenzo micheli and enrico ristori, of whom he is considered a disciple. figure 2.bust of enrico dante fantappiè by d. gabbrielli in the cemetery of the holy gates as professor of architectural drawing, fantappiè entered the most important competitions in florence at the beginning of the twentieth century. he won a silver medal for his design of the façade of the basilica of s. lorenzo and took second place for the design of the central national library, gaining proper recognition from florentine artistic society. in the meantime, he started working for private citizens. the first important job was villa vespasiana (1902) in calenzano, a fine example of a liberty villa in tuscany. he also came into contact with modernism, as shown in works such as the cottini cottage in florence (1906-1907, now destroyed) and the bonciani, toya (1910), sbertoli (1912), and ranieri–biondani (1913) chapels in san miniato cemetery. at that time, his professional commitments were typified by a preference for the late renaissance style, which was an essential part of eclecticism in the 1920s. fantappiè also designed seven buildings along via fiume in florence, and from 1919-1929 he planned and supervised all the activities on the initiative of some florentine industrialists and traders. he was appointed architect of san miniato cemetery in 1911, and he was an in-house member of the academy of the arts of drawing, becoming emeritus in 1927; thereafter he was an honorary member of the bologna academy of fine arts. in the 1930s, he worked to enlarge antella cemetery (1933), then he designed the war memorial, the primary schools and the town hall in signa (1933-39). in his later years he went blind and could not work anymore. he died at his home in florence on august 2, 1951 [cirri 2003, torelli vieri 1913-14, cresti 1991]. 4. the bogliaco bartolani chapel: a brief description at present, our research has not discovered much information about the bogliaco—bartolani family, its history and its reasons for building a monumental chapel in florence. all we have is the inscription on the tomb: that the owner, adriano bogliaco, was a doctor who was born in 1840 in adrianopoli and who died in 1911 died in florence. the chapel, designed in eclectic style by architect fantappiè, was built by bencini in 1913, according to the notice on the left of the entrance. the building is composed of serena sandstone blocks, also known as macigno stone, obtained from quarries in fiesole. the chapel has a square shape and a copper dome engaged on lateral gables. on the top of the dome there is a copper cross. the structure is simply decorated with two levels of frames, some red and white limestone angular tiles and a bronze inscription in a limestone frame. there are also bronze decorations along the side elevations. in addition to some angular medusa heads, alternating with gables, there are two levels of bronze angle brackets, closing the two levels of the frames. on the upper level, there is a bas relief of an hourglass [cirri 2003, cresti 1991, salvagnini 2001]. figure 3.aerial view of the cemetery of the holy gates and the surrounding area; the position of the bogliaco bartolani chapelis marked in yellow. (image courtesy geoscopio -regione toscana) figure 4.the bogliaco bartolani chapel at the cemetery of the holy gates in florence. 5. the initial part of the study—work on the chapel 5.1 introduction the current status of the cemetery is of a decaying place, with pressing requirements for the restoration of many of the chapels and the recovery of the connecting spaces. many studies on the major chapels of the cemetery have been carried out by the diagnostics laboratory of the specialization school of the university of florence. starting from a survey of the monument, both of its geometrical characteristics and the material texture on all of its accessible surfaces, the studies continued with research on the building materials and the main deterioration that occur on the exterior surfaces. all of these studies were conducted in the most economical way and with the simplest methods: a reflex camera, a measuring tape and careful observation of damage [verdiani, mancuso, pasquali 2016]. figure 5. a picture of the survey campaign of the chapel. 5.2 the survey of the bogliaco bartolani chapel the interior of the chapel was not included in the survey; as it is a private building, access is not allowed to visitors. the direct survey campaign was carried out with a simple sketch pad, a laser distance meter and a roll-up tape measure. after the sketches were made in situ, the chapel was redrawn in autodesk autocad 2016 and the dimensions noted. figure 6. 2d rectified representation of the bagliaco bartolani chapel. a photogrammetric survey was carried out to obtain accurate results in the plotting of the external facades. the photographic campaign consists of a total of 40 photos taken with a nikon d7000 equipped with a nikkor 16/85 mm lens and using a tripod. after the photographic campaign, which was shot in such a way as to avoid harsh shadows on the monument, the photogrammetric process began with use of agisoft photoscan 1.2.0. figure 7. phases of the photogrammetric survey of the bagliaco bartolani chapel. this process was carried out only on two of the four sides of the chapel, because the remaining two are very close to the adjacent chapels and thus inaccessible to a photographic campaign. the first passage consisted of the alignment of the 40 photos, ending with the sparse pointcloud; then markers were used to obtain a more accurate alignment, which has as a result the dense pointcloud [verdiani, mancuso, pasquali 2016, mancuso pasquali 2015]. after these two important passages, one can build the mesh and the texture of the chapel, and finally export the ortho-images of the sides. 6. the second part of the study—work on the chapel 6.1 analysis we began the study by cataloguing the different materials of which the chapel is composed. then an examination of the laying of blocks helped us to understand how the serena sandstone blocks were used by fantappiè. this was followed by a study of the chapel’s orientation and the way the sun struck it in different seasons and times of day. finally, we identified the various form of deterioration of the building materials and mapped them, comparing the damage with the incidence of the solar rays; this was done with the physical render on maxon cinema 4d. sunshine affects the chapel’s state of decay in a variety of ways. the chapel lies on the southwestern rampart of the cemetery of the holy gates. it is surrounded on three sides by chapels, while its southeastern facade, the front, is open and unshaded for several meters so it enjoys plentiful sunshine all year round. the other sides are so close to other chapels of the same height that little sunshine reaches them. this orientation study provides an overview of what prevents solar radiation all year round. figure 8. study of the incidence of solar rays on the fronts of the chapel. 6.2 building materials analysis the analysis of the deterioration of the building was developed from the study of its building materials, primarily the big serena sandstone blocks, laid almost completely dry in alternating courses and regular geometries. just as is the case with a big puzzle, where each piece can occupy one and only one position, each block has been worked to fit into a precise arrangement and is designed for just that part of the building. the delicate decorative elements, largely derived from the working of the structural blocks, chase each other on the façades according to careful symmetrical canons. figure 9. building materials unfortunately, we have lost the brilliant and uniform gray typical of that stone, which surely played a significant role in enhancing the simplicity and elegance that characterize the building. the first classification of the materials of the chapel was made according to their typologies. the chapel is made of two different stones, serena sandstone and limestone, and has three different metallic elements: the copper of the roof, the bronze decorative elements and the iron door and window. the second classification regards in particular the serena sandstone blocks, which were differentiated by their positions as shiner courses and stretcher courses. 6.3 state of deterioration the long-standing lack of maintenance of the chapel is clearly demonstrated by traces of decay. in particular, the surfaces of the serena sandstone blocks have been discolored due to dripping rain water that carried traces of bronze, limestone, and the copper of the roof. the runoff of the rain water was originally guaranteed by the tightness of copper roofing and the rods connected to it. the rods, discrete and functional even in the absence of drainpipes, prevented the rainwater from soiling the surface of the sandstone. now the main cause of the alterations to the surface and the color of the serena stone is the roofing: severely oxidized and deformed, and missing in several places, it allows the release of oxides, and the moisture cannot pass out of the masonry. large drops flow from the cornices closest to the cover, and in particular from the zones underlying the bronze bas-relief decorations depicting the medusa heads. from there it spreads along the corners of the building, down to the ground. a thin but extensive biological patina almost completely covers the walls, altering the original appearance of uniformity. in areas less exposed to sunlight and in the basement, the bright green color of the wall denotes the presence of moss. conspicuous are also the oxidation of the elegant wrought iron gate, now largely damaged. the deposits in various shades of light green present on angular slabs finely decorated with bas-relief bronze contrast chromatically with the brown base. these deposits are due both to the deposit of dust as well as other pollutants in the atmosphere and to the chemical attack by leaching meteoric material. also noted is manmade degradation, mainly present on both the stone wall and on the entrance gate, where there are a number of holes, perhaps due to a criminal act such as the discharge of firearms [vergès-belmin 2008]. 6.3.1 impact damage: bullets description: any alteration or loss of material in a built heritage, clearly due to a mechanical action or manually induced. causes: lack of maintenance and neglect; vandalism; wars and/or fires. 6.3.2 soiling by rainwater description: deposit of a very thin layer of exogenous particles giving a dirty appearance to the stone surface. the contaminants are transported to the surface by dry deposition or wet deposition, such as rainwater intrusion. water pathways are often limited to narrow stripes on the stone cornice, along a well-shaped edge. causes: presence of biodeteriogens; atmospheric pollutants (soot and dust); hydration (some minerals change their color when in contact with water, changing the colors of the structure); staining from water absorption: damp areas; minerals that exhibit a color change when exposed to light, heat, radiation; chemical assault caused by run-off rainwater (acid rain) and deposit of atmospheric particles; differentiated support absorption. 6.3.3 disintegration and powdering description: loss of cohesion or granular disintegration of finely grained stones. causes: thermal stresses; water leakage and capillary rising damp; presence of biodeteriogens; crystallizations of soluble salts; freezing/thawing cycles. 6.3.4 blistering description: separated, air-filled, raised hemispherical elevations on the face of the stone resulting from the detachment of an outer stone layer. this detachment is not related to the stone structure. causes: soluble salts; rising humidity phenomena; solutions of continuity resulting from the presence of cracks and/or lesions; different dilatation between structural materials and finishing; solutions of continuity consequent to mechanical vibration; installation errors in work and little use of sand or suitable mortar. 6.3.5 fragmentation chipping description: the substrate remains apparently sound on both side of the detachment plane. the stone breaks into portions of variable dimensions that are irregular in forms, thickness and volume. we can see two types of detachment: first chipping and then blistering. causes: strong presence of rising damp; obvious phenomena of salt infiltrations and formationof efflorescence; ice on the surface layers; detachment caused by cracks or fractures; relative expansions between supporting materials and finishing; detachment caused by stress and mechanical vibrations; errors in use of unsuitable sands and mortars. 6.3.6 encrustation description: coherent layer, generally adherent to the substrate, composed by inorganic chemical or biological systems. causes: humidity; atmospheric pollutants (soot and dust); chemical assault caused by run-offrainwater (acid rain) and deposit of atmospheric particles; water leaking. figure 10. deterioration mapping of the facades of the bartolani chapel. 6.3.7 oxidation description: metal oxidation takes place on a metal's surface, especially on copper, iron, and the various alloys while oxygen is present. exposed metals are affected by various conditions such as water, air, soil, sulfur compounds, acids, oxidizing agents, salt solutions, organic materials, etc. rusting is the common term for corrosion of iron and its alloys, such as steel. this type of damage typically produces oxide(s) or salt(s) on brass, bronze and copper. causes: presence of biodeteriogens; weathering exposure; material roughness. 6.3.8 discoloration staining description: chromatic alteration that may affect the surface. causes: presence of biodeteriogens; presence of damp patches; high humidity and poor ventilation (dark mold stains); oxidation of metal elements such as iron (linchpins, planks, u-bolts, clamps, gratings) and copper. 6.3.9 missing parts description: detachment and loss of parts. a generic term used when the kind of degradation is difficult to describe. causes: human activity; presence of strong rising damp; structural problems; detachments caused by crack or fractures; detachments caused by thermal shock close to metal components; errors in use of unsuitable sands and mortars. 6.3.10 moss and lichens description: presence of moss, lichens and plants on the stone. causes: spores and seeds settle on the stone surface, in fractures and/or cavities; concurrence of conditions, such as enough light anto photosynthesize optimally, air (carbon dioxide and oxygen), water for metabolic processes, minerals and alkaline ph. 6.3.11 biological colonization description: thin covering or coating layer, generally of an organic nature, generally homogeneous, generally green. a biofilm consists of very few cells of different microorganisms and it often creates multicolored biopatina. causes: metabolism of microorganisms present on a stone; morphological characteristics of the substrate (roughness, harshness, recesses); high relative humidity; presence of minerals. 6.3.12 cracks and hair cracks description: degradation that occurs in the detachment of materials. it can induce a mutual displacement. causes: thermal shocks and cycles of freezing and thawing; structural problems and instability of loadbearing walls; mechanical and physical contrast between load-bearing walls and finishing; corrosion of iron parts; different thermal expansion between load-bearing walls and finishing; interface decay between brick and mortar; weed roots. 7. comparing deterioration phenomena and architectural form in the same area of the cemetery is located the chapel of the toja family, designed by fantappiè, and very similar in materials and design to the bartolani chapel. in order to better understand the relation between architectural form and deterioration risk, the two chapels, were globally observed for their shape and building materials, and then were analyzed with respect to three of their main degradation phenomena. 7.1 the toja chapel by e. d. fantappiè in the cemetery of the holy gates florence the architect of the toja chapel was fantappiè; it was built in 1910 by sandrini. the chapel is characterized by its regular geometric structure: it has a square shape and in structure and decorations it reflects the typical features of secessionist architecture. the building has a monumental entrance, marked by a short staircase in serena sandstone blocks. it is bordered by two wings decorated with a band that continues along the walls of the building. the gate has a pediment decorated with carved geometrical elements. the copper cover is bounded by a high leap. the side elevations have no openings because there are burial niches in masonry along the inner walls. 7.2 examples of similar decay phenomena the problem of lack of maintenance, which also afflicts this chapel, suggests some reflections on the stone material with which they were both built and on their deterioration, one century after construction. a comparison between the two chapels is a useful starting point for consideration of the serena sandstone and its deterioration phenomena. used since the archaic period, this stone reached its peak in florence when it was used by filippo brunelleschi for its peculiar characteristics. figure 11. the toja chapel – entrance. 7.2.1 the copper roof the consequence of the separation between the copper roof and gables can be seen in the different colors of the façade: dark gray where rain water continued to flow and beige in protected areas, although still characterized by patina or by the staining of the decorative elements. figure 12. the roof covering and its related degradation: bartolani on the left and toja on the right. quite the same phenomenon happens in the toja chapel, where the color difference is very clear, both in the central part of the gable and under the corner, where are four antefixes. in the two chapels it should be noted that in the two chapels the water drainage system is the same. 7.2.2 the angular gables from what one has seen before, the attention of fantappiè to the details of corner solutions is quite clear. these laudable and refined decorative elements, however, are not in the same way accompanied by equally detailed care in protecting them from the bad weather conditions. figure 13. the angular solution of the two chapels:bartolani on the left and toja on the right. paying attention to the two solutions shows that in the toja chapel the disintegration and the powdering of the angular area below takes place on a lower level than that of the bartolani chapel. this difference could be due to the slight difference in the geometry of the two cornices. 7.2.3 the back wall of the chapels the two chapels are both characterized by a high rear window. another similarity on the backside is the presence of dripping rainwater that carried with it part of the colors and materials of the cornices and the overlying decorations. figure 14. the back wall of the two chapels: bartolani on the left and toja on the right. even in this case, as to the staining by oxidation, the similarity of the deterioration is geometrically evident: the most protected area has maintained a light gray to beige; the most affected area has changed its color in a mixture of dark gray and moss green. 8. conclusions the holy gates cemetery, a central place for the religious life of florence, marked a focal point for the history of the city and its evolutionary process, becoming a monumental emblem of our cultural heritage. at the beginning of the twentieth century this cemetery provided an opportunity for many architects to research and experiment with a new modern style. enrico dante fantappiè built several chapels for rich customers with similar materials and architectural composition, including the two examples analyzed here, the bogliaco bartolani chapel and the toja chapel. nowadays many things are changing; the wealthy families of the last century have no successors and for this reason their memory will be lost due to the state of abandonment of their tombs. most of the chapels, which in the past were architectural jewels, today show signs of degradation. in some cases, the chapels conserve their original features, especially if family members who can maintain them are still living or if the funeral tombs were bought by other people and restored. a possible solution to avoid losing the abandoned part of the cemetery is the public general conservation intervention of this architectural heritage that belongs to the collective community. public institutions could support the costs of maintenance, verify property issues and identify operating and economic modalities. in particular the method illustrated for the specific study of the bogliaco bartolani chapel could be extended to other funeral architecture in this cemetery, beginning with a quickly organized survey and photogrammetric campaign and proceeding with a deep observation of damage. in this case the speedy survey could be implemented by new diagnostic methods, since in fact every chapel has different characteristics, peculiarities, materials and degradation phenomena. the most important monuments of florence, as well as most of the chapels of the holy gates cemetery were built with serena sandstone, a typical material of the region that was employed over the centuries in architectural traditions. the detailed study of this type of stone could be helpful for understanding similar use and degradation phenomena in other monumental architecture. to conclude, a specific and correct analysis of the geometrical characteristics, material texture and state of deterioration allows us to identify correct restoration techniques and an efficient maintenance plan to preserve an important collection of monumental architecture. 9. references stefano bertocci and marco bini marco. 2012. manuale di rilievo architettonico e urbano. novara: cittastudi. rossana bossaglia. 1987. archivi del liberty italiano: architettura. milano: franco angeli. luciana cappacioli and luigi lazzareschi. 1999. la città e i luoghi di sepoltura. firenze: giunti gruppo editoriale, 14-26, 73-77, 107-109. giovanni carbonara. 2001. trattato di restauro architettonico. torino: utet. graziella cirri. 2003. guida ai cimiteri comunali di firenze. firenze: polistampa. 7-28, 41, 71. carlo cresti. 1991. firenze 1896-1915: la stagione del liberty. firenze: alinea, 62, 315. maria adriana giusti. 1996. le età del liberty in toscana. in proceedings of the conference in viareggio, 29-30 september 1995. firenze: octavo franco cantini editore. angela mancuso and andrea pasquali. 2015. different ways lead to different results? experiences on modern photogrammetric surveying on cultural heritage subject. in proceedings of the 19th international conference on cultural heritage and new technologies 2014 (chnt 19, 2014). vienna: museen der stadt wien–stadtarchäologie. gigi salvagnini. 2001. porte sante:il cimitero di san miniato a firenze. firenze: opuslibri, 7-26, 105, 109, 156-158. giorgio verdiani et al. 2016. il battistero di biella forma archittetonica e modelli di riferimento. in confronti 10. romanico piemontese–europa romanica. architetture, circolazione di uomini e idee, paesaggi. livorno: debatte. torelli vieri. 1913-1914. l'edilizia moderna a firenze. in annuario dell'edilizia moderna. milano: g. a. lombardo editore, 62-77. véronique vergès-belmin. 2008. illustrated glossary on stone deterioration patterns-glossaire illustrè sur les formes d'altèration de la pierre. english-french edition. paris: icomos (international council on monuments and sites) and iscs (international scientific committee for stone). received march 2017; revised july 2017; accepted august 2017. archiving archaeological research data. on requirements, objectives and first experiences from a german respectively saxon point of view reiner göldner, saxon archaeological heritage office, germany preserving digital data over long periods of time is an ambitious task. while most analogue documents are best stored without touching them, digital data need permanent care and curation. regarding some differences between analogue and digital data-lifecycle, complexity, functionality and so on-it can be seen that digital archiving is a new challenge. this paper will deal with the requirements and objectives of archiving archaeological research data, as discussed in a working group of the association of state archaeologists in germany (verband der landesarchäologen in deutschland vla). interesting themes of the discussions were "archive objectives," "worthiness of archiving," "suitability of archiving" and "future use scenarios." this paper will also deal with first experiences in building up a digital archive for archaeological research data in saxony. the archive follows the principles of the "open archival information system" (oais). it is based on professional software that has to be adapted to the special requirements of archaeological data such as excavation documentation. oais defines various complex functions to be performed, e.g., data management and preservation planning. preservation strategies are presented here to give an idea of how to preserve the content and function of archived material while the systems for archiving are changing over time. this is an alternative to the idea that knowing file formats will solve all preservation problems. archiving is the most intensive and most expensive way to store data. but are there no alternatives? this paper will address some small steps that lead towards proper archiving without large budgets. such steps will help to reduce the risk of losing important digital information, and will also bridge the gap until proper preservation tools become available at a reasonable price. this article may be helpful for archaeologists that are about to build up an archive to preserve digital data for the long term. the concept of preservation strategies presented here may also be of interest for specialists in digital archiving. key words: archiving, long term preservation, archaeological research data. sdh reference: reiner göldner, archiving archaeological research data. on requirements, objectives and first experiences from a german respectively saxon point of view,2017. sdh, 1, 2, 17pages. doi: 10.14434/sdh.v1i2.23205 author's address: reiner göldner, landesamt für archäologie sachsen, zur wetterwarte 7, 01109 dresden, germany; email: reiner.goeldner@lfa.sachsen.de. permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal 1. introduction this paper is about archiving digital archaeological research data that typically emerge from archaeological excavations and research projects. archiving is considered to be long term preservation that is not limited in time. archiving means to permanently preserve the content and function of digital data and to provide access to it. in contrast to other views about archiving, the main difference is that curation (realization of preservation planning, preservation strategies) is included. because of the curation effort, it can be stated that archiving is the most intensive and most expensive way to store and to preserve data. this paper results from two main working processes in which i participated, that took place almost parallel to each other and inspired each other in many ways. first, a working group within the association of state archaeologists in germany held an intensive discussion on archiving digital data, starting with several details about file media and file formats and later reaching more general aspects like objectives and requirements. this discussion was very important because until now there has been no full digital archaeological archive at work in germany, neither centralized nor regional. thus, all participants were very interested in finding ways to better preserve the unique archaeological data for the long term. secondly, the saxon archaeological heritage office decided to take the first practical steps in the field of digital archiving, in order to get practical experience in this field. dealing with a real digital archiving system quickly revealed problems, e.g., the effort to basically run the system and the lack of specific preservation strategies for our data. the work on appropriate solutions led to my ideas about preservation strategies and about small steps towards archiving. this article may be helpful for archaeologists who are about to build up an institutional archive to preserve digital archaeological research data for the long term; the paper offers some helpful ideas about basic objectives and requirements. if they have rather small budgets, some advice is given regarding small solutions. there is also a part that may be of interest to specialists on digital archives. this section about preservation strategies presents a new conceptual framework designed to deal with several kinds of archival material, and it is an alternative to the idea that knowing file formats will solve all preservation problems. the first topic to be discussed, "objectives and requirements," contains results from a working group of the association of state archaeologists in germany. it can be seen as a consolidated view of several specialists with a focus on some more general aspects of archiving, i.e. archival objectives and requirements. the next topic, "preservation," contains a very short introduction to the well-accepted reference model oais (open archival information system) and some ideas about preservation strategies that describe how to curate and preserve the content and function of archived material while systems are changing over time (assuming a migration method). two years ago, the saxon archaeological heritage office started the project "archiving archaeological research data" with the aim of studying the opportunities and risks of operating a digital research archive. the third topic to be discussed concerns "first experiences with implementation" of this archive. for all those who work with small budgets "small steps towards archiving" are presented at the end. taking such steps will help to reduce the risk of losing important digital information and will bridge the gap until proper preservation tools become available at a reasonable price. the aspects presented in this chapter are based on ideas i collected from my own work, from the discussions at the working group of the association of state archaeologists and from third parties, e.g., gollins 2009. figure 1. project teaser "archiving archaeological research data" (© photo/assemblage r. göldner) 2. objectives and requirements the information in this section is the result of intensive conferencing and discussion at the thematic working group of the association of state archaeologists in germany [archiving group of vla]. thus, it can be seen as a consolidated view of several specialists (from six german states) that actively address digital archiving in their work. the main goals of that working group were to exchange knowledge and experiences of its members in the field of digital archiving, to bundle archival expertise of the decentralized system of german state archaeology and to support those archaeologists or institutions that are willing to take some first steps towards digital archiving. after dealing with many special questions of digital archiving, like data formats and secure storage, the working group focussed on some less technical and more general aspects that are important in running a digital archive as an organization, i.e. archival objectives and requirements. the following sections present important results of the discussion. these results and some other interesting questions (e.g., should additions, corrections, and editing of archaeological archive material be allowed? what does authenticity mean in relation to digital archive material? what about usage rights for the archive?) can be found in "ein erfahrungsaustausch zur archivierung digitaler archäologischer daten ..." [göldner 2016]. 2.1 archive objectives the archiving group of vla stated the objective of an archaeological archive as follows: the aim of digital archiving is to permanently preserve digital content and digital function of archived material and to provide access to it [göldner, r. et al. 2015, 5]. to clarify the difference between "content" and "function" in this context we assume that "content" is information that is used by people, visual or sensory, and that "function" is information that is used by machine, operational or algorithmic. this objective can be detailed a little more: to securely store the material (prevent damage and loss); to regularly curate the material and to restore or renew it, if needed; to index and register the material; to present the material and to make it accessible. with regard to the use of archived material, archaeological archives are considered as information sources for: the present work of archaeological offices heritage protection and conservation publication and presentation future study and research 2.2 archival value archive material is material of archival value that is suitable for archiving. archival value answers the question "which material, which content, which function is worth of archiving?" and suitability for archiving answers the question "which material is suitable for archiving from a technical point of view?" in general, material is worth archiving if it has ageless, steady value to society. in most cases, "steady value" is interpreted to mean that the material is of particular importance, i.e., it is more prominent than the average material. archive material is a selection of material, because in general not all existing material is worth archiving. in practice, this requirement has to overcome two challenges. first it provokes the opposition of people that cannot throw things away, and second, it demands discussion and establishment of criteria to appraise the potential of the archive material. this general statement can be applied to typical archaeological institutions; the archiving group of vla mentions the following criteria: if it supports future study and research; if it documents heritage that cannot be preserved itself; if it documents ephemeral archaeological situations or activities (e.g. excavation documentation); if it supports heritage protection and conservation; if it is a result of archaeological research. on the other hand, examples of material that is not worth archiving are given: drafts, duplicates, intermediate states, incomplete, faulty or unfinished material. archivists have to check the archival value of the material under consideration. to do so they need archaeological expertise and they have to negotiate specific criteria for specific materials with the producers (i.e., archaeologists). archiving is the most intensive and most expensive way to store and to preserve data. thus, criteria for archival value are needed in order to use existing but limited archival resources in a most effective and reasonable manner. 2.3 suitability for archiving besides archival value there is another aspect to preselection of archive material: which material is suitable for archiving? the answer depends on formal, technical aspects of the archive material, such as type, complexity, connectivity, interoperability and other factors. all these factors affect the preservation strategy, so we can state that material is suitable for archiving if the archive has a reasonable (and specific) preservation strategy for it. from my point of view, an archive must not accept any material for which it does not have any basic preservation strategy. this is a critical aspect, because it requires the archive to integrate competencies of both information technology and the application field (archaeology), a requirement that archives are not able to fulfill. 2.4 future use scenarios more than traditional analogue archives (because digital material ages faster), digital archives have to be concerned about scenarios of future use. but interestingly, there seems to be a lack of imagination; my question about future use was very often answered with the words "just like now." but this answer does not much to establish criteria for preservation strategies that have to guarantee adequate use in 100 years. but let us have a look at some basic ideas we discussed at the working group, with the result that the question of future use scenario was answered as follows. how will the archived material be used in 100 years? it is passively used as information (overview and detail), that is, for instance, in the fashion of articles in popular or scientific journals. it is actively used for scientific re-analysis, i.e., to deeply analyze the archive material with scientific methods and tools with the goal of creating new scientific results. which future use types are possible? visual use, like viewing and reading, maybe also printing, is easy to imagine. machine analysis of texts is quite clear, and may be supplemented by image analysis or similar tasks. functional use with special application software (cad, gis, etc.) is hardly predictable even for few years, but it is and it will be the most interesting use type of digital data. imagining future use scenarios varies according to three hypotheses: future use scenarios will be limited to present use scenarios, regarding the presently collected information. questions of future generations are hardly predictable. probably the data will appear to future archaeologists as a heterogeneous data mound. with a maximum of collected information (more than presently can be used), there will arise new use scenarios in future that we cannot foresee today. 3. preservation in general, there are four preservation methods for digital data, and they all have advantages and disadvantages. the hardcopy method tries to generate a copy of the data at a durable medium like paper or pet microfilm. it is very durable (le500 material is guaranteed to survive at least 500 years), but it needs appropriate storage areas, and it is not well suited for functional data. the technology preservation method tries to preserve current hardware (and software) as long as possible for future use. similar to this approach, the emulation method emulates old computer hardware with modern software and modern hardware. both methods provide an adequate system environment for old data but they are rather complicated and expensive. the migration method uses regular adaptions of the archive data to new computer systems. it is a very flexible and powerful method, hence it is often preferred. the migration method depends on appropriate ways to migrate the archived data without loss of significant content and function. most information in this field is available for preferred data formats, so migration seems to depend on data formats. but this strategy does not fit all needs of archived materials; complex and functional data especially need more complex preservation strategies. as an alternative, a small conceptual framework of four preservation strategies is presented below. these preservation strategies depend on archive material types and lead to several types of archive representations. they also use preferred data formats, but not as a key issue. this section addresses two important aspects of preservation. the first is the well accepted reference model oais (open archival information system), with a short introduction to its functional model. the second aspect refers to preservation strategies that give an idea on how to preserve the content and function of archived material while systems are changing over time. these preservation strategies are the heart of every digital archive, because they guarantee the survival of the archived material. 3.1 open archival information system oais the most important concept for building up and running a digital archive is called "oais", which stands for "open archival information system" [oais magenta book]. oais is a reference model (framework) for an archive to provide long term preservation of archived material. oais describes an archive as an organization that combines people and systems. it provides an information model and a functional model and it determines responsibilities. oais is an iso standard (iso 14721) which is well accepted worldwide. an overview of the oais functional model is shown in figure 2. the functional entities are: ingest: transfer of the archive material from the producer as sip (submission information package) containing both data and metadata to the archive archival storage: securely stores material as aip (archiving information package) and provides data for access and for preservation processes (e.g. migration) data management: organizes all kinds of metadata and descriptive information regarding the archived material administration: manages the operation of the whole archive preservation planning: supports all tasks to keep the archived material accessible and usable over the long term, e.g. preservation strategies, technology monitoring and risk analysis access: allows users to retrieve data and relevant information from the archive as dip (dissemination information package) figure 2. functional entities of oais ([oais magenta book] page 4-1, figure 4-1) 3.2 preservation strategies preservation strategies give ideas on how to preserve content and function of archived material while systems are changing. an archive needs an initial preservation strategy for each data type that will be archived. from my point of view, there are four abstract types of preservation strategies that are listed below on table 1. the first data type is used for simple visual data. the main aim of this data type is to be perceived (viewed or read) by people. to preserve these data types (and only these) it is sufficient to consider the file format and to comply with approved preservation formats. the second data type includes functional aspects. the purpose of such data is to be interpreted by machine and to provide some (simple, common) algorithmic and operational capabilities. preservation of simple functional data is also orientated by approved file formats, but it additionally needs a careful description of the data structure and context. beyond that, an informative visual representation is recommended. the third data type involves all kinds of systematic, structured information (e.g. lists of archaeological finds, descriptions, geodata). such information will be mapped into standardized datasets and stored in permanently operated server databases. the operation of a server database includes regular data migrations, so it can be considered a good archive. the fourth data type typically contains several files with diverse interconnections and functional and interoperable characteristics. such data typically needs a specific system environment and specific software to be used (e.g. a combination of cad-drawing and georeferenced raster images, used in archaeological excavation documentation). in order to preserve such data, it is recommended that a representation be built that is abstracted from softwarespecific overhead. of course, a careful description is needed and a visual representation should be stored as well. in addition, the original must be kept as long as the required system environment exists. table 1. types of preservation strategies archive representations support various future use scenarios. in the context of preservation strategies, we use the following archive representations: visual representation: for long term use with standard viewing. abstracted functional representation: for long-term functional use after individual customizing. original data: for short term use with an original live system. datasets: for special database use. to use this concept in practice, more specific preservation strategies are needed. the abovementioned types have to be specified in detail according to real data. only the strategy for simple visual data types is nearly ready to use. be aware that without specific preservation strategies curation will collapse. "archiving" is differentiated from "storing" by having sufficient preservation strategies (or preservation planning). from this perspective, preservation strategies are the most important aspect of archiving. 4. first experiences with implementation after some years of theoretical discourse, in 2014 the saxon archaeological heritage office started the project "archiving archaeological research data" with the aim of implementing its own digital research archive. endowed with rather small resources, it took some time to go into production with the first archive service for general material (this is simple and unspecific visual material without any institutional policies and workflows). the current work is to configure the second archive service: excavation documentation. this is not so much a technical problem, but rather a problem of preparing data to be suitable for archiving. the following section presents the first experiences with the implementation of this archive. we began the project with some ambitious ideas about digital archiving. this was preceded by several theoretical discussions about digital archiving (within the archiving group of vla), leading to some reasonable drafts and papers [göldner et al. 2015]. from this starting point, we wanted to gain practical experience and so we decided to acquire an oais compliant archiving system, to implement it with the help of the vendor and to configure it to archaeological material. but soon we reached limits. contrary to the idea of having an easy to use software system that would archive almost all of our data without unreasonable effort, we failed in archiving simple tiff images. during the next months, we learned much about technical aspects of archiving, like tiff file tags. but we also had to revise our theoretical concept. after capturing the structure and requirements of our present excavation documentation we had one big problem: there is quite a lot of digital data that can’t be archived by a simple preservation strategy based on file formats. a solution is the concept of preservation strategies that is presented in the previous section. initially the project combined the skills of archaeology and information technology. but soon it became clear that archiving skills are very helpful as well, for instance, to understand the archiving system workflows. i have often been asked for some basic advice to start digital archiving, and so, based on the first experiences, i try to outline two aspects, important from my point of view, in the following sections: how to become an archivist (collecting skills and performing first tasks) and to follow oais (select reasonable tasks). 4.1 to become an archivist always start with a clear archiving task. archive objectives should be discussed with the stakeholders. there should be clear ideas about the archived material, producers and future users. and of course, there should be some basic resources to start archiving. archives require competent staff. to build up and run a digital archaeological archive you need three skills, archaeological, archival and it-related skills. normally it is not a problem to access archaeological skills at archaeological institutions. but there are also quite a number of tasks for trained archivists, like supporting producers and end users, managing data and metadata, organizing curation and preservation and much more. if there is no professional archivist available, try to get some training. and there are also quite a number of specific it tasks, e.g. to understand data and data formats, to securely store the archived material and to professionally run migration processes if needed. take into account the fact that archaeological and archival aspects interact and that they may be contrary. for example, many archaeologists like to preserve all produced data indefinitely. but they have to discuss issues of archival value and the suitability of data for archiving with archivists. to get training in digital archiving, look at global players, such as digital preservation coalition [dpc], open preservation foundation [opf], the "nestor" network of competence [nestor], the national archives [tna], national library of new zealand [ndha] or the slubarchive dresden [slubarchiv]) read some guidebooks , such as "digital preservation handbook" [dpc], "guides to good practice" of the archaeological data service [ads-g2gp], "it-empfehlungen für den nachhaltigen umgang mit digitalen daten in den altertumswissenschaften" of the german archaeological institute [ianus-it], "nestor handbuch" [neuroth 2010] or "ratgeber zur archivierung digitaler daten" [göldner et al. 2015]) and be sure to be inspired by the ideas of open archival information system [oais]. also be aware of the archaeological archives and related projects like ads, arches, dans, ianus and the archiving group of vla. 4.2 to follow oais the oais model is not a simple approach. as presented above, oais provides a broad framework with many archiving tasks. so it is necessary to adopt this framework to the needs of the particular archive. according to our experiences there are some hints and warnings regarding this process: you cannot buy a ready-made archive. you only can buy some components that help you to operate an archive. do not underestimate the effort to run a real archiving system. have a look at those who run a real archival system, like ads or dans. archiving is the most intensive and most expensive way to store and to preserve data. that is mainly because of the need for preservation planning and continuous curation. it is unlikely that you will be able to implement an archive all at once. that would be too complex, so try to build small and simple partitions. so, my recommendation is to gradually implement the oais: apply criteria of archival value to select archive material. reduce the number of data formats and use data types that are as simple as possible. be sure to have an initial preservation strategy for each data type that will be archived. use the available infrastructure as well and intensively as possible (corporate storage, tape archive, virus check, etc.). keep an inventory with descriptive (e.g., subject), technical (e.g., format) and organizational (e.g., access rights) metadata. because technology does not solve all archiving problems (neither does oais certified software), there is a notable "manual" effort: to establish appropriate archive objectives and requirements (remember the aspects of preserving content and function, of archival value and of future use scenarios outlined above in section 2); to manage the "oais" and to organize all tasks (think about data ingest, maintaining descriptive information, quality checks, storage management, preservation planning, risk analysis, data curation and migration, providing search and access capabilities, daily system operation and so on; see also section 3.1); to develop and maintain acceptable preservation strategies (as described in section 3.2; such strategies depend on the type of archival material and have to be specified according to real data); and to apply them (concerning migration methods it must be guaranteed and proved that all significant features and functions are preserved with regard to future use scenarios. these operations have to be planned, performed and documented with much care and competent staff is needed for all curation tasks). 5. small steps towards archiving as already stated, archiving is the most intensive and most expensive way to store data. but are there no alternatives? this section will address some small steps in the field of digital archiving without having large budgets. taking such steps will help to reduce the risk of losing important digital information. they will also bridge the gap until proper (certified) preservation tools become available at a reasonable price. i would like to combine this section with a warning. david rosenthal said: "especially in the current difficult funding situation, it is important not to give the impression that we can ‘preserve’ digital information with ever-decreasing resources, because then what we will get is ever-decreasing resources. … i'm sorry, but preserving this stuff costs this much. less money, no preservation, just storage." [rosenthal, 2017]. i endorse rosenthal’s view; however, i know some institutions that are far from any adequate funding situations, but which want to take small steps. so, keep in mind that this is not a finished solution but a way to approach the goal. 5.1 responsibility and competency no matter whether you plan a project or a permanent business, start with a clear archiving task that is supported by relevant stakeholders. after that you need someone who is responsible for this task. and, of course, there have to be some basic resources like working time and it infrastructure or some money to pay for appropriate services. moreover, you need competencies in archaeology, in archiving and in it. think about training and self-study to gain the necessary expertise. there are many projects and institutions that share their broad experiences of archiving; please see section 4.1 "to become an archivist" to find suggestions. be sure to have the above-mentioned competencies or at least be sure to know someone with these competencies. 5.2 archival objectives a leading principle in the field of archiving is to permanently preserve (digital) archaeological material with enduring value to science and society. this implies a selection of material. think about these questions: which records have archival value? which criteria could be used to prove that? therefore, minimal quality management is needed. some simple criteria may be: unique scientific results are worth archiving. documentation of heritage that cannot be preserved is worth archiving. not worth archiving are materials like drafts, duplicates, intermediate states, incomplete, faulty or unfinished material. never aim to archive "all" data right from the beginning, because this most probably would lead to a curation collapse due to overwhelming curation efforts. 5.3 secure storage a very basic task is to securely store digital data. fortunately, storage technologies are now advanced enough, so it is not very complicated to obtain some kind of secure storage, if you consider the following tips. don't use any removable media, because the chance to detect and fix errors is slim. use an available corporate storage, data center or online storage that is managed by professional it staff. such systems should use redundancy (e.g. raid), and backup (e.g. tape backup). to achieve even more security, you may ask for geo redundancy with two or more storage systems at distinct locations, but that is a rather high-level requirement. think about signatures or checksums to check and prove integrity. think about virus checks to prevent malware from being archived. within the oais reference model these aspects are addressed in the section "archival storage function." 5.4 complete inventory another important element is an archive inventory that helps to find and manage data. without any inventory, searching would be complicated or impossible. some basic metadata has to be recorded for every entity of archived material; usually it is differentiated into descriptive, technical and organizational information. first, you need descriptive metadata. see the core elements of the dublin core standard [dc] to get inspired. think about creator, title and subject as minimum. you may need some additional key attributes to link to important resources outside the archive. second, technical metadata are required. this includes the original filenames (and possibly a structure map of a set of files and directories), the data format (best to use the pronom identifiers) and the dates of creation and modification. some tools to detect data format and checksum are freely available (e.g. droid). and third, you need some organizational metadata with access rights, copyrights and retention policies. to store these metadata, any kind of available document management system would be helpful. but in many cases a structured file system would be sufficient, if file names and directory names include basic meta-information. this could be complemented by some details stored as spreadsheets (e.g. the inventory of a directory). in regard to the oais, the inventory addresses the "data management function" and the "access function." 5.5 smart curation as outlined above, preservation strategies are very important to long term preservation. but how to keep them simple and inexpensive? the best way is to avoid complex data types and to restrict archival material to only a few simple data types (see table 1 above). you may follow this advice for smart curation: reduce the number of your data formats to reduce curation costs. only use simple data formats, because there are simple preservation strategies for them. understand your file formats as well as possible so that you can detect preservation risks. observe changes in technology regarding the archived data formats. migrate obsolete data to contemporary formats. remember to test all migration steps and to prove the preservation of content and function. document all migration steps. do not forget the different types of archival representations (see above), as you may benefit from using more than one: original data, visual representation, abstracted functional representation and dataset. for example, think about a ms access database file; with some tables of data, some data entry forms and some reports for presentation, this file is the original data representation. a set of reports with all important data may be printed or exported to files using pdf/a format, which is a visual representation. all tables may be exported to files using xml/xsd, completed by a structural description, that is an abstracted functional representation (that does not care about software dependent user interface). the oais preservation strategies are part of the "preservation planning function." a basic set of preservation strategies follows: use well accepted archive formats for simple files at visual standard formats: store text files at pdf/a format, store image files at uncompressed baseline tiff format, store drawings at svg. use less well accepted archive formats for more special files at functional standard formats, add a visual representation and a clear description of the data structure store spreadsheets at csv or xml format using utf-8 encoding, store cad data at dxf format and add characteristic plans at pdf/a or tiff format (and maybe store the original), store geodata as shapefile or gml and add characteristic maps at pdf/a or tiff format (and maybe store the original). put systematic information into systematic data structures (datasets, geodata) and use permanently operated server databases to store systematic, structured information. the idea of preserving digital data without large budgets is not new. my first ideas were presented at chnt 14 [göldner 2010], not so far from the revision presented here. another interesting approach is "parsimonious preservation" [gollins 2013, gollins 2009], that argues against overestimation of risks like storage disaster and format obsolescence. this is very helpful, but carefully read the chapter "something to note" at the end of gollins 2013. gollins’ ideas are about a "foreseeable future (5 to 10 years)" and do not include any preservation strategies. that is not sufficient from my point of view, because problems are delayed but not solved. my clear recommendation is to have appropriate preservation strategies from the beginning. the operation of archive systems is costly, even if you try to save money as mentioned above. thus it may be interesting to regard alternatives: use shared or cloud systems and look for service providers for system parts like storage or for a whole digital archive. in this case pay attention to certifications like the "data seal of approval" [dsa], "trustworthy repositories audit & certification" [trac] and "nestor-siegel für vertrauenswürdige digitale langzeitarchive" [nestorseal] and in addition pay attention to an existing exit strategy (to preserve your data beyond the life of the service provider). the hope remains that professional and subject specific (or adjustable) archive services will come into being in the near future, so that smaller institutions could benefit from this development. 6. résumé considering requirements, objectives and first experiences in the field of archiving archaeological research data, i would like to put a warning first: there are three critical ways to cause a "curation collapse" at the archive: ignore archival value. accept unsuitable material. operate without a preservation strategy. on the other hand there is the oais reference model, a basic framework for long term preservation. there is a lot of expert knowledge and experience and there is even oais compliant software available now. if you intend to start digital archiving without a big budget, remember these useful and small steps towards archiving: set responsibility and gain competency; establish archival objectives; care about secure storage; build a complete inventory; develop preservation strategies; perhaps that is not a perfect archive, but these steps prevent the occurrence of the main preservation risks with reasonable effort. these steps are also a very good preparation for migrating available data to a professional archive system. so, start now, find someone responsible, build up an archive step by step and preserve your digital assets for the long term. 7. references list of references tba reconstructing pre-industrial long-distance roads in a hilly region in germany, based on historical and archaeological data irmela herzog, the rhineland commission for archaeological monuments and sites, germany the aim of this contribution is on the one hand to map pre-industrial long distance roads located in a hilly region east of cologne, germany as exactly as possible and on the other hand to assess the accuracy of least-cost approaches that are increasingly applied by archaeologists for prehistoric road reconstruction. probably the earliest map covering the study area east of cologne dates back to 1575. the map is distorted so that rectification is difficult. but it is possible to assess the local accuracy of the map and to transfer the approximate routes to a modern map manually. most of the area covered by the 1575 map is also depicted on a set of more accurate maps created in the early 19th century and a somewhat later historical map set (ca. 1842 ad). the historical roads on these rectified historical maps close to the approximate roads were digitized and compared to the outcomes of least-cost analysis, specifically least-cost paths and accessibility maps. based on these route reconstructions with limited accuracy, lidar data is checked to identify remains of these roads. several approaches for visualizing lidar data are tested to identify appropriate methods for detecting sunken roads. possible sunken roads detected on the lidar images were validated by checking cross sections in the digital elevation model and in the field. key words: historical maps, lidar data, least-cost analysis. sdh reference: irmela herzog. 2017. reconstructing pre-industrial long distance roads in a hilly region in germany, based on historical and archaeological data. sdh, 1, 2, 642-660. doi: 10.14434/sdh.v1i2.23283 1. introduction the aim of this study is to analyze the potential and limits of the combination of two approaches that are frequently applied in archaeological research to reconstruct the exact location of old routes: leastcost analysis and detection of archaeological sites using high resolution digital elevation models, derived from airborne laser scanning missions data (lidar data, also known as als data). the test case consists of the roads depicted on a historical map created in 1575. this map covers about 500 km² in a hilly rural region east of cologne, germany (figs. 1a and 1b). for the last decade, both author's address: i. herzog, lvr-amt für bodendenkmalpflege im rheinland, endenicher str. 133, 53115 bonn, germany; email: i.herzog@lvr.de permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal least-cost analysis and the applications of lidar data have become increasingly popular, resulting in a multitude of archaeological case studies. due to distortions and several other reasons, only the approximate modern location of the roads depicted on the map created in 1575 could be reconstructed. the initial hypothesis of this study expected that least-cost paths (lcps) close to the approximate old roads indicate the location of these routes more precisely. moreover, sunken roads with similar direction and close to the approximate old roads should indicate the exact location of the historical roads. therefore, the areas close to the approximate old roads were inspected in visualizations of the lidar data, and possible sunken roads were digitized. the issues of transferring the roads depicted on the map created in 1575 to a modern map are discussed in the next section. the section also introduces several later historical map sets that provide additional information on the location of the features depicted on the map created in 1575. transferring or digitizing selected old roads from these maps results in route bundles that allow assessing the local accuracy of these road reconstructions. the subsequent section presents lcps generated by applying three slightly different cost models. the lcps connect pairs of settlement locations that are close to the approximate historical routes. most of these settlements were already recorded in historical sources dated before 1510 ad. moreover, an accessibility map based on one of the cost models shows possible corridors for the historical routes. another section investigates adequate methods for visualizing and detecting sunken roads in lidar data for some test cases in the study region. the most appropriate methods are applied for the high resolution digital elevation data covering the study area. the section also discusses the issues of identifying sunken roads in lidar data and methods for validation. a map of the possible sunken road sections close to the approximate historical routes is presented. finally, the limits and potential of both the least-cost and the lidar analysis for precisely identifying the exact location of the historical roads are discussed, as well as outlines for future research. 2. approximate digitalization of the roads on historical maps in 1575, the eldest son of the famous cartographer gerhard mercator created a map that was part of the evidence presented at one of the highest judicial institutions of that time. the map was commissioned by the rulers of the berg territory in the course of the dispute with the rulers of homberg concerning the boundaries of these territories [mercator 1575]. this map, consisting of twelve sheets, is still preserved but in a fairly bad state. a reconstructed version of the map based on the original map and some later copies was published in 1995. the approximate scale of mercator's map is about 1:25,000 covering about 500 km2 of a hilly region east of cologne, germany (figs. 1a and 1b). the study area considered here is somewhat smaller because of data availability; previous research relied on a list of place names and the year when these sites were first mentioned [pampus 1998]. nearly all of the place names could be located on maps created in the late 19th century, and this allowed geo-referencing the centers of the settlements [herzog 2015]. the study area is the intersection of the areas covered by pampus and by mercator's map. figure 1. geographical location of this study: a) area east of cologne (black triangle) in germany; b) the study area delimited by a dark green line; settlement locations depicted on the mercator map are shown (dem data provided by the ordnance survey institution geobasis nrw). mercator's map shows several long-distance roads. some of these coincide with boundaries and were therefore probably drawn with extra care. another road was probably not important for the dispute and its map depiction ends about 5.4 km east of wiehl, well within the area covered by the map. if a historical map can be rectified by a simple transformation, transferring the roads to a modern map by digitizing is fairly easy. but the comparison of the true distances and the distances on the historical map presented in the next section demonstrates that a simple transformation is not adequate. 2.1 assessing the accuracy of the mercator map to assess the accuracy of the mercator map, an artificial coordinate system was constructed for this map. the artificial coordinates of 348 settlement locations (mostly consisting of several houses only) on the historical map were recorded (fig. 3c). for each of these locations, the corresponding true coordinate was derived from the mapping of the place names included in the pampus list referred to above. a delaunay triangulation [de smith et al. 2007, 113-115] of the 348 settlement locations on the modern map was generated. the length of each of the 1029 edges connecting neighboring settlements was computed. very long edges do not allow us to assess the local accuracy; therefore, 42 edges whose length exceeded 3.5 km were deleted from the edge set to be considered. moreover, 48 very short edges (length below 0.5 km) were omitted because cartographic difficulties are expected when drawing settlements that are very close together. the median length of the remaining edges is 1.28 km. fig. 2 shows the resulting triangulation edges. using the artificial coordinate system, the straight-line distances of the lines corresponding to the triangulation edges on mercator's map were computed. for each edge on the modern map, the length factor is the ratio of the line length on mercator's map to the corresponding triangulation edge length. if the historical map is not distorted, a constant length factor is to be expected; deviations then indicate settlement locations where the center moved or errors. fig. 2 shows that the length factor varies in the range of 4.3 to 67.3. figure 2. comparison of the distances between neighboring settlements. the variation of the length factor comparing mercator and modern map distances is quite high. moreover, no systematic distortion pattern can be recognized the average length factor is 16.2, the median is 15.5. the length factor of 514 out of 939 edges is in the range between 12 and 20. fig. 2 shows only a very few locations where very short and very long edges meet, indicating that the settlement centers on the historical map and on the modern map do not correspond. in fig. 2, no pattern can be detected in the spatial distribution of the distortions of mercator's map. a more detailed illustration of the map distortion is given when comparing figs. 3a and 3c. the locations of the place names listed by pampus [pampus 1998] are shown in fig. 3a. those locations that are recorded on mercator's map are marked by a white dot in fig. 3a. in fig. 3a, the edge connecting waldbröl, the village with a church, and brenzingen, is dark green, i.e. the distance indicated on mercator's map is much shorter than the true distance. in contrast, the edge between büscherhof and baumen is red because the distance on mercator's map is much longer than the true distance. figure 3. a) detail: triangulation of neighboring settlements (see fig. 2); b) approximate routes reconstructed on the basis of settlement locations and water bodies; c) digitized topographic features of a mercator map section roughly corresponding to the modern map sections a and b. unfortunately, the publishing fee for a very small section of this map is quite high, so only the most relevant digitized features are shown. (a and b are based on the digital elevation model dem25 provided by geobasis nrw) the discussion above shows that rectifying mercator's map is very difficult. therefore, the roads were not digitized from the historical map directly. the approximate historical roads were transferred to a modern map, based on place names and water bodies that are depicted both on mercator's and more recent maps. fig. 3b and 3c illustrate this approach. the historical map depicts a long-distance route in the area between isengarten and waldbrül, but closer to isengarten, and fairly close to hahn. unfortunately, romberg is missing on the mercator map, therefore it is not possible to decide if the road ran north or south of romberg. a reviewer suggested using the qgis geo-referencer with the thin-plate option to rectify the map. the 348 known settlement locations on the map served as control points. on mercator's map, each settlement is indicated by a symbol (mostly a red dot) and a small image depicting a few houses and sometimes a church spire or a castle. the control points were placed on the symbol. the result of the qgis geo-referencer is an uncompressed tif file of nearly 1 gb; the mean error is 9.1 pixels. the rectification was successful in that the symbols indicating settlements on mercator's map were placed very close to the corresponding control point location on the modern map. but often the small images of houses are severely distorted in the rectified map, and some of the place names are no longer readable. two black holes, the larger one with a diameter of nearly 2 km, point toward some trouble. the location of small streams in steep areas most probably did not change much over the past 500 years, but for some creeks distances of 400 m or more can be observed when comparing the rectified and the modern positions. most sections of the transferred mercator routes are within a 200 m buffer of the rectified routes. large distances are mainly due to the fact that the topography was taken into account when transferring the historical roads to the modern map. for instance, the routes avoid crossing streams. a road on the ridge that is also a drainage divide, midway between waldbröl and baumen, was drawn on this ridge. this road is closely related to the historical boundary. on mercator's map the road is labelled "die alte holes straiß"; the german word "alte" implies that this road existed a long time before the map was drawn. another road on mercator's map was labelled "die alde broederstraiß"; this road runs in a west-east direction starting in drabenderhöhe towards odenspiel (fig. 4). so some of the roads analyzed in this study are considerably earlier than 1575. 2.2 additional historical maps covering the study area the dispute concerning the territory boundaries continued after 1575, and this was the reason why the waye map [waye and waye 1607] was created. the original map has disappeared; the copy of the map published in 2004 relies on two copies drawn about 100 years ago. this map is mainly a modified copy of mercator's map; some of mercator's road sections are missing, some are added. the approach used for transferring the road sections depicted on mercator's map to the modern map were also applied for the waye map (fig. 4). the set of maps finished by ploennies in 1715 [ploennies 1715] also shows the main long distance roads of that time. these maps are distorted, too; therefore the routes were manually transferred to the modern map as outlined above. erich philip ploennies worked as a cartographer for the rulers of the berg territory. unfortunately, part of the study area belonged to another territory at that time. for these areas, ploennies' maps show only the main settlements and the road depictions are less precise. this is the reason why the west-east connection north of waldbröl derived from the ploennies maps appears very straight and deviates from the routes in this area on both the mercator and the waye maps. for most other road sections, the transferred mercator, waye and ploennies roads coincide quite well (fig. 4). figure 4. approximate routes reconstructed on the basis of settlement locations and water bodies (background map: dem25 provided by geobasis nrw). in his book, nicke [nicke 2001] describes the long-distance roads in the study area and beyond. the approximate location of the roads based on nicke's description is also shown in fig. 4. nicke knew the historical maps in this area, and so the routes derived from his descriptions differ only slightly from those transferred from these maps. the first maps of the study area that could be rectified, though with limited accuracy, are attributed to karl von müffling. beginning in 1817, he continued the work of a french group of engineers led by the military geographer jean joseph tranchot after the french occupation of the area west of the rhine in 1794 [tranchot and von müffling 1801-1828]. karl von müffling was also the head of a group of prussian military officers commissioned to create a set of maps covering the prussian territory [von müffling 1836-1850] known as uraufnahme. the subset of these maps relevant for the study area was completed in the years 1840 to 1845. figure 5. section of the study area on historical maps and on a modern map, showing also the modern water body layers (wms provided by geobasis nrw). although the web map service (wms) provided by geobasis nrw for the early von müffling maps is based on an improved rectification of the map sheets, some of the map sheets do not fit well (fig. 5 leftmost image; fig. 6). the map section in fig. 5 suggests not only that the rivers and creeks underwent some regulation but also that position errors of 300 m might occur. the early von müffling maps, as well as all later maps on this scale, record many roads and paths, but it is hard to distinguish between main and minor roads. based on the wms for the early von müffling maps, the roads closest to the mercator roads were digitized (fig. 6). gaps in this reconstructed road network are due to the fact that the early von müffling maps do not cover the total study area; sometimes, no corresponding road was found on the von müffling maps. the later von müffling maps (uraufnahme) cover the entire study area, and the accuracy was improved, although some problems, especially close to the border of the map sheets, remain. as for the earlier map, fig. 5 (1845 ad) shows the effects of river and creek regulation as well as the difficulties in distinguishing between main and minor roads. the roads closest to the mercator roads were also digitized based on the uraufnahme (fig. 7). the map set created between 1891 and 1912 is also known as neuaufnahme (fig. 5, 1894 ad). compared to the previous map sets, the accuracy is improved once again; the borders of adjacent map sheets fit very well. the black and white map image supports readability of the place names. this is why this map set was mainly used for geo-referencing the place names in the list by pampus [pampus 1998]. on the modern map (fig. 5, 2005 ad), the rivers and creeks are regulated, and the small town of morsbach, which hardly increased in the time between 1820 and 1894, covers a larger area. figure 6. roads close to the approximate mercator routes on the rectified early von müffling maps (wms provided by geobasis nrw). the map section marked by a black frame is enlarged. 3. least-cost analysis the road bundles consisting of the initial transferred mercator and waye routes as well as the closest roads digitized from the rectified early and later von müffling maps provide the ground truth for the lcp calculations. during the last decade, least-cost analysis has become increasingly popular in archaeological research, resulting in quite a few publications. a review of fairly recent case studies can be found in [herzog 2014]. digital elevation model (dem) with a cell size of 25 m provided by geobasis nrw. this dem is based on lidar data, representing the modern surface with high precision. appropriate cost models for reconstructing old trade routes in a region overlapping with the study area were already derived in earlier research [herzog 2013a]. lcps avoiding wet soils and with a critical slope of 13% fitted best to the trade routes. the critical slope is the transition when it becomes more efficient to use switchbacks instead of the direct uphill or downhill route. the critical slope of most vehicles is significantly below that of walkers, mostly in the range of 8 to 16%. slope dependent costs were modeled by the symmetric quadratic function discussed by llobera and sluckin [llobera and sluckin 2007]. for a given critical slope š, the formula for estimating costs of movement on a gradient of slope s is cost(s) = 1 + (s / š)2 where š and s are percent slope values. for the lcps presented in this study, the critical slope š was set to 12%. moreover, wet soils were considered as barriers. for raster cells locatedin wet areas, the slope-dependent costs were multiplied by 5. the multipliers 4 and 6 were tested alternatively. numbered list of place names and the year when they were first mentioned in historical sources according to pampus [pampus 1998]. table 1. target locations of the lcp calculations. numbered list of place names and the year when they were first mentioned in historical sources according to pampus [pampus 1998]. no. place name year 1 waldbröl 1131 2 reinshagen 1166 3 ründeroth 1174 4 oberwiehl 1316 5 drabenderhöhe 1353 6 erdingen 1382 7 oberzielenbach 1464 8 oberelben 1484 9 seifen bei spurkenbach 1487 10 hardt (reichshof) 1509 11 ruppichteroth 843 12 altenherfen ? 13 kohlberg ? 14 halsterbach 1509 15 dümmlinghausen 1465 16 kalbertal 1388 list of point pairs (p1, p2) to be connected by lcps. numbers in the p1 and p2 columnsrefer to the numbers in the place name list on the left. p1 p2 1 9 2 7 1 9 11 8 12 6 13 7 6 10 5 6 5 4 4 16 5 3 14 15 for possible ford locations identified on the earliest von müffling maps, a multiplier of 2 was chosen. buffers for line-shaped water bodies ensure that diagonal barriers cannot be breached. the algorithm applied for lcp calculations allows spreading in 24 directions. figure 7. results of least-cost path calculations: the lcps are very close to the historical routes. in some sections of the routes, a wetness multiplier of 6 generates lcps deviating from the historical routes, suggesting that multipliers of 4 or 5 are more appropriate. the map section marked by a brown frame in the map on the right is shown in the left part of the image at a larger scale (background map: dem25 provided by geobasis nrw). south of wiehl, the bundle of possible routes covers a broader zone than in most other parts of the study area. the lcps connecting points 5 and 6 are located in the center of the broad zone. the lcps in the eastern half of this zone are very close to roads depicted on the historical maps created between 1840 and 1845; these roads were not selected when digitizing the closest roads to the approximate mercator routes. for the short road between points 1 and 9, the lcp is closest to the road digitized from the early von müffling maps. corresponding roads are also depicted on the later von müffling maps, but these were not as close to the approximate route as the ones digitized. the lcp results are supplemented by an accessibility map (fig. 8). accessibility can be measured in terms of the size of the site catchment. when considering catchments of different sizes, the inner catchments are generally more important than the bands at a distance. this distance decay can be modeled by a least-cost kernel density estimation (kde) approach. technically speaking, the accessibility of each raster cell in the study area is calculated by least-cost kde for a dense grid of points applying a radial-symmetric epanechnikov kernel with a radius of 1 km (for details see [herzog 2013b]). figure 8. background: accessibility map based on least-cost kernel density estimation; the radius of the kernel is 1 km; multiplier 5 for wet areas. the cost model applied for the least-cost kde calculations is again the slope-dependent cost function with a critical slope of 12% combined with a multiplier of 5 for wet areas. a radius of 1 km was chosen because this radius was suggested by llobera [llobera 2000] for calculating accessibility at a middle range. fig. 8 shows corridors of high accessibility; these are the ridges in this landscape. the areas surrounding rivers and creeks were assigned low accessibility values. nearly all routes are located within high accessibility corridors. within such a broad corridor, small deviations from the least-cost path result in small amounts of extra costs. therefore, it is plausible to assume that lcps within narrow corridors of high accessibility reconstruct historical routes with higher reliability. 4. detecting traces of sunken roads using lidar data the previous sections identified several possible routes for the roads depicted on mercator's map. for most road sections, the results of the initial method used to transfer the roads on the modern map were not too bad. probably the true roads can be found within a small buffer zone enclosing the possible routes discussed above. the aim of this section is to analyze lidar data in the vicinity of these possible routes in order to detect traces of the old roads. such traces indicate with high probability the correct location of the historical roads. the first step towards this aim is the selection of appropriate methods for detecting sunken roads. 4.1 identifying suitable methods for visualization of sunken roads in lidar data nowadays lidar data of the study area is readily available. the ordnance survey institution responsible for the part of germany including the study area provides a wms with several different relief shading visualizations of the lidar data (fig. 9, ordnance-survey images). in fig. 9, the image with the label "hillshade (ne)" clearly shows the disadvantages of considering only one hill shading direction (in this case: north east). figure 9. sunken roads visualized by several methods (based on lidar data and wms layers provided by geobasis nrw). several alternative methods have been published, with the aim of improved visualization of archaeological sites. some of these methods like slope maps are implemented in most gis programs. two software programs are freely available that provide methods developed for archaeological feature detection: livt [hesse 2014] and rvt [zakšek et al. 2016]. livt was written by ralf hesse at the state office for cultural heritage in baden-württemberg [hesse 2016]. the software requires a 64 bit windows operating system; none of the standard geospatial data abstraction library (gdal) output formats is supported, so that importing the results to a gis other than global mapper is hardly possible. due to these limitations, the rhineland commission for archaeological monuments and sites in bonn mainly works with rvt [kokalj et al. 2011; zakšek et al. 2011]. moreover, the gis software mapinfo with the plugin vertical mapper is used, which also supports some of the visualization recommended for lidar data [herzog et al. 2016]. the ordnance survey institution geobasis nrw pre-processed lidar data resulting in a raster grid with a resolution of 1 m (dem1). the rhineland commission for archaeological monuments and sites obtained both the dem1 and the dem1l consisting of irregularly distributed lidar points. the dem1l is also the result of pre-processing; for instance, points on the roofs of buildings are removed so that the point cloud has some gaps. these gaps complicate the interpolation of the dem1l data, and interpolation with a large search radius is quite time-consuming. in forest areas, hardly any improvements are visible when using higher resolution dems based on dem1l data instead of dem1 data [herzog et al. 2016]. for these reasons, all images in fig. 9 are either based on the wms layers or on the dem1 data. hesse [hesse 2016] mainly recommends the methods accessibility and sky-view factor for sunken road visualization, whereas in his view the results of shaded relief and trend removal or local relief model are only moderately suitable. unfortunately, the accessibility method is only supported in his livt program. our tests of different visualization methods suggested that besides the hill-shading approaches, "local relief" and "openness negative" provide the best results in terms of sunken road detection (fig. 9). but fig. 9 also shows the difficulties of reliably identifying sunken roads based on lidar images. some dendritic structures are visible in the southern part of the map section considered, but are these remains of sunken roads? if a linear depression is rather short, fairly narrow, not very deep or not accompanied by a bundle of other linear depressions, the risk of misinterpretation rises. sunken roads with a fairly steep gradient may have been modified in width and depth by heavy rains in the past (pers. comm. renate gerlach) so that they can be easily confused with the remains of a temporary or small creek not recorded in modern topographic data. therefore, validation is required for sunken road candidates detected by visualization of lidar data. an initial validation can be performed by checking cross sections in the dem. yet the features detected on the computer screen are best validated by surveying in the field (or in the forest). so on a nice sunday in october 2016 a fairly small number of the locations with possible sunken roads were visited and some photographs taken. no obvious misinterpretations were detected. 4.2 results of sunken road detection using lidar data visualizations the dem1 is supplied in ascii files that contain a list of x, y, z coordinates, each file covering 2 km x 2 km. these files were converted to the esri ascii format; files in this format can be processed both by rvt and vertical mapper. the study area is covered by 141 of these 4 km2 tiles; 83 tiles are intersected by the approximate mercator routes. a tool written in the programming language mapbasic assisted the process of identifying and digitizing the sunken road candidates in mapinfo. when clicking on a location, the rvt results available for the corresponding tile are shown, and by another mouse click the desired visualization is loaded. figure 10. possible sunken roads in the vicinity of the approximate mercator routes are mostly visible in forest or brush areas. nevertheless, the time required for identifying and digitizing the sunken road candidates on such a large number of tiles with different visualizations available should not be underestimated. quite a few linear depressions were detected that should be validated by surveying because these features do not look exactly like typical sunken roads. several other interesting non-linear features were discovered as well. in the end, 1514 possible sunken roads with an average length of 93 m were recorded (fig. 10). nearly all of these sunken road remains are located in land used by forest or brush; hardly any of these features are still visible in fields or meadows. many of these features form typical bundles (fig. 9), and so the exact location of the historical road cannot be determined. the majority of the sunken roads are fairly well aligned with the approximate mercator routes. some are nearly perpendicular to these routes, suggesting minor roads. some of these minor roads must be very old as well, because on the mercator map even some of the church villages are not connected to the roads depicted. 5. discussion and future work with the lidar data processing presented above, including validation, many sunken roads associated with the routes depicted on mercator's map can be identified with high reliability, but this is quite time consuming. a study comparing several work flows for automatic extraction of sunken roads was published in 2014 [vletter 2014]. misclassification rates are not given in that study and it seems that the number of cases tested is fairly low. but for validating a procedure for automatic extraction of sunken roads, a large training set of verified sunken roads of different lengths, widths and slopes is required. so the automatic extraction still remains a task for further research. fig. 11 shows that nearly all possible sunken roads were identified in areas of high accessibility. but this is mainly due to the fact that the approximate mercator routes are located in these areas; only the lidar data close to these routes was inspected. sunken roads can be detected in many forest areas at some distance from the historical roads considered here. these are most probably the remains of roads connecting the settlements not located close to the main historical roads depicted on the mercator and the waye maps. a large number of these off-main-road settlements existed in 1575 (figs. 1b and 3c). additional research is needed to determine if the remains of main and minor roads can be distinguished and if typical features allow dating of the sunken roads identified. the visual inspection of the distribution of the sunken roads recorded creates the impression that the vast majority of these features are part of bundles and that most of the bundles are aligned with the approximately reconstructed roads. statistical testing of these hypotheses is not straightforward, because the observed sunken road remains are not independent from each other. therefore, further research should also be directed towards these issues. figure 11. accessibility map (see fig. 8) and sunken roads in the vicinity of the approximate mercator routes. the map section marked by a black frame in the map on the left is shown in the right part of the image at a larger scale. 6. acknowledgements the author would like to thank sandra gosteli for scanning the historical maps and julia stratbücker for calculating part of the images shown in fig. 9, as well as nearly all rvt visualizations of lidar data available at the rhineland commission for archaeological monuments and sites. moreover, the author thanks the reviewers for inspiring suggestions. 7. references irmela herzog. 2013a. least-cost networks. in archaeology in the digital era: caa 2012. proceedings of the 40th annual conference of computer applications and quantitative methods in archaeology. southampton: caa. 240–251. irmela herzog. 2013b. calculating accessibility. archaeology in the digital era, volume ii. caa 2012. proceedings of the 40th annual conference of computer applications and quantitative methods in archaeology. amsterdam: caa. 720–734. irmela herzog. 2014. a review of case studies in archaeological least cost analysis. archeologia e calcolatori 25 223-239. http://www.progettocaere.rm.cnr.it/databasegestione/open_oai_page.asp?id=oai:www.progettocaere.rm.cnr.it/databasegestione/a_c_oai_archive.xml:808 irmela herzog. 2015. analysing settlement patterns in the bergisches land, germany. in proceedings of the 19th international conference on cultural heritage and new technologies 2014 (chnt 19, 2014). vienna. 15 pages. http://www.chnt.at/proceedings-chnt-19/ irmela herzog et al. 2016. systematische auswertung von lidar-daten im rheinland. archäologie im rheinland 2015. 25-27. ralf hesse. 2014. livt: lidar visualisation toolbox, version 1.0.0.19. https://sourceforge.net/projects/livt/ ralf hesse. 2016. visualisierung hochauflösender digitaler geländemodelle mit livt. u. lieberwirth & i. herzog 3d-anwendungen in der archäologie: computeranwendungen und quantitative methoden in der archäologie workshop der ag caa und des exzellenzclusters topoi 2013, berlin studies of the ancient world: edition topoi. 109–128. žiga kokalj et al. 2011. application of sky-view factor for the visualization of historic landscape features in lidar-derived relief models. antiquity 85 (327): 263–273. marcos llobera and t. j. sluckin. 2007. zigzagging: theoretical insights on climbing strategies. journal of theoretical biology 249 206-217. marcos llobera. 2000. understanding movement: a pilot model towards the sociology of movement. gary lock beyond the map. archaeology and spatial technologies. amsterdam, berlin, oxford, tokyo, washington dc: ios press. 65-84. arnold mercator. 1575. grundtliche beschreibungh vnd gelegenheit etlicher warer grenntzen dem bergischen ampt windeck vnd herschafft hombergh betreffend. copied by hans weirich in 1995. published in 1999, along with 2 pages describing the history of the map by hans weirich, lothar wirths, and klaus pampus: grenzen des bergischen amtes windeck und der herrschaft homburg. bergischer geschichtsverein, abt. oberberg e.v. karl von müffling. 1836-1850. preußische kartenaufnahme 1:25.000; uraufnahme. wms: http://www.wms.nrw.de/geobasis/wms_nw_uraufnahme. information on the maps: http://www.bezreg-koeln.nrw.de/brk_internet/geobasis/sonstige/historische_karten/1836/index.html herbert nicke. 2001. vergessene wege. das historische fernwegenetz zwischen rhein, weser, hellweg und westerwald, seine schutzanlagen und knotenpunkte. nümbrecht: martina galunder verlag. klaus pampus. 1998. urkundliche erstnennungen oberbergischer orte. beiträge zur oberbergischen geschichte. gummersbach: sonderband. erich philip ploennies. 1715. b. dietz topographia ducatur montani (1715). bergische forschungen xx. michael j. de smith et al. 2007. geospatial analysis. a comprehensive guide to principles, techniques and software tools. leicester. jean joseph tranchot and karl von müffling. 1801-1828. kartenaufnahme der rheinlande 1:25.000. wms: http://www.wms.nrw.de/geobasis/wms_nw_tranchot.information on the maps: http://www.bezreg-koeln.nrw.de/brk_internet/geobasis/sonstige/historische_karten/1801/index.html willem f. vletter. 2014. (semi) automatic extraction from airborne laser scan data of routes and paths in forested areas. second international conference on remote sensing and geoinformation of the environment (rscy2014). 11 pages. doi: 10.1117/12.2069709 johann waye and jordan waye. 1607. eigentliche description theil des bergschen ambts windeck samt anstossende grentzen map reconstructed based on two late 19th/early 20th century copies by hans weirich in 1994. published in 2004, along with 2 pages describing the history of the map by kurt hamburger and hans weirich: die wayekarte von 1607. ein kartendokument zum siegburger vergleich. bergischer geschichtsverein, abt. oberberg e.v. nümbrecht-elsenroth. klemen zakšek et al. 2011. sky-view factor as a relief visualization technique. remote sensing 3 398–415. klemen zakšek et al. rvt: relief visualization toolbox, version 1.2 (64 bit). http://iaps.zrc-sazu.si/en/rvt#v received february 2017; revised april 2017; accepted august 20 2017 the black church cemetery: interdisciplinary approaches to the study of a medieval urban skeletal assemblage (braşov, romania) daniela marcu istrate, institutul de arheologie "vasile pârvan", romania annamaria diana, the university of edinburgh, uk the aim of this paper is three-fold: 1) to present results of the archaeological excavations conducted in the area surrounding the black church in braşov (transylvania, romania); 2) to show the outcome of the analysis of a small human skeletal sample; and 3) to stress the importance of biocultural interpretations of burial sites for a better understanding of the process of urbanization in southern transylvania. during the middle ages braşov, founded in the 12th century by central european colonists, was a flourishing multi-cultural and multi-ethnic urban community located in the heart of the carpathian mountains (transylvania, romania), and a busy crossroad for travelers merchants and diplomats from romania, other european countries and the middle east. between 2012 and 2013 a team of archaeologists conducted rescue excavations in the area surrounding the black church, unearthing a stratigraphically challenging complex of structures formed by centuries of uninterrupted human habitat, and over 1,400 graves in the medieval cemetery annexed to the church. the observation and interpretation of burial practices, grave goods and funerary topography, integrated with the demographic and pathological profile of human skeletal remains from 170 burials have shed new light on the life and death of the members of this middleclass population. in fact, bio-social and bio-cultural patterns were identified through the integration of multidisciplinary sources of evidence. the team involved in the post-excavation processing of archaeological materials from the black church cemetery is keen to promote further investigations of the archaeological site presented here, which is of inestimable value for the reconstitution of the development of urban life in medieval and modern eastern europe, and to present the lesser-known, albeit no less interesting, romanian cultural heritage to international scholars and to the general public. key words: medieval transylvania; funerary archaeology; biocultural studies;human osteoarchaeology; paleopathology. sdh reference: daniela marcu istrate and annamaria diana 2017. the black church cemetery: interdisciplinary approaches to the study of a medieval urban skeletan assemblage (braşov, romania). sdh, 1, 2, 16 pages. doi: 10.14434/sdh.v1i2.23233 authors' addresses: dr daniela marcu istrate, senior archaeologist, institutul de arheologie "vasile pârvan", bucharest, romania; email: damasus2000@yahoo.com; dr annamaria diana, human osteoarchaeologist; email: omseti@hotmail.com permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh © 2017 sdh open access journal 1. archaeological analysis 1.1 braşov: the origins the city of braşov is located in central-western romania, in transylvania, a region which in the middle ages belonged to the hungarian kingdom. transylvania was conquered gradually by the hungarians during the 10th-11th century ad, and, by the 13th century, its territory was included in the political, administrative and religious structures of the kingdom. a decisive role in the shaping of this region's societal and political organization was played by colonists. settlers from central europe (generally called saxons) were enticed to settle in transylvania by the promise of significant privileges [nşgler 1992; crîngaci ţiplic 2011]. from the second half of the 12th century to the beginning of the 13th century, this process of colonization in south transylvania led to the formation of a network of settlements [niedermaier 2002; 2004]. among them, the most important was sibiu, which became the main religious, political and cultural center for the local german community, and one of the most relevant cities in hungary [marcu istrate 2007]. braşov (or kronstadt in german) was the second biggest city, becoming at the end of the medieval ages the most populated and advanced commercial center in transylvania [roth 2010; philippi 1996]. figure 1. the black church today (photo: daniela marcu istrate). the settlement is mentioned for the first time in 1235, by the name corona, as the location of a premonstratensian monastery: "claustra sororum . . . in hungaria . . . dyocesis cumaniae corona" [philippi 1996]. this religious building's existence was short-lived, as it was destroyed by the tartar invasion of 1241. in 1252, although not yet definable as a "city," braşov/kronstadt surely was the most developed and important settlement in the area, mentioned in the sources as the politicaladministrative center of the region. by the end of the 13th century, two further tartar invasions devastated the settlement (in 1278 and 1285), and any economic and social advancement taking place at the beginning of the 14th century was once again halted by the invasion in the year 1345. around the year 1370 construction began on a catholic parish church dedicated to saint mary. the building process lasted for over a century and produced the largest gothic church in southeast europe, greatly admired for its architectural and artistic value, and today known as the black church (figure 1) [kühlbrandt 1928; vătăşianu 1959; entz 1996 nussbşcher 2008; bálint 2009]. little to no written information has been preserved from the early period of this history. local written sources are not very informative for the period up to the end of the 17th century, and were lost in the year 1689 following a devastating fire that almost entirely destroyed the historical center and the most important administrative buildings and churches. furthermore, although accounts and diaries left by foreign travellers and diplomats of political, economic or cultural exchanges with the transylvanian center [murgescu 2001] can be significantly enlightening, such sources have to be taken with a grain of salt, especially when clearly subjective. thus, archaeology remains the main source of information for the reconstruction of this long period in the history of the city, especially as regards its origins. figure 2. plan showing trenches excavated around the black church. 1.2 the city center rescue excavations between 2012 and 2013, the historical core of the town, including the area of the parish black church, was archaeologically investigated before restoration work was initiated. the research was accomplished by digging narrow trenches and by the occasional excavation of variously shaped and sized open areas (figure 2). although it would have been beneficial, large-scale surface research could not be conducted for several reasons, the foremost being the safety of the existing buildings and compliance with traffic regulations in the area. archaeologists unearthed an enormous amount of information and remains: traces of habitation (hearths, dwelling areas, pits, annexes, latrines, etc.), potsherds and objects made of metal, glass, stone and bone, fortified structures, and a cemetery. the archaeological context has shown that the first dwellings, built with earth and wood around the year 1200 ad, were followed in the 13th century by constructions of stone and mortar, which occupied a larger area. furthermore, while dwellings probably belonged to one of the western colonists' first settlements, stone buildings must have belonged to the monasteries successively mentioned in this area in 1235 (premonstratensian) and in 1388 (cistercian) [marcu istrate 2015]. as a result, data regarding the evolution of the church and other buildings, burial customs and the daily life of the inhabitants have been observed through the preliminary interpretation of archaeological contexts and finds. 1.3 the black church cemetery the most important achievement of the rescue archaeological research presented in this paper was the opportunity to excavate a significant area of the parish graveyard, which is now the second largest medieval graveyard excavated in transylvania. the cemetery was established around 1200 ad and remained in use long after the reformation until ca. 1800. while in the middle ages interments especially occurred in the northern area, in the modern period they were located in the southern and the northern areas, quite close to the neighboring houses. even though in other transylvanian towns cemeteries were moved outside the walls during the reformation (in the middle/second half of the 16th century), the black church cemetery appeared to become even more crowded in the 17th and 18th centuries. given that the community continued to bury their dead in the same area over a period of several centuries, the churchyard slowly but inevitably became a deposit containing more human remains than earth. in fact, archaeological stratigraphy showed up to 6-7 layers of graves, and, especially north of the church, a density of 15 graves per square meter. overall, more than 1,400 funerary features were registered and investigated. 1.3.1 the stratigraphical and architectural context as mentioned above, the black church cemetery was a crowded urban cemetery located within a complex archaeological stratigraphy. many burials cut through pre-existing structures, such as the walls of early masonry buildings, adobe and charcoal layers left behind by the earliest dwellings, and disturbed earlier graves, consequently destroying human skeletal remains and mixing the soil context. moreover, quite a few graves were cut by the foundations of more recent masonry structures, especially by those of the parish church and its chapels, and of the parish houses and other associated buildings (figure 3). figure 3. medieval graves disturbed by the foundation of st. mary's church (photo: daniela marcu istrate). the listed activities led to the disappearance of many graves—the only trace left of them is the impressive quantity of disarticulated bones found in pits and in the soil between the surviving graves. considering the evolution of other medieval urban cemeteries, it is likely that only one-third of the burials (probably considerably less) could still be identified as such at the moment of our investigation. while the complications listed here greatly affected the excavation process, they also were key to the understanding and dating of the evolution of the site. 1.3.2 spatial distribution, burial ritual and chronology the majority of graves, represented mainly by individual burials, seemed to be randomly distributed over the entire surface, with a tendency towards overcrowding north of the paris church. another characteristic was the presence of grave clusters – small areas where a large number of dead were buried at once or at different points in time (figure 4). while smaller grave clusters could be accidental, several large ones, south and west of the church, may have functioned as family graves. at the current stage of analysis, however, other reasons cannot be excluded. in addition to individual and multiple burials, pits with re-interred bones and ossuaries containing disturbed or intentionally exhumed bones were also exposed. the cemetery was delimited by a solid stone wall, with a thickness that may have exceeded 1 m: remnants of this wall, with several restoration stages showing slight changes to its extension, were identified in the eastern area of the square. in time, buildings took the place of this enclosure wall, and the funerary area became increasingly smaller and closer to the church. the funerary space was not organized, the placement of graves suggesting that it was used by the entire community as joint property. figure 4. area showing burial clusters (photo: daniela marcu istrate). graves were dug in a sandy matrix, filled with stones, mortar and brick fragments, and numerous human bones. several burial positions were identified [marcu istrate 2015]; dominant, however, was the custom of placing the deceased's forearms overlaying the body. although the majority of individuals faced east, lying on their back, about a fifth of the graves had different orientations. the unusual orientation of the latter could be attributed to the fact that the medieval gravediggers used the wall of the church as a reference to establish where east and west were. thus, behind the choir, where the church walls curved, so did the burials' orientation. furthermore, a very small percent of graves (about 7%) yielded inventory items, coins or clothing accessories. two factors contributed to limiting the establishment of a chronology for the cemetery: 1) the uniformity concerning burial ritual and funerary inventory—as would have been expected for a medieval christian cemetery, and consequently, 2) the fact that absolute chronology indicators (coins, relationship with dated structures) represented only 10-12% of dating elements. thus, the identification of chronological sequences was attempted by combining the topographic method (based on the relations between the graves reflected in a harris matrix) with the analysis of the context and the relationship between graves, built structures and artefacts. figure 5. burial layers on the northern side of the cemetery. 1.3.3 stages of use the topographic-chronological analysis allowed the identification of four main stages: the early stage of habitation, between the end of the 12th century and the beginning of the 13th century, had burials mainly concentrated north of the area (figure 5). the most common backfill consisted of black soil or black soil mixed with yellow clay; the most often encountered skeletal position was the one with arms and forearms stretched next to the body. the second stage was also concentrated on the northern part of the cemetery, associated with the monastic period, between 1250 and 1370. this level was characterized by pigmented backfills and remnants of earlier vestiges (adobe fragments, pottery and stones), although graves with very clean backfill were also identified here. the position of the arms showed several patterns but dominant was the one where the forearms were placed over the body. during the third stage (ca.1370-1542), beginning with the period when the black church was constructed, the area surrounding the religious building was entirely occupied by the parish cemetery. after reformation in 1542, the cemetery dwindled in size, retreating closer to the church and eventually being abandoned. the graves were dug in an extremely mixed deposit, containing a large quantity of debris and human bones. many of the burials were oriented on a north to south axis. the dead were laid down with their arms bent at right angles and the forearms over the chest area. from the later stages of use of the cemetery, tombstones were retrieved. on one of them the original inscription was scraped off and replaced with a new one: "ano 1752 css." another tombstone (grave m1213), discovered west of the church, displayed decoration consisting of two concentric circles and a cross, but once again the original inscription, located at the opposite end, was illegible. furthermore, coffin traces and remnants were often identified, especially at the level of the later upper layers. most of the time, however, only barely visible traces of coffin wood and/or iron nails survived. consequently, it would appear that about every sixth tomb had a coffin or other similar structure made of wood. some of the coffins were painted, while others had engraved plates – one such metal plate mentions the name of elisabeth, who passed away on 18 july 1783 [marcu istrate 2015]. some of the later structures unearthed in this cemetery may have been crypts, the earliest dating back to the eighteenth century, built between the buttresses of the choir by closing up the space with brick walls. they were later decommissioned, the coffins exhumed (probably to be transferred into the church) and their interior was backfilled with rubble. this action may have taken place around 1800, after the 1788 ban on interments within the parish cemetery [nussbşcher 2008]. after these events, the yard of the cemetery became a public space, being landscaped for pedestrian use. 2. osteological analysis 2.1 materials and methods 2.1.1 burial patterns and condition of the remains a minimum number of 206 individuals from 170 randomly sampled archaeological contexts were analyzed and identified on the documentation provided by the archaeologists. the identification of burial patterns for this group of graves was quite straightforward, given that the majority were individual and, occasionally, double burials. in fact, disarticulated and/or commingled remains were retrieved from only nine archaeological contexts. furthermore, 1228 permanent teeth (still in situ or loose but clearly belonging to a specific individual), 33 permanent loose teeth, and 90 deciduous teeth were counted. the state of preservation of the remains—recorded by scores poor (0-25%), fair (25-50%), good (50-75%) and excellent (75-100%)—was generally good, given that more than 65% of skeletal remains presented a fair to excellent condition. this estimate was obtained by averaging two separate scoring codes, one for the condition of the bone itself (i.e. degree of taphonomic and post-depositional damage) and one for skeletal completeness (i.e. how many bones from a whole skeleton were represented). 2.1.2 analytical methods the osteological analysis was performed by one investigator and all assessments were carried out by visual inspection at the macroscopic level only, given time and funding constraints. for the assessment of age at death, sex and stature guidelines provided by general manuals [buikstra and ubelaker 1994; hillson 2005; bass 2005; white and folkens 2005] and specialised articles were followed. standard methods for the assessment of demographic features were used, keeping in mind the observed population's geographical and historical context of provenience (i.e., when possible, population-specific standards were preferred). biological sex was assessed on adults by crossreferencing scores of the pelvic and skull morphology (as described by walker [in buikstra and ubelaker 1994]) with indices and metric measurements' sectioning points [bass 2005]. on adult individuals, age estimation was carried out by scoring the appearance of the pubic symphysis and the auricular surface ofthe ilium [todd 1920; brooks and suchey 1990; lovejoy et al. 1985; buckberry and chamberlain 2002], and of the sternal rib ends [%#can et al. 1984]. the state of fusion of the medial clavicle [black and scheuer 1996] and of the sacral elements schaefer et al. 2009] and dental attrition [brothwell 1989] were also scored. juvenile (subadult) sex was not assessed, while age was estimated by observation and record of the epiphyseal stage of fusion, dental development and maximum length of diagnostic bones [schaefer et al. 2009]. adult stature was measured by applying regression equations by trotter and gleser 1952 to the maximum length of all preserved diagnostic long bones. pathological and anomalous lesions were recorded by detailed descriptions, photographs and measurements. furthermore, their frequency (number of lesions) and prevalence (number of individuals affected at a specific point in time) were observed by skeletal location, sex, and age. methodological and theoretical principles developed by ortner 2003 and waldron 2009 were mainly followed, together with the indications and case studies reported in other manuals [aufderheide and rodríguez-martín 1998; roberts and manchester 2010] or articles from the palaeopathological, medical and forensic literature. data was collected in databases created ad hoc, and coded in order to be statistically tested at a later stage and to allow flexibility when more data are introduced. 2.2 results 2.2.1 age-at-death a total of 130 adults (63%) and 76 juveniles (37%) composed this population (figure 6). only three foetuses and seven infants were identified (almost 5% of the total together), while eighteen children up to five years of age and thirty-four up to twelve years of age were also recorded (respectively 8.7% and 16.5% of the total). adolescents were only represented by fourteen individuals (6.8%). furthermore, nineteen adult individuals younger than twenty-five and sixteen between twenty-five and twenty-nine years of age (respectively 9.2% and 7.8% of the total sample) were identified; one individual was aged between eighteen and twenty-nine years. thirty-eight adults were aged between thirty and forty years, while only twelve were between forty and forty-five years of age (respectively 18.4% and 5.8% of the sample); two mature adults could only be aged between thirty and forty-five years. finally, thirteen individuals were older than forty-five and only four might have been older than fifty-five years of age (6.3% and 1.9% respectively). a total of twenty-five individuals could only be attributed to the adult category given the lack of specific aging elements. 2.2.2 biological sex the black church assemblage showed a higher number of males among individuals whose sex could be assessed (figure 6). in fact, there were a total of 68 males (of which 25.2% were classified as males with a good degree of certainty, while 7.7% were probably males) and 50 females (of which 17.5% were attributed to the female sex with certainty, while 6.8% had 50% to 75% of probability of being females). finally, among the individuals whose sex could not be assessed, only sixteen (7.7%) were adults and seventy-two (34.9%) were children. figure 6. age-and sex-specific mortality for the black church skeletal assemblage. 2.2.3 stature measurement of the maximum length of the bones of 98 individuals (n = 37 females and n = 61 males) allowed the estimation of their stature. if calculated on the left femur, average female stature was 157.4 cm, with values ranging between a minimum of 146.9 cm and a maximum of 173.4 cm, while male stature was on average 170.9 cm and measured 152.5 cm at its lowest, and 188.4 cm at its highest. 2.2.4 skeletal changes skeletal lesions of different aetiology were observed on more than 60% (n = 135) of the analysed population (table i). the majority of them were adults (74.8%, n = 101), although quite a few of them were juveniles (25.2%, n = 34). furthermore, males outnumbered females (respectively 40.7%, n = 55 and 29.6%, n = 40). dental lesions were the most prevalent (60.7%, n = 82) on both sexes and on adults. degenerative joint disease was observed on 36.3% of individuals (n = 49), activity markers on 25.9 (n = 35) and traumatic lesions on 19.2% (n = 26) of analysed individuals, mostly adult males. infectious disease (17.7%, n = 24) and metabolic conditions (16.3%, n = 22) were mostly observed on females and juveniles. miscellaneous lesions, congenital conditions, dish (diffuse idiopathic skeletal hyperostosis, or forestier's disease, causing ankylosis of the spine) and tumors represented a small percentage (respectively 9.6%, n = 13, 6.6%, n = 9; 2.2%, n = 2 and 0.7%, n = 1) of the pathological sample. table i. skeletal changes observed on the black church cemetery skeletal assemblage. percentages were calculated in relation to the total of individuals included in the pathological sample (n = 139), and in relation to the whole population (n = 206). the total of mni is not equal to the total of the pathological sample given that some individuals exhibited more than one condition. 3. biocultural approaches to the archaeological context multidisciplinary sources of evidence collected for this study have provided a new perspective on aspects of the life-style of the population from braşov, statistically represented by the analyzed group of individuals, over a period of several centuries. although significantly limited by a lack of funds, the main objectives of this pilot project were successfully achieved by revealing important links between the results of the bioarchaeological analysis and evidence from other disciplines. this approach, and the collaboration between scholars from the humanities and sciences, has been increasingly supported and promoted by recent scholarship across disciplines [izdebski et al. 2015]. 3.1 the archaeological and historical context the preliminary post-excavation analysis has already provided invaluable data about the nature of the saxon community's funerary customs and about their development throughout most of the city's existence. the study of graves from a stratigraphic perspective, in correlation with the earthen deposits and with other features and objects (buildings, ruins, modern infrastructure, artefacts), has offered crucial elements in pinpointing and establishing chronological frames. additionally, the graves also proved to be important in interpreting the site; in fact, they were often decisive in establishing its chronology. several renowned personalities have written about bra#ov and its inhabitants. in 1550, georg reicherstorffer described bra#ov as an architecturally and culturally attractive town divided into three suburbs inhabited by communities of hungarians, saxons and bulgarians, while romanians and other small groups of saxons and hungarians dwelled outside its walls [murgescu 2001]. social and economic diversity was striking, and local peasants, mainly of romanian-slavic origin, were pushed to the periphery of the settlement by the privileged newcomers [pop 2003]. in the sixteenth century, the french magistrate pierre lescalopier and the ottoman traveller evliyá çelebi also travelled through bra#ov and praised the city for its high level of civilization and rich trading markets [alexandrescu-dersca bulgaru and mehmet 1976]. at the end of the nineteenth century, the englishman charles boner dedicated a whole chapter of his book of travels through transylvania to the description of the city, providing a date between 1385 and 1425 for the black church's construction and adding a colorful description of the local population [boner 1865]. 3.2 population profile it is legitimate to think that the majority of individuals recovered from the black church cemetery were saxons, given that the saxon community was the most represented in the area within the city walls, where the more privileged newcomers dwelled, and where members of different communities were quite preoccupied in keeping their own identity. in fact, written sources and archaeological and osteological evidence all seem to point towards a somewhat segregated community never or rarely allowing intermarriage, and an urban space with clearly defined social spaces. most children died between five and twelve years of age, while adults died between thirty and forty years of age. this finding is striking, although low life-expectancy (the average number of years a person is expected to live), and higher mortality rates for younger individuals (the proportion of individuals dying in a specific interval of time), were outcomes in line with studies on past populations [chamberlain 2006], and in particular those from the medieval-modern period [ahlström 2011]. therefore, such mortality rates might have been the consequence of 1) a sample bias, or 2) the impact of external factors (e.g. famine, climatic shifts, or epidemics [cf. cernovodeanu and binder 1993]). figure 7. left: mandible showing several linear hypoplastic defects of the dental enamel, older child (5-12 years). right: "candle-wax" formation (typical of dish) on the right anterior view of thoracic and lumbar vertebrae of a male aged over 50 years (photo: annamaria diana). 3.3 "health" and disease despite their relatively "prosperous" environment, the majority of individuals from braşov were not spared high rates of ill-health. adults over 35 years of age were the age category showing higher morbidity levels. furthermore, 10% of individuals displaying pathological lesions exhibited evidence of physiological stress and malnourishment, e.g. porosity of the orbital roof (cribra orbitalia) and defects of the dental enamel (enamel hypoplasia) (figure 7, left). furthermore, data from the osteological analysis, integrated with archaeological data, historical and written sources, allowed the observation of biocultural patterns in specific case-studies, indicating: favorable living conditions for individuals affected by congenital and/or crippling diseases, reaching adulthood despite their complete dependence on others for survival [diana 2015]; gender-related morbidity patterns possibly linked with social status and activity—i.e., men and women presented different disease-specific profiles; the presence of pathological conditions possibly caused by or triggered by "high status" dietary habits — a high prevalence of dental cavities, plaque and antemortem tooth loss, and the identification of dish on three male individuals (figure 7, right). the latter condition, in particular, has been linked to obesity and type ii diabetes and has been frequently observed among skeletal remains from monastic sites; its presence, however, should not be conclusive in considering the affected individual as necessarily of high social status [rogers and waldron 2001]. finally, the appearance of bones showing charring, fissuring and discoloration at specific anatomical locations shown in forensic case studies of fire victims [e.g. buikstra and swegle 1989] might be considered as evidence of victims of historically recorded fires. this possibility, however, is to be further investigated. it is too early to draw final conclusions about morbidity patterns observed on a relatively small group of individuals, given that the herein presented results may (and most likely will) change when the whole assemblage is analysed. however, possible general patterns have been identified, and specific lines of enquiry for a better understanding of the influence of social, cultural and environmental factors in the shaping of the demographic and pathological profile of this population have been highlighted. 4. conclusions observing the development and use of a funerary site for over six centuries by the same, stable community is a rare opportunity in romania. given the substantial amount of human skeletal remains retrieved from braşov's black church cemetery still awaiting post-excavation processing and analysis as well as the wealth of archaeological evidence, including human artefacts and animal bones systematically collected by the excavation team, this assemblage offers an great variety of possible research pathways. we hope to follow up the pilot study presented here with the completion of the post-excavation analysis of all finds, which will allow: the integration of multi-disciplinary sources with the bioarchaeological database; comparisons with other romanian and european medieval and post-medieval cemeteries; isotopic and biomolecular analyses for a better understanding of dietary habits, migration, ancestry, and disease; the interpretation of mass graves/family groups; the interpretation of specific case-studies. this study was aimed at presenting the archaeological context and the biological and socio-cultural profile of a small group of individuals from the black church courtyard. in order to achieve a wider perspective, data provided by osteological and archaeological sources of evidence were interpreted in the light of the historical context. as a result, a better understanding of population dynamics in this area has provided new insights on the history and anthropology of the transylvanian city of braşov, and has showed the enormous potential offered by further analysis of the whole assemblage. 5. acknowledgements the authors would like to thank the local church authorities for allowing the archaeological excavation and access to the black church skeletal assemblage for scientific purposes, and dan o'meara for his helpful comments to improve this paper. 6. references t. ahlström, t. 2011. life-history theory, past human populations and climatic perturbations. international journal of osteoarchaeology 21 (4) 407-419. 1976. m. m. alexandrescu-dersca bulgaru and m.a. mehmet. călători străini despre ţările române: vol. vi. bucureşti: editura stiinţifică. a. c. aufderheide and c. rodríguez-martín. 1998. the cambridge encyclopaedia of human palaeopathology. cambridge university press. á. bálint. 2009. biserica neagră din brașov. noi propuneri privind cronologia şi contextul construcţiei. ars transsilvaniae, cluj-napoca, xix. 5-18. w. m. bass. 2005. human osteology: a field guide and manual. 5th ed. missouri: archaeological society. s. black and l. scheuer. 1996. age changes in the clavicle: from the early neonatal period to skeletal maturity. international journal of 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august 2017. the lapidary of palazzo ancarano. digital technologies and 3d printing to improve knowledge of the stele collection veronica villa, accademia delle belle arti di bologna, italy tatiana pignatale, universitá degli studi di firenze, italy ilenia tramentozzi, universitá degli studi di firenze, italy in academic fields in italy, there are many cases of collaboration between universities and various institutions protecting cultural heritage. this is possible due to the large number of archaeological heritage sites and artifacts requiring restoration interventions and to the fact that there are students who need practice. this is the case in the partnership between the archaeological superintendence of emilia romagna and the fine arts academy of bologna. this collaboration has permitted us to open an important restoration site, where our goal is to recover the lapidary located in the courtyard of the historical palazzo ancarano. the restoration project was developed over a period of four years. each student was assigned the maintenance of archaeological finds, both to produce complete documentation of the intervention(s) made and to provide a record of the methods and materials used. this was done for all the archaeological finds found in the courtyard, which were relocated around the perimeter of the site in chronological order based on historical information. at the end of the restoration and reorganization of the area, it appeared necessary to enhance the collection of steles, in particular those of the pre-roman, roman and medieval periods. by opening the palazzo ancarano's courtyard to the public, we will return it to its original function as a museum. to achieve this, we intend to use appropriate digital technologies combined with the archaeological items on display to enhance the understanding of the collection for all visitors. we will use 3d digital technologies that will accompany the steles and a database with an app will also be created. we intend to provide an instrument that gives clear and detailed information so that all visitors can deepen their knowledge of the collection according to their own interests. key words: lapidary, palazzo ancarano, heritage protection sdh reference: veronica villa et al. 2017. the lapidary of palazzo ancarano. digital technologies and 3d printing to improve knowledge of the stele collection. sdh, 1, 2, 16 pages. doi: 10.14434/sdh.v1i2.23252 authors' addresses: veronica villa, accademia delle belle arti di bologna, via delle belle arti 54, 40126, bologna, italy; tatiana pignatale, ilenia tramentozzi, department of architecture, florence university, via della mattonaia 14, 50122, firenze, italy; email: veronica.villa87@gmail.com, tatianapignatale@gmail.com, ilenia.tramentozzi@gmail.com. permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal 1. introduction palazzo ancarano is currently the main office of the archaeological superintendence of emilia romagna. it is located in the ancient via belle arti, in the historical center of bologna, just a few minutes away from some of the most important monuments in the inner city, such as the two towers and the basilica of san petronio. there is a courtyard inside the building with an entrance that leads to the offices of the superintendence, which houses a modest collection of steles. after five years of logistical planning and studies on stone restoration involving the stele collection in the courtyard of the palace, the lapidary of palazzo ancarano was recreated through the recent collaboration between the academy of fine arts and the superintendence. the work presented here concerns a project proposal for the re-evaluation of the courtyard with the goal of bringing it back to its original function as exhibition path. this can be achieved by combining the study of the objects and contemporary technologies. thanks to the data gathered, the artifacts will be available to a wide range of people through an application that shows the virtual reproduction of the ancient objects. this app will also contain all the information about the restoration work of each student of the academy of fine arts. outdoor installations in the courtyard with interactive 3d printed models are under consideration as well. figure 1. aerial view of the area and identification of the palace. 2. historical stages concerning palazzo ancarano the palace is named after its founder pietro d'ancarano, a renowned citizen and teacher of canon law in bologna and other italian cities during the fifteenth century. pietro d'ancarano descended from a branch of the farnese family established in tuscia, as he declares in one of his most the famous works, the "sextum": "ego petrus de ancharano de nobilibus de farnesio provinciae patrimonii beati petri in tuscia." his biography is known from his writings and letters sent to family members and colleagues, in which there are found details about his life. in a letter dated august 1381 and sent to michele migliorati da prato (the vicar of the city of rimini), he notes that he is a 'doctor utriusque iuris.' in another letter, dated between 1382 and 1384, his temporary return in bologna to avoid inactivity and misery is evidenced by his words: "sumpto gradu utriusque iuris, veni bononiam pro vicario domini potestatis." thanks to his new position, his career took off and he became the repubblica's consultor in venice. he taught in various italian universities from 1387 to 1395, the year of his final return to bologna and to the oldest university in the world, at that time known as "studio bolognese." in this last period of his life, pietro was viceregent of the archdeacon, but in october 1412 the canons of st. peter's basilica created the 'scandalum maximum' in the studio (liber secretus 1938, 197-99) because they claimed the right to exercise the archdeacon's functions in case of pietro's absence. it seems that this conflict was also a consequence of the political position taken by pietro d'ancarano and other jurists concerning the intricate events of the great western schism in 1405. in fact, his objective was the reestablishment of unity. he dedicated his life to teaching and to an active participation in debates on societal issues, so as to encourage young scholars from other cities to come to bologna to study. through his will, he set up a boarding school in his home for poor students. pietro d'ancarano died in bologna on 5 august 1415 and was buried in the basilica of san domenico. this institution, known by the name of ancarano, was located in the residence of the founder in via val d'aposa for more than a century. but in 1532, the whole college was transferred to borgo della paglia, in the district of porta piera, today called via belle arti. by the xviith century, the palace was embedded in a complex of buildings built specifically to house jesuit novitiates. two centuries after its foundation, the college was moved and in 1780 it was abandoned; the jesuit order had been abolished in 1773. palazzo ancarano remained empty until 1804, when its premises were granted to the new national academy of fine arts, formerly clementine academy, where it is still today. in 1925, the academy of fine arts gave some rooms to the royal superintendence of antiquities of emilia romagna. the lapidary in the inner courtyard of the palace was begun at this time. 3. the courtyard of palazzo ancarano as a lapidary since then, the courtyard has contained some funerary monuments discovered during archaeological excavations as well as during construction work in bologna's historic downtown and its surroundings. the archaeological collection consists mainly of roman funerary stones and other objects made of various materials, such as varignana yellow sandstone, and a unique monumental column section in selenite; these are both local materials. the collection also includes imported ancient marbles and limestones, which come from the most remote locations of the mediterranean basin. the preserved inscriptions are from different historical periods: some of these are pre-roman memorial stones; some finds come from the period between the late republic and early empire (end of 1st century bc 1st century ad); and other finds are from the medieval and renaissance periods. among the items in the collection is a medieval tombstone dated to the late 14th or early 15th century, in istrian stone, discussed below in section 4. the pieces can be divided in two main groups according to their time of arrival in the courtyard. an initial nucleus of steles was discovered during excavations in the 1930s in the following municipal locations: due madonne, santa viola, battiferro, and ponte lungo. a second group came during the 1960s from excavations in these communal locations: bitone, arcoveggio, san donnino and san donato. it is interesting to note that the discoveries were made almost outside of historic city center. this is due to the fact that at the time of roman city of bononia, burials were located only in proximity to the main roads that led out of the city. since the early years of acquisition, all the pieces have received sporadic restoration interventions, but these were not enough for their conservation. subsequently, the courtyard arches were buffered in order to get more room for display the objects, and gradually some pieces of the first group were placed along the exterior walls because there was already the idea of creating an exhibition space. the remaining space was subsequently occupied by finds found after the first arrangement. they were organized by following a criterion of similarity of form and size, or of epigraphic character and the arrangement of the written text. despite this intent, the directive to create an exhibition space was soon abandoned. the gradual accumulation of finds has thus caused the transformation of the yard into an open-air warehouse. 4. partnership between the superintendence and ababo in 2012, the idea of creating an exhibition path was proposed again and the restoration project of the lapidary begun. it was the first project promoted by the restoration course of the academy of fine arts of bologna (ababo) in cooperation with the superintendence of cultural heritage of emilia romagna. this partnership was also the result of the proximity of their offices. indeed, the two institutions are in the same block. it was also created to pursue common interests, such as the need for students to apply theoretical studies in the field and the need for the superintendence to restore archaeological finds in the field. the project of changing the intended use of the courtyard was reconsidered. the restoration phase was carried out by thirty-one students guided by four professors, following a precise schedule. students involved were those belonging to the second and fourth years (from the years 2012 to 2016) of the academic course of restoration of stone materials; during this time they implemented a practical testing laboratory, working on real archaeological finds to increase their abilities. thus, the collaboration allowed us to open an important restoration site and to focus on the lapidary located in the courtyard of the historical palazzo ancarano. the initial project was for a period of three academic years; another year was added for the repositioning of the finds in a logical and chronological path along the façades of the inner courtyard. the maintenance of an archaeological find was assigned to each individual student, with the purpose of producing a complete documentation of the intervention, using an inventory document specifically designed and produced under the supervision of the responsible professor, augusto giuffredi. this document includes all necessary information about the archaeological remains and operations performed; the problems of degradation and their mapping; and the materials used for the restoration in the different phases. the result of the work done in the restoration yard is an archive containing 54 inventory documents, each one of which concerns a single archaeological find. this archive was made to preserve of all the archaeological artifacts, in this way leaving a testimony of the work done for those who will have to do further restoration work in the future. figure 2. phases of the restoration yard. the restoration yard work was divided into three phases. more specifically, the first phase included documenting the discovery of the archaeological find and the gathering of all the existing information about it, including, for example, the location where the piece was discovered in the territory of bologna, and the document in which it was transferred to the palace courtyard. in this phase, there was also the cognitive analysis of the find, which was based on the observation of its state of preservation; the analysis of the size and weight of each possible fragment; the photographic documentation; the historic technical execution; the material analysis; the in-depth analysis on the decay and the possible causes for it; and, lastly, a graphic mapping for each type of decay. in the second phase, the stone restoration operations on the artifacts were carried out; this was the most challenging part of the program because it required the students to draw up a specific intervention project for conserving the manufactured article assigned to them. in most cases, the project provided multiple phases of intervention, such as the removal of non-adhering deposits; the preliminary cleaning tests and selection of the most suitable cleaning agent(s); the removal of adhering deposits with compresses; the cleaning with sponges and toothbrushes; and the bonding of possible fragments with resins. at the final stage of the restoration yard work, each artifact was moved from the place where the restorations were done to the inner courtyard of palazzo ancarano and placed in the proper chronological order, situated in the arcades and enhanced with special methods projected ad hoc. figure 3. restoration phases concerning the medieval tombstone codified as v7 (left to right): removalof non-adhering deposits; epigraph frottage; removalof adhering deposits withbiocidal and arbocel compresses. figure 4. restoration phases concerning the medieval tombstone codified as v7 (left to right): cleaning with sponges; bonding of fragments with bicomponent epoxy resin; bonding in vertical position with security straps. figure 5.restoration phases concerning the medieval tombstone codified as v7 (left to right):moving the tombstone into theestablished location on the east façade; control of the resin spillage along the fractures; cleaning of the epoxy resin with ethyl alcohol. 5. the survey with photogrammetric approach the project proposal concerns the re-evaluation of the collection of steles and the palace's courtyard, thus completing the exposition that was planned for it in the second half of the twenties and for which reason it was filled with archeological finds. when the students had completed their stone restorations and the yard was closed, the idea of the project was born. this work was the last stage of the master's degree thesis in stone restoration written by veronica villa at the bologna's academy of fine arts. she was one of the thirty-one students who had joined the project and, in particular, she was assigned to carry out the restoration of the medieval tombstone of istria stone, codified in the stele system of the lapidary as v7. to restore the original function of the courtyard it would be necessary to open it to the public and make an expositive path that would be of interest to a wide range of visitors. the best way to do this would be to install durable outdoor technologies that can share contents with the visitors' devices in an interactive way. the project proposal was developed thanks to the collaboration with students of the architectural department at florence university. the students from florence had already worked on this kind of interactive exposition and they completed the survey of the courtyard and the archaeological remains. they also developed the project proposal in accordance with the requirements. the approach used for the retrieval of metric data was the photogrammetric survey, chosen because this technique is able to obtain a three-dimensional high-quality product without compromising the measurements' accuracy and reliability. figure 6. main workflow of the restoration phases and surveys in the lapidary of palazzo ancarano. the survey began in july 2016 after obtaining the necessary authorization by the archaeological superintendence of emilia romagna in order to have access to the courtyard and to collect photographic data. the was necessary because archaeological remains are protected by italian law, specifically the "decreto legislativo 22 gennaio 2004 n°42 codice dei beni culturali e del paesaggio." this law states that all assets owned by the italian state that are of artistic, historical and archaeological interest are entrusted to the territorial superintendences. the objects that are not exhibited in museums are collected in deposits owned by the state and they are accessible only after obtaining permits. in the case of palazzo ancarano, the academy of fine arts reached an agreement with the superintendence to restore and make accessible to the general public through article 119 of legislative degree no 42/2004, 'dissemination of knowledge of cultural heritage.' it lays down the guidelines of the agreements between the ministry of education and the university. the survey was divided into several stages. first of all, we decided to undertake a preventive inspection of the area to assess the state of preservation of the objects and to determine the best times for gathering photographic data. the photographic survey was the second part of the work and was done with a digital camera, the nikon d3200 with 24 megapixel and with the nikkor 18-55 mm lens. it was necessary to use a tripod in order to avoid micromoving problems during the acquisition of the photogram. the shots were made by the camera set in aperture-priority auto mode, in which the d3200 automatically selects the shutter speed that will produce the optimal exposure while allowing users their choice of apertures. we used it with small apertures (high f-numbers) to increase the depth of field and to bring out details in the background and foreground. the third phase was the direct measurement with the laser measuring instruments and manual tools. the photographic acquisition did not foresee the use of flat targets, because the geometrical characteristics of the tombstones and the courtyard acted as reference points for the correct alignment of the photos and the subsequent building of a sparse cloud. finding the best shooting position was particularly difficult, due to the small dimensions of the palace's internal courtyard; this made it impossible to collect all the photo data necessary for the correct rebuilding of the facades up to their tops. to solve this problem, we have requested some additional permissions so as to have access to the first floor of the building, where there are the administrative offices of the archaeological superintendence, and to create four shooting positions from the windows of these rooms, framing the opposite facade's top. figure 7. main stages of the agisoft photoscan process concerning v7. regarding the survey of the collection's pieces, we located a specific shooting position for each find. at the end of the photographic survey, there was the final phase, which included the processing of data collected through the use of the agisoft photoscan software. this was very intense processing and it included the following: the identification of target areas in the photo; the alignment of these and the generation of the sparse cloud necessary for the subsequent creation of the dense cloud; the building mesh and process occlusion of the holes; and the creation of textures. the product output from this processing was a photoscan mesh too large to be displayed easily by the final users. for this reason, the mesh was simplified to enable faster viewing that is a necessary adjustment to be exploited by portable devices like smartphones or tablets. the 3d models obtained by such data processing pertained the courtyard as an architectonical element and in a more detailed way each archaeological find so that we have different kinds of processing for the expositive path project. these have been organized in a way that enables them to be included in the proposal for the integrative method that involves the use of digital technologies. for informing people about the palace, such integration between the archaeologic patrimony and the innovative technologies is necessary, so that all visitors, from children to scholars, can benefit from our work. 6. project proposal for the courtyard from the three-dimensional model of the courtyard it was also necessary to extract a bi-dimensional survey of it, with which we have been able to design the exhibition path and to position the cognitive panels. these panels present the best outdoor permanent solution capable of grouping the interactive elements concerning each archaeological find. the first graphical elaborations that were extrapolated were the prospects and the zenithal views of the complex actual state. this was necessary because the existing bi-dimensional graphic elaborations of the building have a very low-grade detail and they have not been updated with the actual condition of the courtyard after the restoration work and the rearrangement of the restored steles along the façades. the lapidary's access is located next to a "corridor" in the south façade. the particularity of the courtyard is that it has got the eyesight of the archaeological superintendence, but also the eyesight of some schoolrooms owned by the academy of fine arts. the style of the façades is coherent, although the restoration work done on them has characterized the elevations in different ways. excluding the roof structure, the façades have a height of approximately ten meters, with a variability of ten centimeters due to the slope of the flooring, probably owing to the original instability of the stamping plan on which it is installed. the only staircase that leads to the underground area where the superintendence's warehouse is located is in the corner of the east front. figure 8. vector drawings of front elevations. both the first and the second row of arches were bricked up in the early xxth century in order to create indoor rooms. two windows in the second row of columns on the west front were also bricked up. on the south elevation, the windows on the second floor cover the whole area between the arcades, presenting a different choice for the architectonic restoration of the façade. the arcades were also bricked up; they have a frieze composed of terracotta tiles on which there are little angel faces with wings. the repetition of the frieze reveals a serial production of the tiles using the same matrix. the capitals are made in a composite style with sandstone, differing from one another in the varying forms of acanthus leaves decorating them. the columns under the capitals are of brick; they rest on a molded sandstone base. on all the façades, there is the same string course frame. during the final phase of the work in the restoration yard, the arcades of each façade were numbered to allow a more precise placement of the objects. despite the fact that the east front does not have arcades on the ground floor, the tombstones were placed with the same spacing that was used for the other façades. figure 9. orthophotos of front elevations. through a dimensional analysis of the spaces, we have identified the most appropriate points for the positioning of the panels, which form a path running along the entire perimeter of the courtyard. in the axonometric view, we have inserted the panel construction hypotheses, in which there are fourteen cognitive panels, some placed individually and others arranged in pairs, depending on the need. there are fifty-four archaeological artifacts arranged in the panels, based on their position in the courtyard. the cognitive panels form a support element that encloses various technologies in order to meet the needs of all visitors. information about the objects is printed on a transparent base, so that the visitors can remain linked to the context without any distraction. the panels are different from each other, but they share the same layout of their upper level, on which there is a complete and detailed disclosure about the codes of the pieces positioned on the façade; in front of each panel vector drawings demonstrate the positioning. on these, only the objects inside the panel will be colored. on each panel, there is a detailed description about the object, its history, and its conservation treatment, along with a lot of other helpful information written in italian, english and braille. in the prototype, which is dedicated to the medieval tombstone codified as v7, we have developed all the technologies that we have proposed. these will be used only on the more historically interesting objects. another of our goals is to create an exposition path designed for blind and visually impaired people. for this reason, we have used an embossed plate written in braille, and the graphical illustrations are in relief. in fact, the panels are characterized by a very flat surface so that there will not be any misunderstanding about the panels' functional design. in the central part of the panels there are three-dimensional physical models printed in plastic material, which is useful for understanding all the fragmentary remains that were reassembled during the restoration. figure 10. axonometric view of exhibition path and detail of the prototype panel about v7. on the v7 panel, the model is presented as a new learning system for children, who can reassemble the medieval tombstone directly on the panel using a system of magnets. this model is also designed for blind and visually impaired people, who can immediately and completely understand the remains using their tactile sense, thanks to the small dimensions of the model. in the lower part of the prototype panel there is a wireframe reconstruction of the original item, which highlights some details of the object that are barely visible to the naked eye. specifically, this is accompanied by a particular deepening of the epigraph on the medieval tombstone v7 and its probable translation. on all panels two qr codes will be positioned and visitors will be able to read the details of all the artifacts from the dedicated exposition app, with their smart devices simply framing the codes. these are certainly not new technologies, but their combination may be the right solution to increase peoples' interest in and understanding of the archeological patrimony of the lapidary. 7. digital proposal for a complete understanding of the steles the specific survey of every single tombstone was made in order to have a work of impressive quality so that we could get the best results during the making of digital 3d models of each artifact. these high-quality 3d models will have to be suitable for visitors' devices, which, due to their technical limitations, cannot open and manage the very complex files. as a result, these files will be converted into a light and simplified format with fewer details, but keeping high quality images. the big and complex files generated from the survey were used to enable the 3d printing process to be done using plastic material so as create 3d physical models, which are the main part of the alternative learning process about the artifacts, as mentioned above. the idea of creating a dedicated app for the lapidary exposition was the result of an analysis made for understanding the potential of the path and the types of visitors that could be attracted by it. the main advantage of having an app of the lapidary is to have the entire database of all the finds placed in the courtyard of palazzo ancarano on hand and available to all users. these finds are to be organized in a digital list, in which each one has a section with all the information about itself, constantly updated by the lapidary's staff and by researchers. the users can select the artifact about which they want to know something more, and they can read about the technical specifications of the restoration, view the photos of the previous phases and see the inventory document of ababo about the work on them. one of the more interesting functions could be the insertion of information about the phase before the restoration of each one of the remains. for example, such information could include the printed documentation digitalized and presented by the students who did the work on that tombstone; the photographical documentation about the state of the object before restoration in comparison to its present state; and of particular interest, details about the diagnostic phase of the causes of degradation and how this is linked to the subsequent restoration process. these features would be extremely useful, because in this way there could be a database that would be accessible from everywhere and by everyone, with a lot of high quality information and files, so that many professionals would be able to connect to this database and develop studies about the lapidary. in the app, there is also a link through which users can connect their devices to the collection of 3d digital models by sketchfab, loaded into the database by the lapidary's profile on this hub. users can access it directly through the second qr codes on the panel. this solution was chosen because the visualization of 3d models on mobile devices is already a consolidated technique to give the user a complete understanding of an element. it is done with the younger generations as the target, because developers want to educate children and teenagers about the conservation of the archaeological patrimony using tools such as mobile devices that they know very well. moreover, not only students, but also ordinary people and scholars as well, can learn many new and interesting things by engaging in game-playing or an interactive learning process, thus increasing the community's interest in the local archaeological and artistic patrimony. figure 11. overview of the app's contents, an example of some information available about v7: graphical diagnostic of decay, photographic data and 3d digital model. the method applied to palazzo ancarano's case is, at this time, only a project proposal, so it is not possible to get numerical data on the real usability of the site; however, it would allow the lapidary not to return to being just an open-air storage, regardless of the potential visitors. the increase in interest is only one of the purposes pursued by this method, and in fact the documentation produced would remain as a testimony available to the public, even if it changes its intended use. in addition, this method is also proposed as an example of re-evaluation for those places of historic and artistic importance which have been left to their own devices and which may not have the relevance that they should have. 8. conclusions the reorganization and redevelopment of the palazzo ancarano's lapidary was one of the first restoration school yards sponsored by the academy of fine arts in collaboration with the superintendence of archaeology, fine arts and landscape for the metropolitan city of bologna and the provinces of modena, reggio emilia and ferrara. in the four years of the construction of the site, several students were able to study the field of restoration of stone materials and increase their knowledge, acquiring a solid foundation in order to properly restore of works of greater importance in their later career. through the restoration, each mobile artifact belonging to the stele collection recovered a correct reading inside the lapidary. the museum function of the courtyard had been totally lost because of the state of abandonment of the works accumulated over the previous years, but now it has been gradually restored by designing an exhibition path based on the needs dictated by the present artifacts. the project proposal presented here promises to be the necessary catalyst to reverse the previous state of abandonment. this work began as an agreement between students and ended with the integration of their operations with technologies capable of attracting the public interest. this could be a method applicable in many national territories where there are sites that are currently abandoned because they are not considered relevant or due to lack of funds. many of these have fallen into a state of deterioration and they need restoration interventions on artifacts to recover their cultural heritage, for the value of the archaeological site where they are and for the maintenance of its historical identity. 9. references francesca bocchi et al. 1997. atlante storico delle cittá italiane. emilia romagna: bologna ii. bologna: grafis. bruno breveglieri. 1985. osservazioni sulle lastre tombali bolognesi di soggetto militare in il carrobbio, volume xi. bologna: parma, 45-57 bruno breveglieri. 1986. scritture lapidarie romaniche e gotiche a bologna. osservazioni paleografiche in margine alle iscrizioni medievali bolognesi in istituto per la storia di bologna. fonti per la storia di bologna. sala bolognese, bologna: arnaldo forni. bruno breveglieri. 2012. il borgo ricco di bologna alla fine del duecento in stenna storica bolognese, volume lxii. granarolo 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chrysanthou, k. cain, n. silberman, f. niccolucci. proceedings of vast (2004), the 5th international symposium on virtual reality, archaeology, and cultural heritage. 271-279. treccani. 2015. pietro d'ancarano. in dizionario biografico degli italiani, volume 83: piacentini-pio 5. roma: istituto della enciclopedia italia. giorgio verdiani. 2016. ricostruire nel virtuale e nel reale, esperienze tra musei e divulgazione. in musint 2, nuove esperienze di ricerca e didattica nella museologia interattiva. firenze: firenze university press. 195-208. received march 2017; revised july 2017; accepted august 2017. the reconstruction of drawn architecture fabrizio i. apollonio, federico fallavollita, elisabetta c. giovannini, riccardo foschi and salvatore corso university of bologna, italy among the many situations that arise in the process of digital hypothetical 3d reconstruction, a particular case is that of unbuilt projects. such projects were designed but remained on paper, with the result that, although documented by technical drawings, they posed the typical problems that are common to other cases, which range from 3d reconstructions of transformed architecture to destroyed/lost buildings and parts of towns. these case studies, which start from old drawings, have to be implemented by different kinds of documentary sources that are able to provide-by means of evidence, induction, deduction, and analogy-information characterized by different levels of uncertainty and related to different levels of accuracy. all methods adopted in a digital hypothetical 3d reconstruction process show us that the goal of the researchers is to be able to make explicit, or at least intelligible, a synthetic/communicative level representative of the value of the reconstructive process that is behind a particular result. this can be accomplished through a graphical system. the result of a reconstructive process defines three aspects of a structure, intimately related to each other: shape (geometry, size, spatial position); appearance (surface features); and constitutive elements (physical form, stratification of building/manufacturing systems). this paper presents the use of 3d models as a means to document and communicate the shape and appearance of unbuilt architecture while tracing the uncertainty and accuracy that characterizes each of the reconstructed elements. key words: 3d digital modeling, 3d virtual reconstructionm, architectural drawing, reconstruction process sdh reference: fabrizio i. apollonio et al. 2017. the reconstruction of drawn architecture, sdh, 1, 2, 16 pages. doi: 10.14434/sdh.v1i2.23243 1. introduction the topic of the reconstruction of the artifacts of a vanished, lost or non-existent past can be traced to the age of humanism in fifteenth century italy. during that period, when interest in classical culture and history was keen, some scholars began to collect and study greek and roman antiquities, author's address: fabrizio i. apollonio, federico fallavollita, elisabetta c. giovannini riccardo foschi and salvatore corso, dipartimento di architettura, università di bologna, viale del risorgimento 2, 40136 bologna, italy; email: fabrizio.apollonio@unibo.it; federico.fallavollita@unibo.it; elisabettacaterina.giovannini@unibo.it; riccardo.foschi2@unibo.it; salvatore.corso2@unibo.it permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal initiating, in the field of art and architecture, the study of vitruvius’ de architectura, the edito princeps of which dates to 1486 [cf. vitruvio 1556]. these interests led both to the birth of archaeology and also to the publication of important new treatises on architecture, including, notably, leon battista alberti’s de re aedificatoria (1450), sebastiano serlio’s i sette libri dell'architettura (1537), and andrea palladio’s i quattro libri dell’architettura (1570). these treatises contributed to the development of the architectural culture of the renaissance. since the time of the humanists, the topic of reconstruction (in the beginning as a physical model and nowadays as a digital one) has continued to interest scholars in a wide range of disciplines that study the past, including history, archaeology, paleontology, architecture, art, literature, etc. ciriaco d’ancona (1391-1452) was an early humanist with a strong interest in the dcoumentation and reconstruction of the monuments of the past. he was a merchant and diplomat from ancona, a selftaught humanist and antiquarian. ciriaco d’ancona was “the most enterprising and prolific recorder of greek and roman antiquities, particularly inscriptions, in the fifteenth century, and the general accuracy of his records entitles him to be called the founding father of modern classical archaeology” [bodnar, foss, 2003]. bodnar 1960 presented a biography of ciriaco as well as a detailed analysis of the inscriptions that he collected throughout his journeys along mediterranean littoral and in the middle east. also included was a map of sites mentioned, and ten plates with reproductions of ciriaco’s original drawings. according to bodnar and mitchell [bodnar, 1960; mitchell, 1974], ciriaco was the first modern european to describe the acropolis of athens and the parthenon. thanks to him, his contemporaries could have the first hypothetical drawing of the parthenon, which ciriaco called by its name, instead of “the church of santa maria,” as it had been known until then. after his visit in 1436 thus, ciriaco wrote that he had admired “mirabile palladis divae marmoreum templum, divum quippe opus phidiae” [“the admirable marble temple of the goddess athena, a truly divine work of phidias”; nizzo, 2010]. one of the plates published by bodnar allows us to compare ciriaco’s parthenon drawings with that of giuliano da sangallo (1445-1516), which represents an interpretation of two of ciriaco’s original drawings: one dedicated to the front and the second one, now lost, of the frieze. sangallo’s drawing is very different: it changes the proportions of the elevation of ciriaco's parthenon; removes three columns from the front colonnade; adds composite capitals to the doric columns; rearranges the metopes from the south side to the north (the side represented in his drawing); and puts, just behind and above the pediment of the temple, a kind of attic supported by columns placed on pedestals. ciriaco’s methodological approach was based on (a) first-hand investigation of the monument, a direct approach to the ancient spolia, tested in the field; (b) study of the texts of ancient authors, whom he called nobiles auctores (quoting among others pliny’s naturalis historia xxxvi, 18, and also the aristotelian de mundo, 6399 b 34); and (c) comparison with the stylistic characteristics of contemporary works presenting the same stylistic features. in contrast, giuliano da sangallo’s approach was based on his interpretation of ciriaco’s two drawings and on his own architectural knowledge gained from the study of ancient monuments that he had found, surveyed and drawn. 2. 3d reconstruction after an architectural drawing these two cases of interpretative drawing of the parthenon well represent the typical problems of the reconstruction process since ancient times: the proper use of documentary sources, their interpretation, and the transparency of the process that led to the reconstructive (hypothetical) result. for the completion of the reconstruction process, and then in the case of the virtual reconstruction for defining the shape, size and material characteristics of each element of an artifact, we are often faced with the presence/absence, certainty/uncertainty, and accuracy/inaccuracy of information. such information is derived from sources that we have, and where these are deficient, by the possibility of finding specific reference material useful to the formulation, more or less reliable, of the hypothetical reconstructions. each source or reference utilized is characterized, therefore, with regard to information that can be inferred and which is related to the reconstruction process by a specific degree of uncertainty or reliability and by a degree of accuracy. to bridge the gap between the presence/absence of information and the resultant knowledge/ignorance and then to formulate a hypothesis by expressing a form of ignorance about a proposition, we should understand the category of ignorance that is relevant. unfortunately, from an epistemological point of view, a fixed definition of uncertainty/reliability/ambiguity does not exist. there is not a standard and shared method to visualize this kind of uncertainty [kensek, 2007; strothotte et al., 1999; pang et al., 1997; zuk et al., 2005; perlinska, 2014; bakker et al., 2003 ; borghini, and carlani, 2011; apollonio et al., 2013; vico lopez, 2012; georgiou, and hermon, 2011; demetrescu, 2015; apollonio, 2016; lulof et al., 2013]. there is a wide range of definitions with reference to the various fields of knowledge and different approaches, some less generic than others, concerning both the uncertainty and the ways of representing it. there is, not surprisingly, a copious literature on this topic, including surveys of the problem [edwards and nelson, 2001; otto et al., 2010; bonneau et al., 2014; masuch and strothotte, 1998; thomson et al., 2005; brodlie et al., 2012; pang et al., 1997; pang and furman, 1994; boukhelifa and duke, 2009]. some research fields– e.g., spatial modeling, law, medicine, geology, as well as archaeology and the history of art and architecture–have defined inferential reasoning and incomplete evidence, on the one hand, to formally express beliefs in order to make a judgement or evaluate a hypothesis, and, on the other hand, to have explored the notions of mathematically and visually expressing uncertainty. when uncertainty is related to a lack of information arising from randomness, such as results by chance, we call it aleatory: it is objective that the results differ each time an experiment is run, depending on chance, and thus we use probabilistic modeling to describe it. when uncertainty is due to a lack of knowledge, which means knowledge that in principle could be known, but in practice is not, we refer to the type of uncertainty called epistemic: it is subjective; it is uncertain due to errors that practically cannot be controlled and can be described by non-probabilistic modeling. [bonneau et al., 2014] the reconstruction process, using a given set of documentary sources, requires a procedural pipeline based on a semantic system, able to define a set of preparatory and operational phases— complementary between them—in order to investigate the sources and, when missing any information, the related or integrative references [apollonio et al., 2013; münster et al., 2016; pfarrharfst, 2016]. such types of information may be used and elaborated in order to define a structured modeling procedure based on different levels of interpretation, characterized by a progressively increasing ordinal scale of uncertainty [apollonio et al., 2013; apollonio, 2016]: reconstruction based on archaeological/architectural evidence reconstruction based on original drawings reconstruction based on design data related to stylistic/coeval similarities reference to treatises, books, journals, articles or architectural guidelines written by the author (architect/artist) of the artifact studied reference to treatises, books, journals, articles or the manual that the author (if known) has or could have used as his own reference interpretative hypotheses related to a specific architectural style and/or historical period interpretative hypotheses based on static analysis, referring to coeval construction systems, constructively plausible and compatible with the project reconstructive conjectures, failing references each of these categories is defined, in fact, by its own degree of accuracy related to geometric, dimensional, formal, material and construction data that we can derive, infer or assume from the documentary source(s) available for each single element of that case study. figure 1. comparison between two different kinds of sources (left: arch of septimius severus, roman forum, rome; right: porta aurea, ravenna), characterized by same uncertainty and by different accuracy. the determination of the shape of an object (geometry, size, spatial position) is based on procedures— a sort of “playback” of the architectural design and building process—embodied through the definition of a given degree of accuracy, connected, in turn, with the scale to which the process of modeling could be related (fig. 1). in the pre-digital design process, the scale of representation of an object/artifact defined the accuracy of information obtainable from it. with the advent of digital tools, modeling and representation can coexist separately. modeling procedure defines the shape of an object up to a scale of 1:1 (related to dimensional accuracy chosen based on the unit’s working environment in which we operate); representation displays the model produced with its own attributes and up to the desired level of detail. the shape (dimensional and geometric consistency) of an artifact becomes the first area where we need to clarify the level of geometric accuracy of the reconstruction process, and therefore it defines its semantic structure that hinges on the same valuation method. therefore, the resulting uncertainty validation of the reconstructed model is based on different levels of interpretation of source data, characterized by a progressively increasing level of uncertainty of the geometrical definition (accuracy) of the constitutive elements of the artifact. archaeological/architectural evidence (reality-based data; stratigraphic record), original drawings (survey/plans/sketches characterized by a low level of dimensional accuracy, etc.) refers to the hypothetical reconstruction based on evidence derived from the architectural or archaeological artifacts or real items. the level of accuracy of real-based data, therefore, is determined only by the intrinsic accuracy of the instrument or by the surveying and measuring technology used to detect the object (fig. 2). figure 2. comparison between two different kinds of sources on the same monument (arch of septimius severus, roman forum, rome), characterized by different uncertainty and the same accuracy. the conjectural hypothetical reconstruction, which, owing to a lack of any documentary source or references, depends on the researchers’ “common/scientific sense,” is based on their accumulated knowledge or, whenever necessary, on their imagination. sometimes the design data are related to stylistic/contemporary similarities, references to treaties, books, journals, articles or architectural guidelines written by the author, interpretative hypotheses related to a specific architectural style and/or historical period or referring to contemporary construction systems. among the different types of sources, we could use are 3d models/findings; data from 3d survey (tls, sfm); technical drawings (historical, cadastral, maps, 2d survey); multimedia (animation, video, rendering, photos); 2.5d representation (reliefs, bas-reliefs); drawings (engravings, sketches, paintings); and texts/verbal descriptions. however, in the case of projects of unbuilt architecture, drawings, sketches, images and pictorial representations are the only sources to which we can refer to develop a hypothetical reconstruction (fig. 3). 3. two-dimensional drawings and the precision of 3d models therefore, with reference to the scale of uncertainties, the reconstruction of architecture designed only in accordance with drawings or sketches, is characterized as a process attributable to the second degree of certainty (see list above). the type and graphical characteristics of the sources, as we saw above, also affect the degree of accuracy and therefore the detail of the reconstructive hypothesis. we have accumulated nearly fifteen years of experience in the field of reconstruction of architectural projects that were never built. over the years, we have reconstructed and published many projects of various architects. besides the virtual reconstruction of unbuilt buildings or other architectural structures, we place emphasis on research concerning three-dimensional models as a research method, transfer of knowledge, and new forms of memory. the research for procedures, methods and techniques applied to the digital representation of architecture and their educational use leads us to utilize three-dimensional models for the knowledge, reading and analysis of representative cases of architecture. the designs of andrea palladio remained on paper, so did those palladio published in i quattro libri, the designs by claudenicholas ledoux (1736-1806) for the ideal city of chaux, the design for the foro bonaparte by giovanni antonio antolini (1753-1841) and the utopian designs for “cesena nuova” and “cesenatico nuovo” by mauro guidi (1761-1829). they represent a sufficiently broad sample of typological experimentation. the drawing and the representation, in this case, become the means for the development of interpretive models in which, despite well-structured guidelines, the intention of reproducing the original design idea is mediated by the subjective vision of the represented project. the documentation of this cognitive process is an integral part of the ongoing debate on transparency of information and the configurative possibilities of architectural elements in the 3d virtual reconstructions. here we shall attempt to give some answers to the questions raised in this debate. figure 3. virtual reconstruction: a. palladio, villa mocenigo. perspective longitudinal section figure 4. virtual reconstruction: a. palladio, villa mocenigo 3.1 3d reconstructive hypotheses after palladian drawings for the reconstruction of 3d digital models of palladian buildings, we used as documentary sources original drawings by andrea palladio for designs of villas (fig. 4), palaces and other buildings. these drawings are preserved in various archives [e.g., riba, london and the civic art gallery of palazzo chiericati, vicenza]. we also consulted the drawings published in the second book of i quattro libri, accompanying the representations of many houses ordered from him [palladio, 1570]. the original drawings are usually a plan and an elevation representing designs of unrealized villas or variants (as ideal designs) of those built by palladio during his career. they are drawings elaborated with the aim of presenting a design, tracings juxtaposing plan and elevation, following a form of architectural representation perhaps first adopted by antonio da sangallo. in the drawings elaborated for a client, the measurements are depicted with care in order to not disturb the graphic quality of the drawing, reporting, in some cases, a scale bar in terms of the foot of vicenza, or indicating, in others, the size of the rooms, widths of colonnades or porticos, or intercolumniations. the drawings depict some architectural detail: the shapes of the rooms’ ceilings (rib, cloister, lunetted vaults); watercolor highlights the thickness of the walls, and the chiaroscuro effect of the openings in the façade. in some cases, these are just sketches attributable to planimetric study for projects of villas, some of which becamebuildings, others remained unbuilt. 3.2 the projects of c. n. ledoux for the ideal city of chaux 3d models of reconstructions of ledoux’s projects were produced after drawings published in the volumes of l’architecture [ledoux, 1804; ledoux, 1847; gallet, 1991], first published in 1804, consisting of a long explanatory text illustrated by hundreds of engravings. these are detailed engravings that collect plans, sections and elevations, whose task is to describe and document the formal, geometric, distribution and architectural characteristics of different kinds of buildings (fig. 5). in some cases they are illustrated by perspective views (fig. 6) that render projects within a typical countrylandscape context, characterized by trails, paths, tree lines or masses of trees, mountains, rivers; some include human figures and animals. all the plates reproducing technical drawings are accompanied by a graphic bar scale in toises du chatelet. figure 5. virtual reconstruction: c. n. ledoux, maison de campagne, planche 21 figure 6. virtual reconstruction: c. n. ledoux, chemin de saint denis. 3.3 the digital reconstruction of unbuilt architecture designed by giovanni antonio antolini giovanni antonio antolini (1753-1841) was an italian architect, urbanist, engineer, writer, and professor at the university of bologna and at milan’s brera academy. from 1797 to 1813, he worked on many important neoclassical designs for buildings that were never constructed, probably because of the high costs arising from their visionary nature and urban scale [antolini, 1806; antolini, 1797]. his drawing abilities were considerable. it is not unusual to encounter inconsistencies in the hand drawn plans of many contemporary architects, especially between sections and plants, stairs and facades, but in antolini’s drawings this happens very infrequently. furthermore, the classical orders were often detailed on documents presented with the project boards or in separate writings [antolini, 1785; antolini, 1803]. this means that during the digital reconstruction there is no need for many subjective interpretations and personal conjectures, or to consult other architects as references, because there are few incoherencies and omissions in antolini’s designs. 3.4 digital reproduction of original drawings alongside the considerations concerning the accuracy of the information inferred from drawings, we can consider other assessments regarding the digital reproduction of documents or original drawings. these aspects relate in particular to the accuracy of the reproduction of graphic signs and color fidelity, where, in addition to the geometric information in the drawings, we can include information regarding the treatments of the architectural surface (fig. 7). figure 7. virtual reconstruction: g. a. antolini, foro bonaparte, entrance of the thermae. figure 8. virtual reconstruction: g. a. antolini, foro bonaparte, entrance of the thermae. without going further into these topics related to the digital reproduction of drawings [beltramini and gaiani, 2003; corsi et al., 2011], which is beyond the scope of this article, we used high-resolution scans as a digital basis for the 3d reconstructive modeling. these were obtained from original drawings or from facsimiles in books. in addition to considering the strain on the paper that was used for the scans, which was offset in most cases due to the presence of a graphic scale, the inherent precision of the drawings was estimated on the basis of the graphic sign of less thickness, according to the graphic representation of scale and the factor of approximation introduced by digital reproductions that were scanned. by way of example, we can affirm that the 3d digital models obtained from original drawings at a scale of 1: 100 have an accuracy of ± 3.5 cm whereas those obtained from drawings at the scale of 1:50 have an accuracy of ± 1.75 cm (fig. 8). 3.5 methodological approach to 3d virtual reconstruction based on drawing the hypothetical reconstruction begins with the creation of a three-dimensional model of the edifice as is inferred by the plan and elevation depicted therein. this type of reconstruction requires an analytic method of construction based on a semantic system, as not all the information necessary for completion of the model is obtainable only and univocally from the drawing itself. as a preliminary step, we identified some design references belonging to the author’s methodological sphere more or less contemporary to the case study, and to the drawing used as a source, owing to the stylistic similarities that these can present; thus they can be used as a means of verification of formal and architectural features. to solve several basic design issues, we conversely used books or treatises on architecture as references. these included the first part of palladio’s i quattro libri, as well as the handbook published by antolini, in which the architect presents his formulas for orders, for measurements of the rooms, the design of the stairs, and for the design of architectural details (columns, pilasters, moldings, architraves, sizing of doors and windows, etc.). these are the references for the entire design system. we could not model other elements based on the information obtainable from the drawing. this required more perceptive interpretations obtained by referring to other treatises, i.e., serlio’s i sette libri, and by focusing primarily on the building systems used at that time in order to formulate reconstruction theories that were plausible from a technical, structural and design point of view. 3.6 the case study of villa mocenigo based on drawings edited by andrea palladio the case study of villa mocenigo by andrea palladio can illustrate, in an emblematic way, the theoretical considerations discussed above (fig. 9). the reference information is provided by one palladio's sketched plan of a villa at dolo for leonardo mocenigo, stored at riba. the events that mark projects for the villa mocenigo are very well articulated. palladio was most likely commissioned for the villa project in 1554, when it is known that leonardo mocenigo purchased stone for the construction in the “brolo” that he inherited from alvise mocenigo the elder. this was placed in a southern lane of naviglio brenta, between dolo and paluello. the work continued with some interruptions, partly resulting from the owner’s commitments abroad as ambassador to emperor ferdinand at least until 1564. unfortunately in 1581, his son, alvise the younger, entrusted to cesare franco the renovation of the villa. further work was done to make the palladian building unrecognizable, and it was demolished at the beginning of the nineteenth century. the villa had a traditional layout with a hallway and a pronaos with four composite columns. it is much different, however, from the plan published in the table of palladio’s treatise (f. 66), showing a building developed around a peristyle with four colonnade fronts, of which the two largest were framed by rustic curvilinear features. the riba designs propose variants on the same theme. the drawing, numbered xvi/1r in the burlington-devonshire collection, represents a building reminiscent of giuliano da maiano's villa of poggio reale near naples of 1487-88. the drawing numbered xvi/2 represents a design based on the plan of falconetto's villa vescovile, and the drawing numbered x/1v is a sketch design for the plan of a villa, similar to the project published in i quattro libri. there is a central peristyle around which the villa’s rooms are laid out, but with only one court, the lower one, framed by “barchesse,” while the upper court is simply designed as an italian garden. the reconstructive hypothesis shown in fig. 9 refers, however, to the sketch numbered x/2r, which—albeit the least defined among all the ones related to the villa’s design–has some characteristics that lie as an intermediate solution between the drawings cited above (xvi/1r, xvi/2, x/1v) and the proposal of i quattro libri. figure 9. virtual reconstruction: the case study of villa mocenigo designed by andrea palladio. the colonnade peristyle has a rectangular shape of 70 x 50 vicentine feet; the lower court is framed by curvilinear “barchesse”; the upper court opens from a c-shaped colonnade with two “barchesse” on the short sides. the sketch presents only the plan of the ground floor of the building, giving an indication of the layout of the main rooms, the positioning of the stairs, the layout of the colonnades and some measurements of the rooms. it therefore allows us to formulate a reconstructive hypothesis of the planimetric layout of the villa, with a high degree of uncertainty (grade 2) and an intrinsic accuracy defined by the unit of measure used by palladio, the vicenza foot (equal to 35.6 cm). the thicknesses of the walls were defined on the basis of the constructive features indicated by palladio himself in his treatise (grade 4) and detailed by larry sass [sass, 2007 ] (grade 4). as regards the elevation, as well as the information relating to the parts not defined in the riba x/2r sketch, the reference was the text and drawing relating to the villa mocenigo published by palladio in table 66 of book ii of his treatise. these constitute documentary sources of uncertainty of grade 3, as they represent “data related to stylistic/contemporary similarities” in the specific data related to a different solution for the same design, made by the same architect, and with a grade of accuracy defined by the unit used by palladio also in the treatise, which is always the vicenza foot. concerning the architectural details, orders, moldings and frames as a reference, the indications given in palladio’s treatise have been adopted. there we find the characteristics of the ionic and corinthian architectural orders, the moldings of the door, and the window frames. such data sources reflect references of uncertainty of grade 4, because they represent “reference to treatises written by the same architect.” the highest degree of accuracy, such as the dimensions of stylistic elements (capitals, friezes, balustrades, decorations), are obtained from the diameter of the column adopted for the building (whose measurement for villa mocenigo is indicated in table 66). this is assumed as a reference measurement unit (or module) in order to understand the proportions of all the other constructive and stylistic elements of the construction. 4. conclusion and future work even if the digital reconstruction based on architectural drawings or sketches represents only a small part of the wide range of types of reconstructive paths, the process itself is particularly significant, inasmuch as–beyond the definition of formal and geometric characteristics of an artifact–it adds to the issues related to the certainty of the data used as a source and also to the question related to the accuracy of granularity of the data itself, only partially considered in this paper. however, we still must explore all the issues related to the formulation of the hypothetical 3d reconstruction of the material characteristics of the building that was just designed and never built. although there does exist information related to the definition of the characteristics of the surfaces of a building (walls, floors, cornices, columns, etc.), the acquisition and the interpretation of those data always pose additional issues related to the reliability of the data itself, to its interpretation and to the certainty of the solution adopted. these are the problems related to the acquisition and interpretation of the data found in the drawings, owing to the aging that the medium (paper or other material) underwent—like any archaeological find—and that leads to inevitable chromatic alteration, to changes and deformations of the surface, and to losses or damage. 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unknown codes, and the inherent difficulty of combining data from different excavations. these problems are commonly addressed by archiving and publishing harmonized data, which enables searching through combined datasets, but at the cost of losing important detail. an interchange format for digital archaeological data was clearly needed. the authors played a major role in the drafting group for what would later become the "sikb0102" interchange standard. the standard focuses on: 1) keeping the original level of detail while providing a harmonized view; 2) serving archiving as well as data interchange in active projects; 3) control of versions; and 4) making sure that relationships, the key to solving archaeological mysteries, are central. an unusually flexible interchange format was created that can hold detailed data together with, and linked to, harmonized data. having the harmonized data makes it easy to search and combine datasets, while having the related detailed data makes it possible to drill down to the original level of detail. archaeological data is all about structure and location; therefore, the authors have taken care to include vector geo-location data in the specification as well. combining all these aspects in one interchange format makes the sikb0102 specification stand out. in the netherlands, archaeological research data must be provided to the national archival institute (dans), and the kna (quality standard for the dutch archaeology) requires submission of the data to the national archive. today the kna requires archaeological excavation data to be provided according to the sikb0102 specification, which is a big step forward in re-using archaeological excavation data. keywords: exchange, archival, excavation, harmonization, xml sdh reference: wouter boasson & ronald m. visser. 2017. sikb0102: synchronizing excavation data for preservation and re-use. sdh, 1, 2, 19pages. doi: 10.14434/sdh.v1i2.23262 1. introduction during the last decades in the netherlands, there has been a substantial increase in the number of excavations and excavators, and also an increased use of digital tools in archaeological research [visser et al. 2016]. author's addresses: wouter boasson, raap archaeological consultancy, leeuwenveldseweg 5b, 1382lv, weesp, the netherlands; email: w.boasson@raap.nl. ronald m. visser, saxion university of applied sciences, handelskade 75, 7417dh deventer, the netherlands; email: r.m.visser@saxion.nl. permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal archaeological excavations are destructive by nature. this implies the need to properly document the discovered objects, for two reasons: 1) the in situ cultural heritage is destroyed, and 2) it should always be possible to re-interpret the primary data, an important part of scientific research in general. this makes it necessary to document the data in a way that will be understood by current and future generations of archaeologists. however, since the emergence of databases in archaeological research, each archaeological company or institute has developed its own digital systems. when data have to be exchanged, this leads to various, often undocumented, conversions of data. problems that can arise during these conversions have ranged from fairly easy to solve issues, such as non-matching object and property (table and field) names, through different but easy to understand data-structures, to a complete lack of understanding of the codes or structure. dutch archaeology is blessed in having dans (data archiving and networked services; https://dans.knaw.nl/nl) whose mission is to make all data technically available by converting multiple formats to a few open and future-proof, ascii text-based formats (e.g. xml and csv) with inclusion of the requisite metadata. in the netherlands, archaeological contractors are required to send the excavation data to at least three different repositories or databases, each with its own rules with regard to formats: all the digital documentation of excavations is required to be sent to the dans-easy repository. all the excavated finds, along with both digital and analog documentation, must be delivered to an archaeological depot for permanent storage, including descriptive documentation. the archis database [roorda and wiemer 1992] from the cultural heritage agency of the netherlands is designed to keep track of indicative data for archaeology, which could be seen as a harmonized summary of the excavation data. until a few years ago, each of these institutes had its own regulations and formats for delivering data. dans was the least demanding: every dataset that seemed to be accompanied by proper metadata was accepted. archaeological depots had very diverse demands, ranging from almost none to the very specific. updating archis required manual data entry. this used to be a very time-consuming and thus expensive process for archaeological contractors. clearly, this was not a desirable situation. providing excavation data in various formats is costly, and there is no defining standard that makes sure that the data will be easily reusable for future research. a common data format to exchange data would be of benefit to the archaeological community, but designing it was hampered owing to the many different requirements. the most interesting part of such an undertaking is to align all the data providers and institutes involved; the more people, the more opinions that have to be harmonized. nevertheless, the benefits were acknowledged by all institutes and organizations involved. the sikb (foundation for infrastructure quality control of soil data, including archaeology; www.sikb.org) was invited to manage the development and availability of a data exchange format for the core data that must accompany the physical objects sent to the archaeological repositories, which would solve at least part of the problem. the sikb had successfully designed a data exchange format targeted at soil characteristics data (sikb0101 protocol: http://www.sikb.nl/datastandaarden/sikb0101-bodembeheer), and it already safeguarded the dutch archaeology quality standard [willems and brandt 2004; http://www.sikb.nl/archeologie/richtlijnen/brl-4000]. the sikb also has the full infrastructure in place to manage standards, both for data exchange as well as other standards, such as formal guidelines (e.g. the dutch archaeology quality standard, also known as the "kna"). both existing dutch standards formed the starting point for the development of a new exchange standard. since 2011, the authors have played an important role in designing the sikb0102 exchange standard (http://www.sikb.nl/datastandaarden/richtlijnen/sikb0102). the format will be presented in this paper. it started out as a digital "packing slip" when delivering finds for long-term storage in the depots, but during the discussions we realized that this provided a unique opportunity to develop a standard that enables a harmonized exchange of data. the new sikb0102-format enables the exchange of an archaeological dataset while keeping full detail. the qualities of the format are also reflected in its acception as a national "open standard," which one should comply with unless it is not possible (forum standaardisatie: https://www.forumstandaardisatie.nl/standaard/sikb0102). for the past couple of years it has been obligatory to use the sikb0102 format when exchanging archaeological data in the netherlands. however, the format was never presented to an international public, and it is not well known outside the netherlands. for example, the development of the emerging crmarchaeo-model (http://www.cidoc-crm.org/crmarchaeo/) would have benefitted from our experience in developing the sikb0102-format. this paper aims to share the format, its strengths and shortcomings. however, before describing this format, we will first briefly explain the dutch excavation and documentation method. 2. excavation datasets in "exploded view" the typical dutch excavation dataset reflects the fieldwork methods, which will be briefly described here. two major different excavating types can be distinguished: planes and cross-sections for feature-based excavations, such as settlements, or sieving grids when features are virtually absent, generally for the lithic periods. a distinction is made between the observations, the analysis and the metadata. typically, in the analysis phase of a research project, relationships are discovered, and these should be stored. this is a different type of information: interpretations instead of observations, and storing interpretative information should ideally not touch the observations. this section also includes examples of common implementation strategies. 2.1 data objects for feature based excavations the feature-based excavation is the more common, having the following workflow and administrative objects: the larger excavations in the netherlands are usually segmented into trenches on the order of meters to several tens of meters wide, and sometimes over 100 meters long. within this trench excavation, planes are prepared for documentation and further inspection. these planes are created based on stratigraphy. while digging to the desired level, care is taken to collect finds. the plane will subsequently be investigated for features. the features will be mapped mand related to the plane where they were seen. the features are cut in half and dug out, to check for fillings and finds. a cross-section of a feature is generally drawn and is called a "coupe" in dutch (fig. 1). figure 1. conceptual view of a feature (posthole), with two fillings, with the contours as observed in the plane as well as in the "coupe." collected finds are linked either to the plane and an administrative subdivision ofm the plane, or to a feature and possibly a filling. for large features sometimes administrative subdivisions of the feature are made (segments). the walls of the trench give insight into the stratigraphy; in fact they are cross sections, and they are treated much like the excavation plane, since it is the vertical version of a plane. features and finds observed are documented. if possible, the features are related to features in the excavation plane. the entire process could be repeated multiple times when several stratigraphic levels of interest are expected. the basic (field) observations translate to a very basic and common logical set of data objects, mapping 1:1 to the observed objects, as laid out in fig. 2. note that not all data objects are present; in general, the interpretative information layer is omitted for clarity, as well as descriptive data about drawings, documents, images, find packaging information and project metadata. note that the relationship between feature and plane has a many-to-many cardinality, which is logically true: one feature may be observed in more than one plane, and multiple features can be observed in one plane. when implementing a data structure, various excavators deal differently with this phenomenon, which is one of the challenging areas when creating a standardized data exchange model. there are two common approaches: every time the same feature is recognized, it is re-entered as a new feature in the database, referencing the actual plane where it was observed, but with the same feature number. each feature is only entered once, referencing the first plane where it was observed. disadvantages: the first approach creates phantom objects in the database, while the second method lacks the links with other observations of the same feature. this could easily be solved by inserting an extra relation layer that links a feature to a plane, instead of directly referencing the plane table, but despite being the solution that best resembles the real-world situation, it is regarded as complex and/or time consuming. figure 2. basic logical data structure of the administrative objects, field observations and artifact details in a dutch plane/feature based excavation. note that the three find objects represent finds collected in a different way, but they are basically all find objects, with the only exception that the relationship differs. databases are often not correctly normalized to the 3nf [codd 1972] or bcnf form [codd 1974], possibly a left-over from paper-based documentation, where providing redundant information is of great help, not to say necessary, during the analysis phase of a project. examples: with each find not only the feature number is registered, but also the trench and the plane, which is redundant as long as a feature object can be uniquely referenced. the feature itself will reference the plane. composed keys (e.g. a find number) are often created by separating the different parts of the key with a . (dot), where they are actually different properties of the object. e.g., find one may reference feature 2.5.7 (which is feature 7, observed in plane 5 in trench 2). both examples are considered bad practice as they are error prone (contradictory information) and difficult to manage in a database. 2.2 sieving grids in this type of excavation, the digging is restricted to the removal of the topsoil. within our layer of interest, primarily the soil is lifted in small quadrants and sieved to detect (small) finds. the major difference with the plane/feature is that when sieving a grid, the plane is subdivided into small segments (e.g. 0.5m x 0.5m), and the finds are linked to these small segments as well as to a layer (zlevel), not to be confused with the stratigraphic layer. fig. 3 shows the data objects and their relations; here the interpretative layer as well as various metadata objects are omitted for clarity. figure 3. logical data objects matching the field observations in a grid-wise filtering excavation. 2.3 the analysis layer new insights acquired by analyzing the excavation data must be stored in the database as well. it is important to separate interpretation from observation, as for re-use the observed data must be available for re-interpretation. the results of analyzing the observations could be stored in the form of setting additional properties of already existing objects, e.g., a concluding age for a specific feature, based on find information. it could also lead to new data objects, the most notable example being the structures (e.g., a set of postholes making up a building). this is all additional information on top of the observed objects. structures: each structure should be represented by a data object, which can be linked to multiple features. stratigraphic layers: features (and finds) are linked to a stratigraphic layer; the link must be observed in the field. but often there are uncertainties, especially when linking stratigraphic layers between geographically separated locations (separated trenches). errors are usually detected and corrected later, and in an ideal dataset we should have the initial observation separated from the final interpretation. we should have an object representing a stratigraphic layer, which can be referenced from the features. detailed find descriptions: additional information, usually stored in objects with a data structure matching the properties of interest. they link to the finds, in order to have them coupled to the correct features and structures. dating: finds, features and structures are usually given an age or date. most often this is bidirectional, derived from the supposed stratigraphic layer in combination with the artifact characteristics. this information is added to the respective objects. 2.4 geodata the geodata provides information on where the features and finds were located. the level (height information) of the planes is measured, to create a digital elevation model (dem) of the historic site. the contours of features are registered as well. the locations of the finds are not always registered, in which case they can be located by linking them to a feature when found in a sufficiently spatially defining feature (small features, e.g., postholes). data collection is most often done using a gps or rts (robotic total station) set, but the measurements are taken in a way that does not deliver a full 3d dataset. geometry data collection is aimed at creating a 2d-documentation of planes and cross-sections instead of 3d volumes.1 therefore it is often not possible to derive relationships between finds and features from the geodata. this is solved by always registering these relationships in the database. excavations datasets usually have their geodata stored in geodata files, separated from the object descriptions (features, finds, etc.), and therefore a formal link is impossible. common practice is the 1digitizing the contour of a feature in a plane does give the z-component of each measuring point, but a feature is not registered as a volume. use of naming conventions, but they are by no means standardized. for example, the geodata file "project_t1_p1_ft" probably contains the features in plane one, trench one, but it is also possible that all features were combined, where the geodata table has additional attribute columns for trench and plane number. 2.5 metadata to be able to understand the data, additional information on the data and documents is required, including code books (thesauri), relations between different data files, and descriptions of documents (e.g. reports and images) that are part of the dataset. general information may also be of value for the discovery of datasets and judging the quality. from a technical point of view within the context of this paper, the metadata is not very interesting, as there are already many standards (such as the well-known dublin core; http://dublincore.org). however, the relations between various files containing tabular data is of high importance for linking the data. the code books used in a dataset are also of crucial importance for understanding the data, as the stored information is in many cases somehow coded for the sake of size and search options, and not having proper code books renders a dataset useless. 3. sikb0102 the sikb0102 specification is an attempt to make archaeological research data exchangeable by using an exchange format that accommodates all relevant information from any dutch excavation. in order to accomplish this, it should be possible to map common data structures in use at excavations to the exchange specification. this leads to a basic functional specification: the various object types that should be included are determined by the requirements for carrying out an excavation. these are described in the kna standard (nl: "bouwstenen referentie," en: "building blocks reference"). also included must be the objects needed to contain the information required by the archaeological repositories. the dataset should include observations and interpretations. the required properties were determined by the absolute minimum requirements to get a basic idea of observed objects at the excavation site, together with enough information to handle the objects handed over to the archaeological repository. in plain language: the minimum set of attributes that is always present, even in a worst case excavation scenario. all possible relationships between the various objects (regardless of type) must be included. common code books must be used. metadata documenting the project, images, documents and additional data files (e.g., geodata files) must be included. to add the option of exchanging an excavation dataset in full detail, the following requirements have to be met too: it should be possible to add additional attributes to any predefined (standard) data object. original terms should be included for enhanced detail where the default code booksfall short. mthe original terms must be provided with a description. it should be possible to integrate spatial data. it would be useful to have the option to exchange data multiple times, and update, remove or insert records. this would be especially helpful when exchanging data with other researchers during the lifetime of a research project. 3.1 mapping original excavation datasets onto a generic structure in the case of the dutch excavation datasets, the (data) objects that should be present in an exchange format are known. difficulties arise when trying to map the various methods and data structures in use for the trench, plane, feature, filling, segment and find objects. there are multiple issues involved that together form the challenge of designing a proper data structure (objects and relations). structure challenges: not all object types are always present (often segments are left out). various solutions are in use for linking finds with their containing objects (feature, plane, sieve grid), and constructions typically become complex because different find collection strategies are used . for example, some implementations use different find tables for each collection strategy (fig. 2), while others introduce dummy objects to keep the relational integrity or just plain ignore errors in the presumed database constraints. key/numbering issues: numbers could even have a meaning (such as that filling [0] represents the intersection between the excavation plane and the feature, at its first occurrence), or, because finds must be linked for relational integrity in the database, a dummy feature [999999] exists, which represents finds collected in the topsoil dumping area beside the trench. primary keys could be business keys or pseudo keys (an id assigned by the database). composed primary keys are not always present as such in the database; they could be just strung together, separated by a dot. some data, notably the spatial data, is typically stored in separate files. here the direct link is missing, makig it necessary to describe the relationships in the metadata. relationships and stratigraphy: not every relationship can be foreseen, unless for each and every possible relationship a link object exists. this is unwanted, as the number of object link tables explodes. given the goal of accommodating every single excavation dataset, it should be possible to create any link. an examples of a commonly overlooked candidate for a relationship: two features may be linked when they appeared to be the same (separating observation and interpretation). stratigraphic relationships are extremely important. these are usually relationships between features, but also structures may be stratigraphically related, if desired. a provision must be made to accommodate these relationships. in an exchange format, these issues must addressed in such a way that a source dataset can be converted to the exchange format, with no loss of detail. solutions the structural issues require first of all a conceptual and coherent approach, as the multiple issues are somehow interrelated. the conceptual approach is necessary here, as in the excavation database many object-identifying numbers, often used as (primary and/or foreign) keys in a database, also have a meaning. as relationships differ among the various database implementations and the meaning of the numbers as well, the data exchange format must be agnostic to these differences, but nevertheless be uni-interpretable. relationships in the exchange format must use internal object identifiers to createm the links between the various data objects. the original keys of the dataset may be left out, as long as they are not necessary in order to link to external files or documents. the flexibility required by the different solutions of the researchers with regard to feature relationships was solved by introducing the concept of an "observation." this is a required object, in fact an extra link layer, which makes explicit which intersection with a feature is described (which plane, and optionally which filling; the method has to be added too, in order to distinguish between making a "coupe" (fig. 1), and a horizontal or vertical plane view). this allows for relating the single instance feature model to one or more planes, as well as multiple instances of feature models (of actually the same feature) observed on multiple planes. see fig. 4. figure 4. the observation layer, which describes the observation method for a feature contour, and allows for linking a feature with multiple planes (horizontal and vertical). the complexity of linking finds to the context where they were encountered, which can be of different types (see fig. 2 and fig. 3), is solved by introducing a second link layer. the find itself connects to the find context, which is a link object designed to link with objects of different types; a spatial object can always be included. this context link object can link directly to, among others, a feature or a plane, to the observation layer in order to more precisely describe the context, or to a segment. this cleans up the find objects, and optionally allows for re-use of the relationships in case many finds were encountered in the same context, which compacts the dataset. geo-information should be fully integrated and linked to the appropriate (descriptive) data objects, while validating links to external files is hardly possible. all data objects that could have a related geo-data object may reference a chunk of gml (geography markup language, http://www.opengeospatial.org/standards/gml), a broadly supported xml standard for exchanging geo-data. the most common relationships are part of the structure of the sikb0102 formatted dataset, which facilitates validating, and hints to the user that the relationhip should be made. besides this, the sikb0102 format includes a "relation store," where any object can be related to any other object, in a structured way. each relation must have a code designating the type of relationship. the standard code list is currently targeted at stratigraphic relations,and one generic type, but could easily be expanded by allowing more values. 3.2 custom attributes archaeology is science, with the invariable diversity in registered attributes, depending on a specific research subject. it is possible to include many common attributes, but it would be impossible to be complete. in addition, it was considered not acceptable to force excavators to rewrite and translate their entire coding system, especially given that many excavations that still must be exchanged using the sikb0102 format are already in a finished state. solution part of the sikb0102 specification is an additional "attribute store," that allows for adding custom attributes in a structured way, including metadata. the basic principle is to create a data object representing the attribute, which specifies: to which standard data type the attribute belongs (e.g. a find). a description of the content. data type. each instance of a data object that has extra attributes specified may add an attribute value object, containing the link to the data object as well as to the attribute definition. 3.3 code book usage and original terms the typical code book (thesaurus) is incomplete. from a scientific point of view, it cannot be complete by definition, as new insights are gained during research. however, a common code book is needed in an interchange format, as this is the only way to create a common picture and make datasets uniformly searchable. on the other hand, a dataset would be of much more value when the original terms used by the excavator, including the descriptions, were available too. in dutch archaeology, a standard code book exists (https://cultureelerfgoed.nl/dossiers/archis30/archeologisch-basisregister-plus), but it is widely acknowledged that it lacks detail. solution the sikb0102 exchange format stands out, as it allows for adding an extra information layer with codes (the code reference list) for each property that has a standard code book. this enables a harmonized conversion and exchange of code books or thesauri. the additional information layer links original codes with the required code book, and provides room for a description, and it also must be used when providing codes for custom attributes. 3.4 handling updates: versions we have to look at different aspects of versions: updates to the code books: it is necessary to be able to handle changes, as the national standard code books change every year. updates to the datasets: when working together in a project (e.g. a consortium of excavators, subcontractors) it would be nice to be able to send updates of a dataset, so that instead of fully replacing it, only updated, deleted or inserted records would be processed. updates to the user provided code reference lists: with changing standard codebooks, the links with the original terms must also be updated; this has to be done by the data provider, the dataset constructor. solution for each of the above-mentioned types of updates, a mechanism is in place in the exchange format. code book updates are being handled by a classic mechanism where every code is annotated with: a version number (x.y.z) date of version state in this way it is possible to check which codes are not valid anymore (withdrawn), and which ones are valid. only valid codes may be used during exchange, but values cannot be updated. this is sufficient for many purposes, especially when the code represents the state at a specific moment in time. dataset updates are handled by assigning universally unique identifiers to each data object exchanged in the sikb0102 format (https://en.wikipedia.org/wiki/universally_unique_identifier). they should be considered stable and unique, so that, e.g., feature 1 of project x by contractor y always has the same uuid, but no feature 1 of any other project should have the same uuid. these identifiers can in that case double-act as identifiers for linking data (within a sikb0102 dataset), as well for handling updates. updates can be handled by checking for changes, deletions and new identifiers in a dataset. note that this eliminates the problem of renumbering keys in the original dataset; they are replaced by the uuid in the sikb0102 dataset. the code reference list includes a property to reference a previous version of the code reference [boasson and boasson 2010]. this is an enhanced form of updating that makes it possible to actually replace records with new versions, and also to look back at previous versions. in the sikb0102 format, this allows for updates to original terms, in combination with changes to the related standard code books. 4. sikb0102 implementation the sikb0102 exchange format is implemented in xml. xml is a well-known standard for data exchange, and provides several advantages over any other option: ascii text: durable; readability is not depending on a particular piece of software. xml offers good options for validation using the xml schema document (xsd). incorporation of other standards, most notable gml for spatial data, is easy. a well-known standard helps in getting the (sikb0102) standard accepted. other similar standards (e.g. sikb0101) were already implemented in xml. however, one should be aware of the pitfalls of using xml, which was in the beginning of the process a major discussion point. these have been overcome. the most notable issues and the chosen solutions are outlined below. 4.1 general object structure traditionally, relations in xml are created by creating an object hierarchy. in archaeology, where there are many relationships, and many relations to and from the same objects, this would create multiplication of complete data records. to clearly demonstrate the issue, imagine the following. an image was taken of a find, so the image data has to be included in the find object. the find record itself must be included in the feature object, but then includes the image as well. the feature record should be included in the plane record, etc. then there is another set of objects that includes feature objects: the structures. the entire feature object must be included in that case, too. displayed in a simplified structured way, it looks like this (note the repetition): trench 1 plane 1 feature 1 find 1 image 1 structure 1 feature 1 find 1 image 1 this is classic xml. normally, this is technically easy to navigate, but size matters: the file size would easily exceed 100mb, and then it quickly becomes too big to handle with a classic xml document parser which fully loads the data. the solution was to use a relational database-like approach. every object occurs only once, and is uniquely identified. xml offers a good construct to accomplish this, by combining the "unique" constraint with the "key" option and the "keyref" construct. effectively an xml document becomes a relational database in this way. each and every object has an id (uuid) attribute (in the sikb format called: "sikb:id"), with a unique constraint on all objects. a key is defined on every object type, and the keyref creates the references. see the code example in fig. 5. <!-unique constraint --> <unique name="uniqueid"> <selector xpath="sikb:*"/> <field xpath="@sikb:id"/> </unique> <!-key on the feature objects ('spoor' in dutch) --> <key name="spoorkey"> <selector xpath="sikb:spoor"/> <field xpath="@sikb:id"/> </key> <!-keyref linking a filling object ('vulling' in dutch) to a feature object --> <keyref name="vullingspoorref" refer="sikb:spoorkey"> <selector xpath="sikb:vulling"/> <field xpath="sikb:spoorid"/> </keyref> figure 5. overview of the constructs to effectively turn xml into a relational database. the keys act as primary keys, and are implemented as attributes in the data objects; the foreign keys are stored within an element. for an example, see fig. 6. <sikb:spoor bronid="spoor:spoor:1" sikb:id="3041d5e6-1ee2-4f31-aaf612fa3dd26892"> <sikb:naam>spoor 1</sikb:naam> <sikb:grondspoortype>paalkuil</sikb:grondspoortype> <sikb:diepte uom="cm">20</sikb:diepte> </sikb:spoor> <sikb:vulling bronid="vulling:spoor/vulling:10/0" sikb:id="fd7e8d0e-7597-4597-b248-087f2746db9c"> <sikb:naam>vulling 10/0</sikb:naam> <sikb:spoorid>3041d5e6-1ee2-4f31-aaf6-12fa3dd26892</sikb:spoorid> <sikb:kleur>dy</sikb:kleur> <sikb:textuur>zs2</sikb:textuur> </sikb:vulling> figure 6. example of a relation: filling (vulling) points to feature (spoor). blue =key, green =foreign key or reference. note that the uuid data type does not exist in xml, so it is implemented as a string, and constrained with a regular expression (fig. 7): <restriction base="string"> <pattern value="[a-fa-f0-9]{8}-[a-fa-f0-9]{4}-[a-fa-f0-9]{4}-[a-fa-f0-9]{4}[a-fa-f0-9]{12}" /> </restriction> figure 7. string constraint to make sure uus are used (as far as possible). 4.2 code books the code books for archaeology contain thousands of codes. this is hard to handle, as classic xsd constraints in the xml, the xsd explodes, and there is not much controlled room for adding additional information, such as a validity date and state. for this reason, the code books are stored in a regular xml data file, accompanying the xsd structure document. 4.3 context links of finds as explained above, finds are linked to intermediate link layer objects, the "find contexts." these contexts must link to one of several object types (e.g. a plane (segment), or a feature), and additionally a spatial object must be linkable too. xml offers an elegant way of handling this, using a combination of the aforementioned "keyref" constructs, in combination with the "choice" element. the choice element effectively says: one of the following elements must be present ( "element" is the official xml term for what often is called a property, attribute, field or column name; in xml an attribute has a special meaning). in sikb0102 this is implemented as follows (fig. 8): <complextype name="vondstcontexttype"> <annotation> <documentation>relatieobject om de context van vondsten en monsters te duiden.</documentation> </annotation> <complexcontent> <extension base="sikb:basislocatietype"> <sequence> <element name="contexttype" type="sikb:codetype" minoccurs="1" maxoccurs="1"></element> <element name="stortid" type="sikb:uuid" minoccurs="0" maxoccurs="1"></element> <choice minoccurs="0" maxoccurs="1"> <element name="planumid" type="sikb:uuid" minoccurs="1" maxoccurs="1"></element> <element name="spoorid" type="sikb:uuid" minoccurs="1" maxoccurs="1"></element> <element name="vullingid" type="sikb:uuid" minoccurs="1" maxoccurs="1"></element> ... 4.4 original terms code reference the original terms used in an excavation can optionally be sent alongside the harmonized code. harmonized exchange is necessary to enable searching, but the details are relevant for interpretation. technically, the original terms are in separate data objects, which can be re-used whenever relevant, to avoid duplicates. as already mentioned, they are versioned in order to cope with updates. an example of a record with a standard code together with the original term is shown in fig. 9. <sikb:vondst bronid="artefact:artefact:13" sikb:id="f400e32b-e4f8-49d2-9276857d6feb17e7"> <sikb:naam>vondst 6.13</sikb:naam> <sikb:veldvondstid>f64402f8-08fd-4ce6-8512-6617399de305</sikb:veldvondstid> <sikb:aantal>1</sikb:aantal> <sikb:gewicht uom="g">33</sikb:gewicht> <sikb:materiaalcategorieker</sikb:materiaalcategorie> <sikb:artefacttype codereferentieid="5f6b3a2c-6ee8-56b0-bb19a9f0655f58f0">stgl</sikb:artefacttype> <sikb:beginperiode>melb</sikb:beginperiode> <sikb:eindperiode>ntv</sikb:eindperiode> <sikb:geconserveerd>false</sikb:geconserveerd> <sikb:exposabel>false</sikb:exposabel> <sikb:gedeselecteerd>false</sikb:gedeselecteerd> <sikb:verpakkingseenheidid>36c644f0-e0de-486c-b2d7734759e3c77a</sikb:verpakkingseenheidid> </sikb:vondst> <sikb:codereferentie sikb:id="5f6b3a2c-6ee8-56b0-bb19-a9f0655f58f0"> <sikb:broncode>s2.kan</sikb:broncode> <sikb:bronomschrijving>steengoed (metglazuur/engobe)</sikb:bronomschrijving> <sikb:broncodelijst>artefacttype_codes</sikb:broncodelijst> <sikb:standaardcode>stgl</sikb:standaardcode> <sikb:naamcodelijst>artefacttypevaluetype</sikb:naamcodelijst> </sikb:codereferentie> figure 9. example of a find where another code book was used by the excavator. the standard code is present in the find ("vondst") record ( artefacttype"), and the original term is referenced using the "codereferentieid" (in blue). 5. discussion of known issues and qualities the sikb0102 format is not perfect. although great care has been taken to make the xsd as specific as possible and to check as many relationships as possible, there are still many holes in the specification. from the point of data integrity issues, there are still multiple problems. the most obvious problem is that links with external data files cannot be enforced, but knowing how to link them is a necessity for using the full dataset. external data files typically consist of geodata files, and possibly of specialized information that is not part of the required elements. by agreement, it is still allowed to deliver this in external files to the archaeological repositories. the many-to-many nature of the observation object makes it impossible by design to verify if the required relationship between a feature and the plane is in place (the observation refers to these objects). there is a logical bug in the codereferences section: with custom attributes, it is impossible to link to a standard code, but a standard code is required (a dummy could be inserted). given the additional constraints on integrity and the option to add external (data) files, a full integrity check can only be performed using dedicated software. unfortunately, it is impossible to check whether all the data is included in the xml data exchange file. conversion is certainly possible, but not necessarily easy. although the sikb0102 format should be sufficient to deliver only one dataset for all required institutes, the national archis database requires a slightly different organization of find location information, and requires the notion of an "archaeological complex" type, which does not exist in the current format. reading and querying the xml data file. even though the relational database approach reduces file size dramatically, the use of xml has one major drawback—its size. using standard xml querying techniques such as xpath is virtually impossible on larger datasets, and the limits will be reached even sooner when the spatial data is integrated as gml. on the other hand, it is still easy to read using a streaming parser, which requires programming. this will slow down querying, but is not an issue when the data has to be imported into another system, which is mostly the case. 6. conclusion the various institutes involved are in the middle of developing software to actually start using the format; it is acknowledged as a usable format by those who have started using it. still, many excavators have to implement a solution to deliver data in sikb0102 format, but they will be forced to do so by the archaeological repositories, which already, or in the near future, will not accept data in other formats anymore. there is a certain risk of sending less information to the archaeological repositories, as it takes more effort to convert all the data into the sikb0102 format then simply send the excavation data "as is," the regular practice in the past. recommendations: to improve the re-usability of the datasets, the sikb0102 exchange format needs better specifications on how to make sure a future user can establish links with external data files. make the necessary adjustments to improve the link with the archis database. put in place smart checks on the contents, in order to provide warnings for the receiving institute when the data seems incomplete. altogether, the standard can be seen as a success, not in the least because it has been adopted as an open standard, because it is well documented, in the progress of adoption, and well maintained. 7. references erik boasson & wouter boasson. 2010. data integration technology in cultural research. in proceedings of the 15th international conference on cultural heritage and new technologies. vienna: museen der stadt wien – stadtarchã¤ologie, 459-469. e. f. codd. 1972. further normalization of the data base relational model. in r. rustin, ed. data base systems, courant institute computer science symposia series, vol. 6. englewood cliffs, n. j.: prentice-hall, 66-98. e. f. codd. 1974. recent investigations in relational database systems. in proc. ifip 74. amsterdam: northholland, 33-36. iepie roorda and ronald wiemer. 1992. the archis project: towards a new national archaeological record in the netherlands. in c. u. larsen, ed. sites and monuments: national archaelogical records. copenhagen: national museum of denmark, 117–122. r. m. visser et al. 2016. teaching digital archaeology digitally. in stefano campana et al. , eds. caa 2015. keep the revolution going. proceedings of the 43rd annual conference on computer applications and quantitative methods in archaeology. oxford: archaeopress, 11–15. w.j.h willems and r.w. brandt. 2004. dutch archaeology quality standard, den haag: rijksinspectie voor de archeologie. received march 2017; revised july 2017; accepted august 2017. underwater videogrammetry with adaptive feature detection at "see am mondsee", austria marco block, hochschule für technik und wirtschaft dresden, germany cyril dworsky, kuratorium pfahlbauten, austria carmen löw, kuratorium pfahlbauten, austria helena seidl da fonseca, kuratorium pfahlbauten, austria benjamin gehmlich, hochschule für technik und wirtschaft dresden, germany dennis wittchen, hochschule für technik und wirtschaft dresden, germany niklaas görsch, freie universität berlin, germany paulina suchowska, uniwersytet im. adama mickiewicza, poznań, poland benjamin ducke, deutsches archäologisches institut berlin, germany we present a complete, video-based 3d documentation process for the submerged remains of neolithic pile dwellings at the unesco world heritage site "see am mondsee" in austria. we discuss good practice routines and solutions, such as cable management, supporting the unmanned underwater vehicle (uuv) when strong currents are prevalent, and documentation/record keeping. the recorded site is a neolithic lake village dating to the 4th millenium bc. based on initial reconstruction results, we improved the image matching process of our structure from motion (sfm) pipeline (built around the free end-user application visualsfm), by replacing its default feature detector (siftgpu) with our own implementation of adaptive feature detection. the campaign was accompanied by a german television film crew. their documentary was shown on the german public television (ard) broadcast "w wie wissen". key words: unesco world heritage, underwater archaeology, pile dwellings, mondsee, videogrammetry, adaptive feature detection, uuv sdh reference: marco block et al. 2017. underwater videogrammetry with adaptive feature detection at “see am mondsee”, austria. sdh, 1, 2, 547-565. doi: 10.14434/sdh.v1i2.23202 1. motivation and introduction the unesco world heritage ensemble "prehistoric pile dwellings around the alps" consists of 111 archaeological sites in a region that includes adjacent parts of germany, slovenia, italy, france, austria and switzerland. in order to manage the five sites on austrian territory, the kuratorium corresponding authors: prof. dr. marco block-berlitz (archaeonautic), email: block@htw-dresden.de; dr. cyril dworsky (pile dwellings, kuratorium pfahlbauten), email: info@pfahlbauten.at permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal pfahlbauten1 has been established. the kuratorium’s main objectives are to protect unesco-registered pile dwellings (fig. 1) and to actively participate in research on this shared world heritage. in addition, the unesco world heritage convention2 requires a world heritage to be actively developed and used in a public function. due to the sensitivity of the archaeological remains and their concealment under water, this proves to be a demanding task. other world heritage sites are much more accessible, and can be traversed and experienced physically and in a more holistic way. with regard to the pile dwellings, there is no physical accessibility; even for sport divers. restricted diving areas covering the site have been designated and are indispensable to maintain and adhere to national protection laws. this reality requires new approaches for the general public to participate in unesco world heritage sites, i.e. conveying knowledge outside the actual site area, as well as the involvement of citizen scientists in research undertaken by the kuratorium pfahlbauten. figure 1. the unesco world heritage site "see" at lake mondsee. the settlement remains date to the 4th millennium bc and are exceptionally well preserved, because of their location in shallow water. at "see" (am mondsee/at lake mondsee), diving operations are carried out by one of two site managers of the kuratorium pfahlbauten in cooperation with, in most cases, two scientific divers, working several days once a year [pohl 2016]. during these monitorings, a grid of erosion markers is regularly read and documented. in this way, possible endangerment to the substance of the remains or their immediate surroundings, caused by the removal of the protective sediment layer, can be assessed. an active involvement of citizen scientists would further facilitate denser surveillance of archaeological sites, and thus a more sustainable protection of dwellings belonging to the unesco world heritage than our own resources could ever allow. due to strict national regulations, it is nearly impossible for citizen scientists to participate as divers. however, it is feasible to achieve something similar using videogrammetry supported by unmanned underwater vehicles (uuvs), operating in accordance with the current judicial framework. it is 1http://www.pfahlbauten.at 2http://whc.unesco.org/archive/convention-en.pdf [01-07-2017] essential for the implementation of this project that the technology used provides good results with regard to the most accurate documentation possible, is cost-effective and user-friendly. in addition, the recording process must not endanger the substance of archaeological sites. the projects "archaeocopter" and "archaeonautic",3 run by hochschule für technik und wirtschaft (htw) dresden and freie universität (fu) berlin, were initiated in cooperation with the deutsches archäologisches institut (dai) and the archaeological heritage office in the german federal state of saxony. the philosophy of both projects is not to try to maximize the level of detail achievable using highest resolution sensors, but to focus on what is actually required for different practical purposes, and providing robust and cost-effective solutions. 2. the pile dwellings at "see am mondsee" the pile dwelling, or lake village, "see am mondsee" is perhaps the most famous copper age site of austria. it dates back to the 4th millennium bc [ruttkay et. al. 2004]. the site was discovered by matthäus much in 1872. he examined it during the 1880s and established the term "mondsee culture". elisabeth ruttkay (✝2009), one of the most significant researchers of the european neolithic period in austria, studied the mondsee culture from the 1990s onward and came to be convinced that the mondsee material is a sub-group of the neolithic "trichterbecherkultur" (funnelbeaker culture), rather than an independent local culture. therefore, the term "mondsee culture" was replaced by the more appropriate name "mondsee group" in the academic discourse. artefacts (fig. 2) similar to those discovered by much were also found at approximately twenty other underwater sites at lakes attersee and mondsee, as well as on dry land sites in the federal states of lower and upper austria, salzburg and – on the southern side of the alps – in styria [maurer 2014]. the mondsee group material is characteristic of the neolithic pile dwellings (traditionally called "palafittes") settlements of the austrian salzkammergut region [ruttkay 1981]. figure 2. pottery of the mondsee group: black fired ceramics with incise-punctuation, limescale incrustation with typical decorations of wave-like lines, and circles often interpreted as symbols of the sun. 3www.archaeocopter.de the rich inventory of finds, including well-preserved organic materials, at the settlement "see am mondsee" constitutes the most comprehensive source for scientific exploration of neolithic piledwelling cultures in austria so far. after much’s collecting activities, l. franz and r. bernhart examined the site in 1938. in 1951, k. willvonseder and k. schaefer undertook the first diving examinations; and in 1961 salvages were carried out by the mondseer heimatbund under w. kunze. in 1967/68 the state heritage protection office surveyed the site, and from 1982-86, had j. offenberger undertake a surface documentation and a salvage of finds [hirmann 1999]. since 1989, the austrian national research fund fwf has been supporting interdisciplinary projects regarding the prehistoric lake villages of upper austria. this has further facilitated research into trade contacts and comparison with contemporaneous pile-dwelling cultures. for example, objects made of the so-called "mondsee copper", containing a high percentage of arsenic, have been found all across europe [dworsky 2016]. the site was granted unesco world heritage status in 2011. in 2013, the kuratorium pfahlbauten started to implement a monitoring system in each of austria’s world heritage sites. the results show very different topographical and hydrographical situations of the five sites and thus different states of preservation. the lake village of "see am mondsee" is situated at the eastern end of lake mondsee, in a small bay near the lake’s outlet (fig. 3). figure 3. see, mondsee: location and extent of the world heritage site. the outflow of the mondsee, the river "seeache", leads into the southern end of lake attersee. the constant stream of the outflow/outlet causes erosion in the area of the prehistoric settlement, especially during periods of heavy rainfall and high water levels [pohl 2014]. therefore, and in contrast to better conserved lake village sites, "see am mondsee" lies in a very dynamic and constantly changing environment of sedimentation processes, and thus challenging preservation conditions; prehistoric piles are visible and cultural layers with prehistoric material are exposed on the surface (fig. 4). despite these difficult circumstances, prehistoric cultural layers are still preserved up to a thickness of about 50 centimeters in some areas [pohl 2016]. figure 4. see, mondsee: pile-field and prehistoric material on the lake bottom. in order to further and improve future protective measures, more emphasis has to be put on a detailed surface model of the lake bottom, accurate documentation of both erosion and sedimentation processes and the establishment of the exact locations of the most threatened areas of the site. 3. videogrammetry in underwater archaeology over the last two decades, archaeologists have profited from developments in uav (unmanned aerial vehicle) and rapid progress in digital camera technology. at the same time, expertise and methods from aerial archaeology and close-range photogrammetry intersect with each other [luhmann et. al. 2007]. while it seems that most published research currently uses the proprietary software agisoft photoscan4, there is also an increasing role for free and open source software, such as visualsfm5, micmac [deseilligny and clery 2011], openmvg [moulon et. al. 2013] and bundler [snavly et. al. 2006], that can reduce costs while still producing robust, high quality results [rende et. al. 2015]. for our research, we have developed several tools in the java programming language that each serve a well-defined purpose: jkeyframer automatically extracts a set of key frames from a video stream that are well-suited for image-based reconstruction. frame selection is based on a rapid assessment of quality via sharpness and other indicators. jenhancer is a tool for automatic color correction of underwater imagery (for details see block, gehmlich and hettmanczyk in this volume). jfeaturemanager implements a novel, adaptive feature detector for use with blurry images. it is described in detail in section 5 of this paper. the programs jenhancer and jfeaturemanager were developed specifically for use in underwater 3d reconstruction. 4http://www.agisoft.ru/products/photoscan/ 5http://ccwu.me/vsfm/ 3.1 videogrammetry versus photogrammetry the videogrammetric approach [greenwood 1999, pappa et. al. 2003, nistèr 2004. pollefeysm et. al. 2004] to 3d reconstruction (i. e. using frames extracted from video streams instead of single-shot image series as in the common photogrammetric approach [hartley and zissermann 2004]) was successfully introduced to aerial 3d reconstruction using unmanned aerial vehicles (uavs) in the project "archaeocopter", among others. the results of several campaigns have shown that videogrammetry is a fully viable approach to reconstruct single objects as well as complete archaeological areas [e.g. gehmlich and block 2015]. the main challenge in videogrammetry is to compute a solution for a problem involving two contradicting constraints: on the one hand, we want to minimize the distances between corresponding images to maximize the intersection set and produce more 3d points. but on the other hand, we need to maximize the distances between corresponding images to reduce the locational uncertainty of the reconstructed 3d points, as only accurately reconstructed points will be kept for the 3d model. in our experience with recording data while moving, videogrammetry is the more fault-tolerant, more cost-effective and easier-to-use approach, compared to single-shot photogrammetry. the software "jkeyframer", an automatic keyframe selection tool and one of the most important outcomes of the project "archaeocopter", has evolved to allow us to render fast preview models on site. 3.2 aspects of underwater archaeology the recording methods currently used in underwater archaeology are complex and expensive, even when sonar and laser scanning are deployed [moisan et. al. 2015]. the importance of the photogrammetric approach is therefore analogous to its impact on aerial documentation, and the use of underwater photogrammetry is accordingly on the rise [baletti et. al. 2015, pruno et. al. 2015]. the results of land and water based photogrammetry are quite comparable. depending on the setup used, only small details are lost in underwater scenes [troisi et. al. 2015]. currently, scientific divers use cameras with high resolution, plan sets of photos and need special training to work underwater [papadimitriou 2015]. their diving time is limited, depending on diving depth. careful and systematic excavation under water is still a domain of manual human labor. in comparison to aerial documentation with uavs, underwater georeferencing is still a significant challenge. natural or artificial markers on the ground (ground control points, gcp) need to be well detectable and recognizable. determining the real-world coordinates of such points is a problem, because no gps signal is directly available under water. to locate gcp markers with sufficient accuracy, indirect tracking solutions are often deployed. in areas with shallow water, the point to locate can be correlated with a gps-provided point on the water surface via a perpendicular stick [baletti et. al. 2015]. 4. documentation process for pile dwellings at "see am mondsee" uuvs, can be used effectively for both, the documentation of registered archaeological sites, and the exploration of potential new sites. the small submarine "eckbert-ii", based on the openrov6, was developed in the project archaeonautic to fullfil both functions. at the time of writing, it is still under modification [block et. al. 2016, eckbert-ii]. two extensions, for cable management and for finding a balance setup for underwater taring in both salt and fresh water were designed. 4.1 recording and computational setup the main difference and the most critical technical challenge for the documentation of the pile dwellings at "see am mondsee" in austria, was to ensure that neither the uuv nor the attached cable touches the sea bottom or the salient lake dwellings. stable balancing of the uuv with different attachments is an important aspect of successful and safe underwater recording. promising 3d reconstruction results using gopro cameras, structure from motion [rende et. al. 2015] and stereo vision [repola et. al. 2015] underwater were obtained. we added two diving torches on both sides of the openrov, to be able to get good light conditions if necessary, and also one gopro hero 4 be on each side (fig. 5, left). another practical aim of the mondsee campaign was to evaluate whether the miniature uuv "eckbert-ii" would be able to document the pile dwellings so efficiently that it could be done periodically, making our approach suitable for long-term underwater site monitoring. figure 5. the images show "eckbert-ii" submerged in lake mondsee. left: a flexible cameraand lighting setup can accommodate different recording needs and environmental conditions. to document the pile dwellings, three gopro hero 4 be were attached to the uuv. subsequently, weights and buoyancy bodies were combined to balance the uuv. right: recording can be done in complete darkness, thanks to the diving torch setup used. under these extreme conditions, 3d models can still be produced successfully. the pro led scuba 860 with 860 lumens and a potential maximum depth of about 100 meters was chosen as diving torch. it outperforms the gopro standard case that offers only about 40 meters of diving depth. one torch is placed 15 cm in front and the other 15 cm behind the centrally placed gopro. both torches produce a homogeneously lighted area around the field of recording (fig. 5, right). 6http://www.openrov.com figure 6. left: to each side of the openrov, two diving torches and one gopro hero 4 be were extended. middle: to improve the control of the uuv, a human diver supports the cable. in doing so, the diver decreases the pulling force from the base while increasing the level of movement control over the uuv. it is like «walking the dog». right: the recording strategy with parallel and crossing stripes is similar the aerial documentation. figure 7. the base camp, placed to the north of the site, provides a workplace for the operator ("pilot"), who remotely controls the uuv via a laptop. lower right: equipment containers conveniently double as mobile control desk. "copilot 1" stands close to the base to manage the cable and communicate via gestures with the uuv’s supporter/diver. similar to uav-based documentation, when no live information about the uuv’s current position is available, a second copilot is placed to the side of the surveyed area and provides an estimation of distance. the strategy for recording video in underwater scenarios (fig. 6) is quite similar to the grid-based version used in aerial recording [gehmlich and block 2015]. compared to a uav, "eckbert-ii" lacks one degree of freedom (it is not able to move sideways). 4.2 documentation area the base camp for the uuv’s operation was set up on a meadow to the north of the site, since there was no public access to the (closer) areas south and east of site. using a 100-meter-long cable, the area to survey could be covered in its entirety (fig. 7). as fig. 10 (left) shows, a regular, georeferenced frame of about 10x30 meters was placed inside the archaeological site and relocated several times (archaeological field work supervised by johann offenberger7, see also [hirmann 1999]). the frame’s position was recorded by the archaeologists and could therefore be used to georeference the resulting 3d model. 4.3 team communication a short briefing is part of the routine before every documentation job. upcoming diving sessions are discussed among the team. during the diving session, communication between copilot 1 and copilot 2 is done via walkie-talkies with headsets (detewe outdoor 8500 pmr). the pilot runs the base and controls the uuv via laptop. control channel and video stream between uuv and pilot are realized via web services. placed close to the pilot, the first copilot manages the cable to the uuv and communicates via gestures between the pilot and the uuv supporter/diver. some gestures are equivalent to international hand signals used in diving, but additional communication codes are necessary when controlling the uuv (tab. 1, see in appendix). the base operator minds the diving time and keeps written protocols. to improve the workflow and identify bottlenecks, it is always advisable to document every step carefully. 4.4 diving sessions and recorded data in the end, there were about eight to ten diving sessions for the film crew and four diving sessions to record useful site data. the openrov is able to work three hours in a row, but the gopro cameras proved to be the energy bottleneck. even with the gopros’ energy saving video mode (1080p at 30 fps), we were only able to work 45 to 60 minutes. therefore, we decided to limit the diving sessions to 45 minutes each. as recording strategy, we used the orthographic double-grid-based approach [gehmlich and block 2015] with a stripe distance of about two meters. as a result, we had about five hours of useful video material out of four diving sessions, comprising more than a half million video frames. 4.5 flexible taring setup the basic openrov is well balanced for salt and fresh water. but if attachments like cameras and torches are added, a new taring setup is needed. to be more flexible, we designed a lightly oversized 9http://mondsee.salzkammergut.at/detail/article/pfahlbau-manuskript-mondsee-weltkulturerbe-see.html buoyancy body for each side. to balance the uuv more sensitively depending on the current setup, additional plumbs were added. the positions of these plumbs are key to balancing the alignment while moving. the postprocessing of recorded uuv sensor data, like inertial measurement unit or depth sensor readings, is also very important, as this can be used to analyze and understand the underwater behavior of the device. in one recording scenario, we tested our flexible taring system. the uuv needed to hold its depth while moving (fig. 8). figure 8. most of the time, the uuv was close to the water surface, as mentioned above. while documenting the pile dwelling remains (section marked by frame) between 14:27 and 14:54, the uuv maintained its depth satisfactorily. when the supporter moved the uuv to the next position manually, small outliers occurred. the results of the campaigns in veruda [scholz et. al. 2016] and mondsee (fig. 11) are promising and show that the flexible taring setup works equally well in both salt and fresh water. 5. reconstruction process and interim results before discussing some challenges and our ongoing work, we want to show some encouraging results. with a camera-to-bottom distance of about 1-3 meters, archaeo3d is able to reconstruct gapfree 3d models from recorded video streams using the original frame data (fig. 9). figure 9. the 3d model above was reconstructed using the original image data with its greenish hue. top: one patch of about five to six meters is shown from two different perspectives. the camera-to-bottom distance is about four meters. although the muddy ground shows faded, blurry structures, the dwelling remains are well recognizable in the processed model. bottom: one stripe of about four to twelve meters. here, a frame with wood elements like trunks and branches can clearly be seen. with a camera-to-bottom distance up to four meters, even images of the slightly muddy ground with its faded and blurry structures could be processed with quite promising results. 5.1 the archaeo3d reconstruction pipeline within the scope of the archaeocopter project, the semi-automatic tool chain "archaeo3d" was developed to optimize and control the complete reconstruction process. videos and photos are automatically imported and processed. the software is able to reorder or swap the processing pipeline’s modules and adjust parameters, depending on the current hardware and the real recording situation and complexity. a combination of visualsfm and cmpmvs [jancosek et. al. 2011] provides the backbone of the tool chain in all archaeocopter related projects. 5.2 adaptive feature detection and pessimistic recording strategy the main issue was the pessimistic recording strategy we used. we decided to record the data at a maximum depth of half a meter, due to the fact that we did not have enough knowledge about conditions inside the lake and we did not know the dimensions of the objects of interest, such as the lengths of the pile remains (as previously stated, the most important restriction was to never touch the latter). at the beginning of section 5 we presented some promising but interim results. we came to the conclusion, that a camera-to-bottom distance up to four meters is sufficient to produce the expected quality of the 3d model. unfortunately, the continuously increasing depth of the prospection area reaches more than six meters. the quality of the recorded video data at a maximum distance of about six meters (or more) was very dissatisfying, due to increasing haze. the more blurry a video frame, the less features are detectable. but a sufficient number of features are necessary to compute the pose estimation (camera reconstruction) in the sfm step, and thereby find the correct relationships between the images. the most frequently used feature detection method is based on lowe’s sift with some pre-trained parameters [lowe 1999]. visualsfm uses siftgpu by default, an accelerated, gpu-based implementation of sift. this approach is a good choice in general and works well in most cases. but when using small images with blurry content, feature detection often fails or detects insufficient numbers of features, so that image correlations cannot be found. to bring more images into the pose estimation step together, we improved our processing pipeline to detect more features by using an adaptive feature detection. common implementations of sift allow to adjust a number of parameters8, like "octaves" or "sigma of gaussian". in most scenarios, a lot of features are detected and to reduce thevtime of matching,vthese parameters are used to filter out weak features. "weak" is used here in the sense of "weaker than others", but most features are still good enough to produce reliable matches [may et. al. 2010]. in our case (where blurry images are processed and insufficient features are detected to match images), the sift parameter to adjust the contrast threshold t to filter out weak features in semi-uniform (low-contrast) regions is of particular interest. the larger this threshold, the fewer features are produced by the detector. our adaptive feature detection starts with t = t and reduces t stepwise by t = t⁄a for all images with t ∈ [ t min, t ]. the algorithms stops if the value of t reaches the minimum tmin or enough features are detected with | f | ≥ fmin. we empirically chose t = 0.02 (standard value used by siftgpu), fmin = 0.0005 and ⍺ = 1.1 to detect a minimum of 18000x0030 features per frame. our adaptive feature detection was implemented into the software modul jfeaturemanager. 5.3 comparison between standard and improved feature detection to discuss the new feature detection approach, we selected one video sequence of about 750 seconds. the sequence starts with a camera-to-bottom distance of about four meters and ends with the deepest point of about six meters. the recorded color space has a greenish hue, nearly unaltered by the cameras’ automatic white balancing. as an experimental image set, we used 1560 video frames automatically extracted by jkeyframer. this set represents the original image data extracted from the gopro videos with a resolution of about 1980×1080 pixels. to optimize the output of visualsfm, we reduced the image size to 1600×900 pixels. we compared siftgpu with pre-trained parameters (the standard feature extraction method used in visualsfm) "m1" with jfeaturemanager using the adaptive feature detection method "m2". the comparison between the number of detected features is shown in fig. 10. 8http://www.mira-project.org/joomla-mira/ figure 10. all 1560 frames are plotted on the horizontal axis. the yellow graph shows the number of features, detected by siftgpu with pre -trained parameters in the set m1. the images are sorted by number of detected features. the orange graph shows the corresponding number of features detected by jfeaturemanager. the sum of all detected features by siftgpu in all frames is 1333287 with a mean of 855 features per video frame, while jfeaturemanager detects 3209372 features with a mean of 2057 features per video frame. the number of features detected using jfeaturemanager was amplified by a factor of 2.4 in comparison with siftgpu. despite the property, that in good images (left margin of graph in fig. 10) the amount of features will be reduced, we detected enough features in blurry images (right side of fig. 10) to increase to chance to find matches. for the original image data set m1, the pose estimation using visualsfm delivers one connected model (50659 3d points) with 350 images and for m2 one model (170502 3d points) with 1137 images. the adaptive value t was located between 0.001146 (minimum) and 0.007009 (maximum) with a mean of 0.003580. the average calculation time for one image was 23.65 sec. such an effective feature enrichment, is, however, a two-edged sword. on the one hand, the feature enrichment process offers the opportunity to integrate more images into one coherent 3d model. but on the other hand, the process slows down and parallel computations need more computing power, due to a quadratic increase of complexity in the matching process. in summary, however, a combination of jenhancer for prior color enhancement (see block, gehmlich and hettmanczyk in this volume) and jfeaturemanager allows us to find more matches between clusters of images (fig. 11). this in turn increases the likelihood of obtaining a complete coherent site model. images of insufficient quality remain a problem, but we believe that we have alleviated the worst constraints for underwater scenarios. figure 11. left: different 3d models based on different feature matching strategies. the largest model contains 1984 frames, but is still underachieved. right: the image at the top gives an idea of the original color of the model. as mentioned before, the automatic white balance was active in the cameras, which strongly influences the outcome of color correction using our own jenhancer software. 6. conclusions and future work the image-based 3d reconstruction of the pile dwelling field at "see am mondsee" was challenging, due to problems with automatic white balancing and a pessimistic recording strategy. most of the recorded data was blurry and far from suitable for a common sfm reconstruction process. nevertheless, after replacing the feature extractor of visualsfm with our own implementation, it was possible to integrate more frames into the 3d model. experiments have shown that adaptive feature detection can significantly increase the number of detected features in an sfm processing chain, which is of crucial importance for constructing complete 3d models. the software package jfeaturemanager, which uses the adaptive feature detection, is not only designed to replace sift. it is in fact a basis for image analysis and a place where different feature extraction methods come together. there are many interesting feature extraction solutions, such as harris corner [harris and stephens 1988], surf [bay et. al. 2008], mser [matas et. al. 2004], fast [rosten and drummond 2006], orb [rublee et. al. 2011], brisk [leutenegger et. al. 2011] or fern [ozuysal et. al. 2007], but all candidates for sfm need to be invariant to affine transformations (scaling, rotation, translation, shearing and any combinations of them). the combination of feature enrichment and image enhancement using jenhancer is a promising approach to underwater videogrammetry. another technical challenge was the need for a more accurate georeferencing method for tracking the uuv while recording. we identified and designed a two-stage-technical solution: in the first stage, a gps buoy is fixed at the cable and placed close to the uuv (fig. 12). this initial solution is oriented towards improved uuv tracking. figure 12. to locate and track the uuv automatically and in real-time, a gps buoy is fixed to the cable between the supporter and the uuv. to extend the maximum achievable distance between the prospection area and the base, and to replace the cable altogether, we are also working on a fully wireless solution. later, in a second developmental stage, we will replace the cable-based setup with a completely wireless communication solution. this is fairly challenging, but the advantages are obvious: the maximum distance between the base and the prospection area would only be limited by the transmission power of the wireless module. the complex and constantly required cable management would be obsolete. the documentation team could be reduced to only two persons. with such a wireless solution, autonomously operating uuvs using fully automated tracking and mapping approaches (with the frameworks ros9 or mira10) would be conceivable. 7. acknowledgements the archaeonautic project was financially supported by the saxon state ministry for science and the arts. the documentation campaign at "see am mondsee" was financially supported by the kuratorium pfahlbauten and accompanied by a german television film crew directed by julia schwenn. their documentary was shown on the german public television (ard) broadcast "w wie wissen". we would like to thank all the people who supported our team in various ways. 8. references caterina balletti, carlo beltrame, elisa costa, francesco guerra, and paolo vernier. 2015. underwater photogrammetry and 3d reconstruction of marble cargos shipwreck. in the international archives of the photogrammetry, remote sensing and spatial information sciences xl-5/w5. 2015 underwater 3d recording and modeling. herbert bay, andreas ess, tinne tuytelaars, and luc v. gool. 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the supporter and the two copilots. due to the head gear, the snorkel and the distance of the supporter, no verbal communication is possible. received march 2017; revised july 2017; accepted august 2017. 503 service temporarily unavailable 503 service temporarily unavailable nginx/1.14.1 microsoft word 24611_gg_v1.docx studies in digital heritage, vol. 2, no. 1, publication date: september 2018 encyclopedic palace ludovica mazzetti d’albertis, la sapienza university, italy in the last decades the world has become rapidly smaller with the destruction of spatial barriers known as “globalization.” it is a term both annoying and exhaustive, signifying a syncretic and global perception of reality. this condition has been further made easy by the enormous amount of data made accessible to us. the accelerated transition from an analogue to a digital world has literally invaded us with information creating not only a huge cultural gap between generations, with all its consequences, but offering at the same time huge opportunities. this paper intends to describe how technology, not without obstacles, has changed the way to communicate culture, and to make it more accessible. our cultural heritage requires technology to be known and furthermore in order to be preserved. present archives and museums, whether large or small, must move along with times, giving large space to technology and to new professional skills. the protection of our heritage requires communication, which plays a decisive role in making everybody knowledgeable. it is paradigmatic today and a duty to use technologies in order to store, preserve, save and communicate this heritage. key words: archives, art, multimedia exhibitions, virtual exhibitions, virtual museums. sdh reference: ludovica mazzetti d’albertis. 2018. encyclopedic palace. sdh, 2, 1, 80-94. doi: 10.14434/sdh.v2i1.24611 1. introduction paul saffo, a technology forecaster based in silicon valley and consulting professor in the school of engineering at stanford university stated in 1997: “it's my belief that technology does not drive change. technology merely enables changes. it creates options and opportunities that as individuals and as communities and as entire cultures we choose to exploit. and it's our response to the technologies that drive change. in other words, first we invent our technologies and then we use our technologies to reinvent ourselves” [adler 1997]. understanding the history of art in all of its forms requires a privileged access to the knowledge of the history of cultures. the artistic product is only a synthesis between subjective and objective reality—and by “objective” we mean the historical, social, economic and cultural context of its production. new technologies are the instruments by which artists express themselves. art has used advanced technology for decades; we need only to think of the pioneers of video art as nam june paik and of the use of electronic images in the 1960s. for years we have been witnessing beautiful installations by important contemporary artists such as bill viola, pipilotti rist and many others. author's address: ludovica mazzetti d’albertis, art history and performing arts department, piazzale aldo moro 5, rome, italy; email: ludomaz@yahoo.it © [2018] by the author; licensee studies in digital heritage, iu, bloomington (in), usa. this article is an open access article distributed under the terms and conditions of the creative commons attribution license (cc by-nc) http://dx.doi.org/10.14434/sdh.v2i1.24611 encyclopedic palace 2:81 studies in digital heritage, vol. 2, no. 1, publication date: september 2018 this writer will never forget the incredible effect of the video homo sapiens sapiens projected onto the vault of san stae at the 2005 venice biennale. the video flickered and canceled the baroque architectural space: a dreamlike show that the public could view while reclining on armchairs. the total involvement of this show reminded us of the works of the great baroque artists the church commissioned to represent epiphanies celebrating the christian dogmas in response to protestantism. magnificent frescoes then reduced the space, creating amazing “trompe l'oeil,” “horror vacui,” and scenography to serve the glory of the church that was losing its power to persuade and was forced to use as expedients the incredible projects of famous masters of illusion: examples are the triumph of the name of jesus (fig. 1) on the vault of gesù church in rome painted by "baciccio,” giovan battista gaulli (1639-1709), or the apotheosis of st. ignatius (fig. 2) by andrea pozzo (16421709) in another roman church, sant'ignazio di loyola. figure 1. giovan battista gaulli, the triumph of the name of jesus, (1672-1675). 2:82 l. mazzetti d’albertis studies in digital heritage, vol. 2, no. 1, publication date: september 2018 figure 2. andrea pozzo, apotheosis of st. ignatius, (1691-1694). over the years, the tools available to art in all its forms have become incredibly more sophisticated, and these same tools can be used by those who valorize art and cultural heritage as an economic and social strategy. the protection of our heritage has to be supported by communication, which comes to play a decisive role in the awareness of the layman. the language of art has changed; now the encyclopedic palace 2:83 studies in digital heritage, vol. 2, no. 1, publication date: september 2018 curators must do the same. today it becomes a paradigm and a duty to use technologies to store, preserve, save and communicate. 2. store "italy, whose archiving rules have finally take-off, should develop them and use them for the multitude of italian archives in order to minimize the threats represented by the chance and the lack of care for the preservation of present and past memories. memories that more of any other should be considered as sacred ones!” [casanova 1928]. these words, written in 1928, are still valid. even if not in its literary sense, this warning applies to all nations, to us and to whomever will come after us. the preservation and care deserved by human history and also by histories closest to us—i am referring to such many private archives still hidden in old wardrobes—must become a common rule. for many years, archivists have greeted new technologies with suspicion and resistance, certainly due to distrust in methods that were considered short-lived or otherwise limited. as well as distrust, those who are engaged in this field of work naturally find it inconvenient to adopt new toys and develop new professional skills. what was widely debated was how to find a standard model for storage—that is, a second level of storage. storing and cataloging images is relatively straightforward, but this is not the case with historical documents. just consider how difficult it is for a student to find a document in a historical archive for the first time: each archive follows its own logic, the logic of its custodian. the first problem to solve is to ensure that the collection and digitalization of documents follow standard rules. while digitization has made this work faster and easier, archives remain an unsolved problem. dissemination of information through the web as well as its coordination are the issues addressed by various european projects such as apenet (2009-2012) and apex-archives portal europe network of excellence (2012-2015), which developed the european archives portal (fig. 4) where the archival resources of various countries are transferred. (italy is a content provider through the state archives information system-sias.) the european portal in turn is a partner of europeana1, another important project of the european commission, aimed at ensuring a single point of access to the entire patrimony of libraries, archives, museums and online audiovisual collections2. europe is working to find the system or systems to share and improve access to cultural heritage in all its forms. the next step is to ensure the continued relevance of those systems. if on the one hand these tools allow us to save and transfer data with great speed, on the other hand we will need to update them eventually. this is the main problem that we experience in relying on technology. these tools alone are extremely fragile and grow rapidly obsolete. we need to reflect on the damage that can be done if you believe that new tools are the complete solution. we are faced with the obsolescence of programs, sometimes combined with non-compliance with shared standards, as discussed previously, or the loss of institutional knowledge of older systems (see the example of the diagnostic considered in section 4); any one of these problems may cause the loss of data. a debate went on for years and did also produce interesting progress, with international projects aimed at modeling technological standards and standardized rules. 1 http://www.europeana.eu/portal/en 2 http://archivi.beniculturali.it/index.php/archivi-nel-web/apex-portale-europeo-degli-archivi 2:84 l. mazzetti d’albertis studies in digital heritage, vol. 2, no. 1, publication date: september 2018 figure 3. the home page of the "archives portal europe" (https://www.archivesportaleurope.net). only practice—and, above all, collaboration between those archivists and technicians who have the delicate task of planning and designing systems—can entrench progress. communicate to preserve: this is the rule. 3. preserve encyclopedic palace human beings have always tried from their origin to leave a trace of themselves. reading a text on archives is sufficient to become aware that man has always had an almost obsessive need to sign, collect and accumulate. every culture, every people whose relics survive today, has used all its faculties to recount itself, from its everyday life to the great act of kings to the adventures of individuals. the great archives of old times of which we now can read only fragments are the immediate demonstration of this truth. nothing and nobody want to be forgotten. collect, accumulate, preserve. "it seems that the museum is a form congenital to the european man, for whom the need to collect precious things for his memory and to store them in a suitable place, has always been a necessity. a dialogue between life and death: to defend objects from death (meaning their disappearance or dispersion); to collect in order to leave memory of oneself; to give new life to these objects by repairing them from the memory of old destruction and damage" [mottola molfino encyclopedic palace 2:85 studies in digital heritage, vol. 2, no. 1, publication date: september 2018 1991]. these collections in turn respond to another need of human beings, to achieve some sort of universal knowledge. massimiliano gioni, presenting the 2013 venice biennale, said: "the dream of a universal and all-comprehensive knowledge goes through the history of art and humanity and links eccentric characters like auriti to many artists, writers, scientists and prophets who have tried, often in vain, to build an image of the world capable of comprehending its infinite variety and richness" [cavallarin 2014]. the "encyclopedic palace" title of the exhibition was patented in 1995 by the italo-american artist marino auriti (1891-1980)3 as an imaginary museum, a 136-storey building, 700 meters high, for an extension of 16 blocks in washington, which was supposed to comprehend all the knowledge of humanity. "today, dealing with the flood of information, these attempts to structure the conscience" knowledge we add "in all-encompassing systems appear to us even more necessary and even more desperate" [gioni 2013]. here come all attempts to save and isolate all our knowledge in all its forms. just a quick search on the web in order to realize that the effort is a real one: "omnia omnibus omnino,” future didactics meant for everyone and, above all, finally accessible. we all agree in saying that "information does not mean knowledge" [krajewski 2013]. this is why the next step is supposed to be elaboration, according to tastes and inclinations of each of us. the personalization of perception through an individual codification dictated by experience. the virtual museum the museum was born as a public institution aimed at conservation and education. today that aim has not changed, but nonetheless the institution has had to reinvent itself. we no longer speak of the construction of additional and more beautiful and sophisticated containers, nor of new theories to be realized in order to satisfy the public at large. this new era requires the old museums, and all their apparatuses, to make themselves increasingly accessible to the general public. today's user can well define himself as a hybrid between analog and digital, between real and virtual, and the museum must therefore accept and satisfy both. many museums have already begun to digitize their collections for academic and security reasons. institutions have responded positively to new media, using them as tools for protection and storage, yet this huge amount of data must now be accessible to everyone. the crucial problem has become converting all this data into accessible, understandable, and attractive formats. the first results of this work were a large number of presentations and web specials online. the "virtual museum,” however, was often little more than a database. the works were often available only in low resolutions. while the sites offered presentations dedicated to exhibitions or individual artists, only rarely did they show the full collection. at a time when the distribution of content is so simple, popular opinion favors free access (without, of course, violating copyright rules). unfortunately, this attitude is not yet unanimous, and even though many museums 3 marino auriti (1891-1980) was an italo-american artist, who escaped fascist persecution. moving with his family in pennsylvania, passionate to mechanics and architecture, self-taught, interested in art in all its forms, in the 50s he developed the project of an architectural structure that would host all the achievements of humanity, from wheel to satellite, from handicrafts to avant-garde art works, building a scale model a 136-storey skyscraper, 700 meters high and divided into 16 blocks in the center of washington, dc currently exhibited at the folk art museum in new york. utopia of a globalized knowledge and the possibility of regulating and cataloging its infinite variety [treccani 2018]. 2:86 l. mazzetti d’albertis studies in digital heritage, vol. 2, no. 1, publication date: september 2018 and archives possess large quantities of copyright-free material, only a few have begun to make it available. rijksmuseum in amsterdam, for instance, launched the rijksstudio in 2012, which allows free access to pieces in its collection: "users can interact with them, 'like' them, share them with others and use them in any way they wish—and more. rijksstudio invites the public to enjoy and explore the images: zoom in, save, manipulate, and share. users are encouraged to download the images and to do something—anything you like—with them. based on their own special interests, site users can create personal collections, saving either complete images or interesting details. this function is broadly similar to pinterest.” at the presentation of the project, taco dibbits, then director of the collections, and since 2016 director of the museum, justified the democratization of the collection: "we believe in the strength of our masterpieces. we also believe that they belong to everyone, and that there is an artist in all of us” [gorgels 2013]. this rather unusual opening answers the need of museums to become visitor friendly, to open a virtual facsimile, the "virtual museum”: closer to the user, full of corridors, details and information, that its real counterpart may not offer, creating a new empathy between new virtual visitors and institutions. visiting a virtual museum is not necessarily a passive activity: a virtual museum may allow a user to curate their own gallery of images according to their own sensibility. the concept of "participatory culture" [giaccardi 2012], intended as a reformulation of the understanding and experience of our heritage, is now dominant. new models of representation and communication answer the needs originated by huge social changes, such as by social media, which implement a new model of aggregation, virtual but real at the same time: we are talking about pinterest or instagram. this free acceptance of a new way of enjoying art, of looking towards the group of non-professional enthusiasts, "culture snackers"[junko 2017], the digital counterparts of cultural tourists, is further facilitated by the new online platforms that make research simpler. google art project, for example, is a search engine with access to a huge number of museums, private collections and state archives; emuseum.net allows us to browse sites in order to discover information and works of a particular artist, see the images, and find the museums where their works are collected. today one may also track auction prices or become a collector with artsy, artprice, artnet, and artvalue, through which you can learn about and involve yourself in the complex and volatile world of art market. these are the new paradigms for the diffusion of art and culture: immediate, involving, and editable according to one's own inclinations. the obstacles for the realization of virtual projects are mainly financial, at least at the beginning. for example, a country like italy should materially digitize itself, but a digital encyclopedia faces administrative and bureaucratic difficulties, not to mention questions of competence or professionalism. given that the digitization of our assets is now routine, cultural institutions, either museums, libraries or archives, must overcome the purely administrative purpose of communicating with the public, continuing to tell stories and to present educational routes. following international guidelines also in our country we tried to better codify a model and a kit, cms movio [caffo and al. 2011] for public and private institutions for the realization of these virtual projects. this document, born from the cooperation between the central institute for the italian libraries database iccu and the central institute for archives icar, in collaboration with the technological observatory for cultural heritage and activities-otebac, both illustrates the state of the art of virtual exhibitions and suggests guidelines. the guidelines, which are also a contribution to the european project encyclopedic palace 2:87 studies in digital heritage, vol. 2, no. 1, publication date: september 2018 indicate [indicate 2012], are the result of a debate among experts and operators from the different sectors of cultural heritage who shared their experiences in a dedicated working group. the digital exhibitions are an effective learning tool, which offer more materials than a real exhibition or museum department could. not only are they superior in the quantity of items offered, their users can dwell on details of particular items, which is impossible in overcrowded exhibition spaces, for as long as they wish. virtual visits to famous museums are a great opportunity: you can look at and browse the works from various points of view, perhaps with a voice or a text that makes you grasp what may go unnoticed in a normal visit. a visit to a real exhibit ordinarily entails a struggle to observe objects on display amid chattering and jostling crowds, or to read minuscule, often irrelevant or shallow labels. looking and travelling from home can be the true luxury given us by technology. but what happens if the experience becomes increasingly passive? if your eye is no longer looking, it becomes only an organ of perception. if you only see what you are told to see, can you build up a true personal and critical judgment? and furthermore, will all this accessible knowledge tend to isolate man? is this delusion that we are able to see everything, to be able to go anywhere, to be part of a group, to share, not limiting in itself? does it generate a vacuous satisfaction? i am mainly referring to the new generations, who do not know what it means to touch the pages of an encyclopedia or to make a music box using the play + rec keys. to read a map or organize a trip driven by the pure taste of discovery (they have already seen everything). we run the risk of perceptual atrophy. we shall not give up the exercise of knowledge. 4. saving “inside caravaggio” is the title of the study days that followed the closing of the exhibition held in milan (palazzo reale, september 20th, 2017 february 4th, 2018). the exhibition was a great success due to the large number of visitors (400,000), but above all for the contribution given by scientific and documentary discoveries, which of course gave rise to new issues. not only did the visitors have the possibility of looking at many beautiful masterpieces very well laid out, they were also able to better understand and appreciate the great artist thanks to scientific tools: all the works were accompanied by their respective x-ray. this result would not have achieved without the contribution of image technicians to the curator’s work. on the second day of studies, we listened to the speech of isabella castiglioni, a researcher of cnr (italian national research council) institute of bioimaging and molecular physiology of the department of nuclear medicine at st. raffaele hospital of milan. the speech “processing diagnostic images of art: a survey instrument,” explained that all diagnostic techniques used in medicine, from fluorescence imagines, ionizing radiation, magnetic ultrasound or x-rays, with the exception of those which use contrast agents, can be used for art research. and that post processing, which is the methodology that can be used once all diagnostic images have been gathered, is presently also used with the same purpose. nowadays, we no longer consider exclusively the qualitative result of the images detected (as in x-rays) but we may also elaborate the images using numeric parameters which can be compared timely. we are now using the same sophisticated techniques and expertise used in medicine using the same technological skills. the results of these studies are very interesting 2:88 l. mazzetti d’albertis studies in digital heritage, vol. 2, no. 1, publication date: september 2018 from a scientific viewpoint and can be used for education and explanation purposes, for instance in art exhibitions or in video representations. one example is the video made of the peruzzi chapel in santa croce church in florence, presented during the “giotto, l’ italia. da assisi a milano” exhibition at palazzo reale in milan in 2015. the result of a very complex fluorescence and diagnostic campaign, using compensatory techniques such as cloning and correction of the collected material, which consisted of a thousand ultraviolet light and natural light frames, is a fascinating three-dimensional video, which also reconstructs in light fluorescence the missing parts of the decoration. as in medicine, where three-dimensional renderings are created to help supporting surgery or radiotherapy, with this video the experts have reproduced the visual experience of the giotto frescos, a virtual restoration also for non-experts. this is the great contribution of technology: it helps us to see what time, negligence and fragility have taken away. the use of diagnosis in art research is not altogether new. indeed, x-ray tubes were already used in 1930 and 1940. cesare brandi4 [brandi 1963] did use spectrographic analysis for the study of works of art to be restored. the results of those scientific analyses have produced a lot of material, stored in museums and archives, having however the defect of not being easily understandable in a modern sense. this is one of the biggest challenges that art historians must face when they analyze images of the past: that of finding the correct way to understand them in order to compare with present material. the modern techniques help us to better understand the artist: procedures, techniques, materials, pigments. all of these documents are a key for historians and restorers who risk, due to lack of knowledge, to permanently damaging masterpieces. presently, thanks to the modern tomographic instruments, which can analyze the minimal surfaces, invasive microscopic analysis can now be avoided. the technical knowledge which is of great use for art historians and restorers, must now also be shared and communicated to the public. the deeper knowledge on the masterpiece, can help us to further understand and appreciate the artist. we feel closer to the artist and better understand his methods, doubts, re-thinking and tricks—in caravaggio’s case, for example, “profili a risparmio” and “preparazione a vista” [vodret 2017] were used to accelerate his work. historical research, style analysis and diagnostic techniques must integrate and combine themselves. this is a challenge and an effort leading us to new models for understanding art. 5. communicating lo stupore e la bellezza5 by retracing the history of art, the use that man has made of images becomes quite evident. images are never a goal in themselves, but they were always meant to communicate, to remember, and to 4 cesare brandi (siena, 1906 vignano, 1988) was an art historian and critic, specialized in conservation and restoration theory. in 1939 he founded the central institute for restoration (now the italian institute for conservation and restoration) in rome. his most important work, theory of restoration, is a key text and still a reference for this discipline. brandi was a proponent of the "tratteggio,” a controversial method of pictorial reintegration through thin dashed lines in watercolor. 5 “lo stupore e la bellezza” [kermani 2017], is the italian title of david kermani’s book “ungläubiges staunen: über das christentum” [kermani 2015]. encyclopedic palace 2:89 studies in digital heritage, vol. 2, no. 1, publication date: september 2018 provoke. all peoples, kingdoms, religions, and cultures whose artifacts still exist have deliberately left memories of themselves by means of images. studying and above all understanding the history of art means knowing and understanding the history of mankind. the relationship between art and theology, for instance, has ancient roots. christianity has from its beginning employed images to tell, and make people talk, about itself. after a short aniconic period, art and religion have walked together throughout history. art has described dogmas and mysteries by means of images following its own aesthetic and expressive canons that cannot however be studied and understood without a careful historical analysis. figure 4. stained glass window of the cologne cathedral, 2007. in the case of christian religion, since the scriptures are stories of human events, their representation also attracts those who seem to be devoid of any knowledge of its iconography. the image has always been a strategic expedient to transmit and spread dogmatic messages. we believe, however, that representation in any case requires knowledge and does not live independently. "words, in fact, 2:90 l. mazzetti d’albertis studies in digital heritage, vol. 2, no. 1, publication date: september 2018 enunciate, declare, explain and clarify, while the holy image is essentially made to show, attract, call attention to, change view, sometimes provoke, convert and comfort" [fogliadini 2015]. the usefulness of images seems very clear from the beginning; the service given to the diffusion of christian religion is quite evident. every age has left great works of brilliant artists who have served with their inspiration and their manners to the “social” and “political” needs of the church. in reading these works we can understand the needs that the church did have in that historical moment. from the hieratic distance of the medieval teaching church to the tale, almost didactic, of the scriptures typical of the first renaissance until the symbols and the epic triumphs of the baroque used by a somewhat weaker and less belligerent church. "the church felt the need to involve everyone in its reform and stimulated the birth of an aesthetic language that could drag them all, rich and poor, educated and illiterate. less was written, and more was composed: theatre, music and scene were assembled in order to create a unique work of art" [daverio 2017]. figure 5. stained glass window of the cologne cathedral, 2007. encyclopedic palace 2:91 studies in digital heritage, vol. 2, no. 1, publication date: september 2018 coming to the present days, we are considering the new window of the cologne cathedral, designed by gerhard richter (fig. 4 and 5). the artist worked for four years in studying colors to be used for his stained-glass windows. the work was not easy, and he did work with other experts (physicians and programmers) to create 72 colors for 72 diamonds: 5184 pieces of colored glass. an enormous window work (13 square meters) which is entirely made of light. it is full of knowledge, but at the same time it does deny the human"[kermani 2017]. the cologne cathedral has found, thanks to richter and of course its patrons, a new light and a new life. if the cathedral is the symbol of a community and of its history, with this operation the symbol became modern: "richter's pieces radiate xxi century" [kermani 2017]. these lines have certainly oversimplified the deep meaning that images have had for religion and vice versa, but they may be useful to justify and understand the way in which we are using them presently. communicate by images helps to stimulate perceptions and emotions, as well as to remind and to transmit the enormous baggage of our cultural memories. the multimedia exhibitions a new aesthetic of information, what lev manovich calls "info-aesthetics," is ascendant. “the discipline of info-esthetics studies how the contemporary culture responds to the challenge of managing, storing and circulating growing quantities of data that leads to new aesthetic sensitivity and communication forms and strategies, from design to architecture, from cinema to the design of human-computer interfacing” [garassini 2005]. a format that is having great success with the public in recent times is the “exhibition-event,” considered by many close to the “blockbuster exhibition” for which italy is famous, and on which several articles and critical pamphlets have been written [montanari and trione 2017]. this due to their model, ostensibly democratic, but above all quite smart in simulating culture. the format of these exhibition-events offers only star artists, whose universal knowledge guarantees easy media communication, becoming practically "brand" artists [montanari and trione 2017]. these exhibitions do offer the opportunity to see works coming from private collections or from foreign museums. however quite often they have been assembled in an unscientific and superficial manner. this does not mean that they do not leave a pleasant memory and also the feeling of having learned something. the proliferation of these exhibitions-events is probably due to an institutional void that should be filled by museums. there is a lack of ideas and money, but above all the courage of changing language is missing. if the institutions rightly do not want this change, which would cancel their role, they do not always refuse the idea of an "explant" of works in exchange for money. they are colluding with these novelties. we are witnessing the devaluation of great artists for purely economic reasons. we agree with the intellectuals and historians who refuse this type of exhibition, little study and much profit, with a greater risk for the works borrowed: out of context, delicate and unique. in addition to the exhibition-events, we are invited to attend another model of exhibition, this time without works, the "multimedia exhibitions": in 2015, van gogh 3d and the caravaggio experience; in 2017, the klimt experience; in 2018, the da vinci experience and giudizio universale: michelangelo and the secrets of the sistine chapel. we are speaking here of actual shows and allencompassing experiences. technology comes into play here. thanks to it we can enter the world of an artist among his characters, in his reality or fantasy, with amazement and wonder just as the populace did in entering the churches (fig. 1 and 2) or witnessing the baroque fantasies. a total 2:92 l. mazzetti d’albertis studies in digital heritage, vol. 2, no. 1, publication date: september 2018 immersion in music and images, a dreamlike and amazing experience. how, then, should we react to the criticisms that these new formats also attract? the problem, in my opinion, lies in confusing these events with exhibitions. let's call them happenings or shows, and let us keep them, but in other categories, as we already do. the exhibitions must be made by museums: this is the point. we must find a way to give a new start to scientific and cultural exhibitions with the continued financial support of institutions. this is the main problem. shows are negative only when they replace another kind of thing, but the fact is that those who produce them have no such intention. the defect lies in the intellectual limitation of not being able to make them live together. they are two distinctive things, having different aims with very different projects and aimed at different users. they may very well be considered complementary because they satisfy a large margin of public. the work of art exists when a relationship with the user is created. this is why this experience is subjective and changeable, reflects emotions and moods. in the case of multimedia exhibitions, aesthetic judgments are not required, but only the usage of sensory stimuli that are variable and not classifiable. we do not ask for a critical judgment with all its implications, but a simple aesthetic pleasure according to our idea of beauty, through our personal filters. doctrines prove the existence of different degrees of enjoyment. the observation of an object of art is never a pure one, devoid of relationships, because we have always been accustomed to classifying what we see or touch. this model of perception is the result of our culture. accordingly, if we watch a multimedia exhibition, that with amplified sounds and images stimulates our senses in an engaging way, our first contemplative state immediately becomes fruition as well as "a real performative action. this must be understood in the etymological sense of the word, as an action that creates meaning and contents: no longer a simple act of observing a work of art, but a communicative-didactic action between two elements, user and work, subject and object of interaction" [finocchi 2011]. naturally this is valid from the more or less didactic essence of the experience and from the intentions of the production itself. to think that the number of art lovers is limited to few people is a mistake. if these new media may in their own way teach something more, then they are welcome. at bottom, they are entertainment, which in our opinion always has a performative value. consider the younger generations, who are filled with information and images the size of a tablet screen: the "multimedia" exhibition for them can have a great aesthetic and educational effect. a beautiful immersion in sound and color can only leave feelings, emotions and memories more alive, an experience that as such is always positive and always enriching. we are witnessing a real change in cultural communication strategies. if these new strategies are the answer to a widespread impoverishment of interest in the containers of knowledge (museums and libraries), then why not leave them aside, with new means of expression and education at the same time. 6. conclusions 2018 is the european year of cultural heritage, whose guidelines are given by the european community site: "the european year of cultural heritage will highlight the richness of europe's cultural heritage, highlighting its role in promoting a shared sense of identity and building the future of europe." the collective memory, the european identity is hidden among the stones of the archaeological sites, among the battlements of the medieval castles, in popular traditions and in the arts. all this wealth is then a source of economic growth, development and exchange with the rest of encyclopedic palace 2:93 studies in digital heritage, vol. 2, no. 1, publication date: september 2018 the world. there is a new awareness of values ??and of the value of our cultural heritage," in particular at a time when cultural treasures are threatened and deliberately destroyed in conflict zones" [eu 2017], the site still reads. we must protect and preserve our riches as best we can, because "the attempt to abolish and erase the memory of humanity is the worst crime for humanity" [daverio 2017]. we can do it with the help of technology. 7. references richard adler, 1997. infoworld futures project interview to paul saffo. infoworld. retrieved sept 2018: http://www.saffo.com/interviews/infoworld-futures-project-interview cesare brandi. 1963. teoria del restauro, einaudi. rossella caffo, tatiana anderlucci, viviana carini, laura ciancio, alfredo corrao, alfredo esposito, tiziana fabris, giuliano granati, valentina grippo, cristina magliano, adriana martinoli, marina morena, maria teresa natale, elisabetta pagani, paola panaccio, elisa sciotti, priscilla sermonti, and giuliana zagra. 2011. mostre virtuali on-line: linee guida per la realizzazione. retrieved september 2018: http://www.otebac.it/index.php?it/320/mostre-virtuali-online-linee-guida-perla-realizzazione www.movio.beniculturali.it/getfile.php?id=57 eugenio casanova. 1928. archivistica, stabilimento arti grafiche lazzeri. retrieved january 2018: http://www.icar.beniculturali.it/biblio/pdf/euca/totalcasanova.pdf martina cavallarin. 2014. l’esperienza della visione. retrieved jan 2018: https://www.wikieventi.it/milano/amp.php?id_evento=77418 philip daverio. 2017. l’arte di guardare l’arte, giunti. eu. 2017. l'anno europeo del patrimonio culturale 2018 prende il via. retrieved january 2018: https://ec.europa.eu/italy/news/20171207_anno_europeo_patrimonio_culturale_it valeria finocchi. 2011. il valore performativo della fruizione artistica. retrieved june 2018 http://ww2.unime.it/mantichora/wp-content/uploads/2012/01/mantichora-1-pag-277-286finocchi.pdf emanuela fogliardini. 2015. teologia, cristianesimo e arte. retrieved january 2018: http://www.teologiamilano.it/teologiamilano/allegati/258/09.teologia%20cristianesimo%20 e%20arte.pdf stefania garassini. 2005. lev manovich: la nuova estetica dell’informazione. retrieved in january 2018: http://manovich.net/index.php/projects/domus-2005-italian elisa giaccardi. 2012. heritage and social media: understanding heritage in a participatory culture, routledge. massimiliano gioni and al. 2013. palazzo enciclopedico (the encyclopedic palace), published on the occasion of the exhibition il palazzo enciclopedico, the 55th international art exhibition of la biennale di venezia, june 1-november 24, 2013, marsilio. peter gorgels. 2013. rijksstudio: make your own masterpiece! retrieved january 2018: https://mw2013.museumsandtheweb.com/paper/rijksstudio-make-your-own-masterpiece/ indicate. 2012. retrieved in february 20018 http://www.indicate-project.eu/index.php?en/94/about junko. 2017. we are culture snackers. medium. retrieved september 2018 https://culturesnackers.com/we-are-culture-snackers-4e988d7e3739 navid kermani. 2015. ungläubiges staunen: über das christentum, münchen, 303 seiten. isbn 9782:94 l. mazzetti d’albertis studies in digital heritage, vol. 2, no. 1, publication date: september 2018 3-406-68337-4. navid kermani. 2017. lo stupore e la bellezza. meraviglia e bellezza dell’arte cristiana, marsilio. markus krajewski. 2013. in massimiliano gioni and al, palazzo enciclopedico, (the encyclopedic palace), published on the occasion of the exhibition il palazzo enciclopedico, the 55th international art exhibition of la biennale di venezia, june 1-november 24, 2013, marsilio. tommaso montanari and vincenzo trione. 2017. contro le mostre, einaudi. alessandra mottola molfino. 1991. il libro dei musei, allemandi. treccani. 2018. auriti, marino. treccani encyclopedia. retrieved september 2018 http://www.treccani.it/enciclopedia/marino-auriti/ rossella vodret. 2017. dentro caravaggio (inside caravaggio), catalogue of the exhibition “dentro caravaggio” held at palazzo reale, 2017-2017, milano, skira, 2017. received february 2018; revised september 2018; accepted september 2018. 503 service temporarily unavailable 503 service temporarily unavailable nginx/1.14.1 microsoft word goleman conversation_v3.docx studies in digital heritage, vol. 2, no. 2, publication date: december 2018 conversation with daniel goleman about the relationship between the person viewing art and the art itself perla gianni falvo, art perception international, italy giovanni valeri manera, art perception international, italy joel zoss, catalan publishing, usa daniel goleman, best known for his worldwide bestseller “emotional intelligence,” is most recently co-author of “altered traits: science reveals how meditation changes your mind, brain and body.” a meditator since his college days, goleman has spent two years in india, first as a harvard predoctoral traveling fellow and then again on a post-doctoral fellowship. dr. goleman’s first book, “the meditative mind: the varieties of meditative experience,” is written on the basis of that research, offering an overview of various meditation paths. goleman has moderated several mind and life dialogues between the dalai lama and scientists, ranging from topics such as “emotions and health” to “environment, ethics and interdependence.” goleman’s 2014 book, “a force for good: the dalai lama's vision for our world,” combines the dalai lama’s key teachings, empirical evidence, and true accounts of people putting his lessons into practice, offering readers guidance for making the world a better place. having worked with leaders, teachers, and groups around the globe, daniel goleman has transformed the way the world educates children, relates to family and friends, and conducts business. key words: art perception, emotional intelligence, neurosciences, meditation, receptive mindset. sdh reference: perla gianni falvo et al. 2018. conversation with daniel goleman about the relationship between the person viewing art and the art itself. sdh, 2, 1, vi-xi. doi: 10.14434/sdh.v2i1.26872 perla gianni falvo: buongiorno! daniel goleman: buongiorno! can i just start reflecting on the subject? telling you my thoughts? first of all, it makes more sense for me to frame this relationship between the person viewing art and the art itself in terms of mindfulness and brain function rather than emotional intelligence per se. emotional intelligence in my view has four parts: there’s self-awareness, there’s self-management, authors' address: perla gianni falvo and giovanni valeri manera, art perception international, via orcagna 53, 50121, florence, italy; email: perla@artperception.org and giovanni@artperception.org; joel zoss, catalan publishing, 900 division street, nashville, tn 37203, usa; email: joelzoss@joelzoss.com. © [2018] by the authors; licensee studies in digital heritage, iu, bloomington (in), usa. this article is an open access article distributed under the terms and conditions of the creative commons attribution license (cc by-nc). http://dx.doi.org/10.14434/sdh.v2i1.26872 conversation with daniel goleman 2:vii studies in digital heritage, vol. 2, no. 2, publication date: december 2018 there’s empathy, and there’s relationship skills. there are some cross connections, but i think the more immediate links are between brain function, meditation, perception of art, and empathy. let me explain. in our book altered traits my co-author, richard davidson, a neuroscientist at the university of wisconsin, and i go through about 6,000 peer-reviewed journal articles on meditation and pick the top 60—just 1%—of the very strongest studies and explain what they reveal about how mindfulness and meditation alters brain function. the two immediate impacts that i think are relevant to someone going to an art exhibit are, first, that it makes people more focused, better able to concentrate and ignore distractions, which you must do if you are going to stand in front of a painting and have a rapport with what that painting is telling you about the world. the other immediate impact is that meditation is very calming, and that means that the part of the brain that reacts to stress is quieter or recovers more quickly. i think that being calm and clear is the best mental state for a person who’s going to an art exhibit. so, i think getting people into that mindful state may be one of the very best ways to prepare them to have real empathy for a painting, for a piece of art, a sculpture, to be really open to receiving whatever it is the art has to offer. one interesting question is, how, as someone enters a museum or a gallery, can we change their mental state so that they’re in this focused, calm, and receptive mindset? this means leaving behind the state of mind that people are ordinarily in while they are walking down the street, or in their offices, or in their homes. in other words, we tend to live in a universe of mental distraction, lack of focus, where we pay attention to whatever is most dominant or most pressing—or actually what’s most emotionally upsetting. it turns out that people spend most of their free time with their minds wandering to problems they’re having in relationships. this is data from a study at harvard. you want people to leave that mind behind as they enter the exhibit, and one thing you said—contact with art can be like a meditation—stimulates a thought from me, and that is to make the first experience at an exhibition a virtual reality event where you capture the person’s senses. that’s what virtual reality does, it creates a world that you want them to perceive. what if that initial experience is a kind of a meditation, maybe just a focus on the breath, maybe a voiceover where you tell people to just ignore whatever thoughts come up, let them go, just be with the natural flow of your breath. this is a very simple meditation that can be done very quickly, and if that’s experience number one when people enter an exhibit, then i think you might help people get as close as they can to the optimal mind state for going through the rest of the exhibit, whatever it is. those are my thoughts. joel zoss: i’m envisioning an antechamber that’s kind of a meditation room before one enters the exhibit proper. dg: i like that. so, the first part of the exhibit is called the preparation room. i don’t know if it’s called that, but it is functionally that. and in that room my feeling is that people welcome a guide. the guide might be a voiceover that explains what inculcates the right mental state to get the most out of the experience you’re about to have, and directs you to sit down in a quiet, semi-dark room. maybe it’s saying, focus on your breath, let go of other thoughts, and so forth. it does that for a few minutes and then says, okay, now enjoy the exhibit. jz: right. and this could be like five minutes? 2:viii p. gianni falvo et al. studies in digital heritage, vol. 2, no. 2, publication date: december 2018 dg: exactly. i like that. i don’t know, what do think about that? pgf: i agree with this. in some of my workshops i’ve tried similar approaches. but those workshops were for just a few people. maybe we can expand this sort of preparation to a larger number of people in a museum setting. sometimes i think we could invite people to a museum just to see one work of art. dg: that’s interesting. so, there’s an interaction effect. two things occur to me. one is that, for example, in new york, if you go to the museum of modern art, one of the first things that happens as you walk toward the exhibit itself is that there’s a room where you can get headsets. the headset is actually a guided tour of the exhibit. in this room that we’re imagining, maybe you get a headset just for the preparation experience. so, there might be one room where in the headset all you do is listen to the instructions, the guided, artistic meditation, or whatever you want to call it. then you go to the rest of it. anyway, that’s just my thought. giovanni valeri manera: maybe headsets could guide a larger number of people though an introduction into a focused state of mind. but the real issue for us is that while these sorts of approaches have been tried, as perla said in small numbers, the point is also to remain focused, not only to start in the right space, but to stay there. and that is something else. dg: that was my thought exactly. the brain alternates between what’s called an orienting response and habituation. the orienting response is something that happens when you look at a piece of art, when you look at something new, original, fresh, and surprising, and the brain perks up. the brain activates, and so you actually perceive it sensually more fully and can get very absorbed in it. this is i think an ideal state to look at a piece of art. but then the brain habituates. habituation means it closes down and you habituate to things that are routine, that you’ve seen hundreds of times. when you walk to work the same way every day you don’t really see the things along the way as you did the first time you took that walk. that’s because the brain is no longer interested, it’s just categorizing: oh, that’s a building, that’s the park, that’s whatever, and otherwise doesn’t spend any energy registering it. but in an art exhibit you want people to stay in an orienting state all the time, and one way to do that is by having surprises along the way. i don’t know what the surprise would be. something that wakes up the brain. jz: a lot of perla and giovanni’s work relies on constantly introducing new ways of looking at art. one of their projects involves what they call the perception room (“chamera di percezione” 1), a room you can walk into where huge, life-size, bigger than life-size, projections of a piece of art surround you—floor, ceiling, four walls— dg: perfect. works perfectly. that’s the kind of thing i’m envisioning. or imagining. jz: so the brain, once it awakens, you want to keep it awake. 1 "chamera di percezione" was an exhibition project developed by perla gianni falvo for the first "digital heritage congress" held in marseille, france, in october 2013. it demonstrated an innovative augmented reality presentation of raphael’s painting "madonna of the goldfinch," using a room where the user could see large-format high-definition images of the painting projected on the walls, making it possible to penetrate the painting while also revealing the recent restoration process. more details are available on the exhibition catalog: perla gianni falvo, raffaello: madonna of the goldfinch, in e-catalogue of the 2013 digital heritage international congress expo, s. pescarin, a. clay, l. de luca eds., isbn 978-88-902028-1-0. conversation with daniel goleman 2:ix studies in digital heritage, vol. 2, no. 2, publication date: december 2018 dg: yes. keep it awake. and the way you would do that is by every so often having a new experience like that, which is out of the ordinary. jz: this might be done be peeling away different layers of perception for a given work of art, for instance by showing what x-rays reveal beneath a painting. these are precisely the kinds of studies that perla and giovanni are pursuing. dg: i think that’s perfect. i think that’s wonderful because that helps people see in a new way, which is very activating to the brain, engrossing. when people are interested the brain is more active. so, i think you’re actually already on the right track, from my point of view. gvm: you are very kind. i wanted to ask you your take on the seven-minute attention span. i don’t remember who mentioned this, but the idea is that normally the human being after seven minutes loses attention and tends to wander off. dg: i think that seven minutes is a little mythic, like “ten thousand hours.” what it means is that after some time—and it varies enormously from person to person and situation to situation—after a certain amount of time, let’s say seven minutes, you get habituated, is what it’s saying. gvm: we saw an interesting study about what people remember following a museum visit that said the vast majority of people who go to a museum completely forget what they’ve seen unless they went there to view a specific piece of art. so, people wander in, they see everything, they forget everything. one thing we are working on is, instead of showing them 10,000 things, maybe we show them one thing. dg: in 10,000 ways— gvm: exactly. maybe that is the rule. in 10,000 ways, but in an experience that is unforgettable. dg: exactly. but let me say something, giovanni. in terms of the cognitive sciences, “forgetting” means you didn’t pay attention in the first place. the more attention you pay the better you remember. so, i think what happens in an ordinary exhibit where you have a hundred pieces of art is that you habituate, which means you’re walking through it, but you’re distracted, thinking about what you’re going to have for lunch or something. in other words, you’re not actually seeing the art. so, by keeping attention high, you create experiences that are unforgettable. there’s something called “flashbulb memory.” everyone i know who was alive at the time remembers what they were doing when john f. kennedy was assassinated. and that’s because those kinds of events wake up the brain totally. and so, you capture in memory what was happening at that moment. what you’re trying to do, it sounds like, is to create not quite that intense an experience, but rather a higher intensity experience of the moment that activates full attention, which means it will be remembered better. on the other hand, you still want to prepare people. because you can look at the same thing a thousand ways and habituate too. jz: well, two things pop into my mind. traditionally, in lakota [american indian] culture, when you’re going to have a council to decide important things you begin with an entertainer who tells jokes, often quite off-color. only after everybody at the council is laughing do you start working on the serious issues. 2:x p. gianni falvo et al. studies in digital heritage, vol. 2, no. 2, publication date: december 2018 dg: that’s great! jz: the thing that performers know, is that one reason to have an opening act at a concert is that it takes people a minimum of about twenty minutes after they come in and sit down to fully arrive and give you their attention. if you don’t have an opening act, the first ten or twenty minutes of the show are often a bit of a throwaway, because the people aren’t there yet. they’re sitting in the seats, but they’re still arriving. dg: right, can you speed up the arrival time, is my question? and you know, laughter oxygenates the brain, it’s another way to activate the brain. so, there’s some neuroscience behind that too. which of course the lakotas knew intuitively. so maybe something really funny is helpful with the arts too. jz: these are ways of getting people in the mood, as it were. dg: exactly. when you say “in the mood” it’s also i would say in that optimal state, is the way to put it. the brain being activated and attentive. pgf: when we talked before about how people focus on art, you said people needed continuing surprises or novelties to keep focused, and that this can be achieved by introducing new elements and points of view—directing the perception of the people like the director of a film, i want to say. you suggest it would be useful to make a special time to prepare people for viewing art, with an introductory meditation, for instance, and perhaps restricting the number of things they see while continuing to show different levels and details of a work of art using radiography, infrared, and other technologies that enable us to see things we normally cannot see with our eyes. dg: so, the principle in brain science is that the brain becomes more active and alert when it confronts something new, novel, or surprising. art itself is new and novel, and what’s surprising is the way you’re presenting it, i think. gvm: so, if i understand you, just to be clear on this point, your idea or suggestion is to have a director sort of role in this work so that we can direct people to different levels of emotional involvement with the work of art. our capacity will be to identify within the artwork different levels, to make it new and surprising using infrared vision or things that are not visible to the eye, in order to achieve this connection and keep it there. we have to keep people focused. dg: so, a couple of things. one is that i liked that you said “emotional involvement” because emotion and attention are different aspects of the same thing. emotion directs attention, and then attention can stimulate emotion. when i say “attention” you can almost insert “emotion.” by getting people to pay more attention you’re making the experience more emotionally impactful. the other thing is, i don’t think you want to overwhelm, i think it’s more a matter of pacing. for example, if you have a completely white-covered, white-painted room and one piece of art in it, the eye is going to be riveted to that piece of art, but it’s because nothing else is distracting you. so, i think another element that you can use to your advantage is not just guiding the person, but pacing, and by pacing i mean that things could be very straightforward and then all of a sudden something surprising happens. you’re very focused on one thing and suddenly—whatever the surprise is, the x-ray or something—pops up. so, it’s some combination, like a melody almost. conversation with daniel goleman 2:xi studies in digital heritage, vol. 2, no. 2, publication date: december 2018 gvm: so exactly, if i understand you well, more than being overwhelmed, it’s the pattern, it’s the rhythm, it’s the succession, that matters. dg: and the surprise is part of the pattern. but it’s an unexpected part of the pattern. pgf: i agree, i totally agree. i think that in art perception, we need to direct the experience of art perception like a film, so people have the experience, and we need to work on those aspects. dg: right, i like your metaphor of the art curator as the director, like for a film. and that’s exactly right because when you direct a film, you’re designing an experience. when you create an exhibit, you’re also designing an experience. pgf, jz, gvm: thank you very much for your time. received september 2018. archaeoastronomy in the khmer heartland giulio magli, politecnico di milano, italy the heartland of the khmer empire is filled with magnificent monuments built over the course of many centuries. these monuments include the world-famous “state temples,” such as angkor wat, and also many other temples as well as huge water reservoirs. using data from google earth as well as gis and reconstructing the ancient sky with stellarium, we investigate the relationships of astronomy with orientation and topography in a systematic fashion, following the methods of modern archaeoastronomy and strictly keeping at bay vague and/or esoteric proposals put forward by previous writers. as a result, a very clear pattern of cardinal orientation and alignment arises, connected with the temples’ symbolism and the management of power by the khmer kings. as a bonus, a comparison with the angkor monuments allows us to put forward an explanation for the anomalous orientation of two unique “peripheral” state temples of cambodia. key words: archaeoastronomy, angkor temples, angkor wat, stellarium, google earth pro. sdh reference: giulio magli. 2017. archaeoastronomy in the khmer heartland. studies in digital heritage volume 1, issue 1 (february 2017), 17 pages. https:doi.org/10.14434/sdh.v1i1.22846 1. introduction the khmer empire flourished between the eighth and the fourteenth centuries ad. the heartland of the empire was located in the vast cambodian lowlands, where the kings developed monumental temple architecture as a means for the explicit representation of their power. as a consequence, a series of masterpieces—and especially the so-called “state temples,” like angkor wat—were constructed [jacques and lafond 2004]. geographically, these buildings were concentrated in the environs of today’s siem reap, first in the area of roulos, and then later in angkor, some 15 kilometers to the north. there are, however, two exceptions: koh ker, located in northern cambodia, 85 kilometers northeast of angkor, and preah khan of kompong svay, 100 kilometers to the east. the khmer state temples are vast rectangular enclosures with a central unit and several auxiliary buildings and shrines. the aims of such architectural ensembles, whose design in many cases also included the construction of huge barays (water reservoirs), were quite complex, since they functioned as royal residences and major cult centers attesting the beliefs and religiosity of the kings. a further funerary function for the afterlife of the king, although likely, has never been proved. until a few years ago the temples were even conceived of as “concentrated state towns,” but recent research and mapping on large scale has shown the complexity of the urbanization of the whole angkor area, casting doubt on the idea of state temples as “capital cities” [evans and fletcher 2015; stark et al. 2015]. author's address: giulio magli, department of mathematics, politecnico di milano, piazza leonardo da vinci 32, 20133, milan, italy; email: giulio.magli@polimi.it permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 studies in digital heritage archaeoastronomy in the khmer heartland     1:2 another important aspect highlighted by recent research is the sophistication of the hydraulic system, which led to an impressive modification of the natural environment. it was organized into three grand areas, with the major barays acting as central collectors and with flow management systems towards the south. the barays thus had both a practical and ritualistic function in being explicitly associated with the state temples and embellished with the mebons, the island temples built inside them [fletcher et al. 2015]. as far as the interpretation of each temple is concerned, the connection between the two khmer religions— buddhism and hinduism—must be taken into account. their relationship was sometimes exclusive and at other times syncretistic, depending on the attitude of the ruling king. documented historical phases of buddhism/hinduism reveal conflict and consequent defacing of the temples' images. in any case, construction of the temples was clearly considered mandatory to demonstrate the greatness and in some sense the divinity of the king himself. the temples thus reflected concepts related to the foundation of power and to the cosmic order. thus, it comes as no surprise that a complex religious symbolism is self-evident in all these buildings. inspiration certainly came from indian sacred architecture [malville 2000; kak 1999; kak 2002] and, in particular, the characteristic layout of angkor wat and of many other temples—a “pyramid mountain” surrounded by a moat—is usually considered to correspond with the cosmology of mount meru and the surrounding sea of milk, from which ambrosia was churned by the gods and demons. the religious symbolism associated with cosmic order is reflected in the orientations of ancient buildings worldwide [magli 2013], and angkor is no exception. it is indeed well known that almost all the temples, enclosures and barays are oriented cardinally. however, although this notion is widespread [petrotchenko 2012], as far as the present author is aware, no attempt has been made to analyze it quantitatively, using the methods of modern archaeoastronomy [ruggles 2015; magli 2016]. furthermore—and curiously—the same pattern is not respected at the two complexes located outside the heartland, so that their orientations can be defined as “anomalous.” this fact has been noticed in the literature, but never explained. yet another point which has been left unexamined is the reported existence of alignments between different temples. in spite of, or perhaps owing to, this lack of professional archaeoastronomical investigation, pseudo-archaeological interpretations of angkor have easily found their way into the popular media. the same holds for the “astronomical numerology” of angkor wat, which has been made famous by a controversial book [mannikka 1996]. the present author has many qualms about this issue, but discussing it would be beyond the scope of the present paper. to study the archaeoastronomy of the angkor temples, a complete database of orientations at angkor has been constructed here using satellite imagery, and the sky over angkor has been reconstructed using the affordances of the planetarium software stellarium. although database (table 1) is presented in a chronological fashion, the reader is warned that not all the datings of the temples are firmly established in the archaeological literature. this allows us to investigate not only orientations but also the probability of intended alignments between buildings dating to different periods. by comparison with the angkor results, the anomalous orientations of the peripheral temples can also be interpreted as representing two different breaks in the traditional pattern of orientation. archaeoastronomy in the khmer heartland     1:3 2. the orientation of the angkor monuments the present author has previously gathered sample data of angkor temples with a precision magnetic compass. however, in order to present a complete analysis based on a homogeneous, reliable and complete set of data, the azimuths used in this paper (reported in tables 1 and 2) have all been obtained with the compass tool of google earth pro. the accuracy of google earth in areas covered by high-resolution images is usually very good [potere 2008], and in particular—as the author has verified by personally comparing satellite data with directly acquired theodolite measures in many different countries—the error in azimuth does not exceed ±½°. the reliability of this estimate is particularly solid in the present case because all the data have been subjected to a double-blind control. in fact, the author was kindly allowed to consult the gis database currently being developed by the greater angkor project, and in all cases the azimuth measures furnished by this database were very close to those of google earth; the two “virtual campaigns” have of course been done independently, that is, without mutually adjusting the way of taking measures. as far as the horizon is concerned, it is flat for almost all monuments (the case of angkor wat will be treated separately) and, as we shall see, the monuments by themselves actually work as artificial horizons. the following monuments have been listed and measured: state temples. barays. the barays were handled as monuments in their own right, since their size and meticulous orientation are difficult to reconcile with purely functional aims. the results of the paper support the view that they were an essential part of the building program associated with the legitimization of kingship. island temples. they were, in many cases, constructed in already existing barays, typically by successor kings. the most important secondary temples, either of royal or private construction. except for angkor wat and the secondary temple of wat athvear constructed by the same king, the main entrance of all the temples is to the east. for each temple, a convention similar to that commonly used for greek temples has thus been followed, viz., the azimuth is given from inside looking out. the results (table 1, reported schematically in fig. 1) show that there is an obvious pattern of orientation towards true east exhibited by all the data. since the rectangular enclosures are sometimes not perfectly squared, in the table both azimuths of the east-west and of the north-south sides are reported, but the analysis is based on the azimuths of the east-west sides. all of the 31 monuments considered lie within an interval as small as five degrees, between 85° and 90°. it is obvious that there is no need of statistics to conclude that the orientation was intentional. a first point is, therefore, fully confirmed: these monuments were connected to ideas of cosmic order in architecture, which imposed an orientation to the cardinal points. but the data tell us more than that. indeed, 19 monuments out of 31 are concentrated between 89 and 90 degrees, and all those temples not perfectly oriented to due east exhibit a slight deviation exclusively to the north of east; not even one exhibits a deviation, however small, to the south of east. are these small deviations only due to errors committed by the builders in the measurement process, or are they intentional? it is clear from the monuments themselves that the khmer architects were extremely precise. the method they used to find the cardinal directions was probably based on the sun, a feature archaeoastronomy in the khmer heartland     1:4 chosen for both religious and practical reasons. indeed, finding north using the stars requires either the observation of the directions of rising and setting of a bright star on a flat, level horizon (a thing quite difficult to achieve in the humid environment of angkor) or the observation of the motion of a circumpolar star (again, very difficult due to the very low height of the north celestial pole). furthermore, owing to precession, no “pole star” was available in khmer times. in contrast, the traditional method of finding cardinal directions by bisecting the shadows of a gnomon on a circle—the “indian circle”—was certainly well known to the khmers. fig. 1. orientation histogram (azimuth in degrees vs. number of monuments) of 31 monuments of the angkor heartland. using this method, a scrupulous astronomer can easily obtain an accuracy on the order of ½°, if not better. we are thus led to infer that even the slight deviations observed in some temples are deliberate. in contrast, if the observed deviations had been caused by errors of measurement, then either a method which leads only to north-of-east errors was devised (which is unlikely), or the results should have been distributed randomly on both sides of the expected value of 90°. the key to this riddle can be found by studying the orientation of angkor wat, to which we now turn. the azimuth of the temple is 270.5°. the likely reason is that the temple was originally dedicated to vishnu, a god closely connected to the west, as can be seen, for instance, in the upper terrace of the bayon, whose western shrine is devoted to him. the orientation of angkor of course implies that a person entering the enclosure from the west gate is looking along the direction of azimuth 90.5°. this slight deviation has an interesting consequence, which is already very well-known [stencel et al. 1976]. looking from the west gate towards the temple at dawn on the equinoxes, the sun is seen to rise just above the central tower, “crowning” it almost vertically. the reason is that at the latitude of angkor the trajectory of the sun is very steep, and therefore a small increase in azimuth leads to a strong increase in height; the “horizon height” of the central tower of angkor wat from the western entrance is ~5° and the center of the sun reaches such an altitude at an azimuth of 90° 40' (fig. 2) (astronomical data in this paper are taken from stellarium, while declinations are calculated with the program get-dec, kindly provided by c. ruggles, which takes into account refraction and parallax). archaeoastronomy in the khmer heartland     1:5 so far, so good for the angkor wat orientation. it is now obvious, however, that if a similar phenomenon must be observed in a temple whose main access is to the east, observation will occur at sunset, and the azimuth of the temple must be slightly misaligned to the north of east. in fact, in this way the direction of the observer looking along the temple axis will point slightly to the south of west, where the equinoctial sun will be seen to disappear just above the temple. fig. 2. stellarium simulation of the sun rising at the spring equinox at angkor. the solar coordinates are: azimuth 90° 40', height 5°. this is the likely explanation for the temples’ orientation slightly to the north of east, and so in particular for the state temples bakong, phnom bakheng and bayon, whose azimuth (“exactly” like that of angkor wat, but in the opposite direction) is 89.5°. the phenomenon of the sun disappearing vertically behind the temple at the equinoxes in this latter case can be verified using google earth 3d visualization. the dimensions of the sun in google earth simulations are relatively big, but despite this the effect is unmistakable, as shown in fig.3. what is the meaning of such spectacular hierophanies? for angkor wat, stencel et al. 1976 proposed a rather complex calendrical function, trying to frame the phenomenon into a series of supposed astronomical functions of the monument which, when viewed from different, suitably chosen points of the esplanade supposedly furnish, for example, the extrema of the motion of the moon at the horizon. this idea, however, is clearly biased by a strong selection effect of the observation points, and in any event there is no evidence that the khmer monuments were used for making precise astronomical observations. the key is instead symbolic: the beautiful hierophany of the sun suspended just above the mountain temples at the equinoxes was very probably intended as a materialization of the connection of the temple itself with the heavens, since it brings about a match between the zenith in the sky and the cardinal directions on the ground. archaeoastronomy in the khmer heartland     1:6 fig. 3. google earth simulation of the setting of the sun behind the bayon at the spring equinox. the recent discovery that the zenith passages were probably also made visible inside the temples [barnhart and powell 2013] supports this interpretation, as well as the well-known general connection of the temple mountain architecture with the axis orthogonal to the earth's surface—the zenith-nadir axis to which, respectively, the temple and its image reflected in the waters in front of it explicitly allude. in fact, although the simplest way to observe the zenith passages is to look for the days in which the shadow of a post vanishes at noon, another effective way is to use a straight vertical tube leading from the open sky into a dark chamber. if the tube is sufficiently long and narrow, the identification of the zenith passage will be accurate and, most important of all, the effect inside the room will be spectacular. this method, which was developed for example in pre-columbian mesoamerica, was very likely in use also in the angkor temples. today, their roofs are open, but the capstones are missing. many such stones, however, are present in the rubble near the temples, and all have a hollow tube running down their axes. the holes allowed rain to hit the holy stone lingas located at the center of many chambers, and also allowed the sun passing overhead to light the same stones in spectacular hierophanies occurring twice a year (zenith passages at angkor occur on april 26 and august 17). the temples of the angkor heartland were thus anchored in the cycle of the sun in two ways: the orientation, related to the equinoxes, and the vertical openings of their chambers, related to zenith passage. yet another way to connect a temple with the zenith passages is, of course, by orienting the building to the sun rising or setting on these days, as occurs, for instance, for the world famous post-classic maya pyramid of chichen itza, yucatan. the azimuth of the rising sun on the zenith passages at angkor is 76°, so apparently no angkor temple was oriented in this way. interestingly enough, however, the cardinal orientation appears to be a pattern, a rule only for the sacred space of angkor, since —as we shall see in section 4— a state temple oriented to the sun rising on the days of the zenith passages actually exists outside the heartland. archaeoastronomy in the khmer heartland     1:7 finally, a few temples remain for which the misalignment is too elevated to be attributed to considerations of visual effects. in particular, the temple exhibiting the worse misalignment with respect to due east, banteay kdei, was probably built long after the construction of the baray which lies in front of it and has the same alignment. thus, the original rough orientation of the baray probably influenced that of the later temple for aesthetic reasons. 3. astronomical alignments between monuments the existence of scores of alignments between different monuments of angkor was noticed many years ago by paris 1941, who, however, offered no explanation for them. he divided his finds into cardinal (north-south or east-west) alignments, sosticial alignments, and “non-oriented” (meaning at least 3 points aligned, but not astronomically) alignments. in total, he proposed 28 cardinal alignments, 26 sosticial alignments, and 11 other alignments. in the present paper we are interested only in astronomical alignments, and therefore just cardinal and sosticial relationships will be treated in what follows (paris also proposed geometric relationships, e.g., temples standing at the vertexes of equilateral triangles, which will not be investigated here). i have subjected all the proposed alignments to a check for accuracy. here are the results: a few are impossible to verify, as they refer to unnamed buildings, or ruins which are not recognizable. a few others are not verified within the error permitted here, namely ½°. all the remaining ones are “correct”; in other words, they have been verified as falling within the degree of accuracy adopted in this paper. among the alignments which are technically verified, the following possibilities may occur. alignments occurring by pure chance. these alignments arise owing to a selection effect. for example, a side of a temple complex is aligned with a corner of another complex and with the opposite side of yet another one, a connection which is far more likely to occur by chance than—say—to determine that the tops of three temples are all aligned on the same meridian. in particular, we must pay special attention when the temples are too far apart and do not allow a direct view. indeed, because of the earth’s roundness, intervisibility between sites (provided that the view is unobstructed) is severely limited. a good estimate is the following: the visibility of an object which is h meters high equals the square root of 13 h expressed in kilometers, so that, for instance, a person 2 meters tall sees on a flat horizon as far as ca. 5 kilometers. the summits of existing temples and/or provisional wooden structures could have been used to trace longer alignments, because when the object sighted is in itself high, the heights must be added to each other and therefore the distance to the horizon increases. however, in this case, too, lines longer than ca. 11-12 kilometers (corresponding to observation points located at heights ~10 meters) must be regarded as extremely suspicious. alignments occurring for technical reasons. the technical problem of tracing cardinally oriented lines is not an easy task. it does not suffice to determine the cardinal directions with a suitable accuracy, but it is also necessary to maintain the same accuracy during the construction of an enormous work of engineering such as the west baray, which is 7.8 kilometers long. as a result, the lines already surveyed can be useful for a purely practical reason; for example, the top of a temple can be used as a survey point when laying out a new project. this procedure generates “true” alignments whose explanation is, however, purely functional. archaeoastronomy in the khmer heartland     1:8 alignments occurring for symbolic reasons. these are possible when, for example, a certain project was connected to another through an astronomical event, or a certain king wanted to create a visual connection with the monument of a previous king. such alignments of course fall into the specific sphere of interest of archaeoastronomy. 3.1 cardinal alignments after careful scrutiny, only a certain number of the cardinal alignments proposed by paris survived the test of the “selection effect.” further, claiming intentionality (according to point 3 above) is possible only if the chronology of the monuments in question is perfectly clear. for this reason, in what follows, only alignments including a well-attested chronology are reported, although i do not exclude the possible existence of a few others involving other buildings, whose chronology is not yet clear. fig. 4. the meridian line connecting lolei with the bakong. (image courtesy google earth; drawings by the author.) our starting point is the first state temple built in angkor-roulos, the bakong, built by indravarman i. the temple was built along with a huge baray, the so-called indrataka, which was located in such a way that the central axis lies on the same meridian (azimuth 180°) as the bakong, located 1.8 kilometers to the south of the baray's center. inside the already existing baray, yasovarman i, (successor of indravarman i) built the lolei, an island temple, which was placed along the very same meridian (fig. 4). in this way, a clearly intentional and symbolic alignment was created. the same king also “delimited” the sacred space of the future angkor by building two temples (phnom krom and phnom bok) on the two small hills which overlook the area from the south and from the east respectively. around the beginning of the tenth century ad, yasovarman i probably also initiated the construction of an even bigger baray, the east baray, which, about 50 years later, was used by rajendravarman ii to create a symbolic configuration quite similar to that of the lolei-bakong. indeed, he built his own state temple, pre rup, on the same meridian as the center of the east baray, and about 1.3 kilometers to the south. archaeoastronomy in the khmer heartland     1:9 moreover, he added an island temple (the east mebon) inside the already existing baray. the position chosen for the east mebon is on the “same” meridian as pre rup. the reason for the quotation marks is that the azimuth of this alignment is slightly off-center (178°), but this is coherent with the orientation of pre rup, which indeed is 88°. in other words, it is clear that east mebon was intentionally placed along the direction orthogonal to the north side of pre rup. interestingly, a very long line (about 7 kilometers) almost lying on the parallel (azimuth 269°) connects east mebon with phimeneakeas, whose original dating is not known, but which functioned as the state temple of the successor, suryavarman i. the victory gate of angkor thom lies along the very same direction and its placement was almost certainly chosen for the very same reason (fig. 5). finally, an interesting combination of alignments also repeats for the largest of the barays, the west baray. here the north side is on the same parallel as the state temple of its builder, the baphuon, which lies at a distance of 2.2 kilometers from the corner, to the east. the prolongation of the south side to the east also lies on the same parallel (azimuth 89.5°) of a temple, the pre-existing bat chum, at some 7.6 kilometers from the south-east corner. finally, at the center of the west baray, the island temple west mebon was constructed by udayadityavarman ii (it is not completely clear if the project of the baray was already initiated by his predecessor suryavarman i). the west mebon is connected with pre rup, since a “parallel” line (azimuth 89.5°) connects the two monuments (later, ta prohm was also to be built on this line). this line is very long (9.6 kilometers), but pre rup is 12 meters high. clearly, since the mebon is at the center of the baray, it is the baray itself that was planned by taking into account three reference points corresponding to the parallels of the sides and the mid line (fig. 5). fig. 5. cardinally oriented alignments between main monuments at angkor. image courtesy google earth; drawings by the author.) the reasons for the construction of the barays (whether they were functional, or ritualistic, or both) is a complex issue of khmer archaeology as a whole and certainly cannot be addressed by the present author. i would only note here that the existence of the above-mentioned alignments, which are certainly intentional, reinforces archaeoastronomy in the khmer heartland     1:10 the presence of a ritual function, since it was the khmer kings themselves who drew attention to these alignments by the construction of the island temples. building such monuments was certainly no easy task. it is difficult to believe that these islands were rapidly assembled during the dry season (and it is unclear to what extent the barays were dry during this season), and it is even more difficult to believe that they were built within the water, so the barays must have been intentionally left in a dry state (by closing the inlet moats) for a suitable time. an exception is neak pean, a mebon probably built together with the baray of the preah khan temple. their construction, therefore, certainly resulted from the direct order of the kings and was motivated by symbolic reasons. the existence of the above-described topographical relationships of the barays with the state temple of their builders allowed construction of the mebons in accordance with existing lines of sight oriented cardinally. the idea of constructing the island temples appears therefore to implement in a quite spectacular and sophisticated way a dynastic continuity which the kings wanted to make explicit (figs. 4,5). creating interconnecting, visual relationships with monuments built by predecessors is a means of stating the continuity of power and the “divine” rights of rulership, according to a mechanism of development of the topography of the sacred space which is similar to those found in completely unrelated cultures [aveni and hartung 1988] for the mayas or [magli 2010] for old kingdom egypt. the existing alignments between barays and temples were easily compatible with this aim. from the point of view of “dynastic” cardinal alignments, there exist two other cases which appear to be non-casual. these are: a very precise (azimuth 89.5°) east-west line which connects the top of the bayon with that of the preexisting temple banteay samrè. the axis runs along the “gate of the deaths” of angkor thom. it is very long (about 10.8 kilometers, as it crosses the whole of the east baray) but the top of banteay samrè could be used as a survey point (fig.4). a perfect (azimuth 180°) north-south line which connects the axis phimeneakeas-baphuon with the already existing bakheng, located outside angkor thom at 2.5 kilometers (fig. 4). the latter is built on a hilltop and there is little, if any, doubt that this alignment is intentional and therefore governed the longitudinal positioning of the phimeanakas-baphuon complex. in both cases, it remains to be determined if these alignments were mere survey lines or, as seems likely, there were dynastic or other traditional reasons which motivated the kings to ask that these connections be incorporated into their state projects. 3.2 solstitial alignments at the latitude of angkor (13° 26' n) the rising azimuths of the sun at the solstices are 65.5°/114.5°. as mentioned in [paris 1941], the existence of as many as 26 solstitial alignments between monuments is claimed. of these, two refer to the western entrance of angkor wat and will be discussed separately. i have subjected all the others to an accurate verification. a few refer to monuments which are not recognizable. my conclusion on all the others is that they are likely to be random. indeed, most alignments refer to secondary monuments and to features which can easily arise from a selection of data. for instance, consider the (very precise indeed!) “solstitial alignment” which connects the northwest corner of the enclosure of angkor wat with the northeast corner of the east baray. clearly such an alignment cannot have any symbolic significance, nor can we imagine an observer who uses these two corners for solar observation. additionally, the alignment would have no archaeoastronomy in the khmer heartland     1:11 practical utility for a surveyor and can therefore be definitively discarded. in practice, the only case of a solstitial alignment which survives this analysis is an alignment connecting the top of phimeneakeas with the center of neak pean, built later. i cannot exclude intentionality, however, from neak pean—restricted only to the main monuments, without considering corners and other features but only the tops—one could trace at least some 20 other “alignments” with pre-existing temples. regarding angkor wat, stencel, gifford and moron [stencel et al. 1976] produced evidence of two supposed solstitial alignments previously found by paris [paris 1941]. for this reason, the notion that angkor wat was a sort of calendrical device became widespread. according to this theory, standing at the west gate (the same position from which the equinoctial hierophany can be seen), the sun at summer solstice rises in alignment with the temple located on the phnom bok hill some 17.5 km to the northeast, while at the winter solstice it rises in alignment with a temple called kuk bangro, about 5.5 km to the southeast. kuk bangro is a small and damaged ruin which is almost invisible in satellite images, and i have doubts that the alignment was ever explicitly verified after paris found it. indeed, today the temple is—and in all probability has always been—invisible from angkor wat. furthermore, its date of construction is not known, and so it could be later than angkor wat. unless a strict historical connection can be made between the two, the alignment is therefore very likely accidental. phnom bok is a hill about 220 meters high, not particularly prominent from angkor wat. the temple on its summit had long existed when angkor wat was being planned, but, although the alignment is indeed verified, to attribute intentionality to it one would have to assume that the entire siting of angkor wat as a whole was largely governed by a desire to create this alignment, something for which there is no cultural basis whatsoever. to summarize, the present analysis does not confirm the idea that any of the temples, angkor wat included, were used as “calendars in stone.” in addition, there is no other evidence showing an interest for the extreme positions of the sun at the horizon by the builders of the angkor monuments. in contrast, in view of the latitude and the climate of angkor, their interest was rather focused on the equinoxes and the zenith passages, which were associated with the main climatic events, the transitions between the dry and wet seasons. 4. the orientation of the two “peripheral” state temples two state temples were founded outside the angkor heartland. the first, koh ker, was built by king jayavarman iv in the mid tenth century ad. the site is characterized by a huge baray and by a 36-meter tall stepped pyramid, which is located on axis with the main temple, the prasat thom. the entire project exhibits a peculiar orientation at azimuth 76° (flat horizon), which is also shared by the short sides of the baray. sometimes topographical reasons—such as the slight south-north slope of the terrain—have been advanced for this orientation [uchida et al. 2014], but it is difficult to believe that the architects of such a huge and complex project might have let this fact alone cause them to rotate the whole design by 14°. if we search for an astronomical interpretation, an answer is readily found. at the latitude of koh ker, azimuth 76° with flat horizon yields a declination of +13° 26'. the latitude of the site is 13° 44' so the main axis is quite precisely oriented to the rising sun on the days of the zenith passages, which of course occur when the sun has a declination equal to the latitude of the site. therefore, when it was decided to change the site of the state temple, a change of orientation was also devised, creating for the first time an explicit connection of the axis with the sun rising on the days of the zenith passages (fig. 6). archaeoastronomy in the khmer heartland     1:12 fig. 6. google earth simulation of the sun rising in alignment with kok ker on the day of the first zenith passage. (image courtesy google earth, drawings by the author.) even more clearly, orientation seems to have been a means of expressing a breakthrough when preah khan of kompong svay was constructed. it is a huge complex: the exterior perimeter of about 5 km per side makes it the largest khmer enclosure ever built [mauger 1939]. the site was connected to angkor by a “royal” road rich in stone structures, such as bridges and “rest house” temples [hendrickson 2010]. the building chronology is difficult to establish, since only one dated inscription (ad 1010) has been recovered. accordingly, the site might have been founded in the eleventh century by king suryavarman i. however, important architectural details point to the first half of the twelfth, during which angkor wat was also constructed. curiously, other details recall the late twelfth to early thirteenth century, pointing to king jayavarman vii, the builder of the bayon. the religious dedication of the complex is equally difficult to identify owing to the interplay between buddhist and hindu elements. the reasons leading to the construction of such a majestic architecture in such a remote place are still subject to debate. since activities related to iron smelting were carried out in this area, it might have been an administrative center. however, the presence of such an impressive, symbolic monument is difficult to explain, and a complete re-analysis of the archaeological setting together with a new mapping of the area is currently giving new insights into this problem [hendrickson and evans 2015]. as far as we are concerned, there is an aspect which has been noticed by all authors but never satisfactorily explained, namely the orientation which is anomalous if compared to the angkor monuments. the complex is indeed clearly rotated to the north of east; mauger gives 27° 24' north of east, but repeated measures on satellite images rather point to 29° north of east (azimuth 61°). it is this value which will be used here. the horizon is flat or nearly flat. the hypothesis which has been proposed by some authors [paris 1941] is that the complex might have been oriented to the rising sun at the summer solstice. however, the azimuth of the midsummer sun with a flat horizon in this region is 24° 30' north of east and therefore definitely far from the observed one (the variation archaeoastronomy in the khmer heartland     1:13 of the obliquity of the ecliptic since ad 1100 is negligible, being about 6'). of course, this does not necessarily mean that the temple was deliberately oriented to another astronomical phenomenon, but topographical reasons are difficult to imagine, and invoking “chance” is equally unsatisfactory, especially when taking into account the strict astronomical pattern which was the rule in angkor's heartland. furthermore, a very clear astronomical solution does exist, involving the moon. as is well known, the plane containing the earth and the moon’s orbit is not the ecliptic, but forms with it an angle of 5° 9'. this has the consequence that the maximal and minimal declinations which the moon can attain are greater/lesser than those of the sun (which of course equal ± the obliquity of the ecliptic, 23° 30') by such an amount. this means that the moon at the horizon can attain azimuths lesser/greater than those of the sun at the solstices. owing to a series of physical reasons, the extreme declinations (also called maximal standstills) are encountered only once every 18.6 years. of particular interest is the full moon closest in time to the winter solstice, since it always attains a declination close to the maximal one in the year of the standstill, culminating very high in the sky and remaining in the sky almost the whole night. preah khan of kompong svay is definitely oriented to the moon rising at the maximal northern standstill. indeed, azimuth 61° with a flat horizon at this latitude yields a declination +28°.the true lunar declination at the site is actually slightly greater, 28° 14', because parallax must be taken into account. this value must be compared with the standstill declination of +28° 39' and again, as is the case of koh ker for the zenith passages, the match is impressive. of course, the role of the moon is quite relevant both in hinduism—where it is identified with the god chandra—and in buddhism, since festivals and recurrences associated with buddha's life are timed by the full moon. the choice of orientation to the extrema of the moon might thus have arisen from this and/or from other specific messages the builder wanted to associate with the temple. to be sure, further archaeological/historical research is needed to clarify this point. there is, however, a second issue related to astronomy which is worth discussing about preah khan of kompong svay. it is known that the temple is located on the same latitude as angkor wat. the accuracy of this coincidence is astonishing: the center of angkor wat is within 1' at the same latitude (13° 24') of the entrance to the inner enclosure of preah khan. the linear distance between angkor wat and preah khan of kompong svay is about 100 km, and therefore no visual connection is conceivable, and it is certainly possible to think that the connection occurs by chance. indeed, to proceed along a “straight” line between non-intervisible positions is a thing which generally makes no sense at all since there are no straight lines on a curved surface (as pseudo-archaeologists in search of “leylines” usually forget). however, the special case of sites placed at the same latitude does make sense, because—although the parallel circle is not the shortest path between two points at the same latitude—the parallel in itself is, in principle, easy to determine using astronomy, and the khmer architects certainly possessed the necessary skills. it is indeed possible to establish latitude by measuring the height of the celestial pole or the height of the sun at midday on fixed days, and this second method was clearly favored in the present case. ancient people interested in the zenith passages of the sun appear to have also been interested in developing precise measures of latitude, as shown, for instance, by the archaeological site of altavista in central mexico. however, even admitting intentionality, obtaining the accuracy exhibited by the angkor-preah khan alignment must have been quite a daunting task, which clearly demands a sound historical explanation and a symbolic, rather than functional, interpretation for the site in connection with angkor wat. archaeoastronomy in the khmer heartland     1:14 5. discussion the angkor temples are masterpieces, built by knowledgeable architects who planned and erected them by taking into account a complex symbolical framework connected with the explicit representation of the ruler’s power and of his relationships with the gods. the results of the present paper show that this framework included the sky, reflecting a world view in which the cycle of the sun and that of the dry and the wet seasons were tightly connected. interest was mainly focused on the equinoxes and on the zenith passages, since both phenomena were implemented in the temples’ architectural features and designs. in a few cases the temples by themselves were not isolated units but were ideally linked with pre-existing monuments, constructing a series of visually recognizable dynastic lines, which are particularly evident in the case of the mebons, the island temples. it is thus the hope of the present author that the research presented here can contribute to clarifying historical aspects of khmer architecture and of the king’s succession. in contrast, the same results show that claims about the existence of scores of inter-connecting, almost esoteric lines between the angkor monuments must be viewed with caution, if not skepticism. 6. acknowledgements the author gratefully acknowledges dr. damian evans and the greater angkor project for their kind permission to double-check the author's data with the gis database they are developing. 7. references anthony f. aveni and horst hartung. 1988. archaeoastronomy and dynastic history at tikal. in anthony f. aveni, ed. new directions in american archaeoastronomy. oxford: bar international series 454, 1–11. edwin barnhart and christopher powell. 2013. the importance of zenith passage at angkor, cambodia. 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(1941), 303–334. michel petrotchenko. 2012. focusing on the angkor temples: the guidebook 2nd ed., michel petrotchenko. david potere. 2008. horizontal positional accuracy of google earth’s high-resolution imagery archive. sensors 8, 12 (2008), 7973–7981. doi: https://doi.org/10.3390/s8127973 clive l. n. ruggles, ed. 2015. handbook of archaeoastronomy and ethnoastronomy, new york, ny, usa: springer-verlag. miriam t. stark, damian evans, chhay rachna, heng piphal, and alison carter. 2015. residential patterning at angkor wat. antiquity 89, 348 (2015), 1439–1455. doi: https://.doi.org/10.15184/aqy.2015.159 robert stencel, fred gifford, and eleanor morón. 1976. astronomy and cosmology at angkor wat. science 193, 4250 (july 1976), 281–7. doi: https://doi.org/10.1126/science.193.4250.281 etsuo uchida, kojiro tsuda, and ichita shimoda. 2014. construction sequence of the koh ker monuments in cambodia deduced from the chemical composition and magnetic susceptibility of its laterites. herit. sci. 2, 1 (2014), 10. doi: https://doi.org/10.1186/2050-7445-2-10 received september 2016; revised november 2016; accepted january 2017. archaeoastronomy in the khmer heartland     1:16 appendix table i. main monuments of the angkor area orientation notes king/date preah ko 90 180 indravarman i 880 bakong 89 179 state temple indravarman i 881 baray indratataka 90 179 indravarman i lolei 90 180 island temple yasovarman i 893 phnom bakheng 89.5 179 state temple yasovarman i 907 baray east 88 178 yasovarman i phnom krom 90 180 yasovarman i phnom bok 90 179 yasovarman i prasat bei 90 180 yasovarman i baksei chamkrong 90 180 harshavarman prasat kravan 90 179 harshavarman i 921 east mebon 86 177 island temple rajendravarman ii 953 pre rup 88.5 179 rajendravarman ii 961 bat chum 90 180 rajendravarman ii banteay srey 90 180 private construction rajendravarman ii 967 phimeneakeas 89 179 date and king unsure rajendravarman ii ta keo 89 180 jayavarman v 1000 chau srei vibol (wat trak) 89.5 179.5 date and king unsure; difficult to measure suryavarman i 1000-1050 baray west 90 180 suryavarman i baphuon 89 179 udayadityavarman ii 1050-1066 west mebon 90 180 island temple udayadityavarman ii 1050-1066 angkor wat 270.5 180 state temple; faces west suryavarman ii 1113-1145 banteay samre 85 175 suryavarman ii 1113-1145 wat athvear 270 180 faces west suryavarman ii 1113-1145 thommanon not measured suryavarman ii 1113-1145 chau say tevoda not measured suryavarman ii 1113-1145 beng melea 89.5 179 suryavarman ii 1113-1145 ta prohm 87.5 177.5 jayavarman vii 1181-1218 preah khan 89 179 jayavarman vii 1113-1145 baray preah khan 89 178 jayavarman vii 1113-1145 neak pean 88.5 178.5 island temple jayavarman vii 1113-1145 bayon 89.5 179 jayavarman vii 1113-1145 banteay kdei 85 175 jayavarman vii 1113-1145 baray banteay kdei 86 176 jayavarman vii 1113-1145 ta som 88 178 jayavarman vii 1113-1145 krol ko 87 177 jayavarman vii 1113-1145 banteay prei 88 178 jayavarman vii 1113-1145 archaeoastronomy in the khmer heartland     1:17 table ii. state temples outside the angkor heartland orientation notes king/date preah kahn of compong svay 60 150 kok ker 76 164 baray 76 165 banteay chhmar 88 178 jayavarman vii 1113-1145 baray 88 178 503 service temporarily unavailable 503 service temporarily unavailable nginx/1.14.1 503 service temporarily unavailable 503 service temporarily unavailable nginx/1.14.1 503 service temporarily unavailable 503 service temporarily unavailable nginx/1.14.1 microsoft word 26218_gg_5.docx studies in digital heritage, vol. 4, no. 1, publication date: june 2020 virtually real or really virtual: towards a heritage metaverse? jeremy huggett, university of glasgow, uk the hype surrounding the impending mainstreaming of virtual reality can seem to prioritize the digital above the critical. with the development of vr said to be at a pivotal point, there is an important opportunity to consider the emergence of virtual heritage and its potential futures. this paper argues that there is a disjunction between the present reality of virtual heritage and virtual reality and discusses the twin challenges of presence and realism within virtual reality. in particular, it highlights a paradox inherent in virtual heritage and virtual reality and proposes the use of ‘loose-realism’ as a solution. ultimately, the challenge is to address the claims that virtual reality represents a new class of information system, or metaverse, in order that virtual heritage fully engages with inquiry about the past. key words: virtual reality, virtual heritage, virtual presence, virtual realism, virtual immersion, archaeogaming. sdh reference: jeremy huggett. 2019. virtually real or really virtual: towards a heritage metaverse? sdh, 4, 1, 1-15. https://doi.org/10.14434/sdh.v4i1.26218 1. virtual devices and virtual worlds virtual reality (vr) has been a long time in coming. in the 1950s the film industry was actively pursuing the creation of sensory experiences alongside developments in wide-screen pictures, stereophonic sound, and 3d images. one system that made it to the prototype stage in 1962 was morton heilig’s sensorama simulator – an arcade-like device which featured a vibrating seat, handles, viewing holes, and a set of vents providing breezes and chemical scents [turi 2014]. perhaps closer to what we now perceive as vr was ivan sutherland’s development of the head-mounted three-dimensional display, nicknamed the ‘sword of damocles’ because it was suspended from the ceiling above the user’s head. the headset presented a pair of miniature cathode ray tube screens providing stereo vision, and the computer-generated perspective wire frame environments responded to head movements [sutherland 1968]. in the 1970s and 1980s, the us air force and nasa continued to explore the development of vr, and in 1985 nasa developed the virtual environment workstation which incorporated a head-mounted display, head tracker, speech recognition, data glove and 3d audio [fisher et al. 1987]. however, technological limitations and cost meant that vr author's address: jeremy huggett, archaeology, school of humanities, university of glasgow, glasgow, g12 8qq, uk; email: jeremy.huggett@glasgow.ac.uk © [2019] by the author; licensee studies in digital heritage, iu, bloomington (in), usa. this article is an open access article distributed under the terms and conditions of the creative commons attribution license (cc by-nc). 4:2 j. huggett studies in digital heritage, vol. 4, no. 1, publication date: june 2020 was largely reserved for areas such as medical simulation, flight simulators, and industrial design, and few people could experience it. attempts to bring vr to the wider public during the 1990s, such as nintendo’s virtual boy and sega’s vr, were commercial failures. however, the rapid development of accessible and relatively affordable mobile and wearable technologies during recent years has brought us to what some have argued is a pivotal moment for virtual reality [e.g. day 2015]. devices such as the oculus rift and the valve htc vive launched in early 2016 with sony’s playstation vr and microsoft’s hololens following soon after. these and devices like them were anticipated to see the rise of consumer-vr [e.g. johnson 2015] although its uptake has been slower than anticipated [e.g. bajarin 2018]. at the same time, increasingly compelling historical worlds were being created as the basis for mainstream gaming. for instance, ubisoft’s historical reconstructions in recent editions of their assassin’s creed games are visually striking and have a considerable degree of historical accuracy while including some modifications to support the gameplay [reinhard 2018a: 188-89]. in the reconstruction of revolutionary paris in 1798 that underpins assassin’s creed unity, for example, rooflines were altered to facilitate the parkour movement traditionally associated with the protagonist [webster 2014], while the highly detailed 1:1 internal and external reconstruction of notre dame cathedral includes modifications creating pathways through the structure as well as different internal artwork required for copyright reasons [makedonski 2014]. released in 2015, assassin’s creed syndicate did much the same for victorian london of 1868 although with perhaps greater license in favor of the gameplay, including the shrinking of distance and omission of some areas of london [kerr 2015] as well as a range of other historical shortcuts [nielson 2015]. archaeological reconstruction came to the fore in assassin’s creed origins, released in 2017, with an open-world recreation of ancient egyptian cities and their surroundings [nielson 2017] produced in collaboration with a number of archaeologists and including an educational mode with over 70 guided tours covering aspects of egyptian life and ritual [macdonald 2018; webster 2018]. this was followed up by the release of assassin’s creed odyssey in 2018 with its recreation of ancient greece [nielson 2018; garst 2018]. ubisoft also released far cry primal in 2016, a game which sought to recreate a mesolithic world incorporating hunting, gathering, and crafting [see brouwers 2016; morgan 2016; riris 2016a,b,c,d]. not surprisingly, ubisoft also moved into virtual reality gaming in order to capitalize on the anticipated mainstreaming of vr headsets, but such games do not as yet incorporate their historical environments (although it is likely that ubisoft’s eagle flight vr uses simplified assets from assassin’s creed unity to create a deserted and overgrown version of paris [e.g. hartup 2016; takahashi 2015]). 2. virtually real heritage? as a consequence of all this creative activity, it is not unreasonable to suggest that virtual reality is at a transformative time. where does that leave virtual heritage? in most cases, authors are agreed that virtual heritage sits at the intersection between vr and cultural heritage, although interestingly most definitions focus on imagery and three-dimensionality and make little reference to virtual reality itself, something that has previously been observed [pujol tost 2008: 106-7]. virtually real or really virtual? 4:3 studies in digital heritage, vol. 4, no. 1, publication date: june 2020 although the scope of definitions of virtual heritage (like that of cultural heritage itself) is broad, ranging in scale from portable artefacts to buildings, settlements, and landscapes [e.g. koller et al. 2009: 2], it remains the case that – as observed over twenty years ago [miller and richards 1995: 20] – the focus of much virtual heritage is architectural [e.g. bogdanovych et al. 2011: 140]. perhaps because many of the early models were associated with museum displays, the question of appearance not surprisingly comes to the fore and there is a strong focus on creating the virtual models – collecting the data, building the models, and, to a lesser extent, archiving the products of virtual heritage. particular interlinked concerns are authenticity and accuracy: for example, roussou and drettakis [2003: 47] argue that the general perception in virtual heritage is that realism directly maps onto the degree of authenticity, and similarly, the level of accuracy, legitimacy and realism of content is seen to be analogous to the level of perceived authenticity [affleck and kvan 2005: 170]. this presents a number of somewhat awkward circular relationships. at the same time, there is frequently expressed concern about the authority of the resulting model. for example, “virtual reconstructions allow us to experience, amongst other things, heritage that is inaccessible and sometimes no longer existing. the manner in which they are produced however, is full of ambiguities ... it is important that the process of interpretation is discussed and highlighted, and the results not presented as absolute truth.” [affleck and kvan 2005: 172]. it is commonplace that the power of the digital visual is to assign a misplaced confidence in the viewer’s mind of the truth of what is displayed, not least when what is modelled is incomplete and/or not available for comparison. the processes behind a successful visual are normally disguised, so that the manner in which it has been produced, the variety of sources, multiple datasets, multiple scales, and the intellectual processes behind them remain invisible to the viewer and are reserved, if at all, for any accompanying process metadata or paradata. to accuracy, authenticity, and authority might be added accessibility since the reality of many examples of virtual heritage is that the often complex and elaborate models are reduced to selected 2d views for presentational purposes, which in some respects makes it little different to the classic visualizations of cultural heritage by artists such as alan sorrell and without many of the advantages of such traditional representations. furthermore, software used in the creation of such models can be proprietary, expensive, and demanding high computer specifications. consequently, models are frequently presented as a series of selected stills, or alternatively as a walk/fly-through in which the experience is tightly controlled and interaction highly constrained. as a result, a series of all-too familiar criticisms of virtual heritage arise: that it is static and lifeless, lacks meaningful context, employs confusing interface designs, has a range of orientation and navigation difficulties, lacks useful feedback mechanisms, lacks dynamic elements (virtual humans/animals, weather, temporal, typological, material, and historic aspects), lacks user engagement and focuses on the guided tour of a largely passive observer, and lacks a sense of place [tan and rahaman 2009: 146-9]. 4:4 j. huggett studies in digital heritage, vol. 4, no. 1, publication date: june 2020 3. looking virtually forward pujol and champion have proposed six major aims for virtual heritage: “first, it should aim to carefully capture objects and processes of scientific, social or spiritual value. second, it should present this information as accurately, authentically, and engagingly as possible. third, it should attempt to distribute the project in a sensitive, safe and durable manner to as wide and long-term an audience as possible. fourth, it should aim to provide an effective and inspirational learning environment that best communicates the intended pedagogical aims. fifth, it should allow the possibility of participating in its construction. finally, it should attempt to carefully evaluate its effectiveness with regard to the above five aims in order to improve both the project and virtual heritage in general.” [pujol and champion 2012: 86]. in different ways, each of these aims is challenging. for instance, the capture of objects is a largely technical issue but how can processes be most effectively captured and subsequently used? accuracy and authenticity are certainly not straightforward issues, but what is meant by ‘engaging’? for whom? and how? the distribution of virtual heritage projects is not simple – archiving is beginning to be addressed, but it remains the case that the distribution of the outcomes is frequently limited by the two-dimensionality of the page or screen. the pedagogical emphasis is interesting: why is this given pre-eminence over analysis and research? the idea of participatory virtual heritage remains largely undeveloped despite a number of projects such as accord [jeffrey et al. 2015], and the focus of these is largely on data collection with questions such as levels of expertise, specialization, and professional ownership frequently coming into play. the last of pujol and champion’s aims remains largely unrealized – there is no detailed evaluation of the effectiveness of virtual heritage as yet. furthermore, if virtual heritage is said to exist at the intersection between virtual reality and cultural heritage, these aims – like the definitions before them – largely omit any reference to virtual reality. indeed, they are essentially generic – replace ‘virtual heritage’ with ‘gis’ or ‘databases’, for example, and much the same aims might equally apply. this is perhaps underlined by champion’s more recent definition of virtual heritage which he defines as: “… the attempt to convey not just the appearance but also the meaning and significance of cultural artefacts and the associated social agency that designed and used them through the use of interactive and immersive digital media.” [champion 2015: 95]. here champion extends the definition beyond the visual – virtual heritage is about more than the eye can see, incorporating the intangible as well as the tangible – and emphasizes the place of interaction and immersion as key aspects of virtual heritage. from this, two particular challenges can be identified: presence and realism, key factors in defining virtual reality in terms of human experience. 4. virtual presence immersive and non-immersive vr are frequently distinguished from each other in terms of the mode of interaction [e.g. elsaesser 2014: 296]: immersive vr employs wearable devices that are capable of virtually real or really virtual? 4:5 studies in digital heritage, vol. 4, no. 1, publication date: june 2020 isolating the senses such that the user feels transported into the virtual world; non-immersive vr uses external manually operated input devices such as joysticks, mice etc. which remind the user that they are operating a device. it is this interaction and immersion that is seen to generate the illusion of ‘presence’, creating a space in which the user appears to dwell rather than presenting an object or experience unfolding in front of their eyes. this might raise the specter of the “flawed pseudo-phenomenology” identified by lock [2003: 261] and also associated with some applications of gis. however, there may be value in the creation of such a dynamic experience. for example, it may be argued that “… having walked, smelt and heard a landscape as it is, thinking of how it might have been, how can we not take the opportunity to walk in it as we have imagined and built it to be? forested, landscaped, denuded of roads and pylons – or are our own landscape archaeologies to be constrained to the apparently, environmentally pristine? and if the bodies exploring these landscapes cannot be the bodies of the past why not explore virtual landscapes more freely, in bodies not wholly our own?” [cripps et al. 2006: 30]. a key question here, though, is whether a dynamic experience actually enhances understanding, especially given that most of our virtual heritage experiences are essentially passive – either still images or walk/fly-throughs. evidence to date suggests that if our objectives in creating these virtual worlds is to provide a means of understanding structure and layout, to experience the feel of a place and a sense of the environment, then the ability to actively navigate and explore the world rather than passively observe it provides a better appreciation [e.g. laing et al. 2007; morgan 2009: 479-81]. however, presence goes beyond the individual’s sense of ‘being there’ within the virtual environment. it can also relate to the presence of social others (real or virtual agents), and the responsiveness of the environment to the individual (their ability to act in and on the environment) [e.g. schuemie et al. 2001: 184]. how the virtual world responds to the presence of the viewer and reacts to their actions within it is key to immersive experience. both are particular characteristics of successful gaming worlds – the success of an open world environment such as provided in ubisoft’s assassin’s creed series or witcher 3 by cd projekt red, for instance, is in part reliant on the experience of non-player characters, associates and enemies reacting dynamically with the player and with each other (see bostan’s discussion of oblivion [bostan 2009], or reinhard’s encounter with an ‘archaeologist’ in assassin’s creed odyssey [reinhard 2018b], for example). more elaborately, the nemesis system introduced in monolith’s middle earth: shadow of mordor/shadow of war series provided a set of enemies who gain experience and skill, and, rather than responding to elaborate branching scripts, remember events: whether or not the player had beaten them, wounded them, or ran away, and use this knowledge the next time the player encountered them. this makes the experience of each player and of each play-through unique [e.g. parkin 2015]. this kind of presence is not yet a feature of virtual heritage, and yet the growth of agent-based modelling in archaeology would suggest that the potential is certainly there to translate these into the immersive virtual worlds from the typically 2d or 2.5d worlds they currently inhabit. rare examples of this approach include work by ch’ng and gaffney who have used vr in conjunction with artificial life to model a mesolithic landscape with agents representing foraging hunter-gatherers 4:6 j. huggett studies in digital heritage, vol. 4, no. 1, publication date: june 2020 [ch’ng and gaffney 2013; ch'ng et al. 2016]. there have also been attempts to integrate 3d virtual worlds with artificial intelligence using second life – for example, to recreate the daily life of the citizens of uruk around 3000bc [bogdanovych et al. 2011; bogdanovych et al. 2015]. elsewhere, simulations may use 3d representations as a means of communicating their results, rather than as an integral part of the simulation [e.g. murgatroyd et al. 2012: 492]. in other instances, virtual heritage agents are simply used as guides, storytellers, or route-planners for the virtual viewer [e.g. champion 2015: 173], with little agency of their own. in all cases, the appearance of the virtual heritage agents and their worlds is considerably poorer than that available in gaming worlds, and hence may not meet the visual expectations of the general user. currently, therefore, virtual heritage agents fall well short of what is possible. of course, one of the challenges of modelling human agents in virtual worlds is the believability of the results – both in terms of the behavior of the agents [e.g. bogdanovych et al. 2015] and their appearance: the disruption of the sense of immersion – the so-called uncanny valley – that we experience when something moves or looks almost, but not quite, like a living creature. indeed, realism, along with interactivity, are the two technological dimensions of vr that support the sense of being in an environment, whether natural or mediated, and more sophisticated simulations (higher immersion) can result in increased presence [diemer et al. 2015: 6]. 5. virtual realism there is a paradox here. the value and utility of a virtual model is commonly linked to its realism and accuracy/authenticity – indeed, this realism is seen as a key factor in successful immersion in a virtual world. the problem is that the use of so-called photo-realistic or hyper-real imagery is often associated with falsely increasing the authority of a visualization. in other words, realism in conjunction with authority/authenticity is seen as necessary for a successful model, yet simultaneously the same realism may actually undermine its authority. for example, frankland [2012] demonstrated that audiences perceive the same information differently when presented with photorealistic and non-photorealistic representations. this is compounded when the cultural heritage either no longer exists or only exists in a partial form, hence: “minus the existence of a real subject with which to authenticate the truth of the image, hyperrealistic visualizations assume a position of authority over the viewer that is primed for exploitation.” [kullman 2014: 22]. gillings describes a cycle of suspicion that results: the realism of a model is tested through a search for clues as to its authenticity which in turn heightens a sense that the virtual representation is increasingly sophisticated in order to disguise and, perhaps, deceive the viewer [gillings 1999: 251]. additionally, as kullman has observed, the deception goes beyond the physical elements and typically incorporates an idealized temporal model whereby each element is depicted in its most attractive, identifiable, or knowable moment in time, creating a series of temporal disjunctions [kullman 2014: 22]. watterson has perhaps pointed one way forward, reminding us that we already suspend disbelief in situations which do not necessarily employ photo-realistic imagery, such as two-dimensional virtually real or really virtual? 4:7 studies in digital heritage, vol. 4, no. 1, publication date: june 2020 theatre stage sets [watterson 2015: 128]. indeed, jeffrey commented that he found the less realistic examples of 3d visualizations more attractive: “false color, dense point clouds, cut planes through structures giving impossible views and especially representations where details and shapes have to be mentally reconstructed from the fragments represented all these have their own particular beauty.” [jeffrey 2015: 149]. jeffrey suggested that these characteristics seem to be largely accidental or incidental, rather than deliberate, and both he and watterson seem to agree that such aspects might usefully be incorporated and developed. watterson’s own approach to visualization, incorporating a variety of data sources in a more explicitly artistic manner, is somewhat akin to what – in the context of landscape design – kullman has defined as ‘loose-realism’ which “infers an ‘incomplete, but not false image’ of the landscape” [kullman 2014: 24], contrasting with the deceptive character of hyperrealism. effectively, therefore, the proposal here is that we should seek to embrace a degree of ‘unrealism’ which might be approached in a number of more playful ways. for instance, we might consider a traditional approach to the illustration of archaeological reconstructions. the visualizations of archaeological artists such as alan sorrell and victor ambrus are something that virtual representations have moved away from, but pencil or ink analog images convey a useful combination of reality and uncertainty with which the viewer must engage. this approach might usefully be translated into a virtual environment, taking the typical digital data derived from photogrammetry, laser scanning etc. and using it as the basis for re-presentation in an analog-style visualization, somewhat similar to the rotoscope animation technique as seen in richard linklater’s 2006 film a scanner darkly or the 1985 pop videos by the norwegian band a-ha, for instance. a more recent example is the work of rose ferraby who has used artistic techniques such as screen printing to provide new perspectives on the representation of archaeological geophysics results [ferraby 2017], and semi-abstract watercolor paintings of archaeological plans, sections and wider landscapes as a means of providing alternative interpretive lenses for viewing archaeological field evidence [ferraby and st john 2019]. as a development of these approaches, we might consider a “collage” methodology in which different sources are incorporated to create a model world. since a typical virtual heritage model often uses data from different sources, a collage approach is in some respects already implicit. however, the focus is frequently on disguising the fact that different datasets are being brought together, whereas a true collage does not seek to minimize the boundaries or differences between the different datasets but uses them as an integral part of the visualization. for instance, watterson’s visualization of skara brae [watterson et al. 2014] employs mixed media including kite photography, laser scans, and live action, and various lighting effects. one of the technical achievements of the resulting film is the way in which the different media seamlessly blend into a combined whole: kite photography merging into live video merging into a model derived from 3d scan data, for instance, with the viewer unable to detect the transitions. alternatively, in a virtual world in which the viewer is encouraged to develop their own narrative, the boundaries between the different techniques might usefully clarify where the real versus the surveyed versus the interpreted begin and end. so a mix of techniques and representations within the same model 4:8 j. huggett studies in digital heritage, vol. 4, no. 1, publication date: june 2020 may be a valuable approach, whereas in the pursuit of realism point clouds, wireframes, and other modes of representation are more commonly considered to be work in progress rather than the finished item. the application of loose-realism might thereby help to address the expectations of truth that watterson’s film and numerous other examples of virtual heritage imagery have encountered [watterson 2015: 126-7]. the challenge is to create a loosely realistic environment that still manages to support immersion and maintain a sense of presence while allowing the users to understand the relationships that exist within it. as vanderbilt [2016] suggests, “realism will be one of the first qualities to be discarded as we make virtual space more realistic”. 6. a virtual heritage metaverse? some believe that virtual worlds will comprise a metaverse, combining immersive vr with physical actors, objects, interfaces and networks in a future form of internet [e.g. smart et al. 2007]: a social, virtual world that parallels – and in some respects, replaces – the real world [mason 2015]. again, the gaming industry leads the way with its development of massively multiplayer online gaming with their large, persistent worlds populated by large numbers of human players. key characteristics of a metaverse include immersive realism, ubiquity (in the sense that it is universal, available, accessible, interoperable), and scalable (in terms of number of users, scene complexity, and range of interactions) [dionisio et al. 2013: 8ff]. these give rise to a series of affordances, including the development of enhanced spatial knowledge representation, the ability to undertake experiential tasks that would be impractical or impossible in the real world, a sense of presence, co-presence and identity construction, and improved transfer of knowledge and skills into real world situations, for example [e.g. dalgarno and lee 2010: 18-23; fowler 2015: 413-414]. proponents of the metaverse argue that the challenge is therefore to move from the independent, isolated virtual worlds currently experienced to an integrated network environment providing for human interaction and culture [dionisio et al. 2013: 28]. a variant of the metaverse can be perceived in terms of virtual worlds representing a new class of information system, combining traditional approaches to modelling and simulation with what chaturvedi et al. [2011: 673] describe as emergent user dynamics supporting emergent knowledge processes. in this case, virtual worlds are seen as a means of visualizing the complexity and multidimensionality of ‘big data’ through combining human pattern recognition skills with immersive visualization in virtual reality [e.g. donalek et al. 2014; marks et al. 2014]. virtual tools can provide varied means of accessing, viewing and analyzing data within a domain which offers spatiality, immersion and interaction [e.g. moran et al. 2015]. although this concept of a new kind of information system would seem to have potential value here, virtual heritage reconstructions instead often seem to be primarily an alternative form of archaeological illustration and presentation rather than something that is or should be capable of driving forward archaeological inquiry which the existence of a metaverse or new class of information system might imply. crucially, the experience does not stop with viewing – action results, and in this regard, the virtual environment parallels the gaming experience, in which the user is required to make choices that affect the outcome in significant ways, and where the experience may differ between users. virtually real or really virtual? 4:9 studies in digital heritage, vol. 4, no. 1, publication date: june 2020 the development of a digital excavation monograph employing a 3d interface [opitz and johnson 2016; opitz 2018] can be seen as an early example of this kind of information system although it presently is primarily an isolated world with internal links. the artefactkit virtual lab [eve 2017; heritage jam 2017] potentially demonstrates the value of linking between virtual environments. as a proof of concept, it enables 3d virtual models of bones and real-world examples to be handled and compared side by side and provides links to remote online datasets for comparative and identification purposes. on a small scale, therefore, this represents a virtual information metaverse based on a combination of the virtual and physical worlds mediated through augmented reality. in some senses, the development of virtual heritage mirrors the development of the web. the virtual heritage equivalent of web 1.0 is where most people are users and consumers of content which is generated and circulated by a few specialists and there is very limited interaction available. arguably we have yet to move consistently from this virtual heritage 1.0 towards the equivalent of web 2.0, in which there is increased interaction, mashups (or collages) which combine different content in novel forms, and a more democratic approach to content creation. whether we can usefully move from virtual heritage 2.0 to the equivalent of web 3.0 with its semantic structures, automated processing and re-presentation of content employing intelligent agents remains to be explored. in a typically perceptive paper on vr presented in 1997, gillings asked what are models for? “… we often find that far from embracing the virtual-models as a new means of exploring ideas, we have exhausted ourselves in addressing and maintaining this cycle of suspicion. as a result the models are left as little more than ingenious images to be viewed and consumed ... they become a closed, end-product, something passive to be gazed at, whether from without, within, a fixed viewing point or a flexible one. in effect, they become the passive images rather than objects of analysis.” [gillings 1999: 253]. although we have made tremendous strides forward in the intervening twenty-two years in terms of data capture, modelling, and presentation, i would suggest that we are more often than not still at the stage of generating ingenious, largely passive imagery designed to be viewed and consumed – and this is equally as true of current consumer virtual reality headsets as it is of more traditional three-dimensional heritage representations. we have yet to fully rise to the challenge and potential offered by virtual reality, and consequently virtual heritage has yet to realize its potential for engaging with and understanding the past. 7. acknowledgements i should like to thank costas papadopoulos and his colleagues on the virtual heritage network ireland committee for the invitation to present and discuss an earlier incarnation of these thoughts as a keynote to the vhni conference at maynooth in november 2015. i am also grateful to alice watterson and paul reilly for their feedback on an earlier version of this paper. finally, i thank the anonymous reviewers and the editor for their constructive comments. 4:10 j. huggett studies in digital heritage, vol. 4, no. 1, publication date: june 2020 8. references janice affleck and thomas kvan. 2005. reinterpreting virtual heritage. in: proceedings of the 10th international conference on computer aided architectural design research in asia (caadria 2005), 28-30 april 2005. new delhi. vol. 1, pp.169-178. retrieved november 12, 2019 from http://cumincad.scix.net/cgi-bin/works/show?caadria2005_a_2b_a tim bajarin. 2018. why consumer vr headsets have potential but need a killer app to survive. tech.pinions [online]. 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studies in digital heritage, vol. 4, no. 1, publication date: june 2020 delusions as much as they need detail. nautilus 32 [online] january 7, 2016. retrieved november 12, 2019 from http://nautil.us/issue/32/space/these-tricks-make-virtual-reality-feel-real alice watterson, kieran baxter and aaron watson. 2014. digital dwelling at skara brae. in: ian alden russell and andrew cochrane, eds. art and archaeology: collaborations, conversations, criticisms. new york: springer, 179-195. doi: https://dx.doi.org/10.1007/978-1-4614-8990-0_13 alice watterson. 2015. beyond digital dwelling: re-thinking interpretive visualisation in archaeology. open archaeology 1 (2015), 119-130. doi: https://dx.doi.org/10.1515/opar-2015-0006 andrew webster. 2014. building a better paris in ‘assassin’s creed unity’. the verge [online] october 31, 2014. retrieved november 12, 2019 from https://www.theverge.com/2014/10/31/7132587/assassins-creed-unity-paris andrew webster. 2018. assassin’s creed origins’ new educational mode is a violence-free tour through ancient egypt. the verge [online] february 20, 2018. retrieved november 12, 2019 from https://www.theverge.com/2018/2/20/17033024/assassins-creed-origins-discovery-toureducational-mode-release received july 2019; revised december 2019; accepted december 2019. microsoft word 24606_gg_v2.docx studies in digital heritage, vol. 2, no. 1, publication date: september 2018 the sensitive perception of cultural heritage’s materiality through digital technologies clément serain, university of paris 8, france this article focuses on the impact of digital technologies in the field of cultural heritage conservation and restoration (i.e., conservation science). it arises from thesis research i am currently preparing at paris 8 university, in france. having observed a renewal of our relationship to cultural heritage through information and communication technologies, i aim to explain how these technologies affect our sensitive perception and consequently our understanding of the materiality of virtually represented objects. in the double context of the museum institution and the conservation-restoration field, whose mission is not simply to transmit objects but also to transmit knowledge about the materiality of these objects, we will try to understand more precisely the effect of these digital technologies on sensory and temporal-spatial perception of objects important to cultural heritage. key words: cultural heritage, digital technologies, materiality, conservation science, museums. sdh reference: clément serain. 2018. the sensitive perception of cultural heritage’s materiality through digital technologies. sdh, 2, 1, 54-66. doi: 10.14434/sdh.v2i1.24606 1. introduction according to art historian charlotte guichard, “the idea of beauty, supported by a humanistic theory of painting and by its elevation as part of the liberal arts, was precisely built against that reminder of materiality within the work of art, that reminder of the object within the art” [guichard 2015]. furthermore, monique sicard explains that “the museum, which conveys the image of an ideal society, generally deals awkwardly with technique of art, which remains part of a daily life, from which it would like to escape” [?]. nevertheless, as a result of the development of conservation and restoration techniques in the 19th century, the appropriation of new materials by artists along the 20th century, as well as the rise of material culture in the 1970s, the materiality of cultural heritage is now a rich field of study, generally called conservation science, attracting many experts. that the growth of conservation science into an institutional field has helped link material preservation and theoretical investigation. furthermore, it has renewed our awareness of the materiality of cultural heritage. this renewal is most obvious in museums as they open storerooms, organize restoration workshops, and even perform restorations in public. at the same time, author's address: clément serain, département hypermédia, université de paris 8, 2 rue de la liberté, 93526 saint-denis, france; email: clement.serain@gmail.com © [2018] by the author; licensee studies in digital heritage, iu, bloomington (in), usa. this article is an open access article distributed under the terms and conditions of the creative commons attribution license (cc by-nc) http://dx.doi.org/10.14434/sdh.v2i1.24606 2:96 c. serain studies in digital heritage, vol. 2, no. 1, publication date: september 2018 information and communication technologies have lately caused an upheaval in the overall museum activities of conservation, research and dissemination [saou-dufrêne 2014]. they have participated in changing our point of view on cultural heritage, and more specifically our relation to cultural heritage from the perspective of our senses. this raises a question: to what extent do digital technologies favor the development of a new sensitive perception of cultural objects regarding their materiality in the context of museum and conservation science? to answer that question, this paper will be divided into three parts corresponding respectively to the sense of sight, the sense of touch and the sense of time and space. 2. the sense of sight seeing in the museum the sense of sight plays a particularly important role within the museum. according to philosopher michel serres, the dominance of images in media pointed to preeminence of the sense of sight. the success of the word “blind” compared to the words “ageusia” (taste loss) or anosmia (loss of scent), he argues, shows through language that the loss of sight is considered especially grave, and thus that it is an especially important sense. that museums employ mediation devices specifically conceived for blind people shows that they privilege sight above other senses. the sense of sight is the sense most closely associated with contemplation and aesthetic experience, the main activities in most museums. the conservation and restoration of cultural heritage do not participate in enhancing the importance of the sense of vision within the museum, yet they have an impact on what we see and thus on what we understand and what we feel while facing a work of art. indeed, the activities of the field contribute to changing the materiality of the cultural heritage object, depending on the way a work of art is preserved and restored. in his analysis of the late fifteenth-century città ideale attributed to luciano laurana, hubert damisch showed, for instance, that “the change of aspect induced by the cleaning did reactivate the interpretation and allowed for connections that were impossible until then [...]” [guillemard 2013]. as a result, restoration can affect not only the legibility of the artwork, but also its comprehensibility. thus, as cesare brandi noted, restoration is both a technical and a critical act [brandi 1963]. conservation and restoration modify the experience and observations of everyone from the art scholar to the casual museum visitor: their experience depends on any interventions performed on the work of art, and, more broadly, on the contemporary theories and practices of conservation science. even though the architect eugène viollet-le-duc (1814-1879) in the nineteenth century could go as far as recreate some parts of the monuments on which he worked in order to give an idea of how these monuments might have originally appeared, in recent years there has been a shift toward preventative conservation. this involves minimal intervention on the art object, aiming, instead, to reveal as much as possible the traces of the different eras through which the work of art passed. the sensitive perception of cultural heritage 2:97 studies in digital heritage, vol. 2, no. 1, publication date: september 2018 seeing the invisible thanks to the development of technology and science, experts can now produce scientific images which show, for example, the different pictorial layers laid on the canvas by the artist and later restorers. through multispectral imaging it is possible to “photograph” the deeper and therefore invisible layers beneath the surface of an art object. these images are used to discern the physiochemical composition of a work of art, to identify some alterations and ancient restorations, and to understand the creative process of the artist. in addition, it is possible through these images to digitally restore the colors of a work of art so that we may see what it might have looked like at a precise moment in its history. multispectral imaging, therefore, enables the researcher to build a history of the conception of the object, or even a history of taste—that is, the researcher can relate the history of the critical and popular reception of the work of art to its historical appearance. the restorer also uses these images to know where and to what extent he can intervene on an artwork. that was the case for the series of analyses carried out on the mona lisa in 2006 in paris by lumiere technology and the center for research and restoration of museums of france [mohen et al. 2006]. these analyses showed that da vinci used a specific method of oil-painting known as the glaze technique the virtual restitution of the mona lisa simulated the removal of the varnish, which in life had yellowed and obscured the original bright colors of the painting. that virtual varnish removal also showed that physically removing the varnish would have been impossible because of the pigments had been mixed with it. in french, what i should call the digital restitution is sometimes wrongly called a digital restauration. the distinction between the two appears not to be made in english. restitution and restauration do not have the same goals: while restauration aims at preserving the totality of the traces of the different eras the object went through, restitution, naturally virtual, aims at giving an idea of what the object might have looked like at a precise time, most often when it was originally created by the artist. if the term “digital restauration” is favored compared to that of “digital restitution”, it is certainly because of two preconceived ideas: first, the idea that restauration aims to return the object to its original appearance; and second, that restitution aims to show how the object looked exactly at the moment of its creation. yet the restitution, whether digital or not, cannot perfectly render the colors, the shapes or the textures of works of art: the technological device is not able to render an exact color, for instance, and the evolution of materials and their interactions make that goal particularly difficult. therefore, digital restitution only proposes a likely former appearance of the object, not an absolutely faithful image of it. aside from its inherent uncertainty, digital restitution cannot show the true appearance of an object because there is no single true appearance. considering the original appearance of a work of art as its true appearance is considering that original appearance as the most important one throughout the history of the object. conservation experts, however, aim to preserve all traces of the object’s past: the changes the object’s appearance undergoes are just as important as its original appearance. digital restitution, therefore, tries to make us see the work of art differently, not better. indeed, seeing the object as it is today and as it was at a former moment of its past are but two ways among many to observe and contemplate it. the artist necessarily conceives the artwork knowing that its appearance will change through time and that, in spite of the changes, the piece of art remains the artist’s own work. therefore, to the work of art’s infinite series of meanings, which allow us to 2:98 c. serain studies in digital heritage, vol. 2, no. 1, publication date: september 2018 understand it in endlessly different ways, we must add its endless different appearances. these appearances, in turn, will expand the meaning of the work of art. we can see, therefore, that the development of digital technologies favors the multiplication of images and arouses the sense of sight in the museum space. on the other hand, when these images are presented in exhibitions, the eye of the visitor focuses not only on the real object, but also on corresponding documents that represent the invisible parts of the work of art and expand the visual perception of the work of art. while the display of works of art on pedestals or inside display-cases gives the impression that the object is frozen in time, these images show that the art object is really a living thing whose appearance changes through time, just as do human beings. the representation of the original appearance of the work of art is all the more alive when it brings us closer to the mind of the artist. however, the presentation of a digital restitution or of another type of digital image cannot afford to neglect providing an explanation to the public. while very suggestive, these images remain scientific documents, which call for an analysis that the public can understand, and the hypothetical nature of digital restitutions must also be explained. besides, it should be noted that these documents rarely leave the laboratory and the expert’s field in order to be presented to the museum public. yet, even though the museum space must be that of contemplation and aesthetic experience, providing these documents would enhance the aesthetic point of view with a more scientific one. these two points of view are not necessarily opposed. indeed, the american artist robert longo’s work, which consists in making charcoal drawings based on radiographies of leonardo da vinci’s works, such as saint john the baptist, can attest to that. 3. the sense of touch touching at the museum unlike the sense of sight, the sense of touch might be the least solicited sense in the museum space. “do not touch” is a fundamental rule, which is common to all museum institutions, yet it shows that this sense is not absent by accident, as it is forbidden for obvious reasons of conservation. besides, it should be noted that the mediation devices for blind people generally are tactile devices. the sense of touch is, as a result, reserved for those who cannot really have no choice, which also shows how the museum conceives the integration of that sense in its space. on the other hand, when the sense of touch is not reserved for blind people, children can also benefit from it, for example, during creation workshops. the sense of touch is thus considered as a primitive act, too carnal and thus too far away from the comprehension of the object from a conceptual point of view, which, besides, underestimates the ability of children to comprehend a work of art. yet, adults, too, would benefit from the opportunity to use the sense of touch in order to be moved and to understand works of art. it is true that artists have always conceived their works to explain things, convey messages or ideas, even more nowadays when the importance of the form of a work of art decreases progressively before the importance of the idea it represents. this situation progressively ended in opposing the world of ideas to the sensible world as was formulated in the myth of the cave by plato. yet, these worlds remain complementary: the sensible world, which includes the sense of touch, is necessary to access the world of ideas. the sensitive perception of cultural heritage 2:99 studies in digital heritage, vol. 2, no. 1, publication date: september 2018 as we have just explained, the need to protect works of art is the main reason for which it is forbidden to touch the works. some artists such as marcel duchamp who, in 1947, entitled one of his works of art “please touch” mocked this very idea. moreover, duchamp’s work was a woman’s breast, an object implicitly designed to arouse the sense of touch, at least in the average male visitor. it is very easy to understand that if everyone could touch art objects, the unavoidable process of degradation would be accelerated, and this would jeopardize the mission and the goal of conservation, that is to say the transmission of cultural heritage. the institutionalization of conservation widely contributed to the prohibition of touching in museums. indeed, the development of techniques of conservation for more than two centuries has led to the taking into account of the fragility of cultural heritage, and thus has favored the idea of a cultural heritage which should not be touched. experts were much less aware of the problems which could be induced by touch before these changes. in that respect, the same institutionalization created authorizations to touch the works of art: only specific professionals, such as restorers, are allowed to touch the art works, but that authorization is to be seen as given in the name of all. indeed, the act of touching and the way restorers can touch works are guided by principles, deontological codes which represent the interests of the overall society, and these rules dictate that the restorer must account for all the values inherent to the work of art. beyond that institutionalization, it is the very existence of conservation which has consequences for the prohibition of touching works of art. conservation is the last step of the process of making an object part of cultural heritage, and it is probably the most important because it is the one that ensures the physical transmission of the work of art, without which its continued existence would not be possible, and the very idea of cultural heritage could not exist. that physical transmission of conservation participates in elevating the artwork to an enshrined object from a conceptual point of view. furthermore, this is somehow paradoxical regarding the use value: when a work of art is given the status of a cultural heritage object, it loses its use value, which, sometimes, implied that it had to be touched. yet, in order to understand the piece of art, it can be interesting to touch it, as we explained earlier. one must conclude that the process of making cultural heritage objects, while aiming at transmitting the work of art to the future generations, sacrifices a part of the work of art which allows us to understand it and thus, to transmit it. moreover, that conclusion characterizes the classical opposition between the mission of dissemination and the mission of conservation of cultural heritage: in reality, conservation has no purpose other than the dissemination of cultural heritage, even though conservation can create a certain limit to transmission and constitutes the tribute to be paid in order to avoid a total absence of transmission. touching the untouchable the difference between the sense of sight and the sense of touch is a matter of space: touching an object implies that we have to share the same space as the object, while seeing an object can be done through any reproduction. that is one of the reasons for which the sense of sight is particularly solicited in the cultural heritage filed, as we talk about images and representations, while the sense of touch is particularly nonexistent. some technologies, however, seem to reinvent the sense of touch in the museum space. here one thinks, especially, of 3d printing. the contribution of this technology in the field of conservation is notable. first, it allows the expert to study a piece of art without touching and causing its deterioration. secondly, it allows the restorer to work as precisely as 2:100 c. serain studies in digital heritage, vol. 2, no. 1, publication date: september 2018 possible on the work of art. thirdly, it allows the curator to present and transport objects with maximum security: by perfectly fitting the object’s shapes, 3d-printed items and protective foams greatly reduce the vibrations in the transport cases, and they favor a good presentation of the works of art in the exhibition rooms. beyond the obvious advantages for art conservation, 3d printing technology also becomes increasingly more important in the exhibition spaces of museums, and not only for blind people. indeed, the idea is to offer a less conventional approach of the work of art by “experimenting” with the object, indirectly, by touching it. the appropriation of the artwork is no longer only symbolical, but it is also physical. that fact leads to a certain desacralization of art: settled inside the museum on a pedestal, as symbolical as it is real, the object now becomes accessible. like the scientific images, 3d printing allows for presenting the work of art as an object, which was built, not like a finished, symbolic object. furthermore, this kind of device now allows us to answer questions which the museum institution was not really interested in until now: what is it, how it is made, and how does it work? though it is indirect, the creation of that concrete, bodily relation with the work of art leads to a new understanding of it, as well as to new emotions which complement the different emotions already induced by the mere vision of the work of art. the integration of 3d printing into the museum space is, therefore, doubly unconventional: for one, it solicits the sense of touch, which was forbidden until now. secondly, it favors the appropriation of the artwork through its matter and not through its symbolic representation. in that respect, the museum soothes a certain frustration which was created by the prohibition of touching: there’s nothing more efficient than a prohibition of sitting in an ancient armchair to make one actually want to sit in it, particularly during a long, tiring visit. however, one must put the use of 3d printing into the context of two “competitors”: the presentation of casts in exhibitions and the sale of sculptures as by-products. casts can indeed be presented in a museum in order for the public, especially blind public, to be able to experiment on the objects by touching them. however, the casting of a sculpture, especially one that is fragile, is not always possible for conservation reasons, as the cast-maker needs to touch them and to risk causing their deterioration. this does not happen when we make a 3d print. on the other hand, the speed with which 3d printing technology is evolving implies the use of a large amount of materials in the future, which will allow for the ever more faithful reproduction of the shape, color or weight of the original. as for by-products, museum shops offer a lot of objects that the visitors can buy, notably reduced sculpture models. the relation to the work of art and its materiality is, however, not the same with an object conceived with 3d printing, because that object can be printed directly at home from a digital file that some museums allow to be downloaded from their website. therefore, unlike the byproduct, which evokes the memory of a gallery visit, the 3d printed object allows people to create their own private exhibitions without even visiting the museums where the art is on display. since the 3d print is created by the consumer, the physical link between the object and the person is much more intimate than it is in the case of the by-product, which the consumer does not create but only can purchase. moreover, 3d technology implies a certain desacralization of art, which had already been induced by by-products. indeed, the objects can now be multiplied at will and are no longer created by the museum’s authority. to conclude, it should be noted that smartphones are beginning the sensitive perception of cultural heritage 2:101 studies in digital heritage, vol. 2, no. 1, publication date: september 2018 to develop 3d scanners. it is clear that the acquisition of 3d models may allow developing the 3d printing practice by different audiences. 4. the sense of time and space the emotion of cultural heritage the perception of the materiality of heritage, as well as the rest of the world, is made possible by our five senses but also through our perception of time and space. time and space condition the reality of the work of art regarding its physical existence: thus, they have an impact on the materiality of the artwork, which evolves through time and is dependent on its location. these evolutions themselves are conditioned by conceptions of cultural heritage and of its conservation through time periods and geographical zones. so, in addition to the materiality of a work of art through the senses of sight and touch, we must also add its materiality through time and space. like the values we attribute to works of art since aloïs riegl theorized them at the beginning of the century, time and space participate in the emotion we feel before the cultural heritage object. however, the values constitute projections of humans onto the work of art, which allow them to be understood, unlike time and space, which are not perceptible except insofar as they are naturally integrated within the material of the art object. the emotion felt before a work of art is mostly the result of time. the work of art allows us to make a link between the present and the past. therefore, the object constitutes a witness to our history, our memory, our roots, our identity, our past, and ourselves. it is, indeed, the quest for our sense of selfidentity that we pursue through the cultural heritage object from the past, and which explains a part of the emotion we feel before it. moreover, the cultural heritage object reminds us of our own human condition, as muriel verbeeck explains: “the common object which is ours, and finds itself chipped, cracked or broken, awakes inside us more than the mere regret of its utility, suddenly put in jeopardy; it evokes the relation with a suffering flesh, subjected to the whims of an existence which is engraved in time. its imperfection draws us to that of human condition, marked throughout its life, preyed upon by old age and death” [verbeeck 2007]. time is not specifically a value of the work of art itself, but it gives it an authenticity value: sociologist nathalie heinich speaks of “the emotion before the authenticity value, which dwells on the permanence of the link between the actual state and the origin of the object” [heinich 2012]. the emotion we feel in front of the work of art is also induced by space. like time, space is not a value inherent in the object, yet it gives it a value of presence. nathalie heinich speaks of the “emotion before the value of presence, which dwells on the proximity with a person, on the feeling of an encounter, of a contact with the beings related to that object.” however, unlike the perception of time, the perception of space is even more linked to human senses as it depends directly on the senses of sight and hearing. at any rate, the fact that the work of art shares the same physical space as its viewer also favors the emotion one feels before the cultural heritage object. the typical example of the mona lisa at the louvre museum shows how much visitors need to find themselves in the same space as that of the iconic work of art, in order to feel an emotion before it. to be sure, that emotion is the result of the experts’ point of view on leonardo da vinci’s work, which gives the mona lisa its 2:102 c. serain studies in digital heritage, vol. 2, no. 1, publication date: september 2018 well-known importance. however, it is also the result of the particulars of the museum space in which it is encountered: all the panels that indicate its location in the museum; the painting’s placement right in the middle of the room, which is itself conceived very much like a greek temple, within which the god’s statue was located at the center; the great throng of people in front of the painting, which makes it difficult to view and approach; or the imposed distance from the painting. all these spatial elements cause the painting to be a physical experience, made possible by the threedimensional space in which it finds itself. the role of conservation regarding the relation of the work of art to space and time is more complex. concerning time, conservation scientists do typically reveal as traces of as many different periods as possible, as we explained earlier. they aim to sublimate the passage of time and, even more, the ties woven by the work of art between the present and the past. concerning space, the institutionalization of conservation somehow makes the emotion evoked by the cultural heritage object conditional on the space in which it is exhibited. it is thanks to the establishment of an institution, that is to say, to the museum, that a work of art is present in the space in which it is located, and that visitors can have physical access to it. however, the activities of conservation scientists do not have any direct impact on the emotion we feel in front of an artwork, which shares the same space as ours. conservation reveals the traces of time on the art object, but it cannot reveal the space in which it used to be: through its state of preservation, the work of art itself can implicitly communicate that, for example, it was once located in a wet environment, but it cannot reveal, through its materiality, the reasons why it was located in such a place and where that place was. yet, given that artworks have been not infrequently conceived to be set in specific places (e.g., the chapel of a church), the knowledge of its former physical location might provide us with significant information in order to understand and see the work of art from a different perspective. feeling the disappeared while the authenticity of a work of art is ensured by the link it creates between the present world and the object’s original world, how does digitized cultural heritage, which is timeless, render that authenticity? as the authenticity of an artwork is not only symbolic but also physical, since it dwells on its matter, the digital representation of the original appearance of a work of art can, for instance, create the link between present and past. besides, it should be noted that digital restitution allows the visitor to see the work of art as it was seen by the artist who created it, which contributes to strengthening the link with the past. however, given its hypothetical nature, digital restitution rather works like a ghost of the past and reminds us, in our quest for origins, that the knowledge of our past and, by extension, of ourselves, can only be illusory. what about digital cultural heritage, which is not represented in its original appearance but in its contemporary one? how can the museum institution convey the emotion of authenticity which we are supposed to feel in front of the original object, in order to reestablish the link between the object’s original world and us? according to cecile tardy, there are three precise moments which allow the “digital substitutes” to transmit that authenticity of the original work of art. the first one is the moment when the cultural heritage object is represented and put back into a context in relation to its original world. the second moment is when the cultural heritage object is put in relation to the space within which it was originally located. the last moment is the “representation of the presence of the museum institution as ensuring the authenticity of the the sensitive perception of cultural heritage 2:103 studies in digital heritage, vol. 2, no. 1, publication date: september 2018 relation between the substitute and the original world of the collections” [tardy 2015]. it is, therefore, by the recreation, under the museum’s authority, of a symbolic and institutional link between our present world and the object’s past world that the authenticity of the work of art can be transmitted. nevertheless, space also plays an important role, as the recreation of that link is possible thanks to the link induced between the object and the museum space, which ensures the authenticity from a symbolic point of view, and thanks to the link between the object and its original location, which guarantees its authenticity from a physical point of view. the staging of the object in its original location is not possible in the museum space, unless a very detailed oral or written description is given or by using certain technologies such as augmented reality. often used in architectural heritage, ar can be used within the museum space in order to offer the reconstruction of a lost part of an object or to digitally communicate the former environment in which the object was once located. to that recreation of the object’s former spatial environment, we must add the use of digital technologies to recreate works of art, which are lost or not, and to put them back into the environment in which they used to be located. this was the case for “the wedding feast at cana” by paolo veronese, currently exhibited at the louvre museum, and reproduced in its original location in the monk’s refectory of the benedictine monastery of san giorgio maggiore in venice. the facsimile object here comes to “compete” with the true object. according to bruno latour and adam lowe, “the aura might come to attach itself to one or the other reproduction, depending on both the quality of what comes to be considered as different versions of a single work, as well as on the success of its inscription within a given location” [latour and lowe 2008]. in that respect, the authenticity of a work of art would above all depend on the place where it is located, which would question the museum’s authority and the conservation of works of art. indeed, can copies benefit from the same privileged treatment as the originals in order to guarantee that “transposed authenticity”? finally, the notion of the space of the work of art must be put into the context of digital technologies. the virtual space of digital technologies is often opposed to real space. yet some experts consider the virtual space as an extension of the real space, in such a way that the virtual space should more accurately be considered a hyper-real space [vial 2013]. one only has to order a pizza on the phone or to publish a controversial message on social media to realize that fact. cultural heritage professionals do understand that fact, too. for several years it was said that virtual visits on museum’s websites were going to replace physical visits in the museum’s space, yet the exact opposite has happened. indeed, the virtual visit is often a starting point from which visitors can prepare their physical visit, during which they will be able to physically experience the object’s presence. therefore, virtual visits will probably never replace physical visits because they are complementary and offer a different experience of the object. it should be noted that the impact of the place upon the emotion induced by the physical authenticity of the object also manifests itself through other mediation devices. for instance, the geolocation devices offered by some museums within exhibition spaces give visitors the opportunity to grasp exactly where they currently are in the museum and also to know how far they are from a work of art they are interested in finding. we might also mention digital social networks, a place where emotions are sometimes exacerbated, which themselves contribute to giving an importance to the place where one is located. on facebook, for example, the user can simply publish his location thanks to a specific feature, and thus he can display the emotion he felt when seeing the mona lisa while at the louvre museum. 2:104 c. serain studies in digital heritage, vol. 2, no. 1, publication date: september 2018 5. conclusion in the context of the museum, the human senses we have mentioned are not addressed in the same way, which creates a kind of hierarchy: we are encouraged to watch, to become aware of the space and time which separates us from the object, whereas touching the works of art is forbidden. yet, the introduction of digital technologies into the museum space seems to renew that hierarchy thanks to an augmentation of each of our senses, which itself conditions the augmentation of the perception of the objects, and thus leads to a renewal of the understanding of the art objects as well as of the relation we maintain with their materiality. however, digital technologies do not come to replace the traditional ways of seeing, touching or feeling the space and time of the work of art. the direct observation of an object is still possible, touching the work of art is still impossible, and space and time are naturally inherent within the object. the question is rather to make our relation to the object’s materiality more complex, through new mediation devices, without changing what already exists. finally, as we explained earlier, these transformations might be analyzed without putting them back into the context of conservation, the field par excellence of materiality. indeed, we must observe that the use of digital technologies within the museum may have a direct impact on conservation practices, while the development of technologies in the field of conservation offers new ways of mediating cultural heritage in the museum space. as a result, we can conclude that conservation is not only a technical act but also that it contributes to examining cultural heritage from the point of view of its materiality. that point of view conditions the comprehension and the perception of cultural heritage by the public, and it is endlessly reshaped by the development of digital technologies 6. references f. blais et al. 2008, “ultra high-resolution 3d laser color imaging of paintings: the mona lisa by leonardo da vinci,” in lasers in the conservation of artworks proceedings of the international conference lacona 7, 435–440. c. brandi 2011. théorie de la restauration, paris: éd. allia. c. guichard. 2015. image, art, and artifact in the eighteenth century: art history and the test of the object, perspective, 1 (2015), 95-112. doi:10.4000/perspective.5805 g. guidi, c. atzeni, and s. lazzari 2003, “3d optical scanning diagnotics for leonardo da vinci’s ‘adorazione dei magi’ conservation” in fourth international conference on 3-d digital imaging and modeling, 2003. ieee 3dim 2003 proceedings, 110–115. d. guillemard. 2013. le point aveugle de la restauration, sa contribution à l’histoire de l’art, crbc (conservation-restauration des biens culturels), 31 (2013), 3-12. b. latour and adam lowe 2008. the migration of the aura or how to explore the original through its fac similes. in t. bartscherer and r. coover. switching codes. thinking through digital technology in the humanities and the arts, university of chicago press, 275-297. a. lowe 2010, a note on the unveiling of the facsimile of veronese’s wedding at cana, coping with the past, creative perspectives on conservation and restoration, in cività veneziana studi 52, gagliardi p., latour b., memelsdorff p., (eds), 8-9. j.-p. mohen, michel menu and bruno mottin 2006. au cœur de la joconde: léonard de vinci the sensitive perception of cultural heritage 2:105 studies in digital heritage, vol. 2, no. 1, publication date: september 2018 dévoilé, paris: gallimard. a. riegl 1984. le culte moderne des monuments, son essence et sa genèse, paris: seuil. b. saou-dufrêne 2014. heritage and digital humanities. how should training practices evolve?, lit verlag münster. m. sicart 2002. comment le musée fait voir, technè, 15 (2002), 56-64. c. tardy 2015. la médiation d’authenticité des substituts numériques. in cécile tardy and vera dobebei. mémoire et nouveaux patrimoines. marseille: openedition press. doi:10.4000/books.oep.453 m. verbeeck 2007. l’œuvre du temps. réflexion sur la conservation et la restauration d’objets d’art, images re-vues, 4 (2007). n. heinich 2012. les émotions patrimoniales : de l’affect à l’axiologie, social anthropology, 20, 1 (2012), 19-33. doi:10.1111/j.1469-8676.2011.00187.x s. vial 2013. l’être et l’écran : comment le numérique change la perception, paris: presses universitaires de france. t. zaman, p. jonker, b. lenseigne, and j. dik 2014, “simultaneous capture of the color and topography of paintings using fringe encoded stereo vision” herit. sci., 2, 1, 23. received february 2018; revised september 2018; accepted september 2018. microsoft word v2i1_formatted_editorial.docx studies in digital heritage, vol. 2, no. 1, publication date: september 2018 editorial bernard d. frischer and gabriele guidi studies in digital heritage co-editors in chief we are pleased to release this new issue of studies in digital heritage (sdh). it contains one regular article and an entire section dedicated to a special issue on the topic: "perceiving cultural heritage through digital technologies." the regular article is a provocative analysis about the ethical implications involved in physically reproducing works of art that no longer exist, using as an example palmyra's arch of triumph replicated by 3d printing and then exhibited in different cities around the world. the special issue section covers different topics connected with the relationship between the observer and the heritage asset when mediated by digital tools such as virtual reality, augmented reality, or some other forms of multimedia. the topics range from philosophical considerations to a technical analysis of existing installations, presenting an overview of an important subject which we hope our readers will find instructive and useful in their own work. we thank our guest editor, perla gianni, for her inspiration in suggesting this issue and for her hard work in struggling with us to bring it to fruition. we are also grateful to the other two guest editors giovanni valeri manera and massimo bergamasco for their valuable help in selecting and revising the authors’ contributions. we have several other special issues in the pipeline, and we encourage our readers to propose to us new topics for future special issues for which they would take responsibility. this is a format of publication where we believe that studies in digital heritage can fill a void. on the management side of the journal, several changes have occurred, including the upgrade of our open source editorial platform to "open journal systems" version 3. this changeover caused some regrettable delays in the production of the current issue. in compensation, we can now rely on this new and more powerful tool in managing the publication process in a way that we hope will be more efficient than before. the first issue of this year also brings studies in digital heritage into stricter compliance with the open access ecosystem. here we would single out a change in policy which we trust will be warmly embraced by our authors: starting with the current issue, our authors are no longer asked to assign the copyright to the journal. the rights to a paper remain solely with the author, using the broadly accepted creative common schema. in particular, the contents of studies in digital heritage are licensed under a creative commons attribution-noncommercial 4.0 international license (cc bync 4.0) moreover, as before, our authors pay no article preparation fee to the journal while retaining the copyright to their own work. the changed copyright policy also involved a slight change in our article template, which now (version 14) includes the following note on the first page of each publication: © [year] by the author[s]; licensee studies in digital heritage, indiana university, bloomington, in, usa. this article is an open-access article distributed under the terms and conditions of the creative commons attribution license cc by-nc 4.0 (https://creativecommons.org/licenses/by-nc/4.0/). 503 service temporarily unavailable 503 service temporarily unavailable nginx/1.14.1 the impact of structure from motion on archaeological fieldwork practice: experiences of the via consolare project in pompeii studies in digital heritage, vol. 4, no. 2, publication date: december 2020 the impact of structure from motion on archaeological fieldwork practice: experiences of the via consolare project in pompeii michael a. anderson, san francisco state university, ca, usa the last decade of advances in image-based modeling (ibm) data acquisition based on structure from motion (sfm) have made it possible as never before to record excavated archaeological deposits, historical architectural remains, artifacts, and geographical surroundings in the field. armed only with digital cameras and low-cost or open-source software, researchers can now produce accurate point clouds of millions of points, capturing archaeological information in high-resolution detail. but what changes will ibm really bring to the standards, requirements, and expectations of practical field methodology for projects operating on shoe-string budgets? since 2010, the via consolare project, a small archaeological research project from a state level university, has employed an entirely open-source and “free for academic use” ibm pipeline to record a variety of archaeological features in insula vii 6 and the “villa delle colonne a mosaico” in pompeii. ranging from surviving architecture, to rubble fill layers, to the interiors of inaccessible cisterns and drains, this work has been carried out in preparation for the eventual coordination of these data into a 3d gis of all recorded stratigraphy. rarely were sufficient resources available for dedicated equipment or personnel to be devoted to this task. while practical implementation, even in a low-budget excavation environment, has confirmed that this technology can indeed augment archaeological field documentation and provide investigation opportunities that would otherwise be impossible, it failed to replace traditional handdrafted recording techniques and was found to present significant challenges and a number of hidden costs. this emphasizes a need for appropriate and cautious planning in implementation, especially in projects with limited means. key words: structure from motion (sfm), image matching (im), free and open-source, photogrammetry, excavation methodology. sdh reference: michael anderson 2020. the impact of structure from motion on archaeological fieldwork practice: experiences of the via consolare project in pompeii. sdh, 4,2, 78-107. https://doi.org/10.14434/sdh.v4i2.27260 the work of the via consolare project has received significant funding from the department of classics and orsp at san francisco state university, with kind permission of the soprintendenza of the parco archeologico di pompei and under concessione from the ministero dei beni e attività culturali e del turismo, roma. author's address: michael anderson, department of classics, san francisco state university, 1600 holloway avenue, san francisco, ca, 94132; email: maa35@sfsu.edu © [2020] by the authors; licensee studies in digital heritage, iu, bloomington (in), usa. this article is an open access article distributed under the terms and conditions of the creative commons attribution license (cc by-nc) https://doi.org/10.14434/sdh.v4i2.27260 mailto:maa35@sfsu.edu structure from motion and archaeological excavation: experiences of the via consolare project in pompeii 1:79 studies in digital heritage, vol. 2, no. 4, publication date: december 2020 1. introduction the acquisition and analysis of 3d data has been an indispensable aspect of archaeological field methodology for more than 20 years at a variety of scales, from digital surface models (dsms) of sites, to total station surveys of architecture or excavations, to the laser-scanning of artefacts recovered. the last decade, however, has witnessed something of a revolution in the acquisition of 3d data that holds the potential to transform the very core of archaeological field practice. from its origins in the field of computer vision, visual perception, and image matching, structure from motion/image matching (sfm/im), belonging to the image-based modelling (ibm) category of methods, makes it possible for researchers to capture point clouds of 3d data from unordered sets of digital photographs acquired with mass-market digital cameras, and processed on consumer-grade computer systems for comparatively low cost as opposed to alternatives such as terrestrial scanning or lidar. initially requiring some computing expertise and comfort with command-line interfaces, these techniques are now available in a number of “free for academic use,” open-source, and commercial packages featuring user-friendly graphical user interfaces (guis). this has made structure from motion 3d data capture more accessible than ever and has encouraged its use at a variety of scales, from the production of localized dems with unmanned aerial vehicles (uav) photography to the digitization and modeling of artefacts and other small finds. [pollefeys et al. 2000, 2003, 2004; doneus et al. 2011; de reu et al. 2013, 2014; olson et al. 2013; green et al. 2014; opitz 2015; roosevelt et al. 2015; sapirstein 2015, 2016; sapirstein and murry 2017; cucchiaro et al. 2020; jones and church 2020]. sfm/im photogrammetry (often shortened as sfm photogrammetry) stands at the center of a 3d revolution in archaeological research, holding the potential for near ubiquitous use within the discipline for a wide variety of purposes. but how do such methodologies integrate with, and augment, the current standard of scientific field archaeology? will these techniques simply replace traditional methods or do they represent a qualitatively different kind of record? since 2010, i have employed sfm-based methodologies in the course of an on-going small project of stratigraphic excavation in pompeii the via consolare project (vcp). since it is run from a state level university, it is largely without the resources of better-funded colleagues, a reality that is shared by numerous archaeological endeavors in a variety of academic and professional contexts. while the “low-cost” and open-source nature of sfm is one of its most frequently-cited benefits, it is notable that out of the numerous recent publications on the use of sfm in archaeology, only a handful have actually opted for open-source over commercial software processes. what impact do these “low-cost” techniques have on the operating practices of archaeological projects that must make use of open-source solutions and compromise in terms of equipment, time, and resources? adoption of sfm technologies on the vcp took place after its research was already well under way and when the revolution in image-based modelling was just beginning to be known to archaeologists. sfm was not adopted in order to push the boundaries of archaeological science, but rather to address pre-existing research needs that were driven by pompeian research questions. while some researchers have pointedly set out to assess the capabilities of this new technology in focused case studies [de reu et al. 2013, 2014; green et al. 2014; sapirstein 2015, 2016; sapirstein and murry 2017; bianco et al. 2018], or even to explore the possibilities of replacing traditional methods of recording entirely [olson et al. 2013; roosevelt et al. 2015], my project has instead explored practical applications of this constantly-developing new technology in conditions that were rarely, if ever, ideal. this 1:80 m. a. anderson studies in digital heritage, vol. 4, no. 2, publication date: december 2020 included operating within a very restricted budget, employing equipment that had normally been acquired for different purposes, and exploring non-standard uses of this technology while focusing primarily on the main goals of the research. now, at the end of ten years, during which time the technology has seen an almost unimaginable rate of development, the release of an ever-changing and ever-expanding range of potential software options (both open-source and commercial), and with the widespread acceptance by projects all over the world, it is worth considering what the actual impact has been on day-to-day archaeological process, methodology, and results in a small, traditional project of field archaeology. the experiences of the vcp do not present a case study of ideal conditions or a formulation of best practices; rather they expose the realities of prolonged everyday use of sfm in a project with many other research priorities, working within the often-improvised solutions that, in my experience, are frequently encountered in fieldwork in italy. accordingly, this paper does not aim to contribute to the scientific assessment or detailed exposition of a technology which has, by now, already been well-explored; rather, it asks whether the lowest cost implementations of this “low cost” technology can still have an impact on the process of archaeological excavation. 2. the via consolare project i founded the via consolare project in order to increase the unit of analysis of the ancient city of pompeii, beyond that of an individual house or city block, to the scale of the city itself. the via consolare, one of the earliest surviving roads through the city, provided the coordinating axis of the research. this thoroughfare connects a number of previously completed campaigns of archaeological research, including the university of bradford’s aapp excavations [jones and robinson 2007; anderson and robinson 2018], excavations in the casa di sallustio [laidlaw and stella 2014], arthur’s exploration of the forum [arthur 1986], examination of insulae 6 3 and 6 4 [carocci et al. 1990], the study of the casa di marco fabio rufo [grimaldi 2014; aoyagi and pappalardo 2015], and numerous investigations by progetto regio vi and beyond [coarelli and pesando 2006; oriolo and verzar-bass 2010; maratini and zaccaria ruggiu 2017; giglio and pesando 2017; dessalles et al. 2015, 2016] and ongoing research by the centre jean bérard, l’école française de rome and le centre camille jullian [zanella 2017; zanella et al. 2016; 2017]. i set out to augment these through architectural analysis and sub-surface exploration of two areas the area of the villa delle colonne a mosaico and insula vii 6, following a practice of stratigraphic excavation in targeted trenches, 100% screening of excavated ancient deposits for the recovery of artefacts, ecofactual floatation of soils, and the full study of the macroand microbotanical remains. taken together with the results of the aforementioned projects, the intent was therefore to produce a ‘slice’ of stratigraphic understanding through the city, running from the area outside of the porta ercolano through to the core of the city and the forum. the precise urban history of this corridor will serve to shed light upon the development of the city as a whole, permitting comparisons between center and periphery, the reconsideration of the texture of the urban fabric, and encouraging city-wide explanations of the processes of urban development (fig. 1). structure from motion and archaeological excavation: experiences of the via consolare project in pompeii 1:81 studies in digital heritage, vol. 2, no. 4, publication date: december 2020 figure 1. via consolare project research areas marked in dark blue. previous and on-going research: university of bradford (green), laidlaw and stella (yellow), carocci et al. (orange), pappalardo and grimaldi (pink), arthur long trench (red), and progetto regio vi (light blue), dessales et al. (brown), zanella et al. (light green). area of the villa delle colonne a mosaico the area of the villa delle colonne a mosaico consists of a large suburban villa on the north-eastern side of the via consolare, which, as it extends beyond the walls of the city, is known as the via dei sepolcri. the villa is situated behind a number of shops and tombs, which serve to seclude three large open areas that appear to have been largely unroofed in antiquity. the southern-most of these coordinated the space behind the tombs into a putative area for funerary ritual, while the main zone held the mosaic-covered columns that gave the villa its name, long ago removed to the museo archeologico nazionale di napoli (mann) (fig. 2a). to the north, a work-yard or cart-access corridor provided access to a number of upstairs spaces and to the villa itself via a monumental entrance. the elite and decorated rooms of the villa were situated in the upper stories, and hence generally do not survive. the service areas, however, which are located on the ground floor, are well preserved. the complex as a whole was built with, and over, an exterior row of 14 shops that served as the substructure so that the peristyle and rooms on the upper stories might enjoy a magnificent view of 1:82 m. a. anderson studies in digital heritage, vol. 4, no. 2, publication date: december 2020 the bay (fig. 2b). though partially damaged during allied bombing in 1943 [garcía y garcía 2006], the villa presents a surprisingly urban fusion of domestic living, commercial space, and ritual activity that calls into question the degree to which it should be considered a ‘suburban’ space during pompeii’s final years. a) b) figure 2. the villa delle colonne a mosaico: a) open space with replaced columns on left, central core and traces of upper stories, right. cart accessway is visible in centre; b) row of 14 shops that supported the upper stories of the villa. insula vii 6 insula vii 6 is situated immediately to the west of the forum baths and nearly adjacent to the forum itself. it consists of five houses interspersed with shops or bars that cluster mainly on its eastern side towards the forum and the baths (fig. 3). a massive, three-part cistern, intended to store reserve water for the forum baths, came to occupy the eastern side of the block by roughly the late augustan period, presenting important evidence for the interaction between municipal building projects and private property [anderson 2015]. primary excavation of the insula took place during a number of different campaigns beginning in 1758 and was finally completed in 1910. by 1943 however, it had been bombed so heavily that much of the area lies in ruins and today and has tended to disappear from most modern research. in fact, the circumstances of its widespread destruction shortly after its exposure means that many details of the 79 ce remain unrecorded. structure from motion and archaeological excavation: experiences of the via consolare project in pompeii 1:83 studies in digital heritage, vol. 2, no. 4, publication date: december 2020 a) b) c) figure 3. insula 7 6: a) central property with peristyle; b) smaller house centred on peristyle; c) atrium of the largest house on the block. 3. from stitched orthophotography to 3d point clouds given the absence of pre-existing, highly-accurate plans for the research areas, an early priority was the survey of these areas using a leica tps 805 power total station. over time, this produced a 3d wire-frame model of standing walls, preserving the outline of each face of every surviving element of architecture, including standing walls, visible flooring or foundations, windows, lintels, and other details (fig. 4). figure 4. surveyed wire-frame dxf model of insula 7 6. colors represent different seasons of survey work. 1:84 m. a. anderson studies in digital heritage, vol. 4, no. 2, publication date: december 2020 contemporary with on-going geophysical analysis and survey, the stratigraphy of the walls was analyzed in order to identify and record any traces of earlier phases of construction, to find evidence for alteration or redecoration, and to reconstruct the overall building sequence. while the wireframe model captured the overall shape of each wall face, the sheer volume of architecture to be surveyed meant that the stratigraphic analysis of the walls had to be carried out independent of the total station survey. previous experience in working on the publication of the university of bradford’s excavations in the casa del chirurgo had demonstrated that time-consuming hand-drawn records of wall stratigraphy not only tended to be inaccurate, but rarely ended up being especially useful in the process of final sequencing. in an effort to increase efficiency, and with an eye to the final illustrations that might be needed for future publication, focus therefore fell on the production of scaled, accurate, orthophotos of each wall surface, which would be used to produce detailed, digitalized records of the standing stratigraphy. the results of the in-field analysis of mortar composition, color, wall fabric, and stratigraphic sequence identified within entire systems of standing walls could then be appended to these records. this information was stored in traditional field notebooks supplemented by extensive wall sketches, afterwards to be transferred to a digital database. in order to provide these orthophotos in the often highly-restricted architectural environment of pompeii, efforts were first directed towards creating accurate stitched ortho-rectified photographs of wall surfaces using the freeware panorama software hugin in a systematic field process [anderson 2009]. while results were promising and could be matched against the surveyed wireframe (fig. 5), this method could not cope with more complicated structural arrangements or three-dimensional features, and it quickly became apparent that a method that captured the full three-dimensional details of each wall surface would be required. figure 5. hugin stitched rectified wall surface in the area of the villa delle colonne a mosaico, 2009. surveyed outline marked in yellow. lacking sufficient resources for a terrestrial laser scanner, in 2008 i began to explore new computational photogrammetric techniques for 3d data acquisition that had recently begun to appear in digital archaeological circles [e.g. ducke et al. 2011; verhoeven 2011; verhoeven et al. 2012a; structure from motion and archaeological excavation: experiences of the via consolare project in pompeii 1:85 studies in digital heritage, vol. 2, no. 4, publication date: december 2020 2012b], which held the promise of being low cost. free options such as automatic reconstruction conduit (arc 3d) [visics 2011], photosynth [microsoft corporation 2011], and early implementations of professional packages such as eos systems’ photomodeler lite and photomodeler scanner [eos systems inc. 2012] were also considered, but commercial products were abandoned when inquiries produced offers of academic licenses that were still well beyond the project budget. following ducke’s personal suggestions in march 2009, and in preparation for the upcoming season of fieldwork, i ensured that the pipeline would run on the project laptop [for details of the process see green et al. 2014]. briefly described, this pipeline involved a multi-step process that began by identifying point matches between images produced first by scale-invariant feature transform matching (sift) [lowe 2004] and later by vlfeat, fed into linux-based bundler [snavely et al. 2006; 2008] which estimated camera positions and orientation. results were then passed to patch-based multi-view stereo software (pmvs) [furukawa and ponce 2010], (windows binaries produced by pierre moulon and alexandre leroy), in order to produce a dense 3d point cloud through image matching. further steps included the use of meshlab [cignoni et al 2008; ranzuglia et al. 2012; 2013; kazhdan and hoppe 2013; cignoni et al. 2009], to process resulting point clouds into useable triangulated and textured 3d meshes. orientation, scale, or georeferencing had to be added manually via 3d transformation in cloudcompare and later through meshlab itself. in the field season of 2009, this open-source pipeline was put to work for recording wall surfaces within my areas of research, especially wall faces. comprehensive sets of photos were acquired for many walls in the study area and organized in preparation for processing on the project laptop (first an amd dual-core turion 64 x2 (1.8ghz) with 2gb ram and an nvidia geforce go 6150, later an intel core i5 3230m with 16g ram, and an nvidia geforce gtx 660m with 2gb onboard) in the field. preliminary processing at a low resolution was possible, running overnight or for multiple days on large groups of images, but given that the project laptop was also necessary for other daily tasks (downloading points from the total station, organizing the digital photo record, preliminary work on autocad models, primary record digitization, etc.), full-scale processing had to be postponed to the off-season on a desktop (intel core i7 920 / 2.66 ghz with 9 gb ram and an nvidia geforce gtx 260 with 896 mb onboard) or on the second, more powerful, field laptop just described. in 2013, the project substituted closed-source, but “free for academic use” visualsfm [wu et al. 2011; 2013] for bundler, due to its streamlined pipeline and graphical user interface, which was easier for team members unfamiliar with command-line interfaces. the software handled the process of matching and bundle adjustment, and also employed furukawa’s clustering views for multi-view stereo cmvs (again with windows binaries by pierre moulon), in order to break up large sets of photos into groups that could be dealt with individually by the computer system without excessive processing time. while i had initially had some intention of publishing our early experiences with this technology, by this time, sfm had already taken archaeology by storm, witnessed by a growing number of conference presentations and publications and aided by an explosion of possible software packages, from open-source solutions, toolboxes for inclusion in matlab, python, or c++, and a variety of closed source, free and paid commercial solutions, including autodesk’s now defunct 123d catch, agisoft’s photoscan (now metashape), among a number of others. due to my previously unsuccessful efforts to find affordable licensing, and because the established method with visualsfm suited current needs, i decided to maintain the open-source (or at least “free for academic use”) pipeline. i was, 1:86 m. a. anderson studies in digital heritage, vol. 4, no. 2, publication date: december 2020 moreover, uncomfortable with the increasingly “black-box” nature of automatic commercial products that produced a final textured model without much user input. i imagined that the higher degree of base-level control that open-source or academic tools provide would permit greater control over the steps in the process, the ability to overcome image sets that produced poor initial results, and would provide a means of ensuring that the process itself was understood by the operators. it should be admitted, however, that none of these priorities was ever actually realized. i also believed that most projects would prefer open-source technologies in order to ensure transparency of process and longevity of results, but counter to my expectations, commercial solutions, particularly agisoft’s photoscan, quickly became widely accepted as an archaeological standard [e.g., verhoeven 2011; verhoeven et al. 2012a; 2012b; de reu et al. 2013, 2014; sapirstein 2015, 2016; sapirstein and murray 2017; olson et al. 2013; roosevelt et al. 2015]. 4. from planned uses to experimental implementations from the outset, sfm produced results far beyond initial hopes, not only successfully fulfilling the primary intended purpose of recording the surfaces of standing walls and architectural features, but also promising 3d data capture abilities that had previously been out of the project’s financial reach. while its intended use for recording surviving architecture remained its primary application, excavation itself rapidly began to encourage extensive experimentation for a variety of additional purposes that expanded the use of sfm on the project considerably. walls the primary intended use of sfm for the via consolare project was to record the wall faces within the research areas so that non-spatial data from wall analysis could be appended. for individual wall faces, and groups of walls, the sfm produced dense, and apparently detailed, point clouds of each face, roughly equivalent to those produced by other projects [doneus et al. 2011; verhoeven 2011; verhoeven et al. 2012; de reu et al. 2013; green et al. 2014; douglas et al. 2015; willis et al. 2016] (fig. 6). while areas of high contrast or features that had not been photographed from a sufficient number of encircling angles could sometimes produce sparse results (angles from below and above were particularly commonly under-photographed), the end result was sufficiently detailed to be able to distinguish different building phases for tracing, when combined with notes and sketches taken from observations in the field. though the initial intention had been to trace and label orthophotos produced from these point clouds in order to produce 2d sections marked with stratigraphic contexts, simultaneous work in producing 3d architectural models of the research areas quickly revealed the absurdity of using a three-dimensional dataset to replicate a two-dimensional recording practice. accordingly, the process of tracing was moved into the 3d modelling package blender 3d, so that tracing could occur directly onto the textured mesh. in a sense, this produced a more detailed wireframe model, but also marked the mesh surfaces for sub-division into elements that could be used to produce solid models of wall stratigraphic contexts. structure from motion and archaeological excavation: experiences of the via consolare project in pompeii 1:87 studies in digital heritage, vol. 2, no. 4, publication date: december 2020 figure 6. point cloud of the “great cistern” on the eastern side of insula vii 6, viewed in meshlab. full structures as more wall surfaces were processed through the pipeline, it became clear that, with appropriate care, it was possible to connect groups of wall faces into single processing jobs that would produce point clouds representing whole systems of connected walls. this immediately presented the possibly of producing a 3d point clouds encompassing the full research area, which might be comparable to the results produced by traditional terrestrial time-of-flight scanners, such as that undertaken by universidad complutense madrid in the nearby casa della diana [maría luzón and del carmen alonso 2017]. it was noted particularly that the sfm method was organic and flexible, permitting each set of photographs to capture precisely the area of interest, such that a wall could be photographed in a sequence that rotates around it from one face and then around to another, effectively producing a point cloud of both sides in a single step. this aspect of sfm is best illustrated by the result from 426 images taken of the eastern side of the via consolare (fig. 7). this experiment, which was undertaken to see if it was possible to provide a quick visual illustration of the archaeological section that is the primary goal of the via consolare project itself, showcases one of the distinct strengths of sfm methodology – the flexibility in the process of data capture. the end result did not depend upon pre-existing surveyed elements, but was completed as a single combined process, which nevertheless captured relative orientation, topology, elevation, and texture for the full length of this street. it was also found that photos taken at different distances from the subject could be used to produce varying levels of resolution in the final point cloud. particular details could therefore be photographed closely within the context of a larger wall, producing an area where the resulting point cloud is considerably denser in areas of interest, while economizing processing time on less important areas. (fig. 8). 1:88 m. a. anderson studies in digital heritage, vol. 4, no. 2, publication date: december 2020 figure 7. raw point cloud of the northern part of the via consolare and via dei sepolcri. viewed in meshlab. figure 8. wall in insula vi 1, with detail of inset ceramic feature achieved through series of closer photographs within the larger overall sfm project. viewed in meshlab. geo-referencing and registration the goal of producing point clouds of full structures presented a number of new challenges, in no small part because it had not been the original goal of the work. the easiest way to combine multiple segments of architecture was simply to process all the files in a single large group, but such an approach was generally found to be too time-consuming to be practical on available computer systems (desktop detailed above), and moreover did not serve to place the results into a scaled and oriented coordinate system. in order to register the fourteen primary segments of walls in the villa delle colonne a mosaico, the previously surveyed wireframe model was used to provide the necessary control points from clearly identifiable features, which, since the photography of these structure from motion and archaeological excavation: experiences of the via consolare project in pompeii 1:89 studies in digital heritage, vol. 2, no. 4, publication date: december 2020 walls had been independent of the survey, proved to be a difficult process. the end result was some variation of scale between the point clouds that required considerable adjustment. though automatic fine adjustment methods were attempted in both cloudcompare and meshlab, these produced unsatisfactory results. settling on exhaustive manual adjustment meant that while the end result was generally acceptable, it was far from infallible. as has been demonstrated, sufficient total station surveyed ground control points (gcps) are a vital element in this process [green et al. 2014], though the preferred coded-target method [sapirstein and murray 2017, 345] was not possible in the opensource pipeline. however, despite these limitations and reservations, the end product still provides a useful nearscanned overview of the site suitable for presentations to the public, and has also proven to be detailed enough to support ongoing walls analysis during the off-season. while it was found that reexamination of evidence of surviving wall plaster and particulars of mortar composition was still best achieved using the traditional photographs (often the sfm photographic collections themselves), the ability to examine the villa from above, to explore the relationships abutting walls on both sides of a given wall at the same time, and to consider the meaning of overall alignments, were found to be particularly powerful analytical uses of the point cloud data. an example of this involved the recombination of now disparate elements of the villa, in order to answer structural questions that could no longer be resolved from any analysis of the extant ruins at the site itself. the eponymous mosaic columns of the villa were removed to the mann in 1838 [pah ii 5, 353; pah ii 5, 355; pah iii 1, 136-137] and were replaced with concrete substitutes that are neither the correct size nor in the original position. using a second, scaled point cloud of these columns produced from photographs of the columns in the museum, it was possible to restore them digitally to their correct location. figure 9. point cloud of mosaic columns relocated within the villa delle colonne a mosaico. viewed in meshlab. 1:90 m. a. anderson studies in digital heritage, vol. 4, no. 2, publication date: december 2020 it can be seen (fig. 9) that the columns were aligned neatly with the nymphaeum fountain to the east, and with the doorway to the north, providing a window into the process of architectural design that would otherwise have been missing from analysis. furthermore, their correct height, which matches the design of the mosaics on the nymphaeum and possibly aligns with other features on the surrounding walls, permits hypotheses regarding possible roofing arrangements in the area that can be tested via digital reconstruction. recording stratigraphic excavation given the apparent capabilities of the technology, it was natural to attempt to extend sfm to the recording of excavation, applied first to capturing the state of trenches at the end of the field season (fig. 10). these experiments quickly led to the expansion of its use to recording every excavated context and feature, and by 2012, sfm photography had become simply another step in the normal pattern of excavation. each time photography was planned to record an aspect of the trench, additional photographs were taken specifically for sfm processing. this ensured that the trench had already been cleaned of footprints and other extraneous materials. moreover, since traditional photography in the trenches normally took place during the time of the most advantageous lighting, sfm photography could benefit similarly. the photographic routine entailed the comprehensive photography of the stratigraphic unit in multiple overlapping passes from at least two directions and at a variety of scales, including the positioning of scale bars on the trench extents and including trench baseline nails to serve as georeferenced points, matching the minima set by de reu [2014, 252], but not the preferred quality of sapirstein and murray [2017: 343-346]. photography was always terrestrial, since the project did not have access to a uav. figure 10. end of season 3d of aa001 in 2009 (left) and aa005 in 2015 (right). viewed in meshlab. while in practice, the primary and immediate use of these trench meshes tended simply to be to showcase each season’s work in final reports, online, and at presentations, the ability to produce a 3d surface of each stratigraphic context immediately suggested a number of more scientific applications. one is the use of sfm to produce scaled orthophotos as a replacement for either traditional hand-drafted plans or total station surveys, against which, it compares quite favorably in terms of accuracy and efficiency, as has now been demonstrated by a wealth of case studies [doneus et al. 2011; olson et al. 2013; de reu et al. 2014; green et al. 2014; douglas et al. 2015; sapirstein 2016; structure from motion and archaeological excavation: experiences of the via consolare project in pompeii 1:91 studies in digital heritage, vol. 2, no. 4, publication date: december 2020 willis et al. 2016; jones and church 2020]. while the 3d surfaces and orthophotos produced by the vcp found similar comparisons, it was also determined that sfm could not replace traditional methods entirely, as discussed below (cf. infra). sfm therefore did not end up replacing hand-drafted planning on this project. instead, comprehensive 3d recording of the trench deposits was always planned to produce a 3d digital model of the whole excavation, with each stratigraphic unit separated as individual layers recorded in topographic detail, and coordinated not only with every other trench and the results from architectural analysis, but also connected to other data recovered from excavation, such as information on artefacts, ecofacts, and soil samples, in the form of a 3d gis. such a resource would represent a higher level of detail in archaeological documentation, and would be a step towards the creation of the sort of useful analytical tool that should be the next step for sfm [newhard 2015]. opitz [2015] has demonstrated the degree to which three-dimensional records can produce refined interpretations in post-excavation analysis, and the impact could only be expected to be greater as multiple trenches, especially those excavated over subsequent years and therefore never comparable contemporaneously, were combined into a unified 3d model of the excavations as a whole. further advantages that have been suggested of a 3d trench model include accurate calculations of the volume of contexts [olson and placchetti 2015], the plotting of artefact densities, and the consideration of the spatial distributions of features, including their z coordinate [klinkenberg 2016; leusen and nobles 2018]. the precise location and orientation of any artefacts visible within recorded surfaces could also be recovered, and sections could be produced post facto from any angle across the trench. such a 3d gis trench record has long been the end goal of a number of different projects [barceló et al. 2003; barceló and vicente 2004; merlo, s. 2004; losier 2007; katsianis 2008; opitz and nowlin 2012], all of whom have tackled this challenge with varying degrees of success. however, while easy to conceptualize, the actual implementation of such a goal is less straightforward. though gis has formed a central coordinating feature of archaeology since the 1980s and 1990s [lock and stancic 1995; lock 2003; wheatley and gillings 2003; conolly and lake 2006], fully-functional 3d gis software has been rather slower in development. current gis software does make it possible to integrate 3d results such as point clouds and textured meshes, but in practice, many of these uses remain effectively 2.5d surfaces rather than volumes, and many of the required 3d statistical analysis tools are not yet generally in place [leusen and nobles 2018]. even esri’s arcscene, the typical destination for 3d meshes, was designed by esri primarily for visualizing the impact of building exteriors in an exterior urban environment [van leusen and nobles 2018: 474]. even though “multipatch” features clearly can be used to represent complicated 3d geometry in this way, and actual 3d gis implementations are taking place [polig 2017; landeschi 2019], relatively elaborate methods are required to squeeze actual 3d functionality out of arcgis [losier 2007; katsianis 2008; landeschi 2019]. in 2008, when efforts were directed towards using a 3d gis to coordinate architectural analysis on the vcp, only grass gis was capable of importing true 3d dxf wireframes, which in any case had to be created first in other 3d editing software. it was therefore decided for the time being to maintain a temporary 2.5d project gis instead, while capturing data that would enable the production of a full 3d gis as the software became more user-friendly. this directed the focus on this work towards the production of 3d solid meshes in 3d modelling software such as blender 3d. such elements could be imported thereafter as multipatch features, voxels, or some other form of 3d solid, to be connected to non-spatial database information within the gis. the vcp has accordingly 1:92 m. a. anderson studies in digital heritage, vol. 4, no. 2, publication date: december 2020 focused not on implementations of trench data in 3d gis per se, but rather the preparation of 3d elements that will be more efficiently implemented as time and resources permit. the first steps towards producing a 3d gis-ready trench model of complex 3d meshes was undertaken in the case study of a single trench that was excavated in 2015 (aa012). it was situated on the western side of the villa delle colonne a mosaico, in an area of a corridor that surrounded it on its ground floor, both separating it from nearby shops to the west, and serving to support the addition of extensive upper stories (fig. 11). this trench produced evidence of eruptive lapilli and volcanic debris that had only been partially explored during primary excavations in the 19th and early 20th centuries. the removal of this material produced a wealth of finds deriving from the final-phase use of the villa and from the collapse of the upper stories during the eruption itself. during excavation, it was decided to employ the use of sfm to record the removal of the volcanic material at periodic stages, so that important information on the exact disposition of finds, their orientation, and condition, would be preserved. this context seemed like an appropriate test of the planned blender 3d pipeline. figure 11. location of aa012 in the area of the villa delle colonne a mosaico, pompeii. satellite imagery: google maps. each set of photographs was individually processed into an sfm point cloud, which was then meshed and textured. these meshes were then coordinated in blender 3d, within the surveyed wireframe model of the villa and its trenches. since modelling software generally does not accommodate geographical-scale coordinate systems, the whole trench was temporarily translated closer to the origin for this work and must be returned to the correct spatial context thereafter. as a preliminary step towards the full 3d meshes that will be needed in a 3d gis, elements of the trench that were persistent between sfm meshes, such as the walls, the dolium, and unexcavated elements, were first cut into small fragments of 3d mesh and then recombined into 3d solids. corresponding elements of structure from motion and archaeological excavation: experiences of the via consolare project in pompeii 1:93 studies in digital heritage, vol. 2, no. 4, publication date: december 2020 subsequent meshes were deleted, producing layers representing the top surface of each layer of the deposit. the next step will be to transform these layers into solid meshes of the excavated deposits. even as mesh surfaces, turning off visibility of each layer permits a step-by-step re-excavation of the eruptive deposits, beginning first with the top layer of disturbed volcanic lapilli and debris (fig. 12a). after the removal of this material, the cleaner, less-disturbed lapilli became visible, surrounding an in situ dolium in use during the final phase of the villa. seemingly for temporary storage, it was surrounded by several vessels to the northeast, including an amphora leaning against the southern wall (fig. 12b). continued excavation revealed a jug that had been used to recover contents from the dolium, which had remained inside during the eruption and had eventually settled to the bottom as the contents were lost. the amphorae and surrounding vessels, heavily damaged by the collapse of the vaulting in this area, were fractured into many in situ sherds (fig. 12c). by continuing to turn layers on or off, the course of the excavation within the dolium, the removal of the vessel inside, and the exposure of underlying packed earth flooring of the pre-eruption phase of this part of the villa can be re-examined (fig. 12d). a) b) c) d) figure 12. 3d model of trench aa012: a) op of disturbed lapilli, b) cleaner lapilli and beginnings of in situ vessel, c) lapilli having been cleared exposing vessels, d) underlying 79 ce level. 1:94 m. a. anderson studies in digital heritage, vol. 4, no. 2, publication date: december 2020 in examining the meshes that represent each removed element of volcanic layers, it can be seen that the orientation and position of individual artefacts recovered are well-documented, permitting the full understanding of their disposition and orientation within the context (fig. 13). this is especially important given that the loose and fragile volcanic deposits can begin to change immediately after exposure, an aspect of excavation in pompeii that seems to have served to limit the level of detail recorded by primary excavations, which generally chose to group finds by room or room zone. [allison 2004: 31]. ultimately, the major finds in this deposit could be separated into individual meshes, or replaced by more detailed meshes produced from the objects after excavation. figure 13. 3d model of aa012. mesh surface reveals locations of bronze fitting, urceus, and marble labrum permitting reconstruction of positioning data and orientation in lapilli matrix. 5. the past 10 years of sfm: changes to field methodolgy on the vcp it is clear that sfm presents a valuable new tool to be added to the repertoire of techniques employed in excavation, and its widespread adoption by numerous researchers will undeniably alter the future standards of digital archaeological field practice as a whole. the past ten years of use of sfm for a number of planned and experimental purposes permits a number of observations to be made about how the use of this technology has actually served to change the field practices of the via consolare project. structure from motion and archaeological excavation: experiences of the via consolare project in pompeii 1:95 studies in digital heritage, vol. 2, no. 4, publication date: december 2020 changes in recording standing architecture the adoption of sfm by the project was driven primarily by a desire for precisely the three aspects of the technology that are the most discussed in archaeological scholarship: speed of recording, accuracy of result, and level of detail documented. the experiences of the via consolare project confirm that even under less than ideal conditions and via an open-source pipeline, these three features hold the power to transform day-to-day practice. certainly, in the recording of wall surfaces, sfm has been revolutionary. by removing the need to spend considerable time recording architectural evidence in the field, greater emphasis could be placed on analysis, understanding, and interpretation, speeding the overall process of study, and dramatically improving the quality of the end product. the bulk of the field study of the walls of two large areas of pompeii, including the recording of their surface topology, was completed in just four seasons of field study, and the resulting record is at a much higher level of detail than would ever have been possible with traditional techniques. changes in recording excavation likewise, the expansion of the use of sfm for the recording of excavated contexts provides reliable and highly detailed records, even of highly complex surfaces such as pottery scatters and deep areas of the trench, both of which are difficult and time-consuming for traditional hand-drafted planning and total station survey alike. the additional step of sfm photography integrated seamlessly within the existing rhythm of photography, measured planning, and excavation without producing significant delay. however, unlike some published case studies of sfm in excavation [olson et al. 2013; opitz 2015; roosevelt et al. 2015], this new recording method did not ultimately replace either the process of traditional hand-drafted planning or the use of a total station to record excavated features on the vcp, but instead served to complement them. it was found that there were a number of important aspects of the recording process that simply could not be reproduced by sfm alone. firstly, unless systems are in place both to ensure the regular production of 3d meshes or orthophotographs and to provide a means of trench-side accessibility (tablets, vel sim.) [olson et al. 2013: 252-255], excavators will not be able to reference or annotate these records in the field [opitz 2015]. while born-digital projects with interconnected data networks are currently trendy and obviously do possess some advantages in overall efficiency and data consistency, these must be weighed against in-field feasibility, reliability, and above all, cost. these factors restrict the numbers of projects for which such systems present a viable field solution, and undermine its value as a low-cost solution. however, the limitations of sfm-based recording also run deeper than such infrastructural requirements. when well-executed, sfm is capable of recording the particulars of the trench, including photographic color, details of texture, elevation, and position in tremendous detail. but excavation plans and sections do not only document trench appearance. they are, more importantly, a record of an archaeologist’s analytical process and interpretations. while many aspects of this thought process can, and should, be recorded in notes, sketches, and other records produced by the excavators, the precise reading of complicated stratigraphic interfaces is best observed and 1:96 m. a. anderson studies in digital heritage, vol. 4, no. 2, publication date: december 2020 documented in direct consultation with the actual archaeological record. this was noted even as sfm began to be introduced more widely to the field [de reu et al. 2011: 1118]. in the work of the vcp, many soil-based contexts are distinguished primarily by the “feel” of the trowel in the soil, by its texture, and by its relationships with surrounding soils. any effort to trace the outline of such a context from sketches or notes on a 3d model in the post-season would be no more than guesswork, no matter how detailed the model might be. it is also true that key elements of an archaeologist’s thinking are stimulated and formalized by the process of planning itself [opitz 2015, rabinowitz 2015]. having to put thoughts into a concrete and accurate form can highlight errors caused by overgeneralization and present further connections as details are explored analytically and mindfully. it is worrying that some who would adopt the sfm method wholesale do so precisely because it is seen to be “objective” and removes the “bias” of human investigators [de reu et al. 2014: 26; roosevelt et al. 2015: 325]. leaving aside the question of whether photography, or its computer-processed end-products, could ever really be considered to be objective and free from human bias, it is worth considering whether such a goal would be desirable, even if it were possible. this view fails to account for a core aspect of archaeological recording. scientific and accurate documentation is obviously important, but the investigator’s interpretation can also be a vital element of the record necessary for subsequence reinterpretation of the excavation results. to excavate without stimulating or documenting this intellectual level of the process would be tantamount to excavating with only photographs, notes, and sketches as the primary record. naturally, there will be some situations in which contexts are mainly structural, or are so clearly distinguishable in the 3d models that such concerns may be less pressing. the nature of the archaeological record and the priorities of each project will need to determine best practice. such was the case for the vcp’s own use of sfm to record walls, for instance. it is important however, that, in the rush to replace traditional methods with sfm, we do not also abandon vital elements of documentation and the archaeological cognitive process. as a result of these observations, the vcp traditional hand-drawn and/or surveyed plans have continued to be used to record interpretations, to document the edges of excavated contexts, and some archaeological details. orthorectified images of sfm-produced 3d meshes are employed to supply details, to provide any information that might accidentally have been overlooked, and to correct for human error in the process. moreover, the combination of these line drawings with 3d surface capture, which may be achieved simply by snapping vectorized, two-dimensional handdrawn plans onto mesh surfaces, provides an excellent synthesis that takes advantages of the strengths of sfm, while retaining the intellectually vital components of traditional methods (fig. 14). structure from motion and archaeological excavation: experiences of the via consolare project in pompeii 1:97 studies in digital heritage, vol. 2, no. 4, publication date: december 2020 figure 14. traced line from hand-drawn plan projected onto 3d mesh surface within blender 3d. using sfm to complement traditional recording still produces a considerable overall net increase in the speed of work undertaken, since excavators can focus exclusively on documenting key interpretative features of stratigraphic contexts, leaving the details and artistic flourishes to sfm. at the same time, the final product is both more accurate and more detailed. these advantages are most evident during periods when time constraints, such as the impending end of a season of excavation, might make traditional methods impossible. image-based modelling can be used to ensure that details are not missed during these inevitably-rushed moments. likewise, sfm has excelled in situations when traditional methods would have struggled to capture complex three-dimensional relationships, such as irregularly shaped sections on the inside of circular pit cuts. unplanned implementations sfm was also found to produce useful results in a number of unexpected and unplanned applications, including the use of datasets that had not specifically been designed for sfm modelling and for producing 3d models of features that were otherwise invisible or inaccessible. in 2012, the via consolare project team was involved in the ancillary study of the architectural stratigraphy of insula vi 1, including the casa del chirurgo, as a part of my work in helping the directors of that project to bring results to final publication [anderson and robinson 2018]. as a part of this work, the face of each wall was photographed from several angles so that they could be referenced away from the field, but without any plan for 3d reconstruction. nevertheless, during the process of finalising the publication, it became apparent that key elements of the house were not present in the original team’s excavation records, including plans of several well-preserved pavements on the northern side of the property and photomosaics for some northern walls intended for a photo-section of the house. in an effort to fill in the gaps, all of these photos were processed as a single job in sfm, in the hope that point clouds of these areas of the casa del chirurgo, however sparse, could be produced. results were similar to those produced by archival image processing attempted by de reu et al. [2011: 1116]. textured meshes were sufficiently detailed to be used to supplement records taken during the 1:98 m. a. anderson studies in digital heritage, vol. 4, no. 2, publication date: december 2020 primary excavations by the university of bradford and to complete the publication, even in the absence of original records, and long after the field work had been completed. this was true even of the pavements, which had only been captured incidentally in the photographs of the walls. in one exceptional case, the orthorectified 3d mesh created from this point cloud made it possible to “rubber sheet” a legacy photograph from 1938 of flooring, which is now largely lost, onto those components that do survive. simple rectification of this image using the room size would not have permitted the precise mapping of control points that was possible with the orthophotograph. the result was a digitally-created plan, that detailed elements of mosaic that no longer exist (fig. 15). the adaptability and flexibility of sfm prevented a delay in publication that could have been considerable. figure 15. point cloud of the casa del chirurgo (left). mesh of current state of floor of ala 8a (center). historical image (after pernice 1938) of ala 8a projected onto mesh to restore missing details of mosaic (right). viewed in meshlab and blender3d. there have also been instances when the vcp has employed sfm simply a means of primary exploration, to examine features in ways that would otherwise have been impossible. for example, in 2013, a working point cloud was produced of the interior of root cavities recovered in insula vii 6, prior to casting them in plaster (fig. 16a). this was achieved by reaching into the voids with a small point-and-shoot camera (canon ixus 105), with flash activated, attempting to produce a full coverage of images. while the process ended up breaking the camera and the resulting point cloud is relatively sparse and noisy, it nevertheless documented the major features of the root cavity and its overall extent, serving to recommend the effort of physical casting. similarly, a point cloud of a cistern, excavated to a depth of 2.5 meters, was also produced from photos taken from a camera on the end of a long rod, extended through a narrow 0.40 meterwide opening that otherwise prevented access and would have thwarted all other recording or investigation methods (fig. 16b). in 2018, another cistern was uncovered with an opening only 0.15 meters wide. similar recording with sfm recovered information vital to the sequencing of this feature within the development of the area, even without the possibility of further physical investigation. such uses were hardly planned implementations of the technology, but showcase the ability to leverage the flexibility of sfm into a tool for archaeological investigation. structure from motion and archaeological excavation: experiences of the via consolare project in pompeii 1:99 studies in digital heritage, vol. 2, no. 4, publication date: december 2020 figure 16. point cloud of root cavity (left) and cistern (right) in aa008 during 2013. viewed in cloudcompare. 6. the next 10 years of sfm: lessons learned while it is clear that sfm recording provides a number of clear advantages, a decade of sfm on the vcp has also highlighted a number of potential challenges and limitations, many of which are exacerbated by the use of a free and open-source pipeline, and the limitations of less-than-cutting edge hardware. image-based modelling with sfm is clearly best implemented as the result of a carefully planned and thoughtfully executed process. the ad hoc and exploratory nature of its early adoption on the vcp, combined with the use of less-than-optimal equipment, led to results that were not always of equal quality to the best results produced by published case studies [doneus et al. 2011; de reu et al. 2014; roosevelt et al. 2015; sapirstein 2016]. this was due in part to the fact that sfm was only one of many priorities for fieldwork and limited funding and size meant that staff, hardware, and software could not be dedicated to this process exclusively. furthermore, guides to practice [sapirstein and murray, 2017] that now exist were not available, and the limitations and capabilities of the technique had to be established through trial and error. it was also related to the financially motivated adoption of an open-source or “free for academic use” process, followed by my decision to remain committed to this pipeline, which also served to generate considerable challenges that might have otherwise been avoided. for instance, georeferencing, an element that is now clearly one of the most important factors determining the end-quality of sfm results and which is now an automated element of many commercial products such as photoscan, proved to be a significant obstacle. while simple scaling would have been sufficient in the project’s initial intended use of sfm for orthophotos 1:100 m. a. anderson studies in digital heritage, vol. 4, no. 2, publication date: december 2020 of standing structures, its expansion to capture more and more complicated models meant that georeferencing steps had to be worked out contemporaneously with research, and within an evolving, and sometimes poorly documented, open-source pipeline that was initially quite limited. this not only tended to reduce the quality of the vcp point clouds, but to delay the final processing itself. at the same time, working with this technology during a period in which it has been developing at a particularly rapid pace, has also created its own difficulties, even within the short period of ten years. point clouds and meshed surfaces produced early on are now considerably less resolute than those produced today. some of these could likely be improved if processed through newer software, or replaced entirely with new sets of photos taken at higher resolutions. others, such as excavation records, are naturally irreplaceable. in a desire to produce a standardized end product, there is a constant temptation to update or reprocess, but the final record will ultimately always be of variable quality. in the digital records of the vcp there are now hundreds of point clouds and models in different levels of quality and at various stages of completion, a fact that has not only hampered efforts to bring the end results together into a finalized product, but can also encourage an endless process of recreation. “time saving” is really “postponement” there can be no doubt that incorporating sfm recording into field research at pompeii produce d a tremendous increase in efficiency in the field. however, it simultaneously increased the amount of time necessary for post-season processing dramatically, from the production of dense models from sets of images, to their subsequent meshing, georeferencing, and texturing, to their final combination and manipulation. the small scale of the vcp’s operations meant that this work has had to be completed on the same computers that were being used for other academic work, including university instruction and academic publication. even when dedicated systems could be employed, the open-source pipeline does not generally possess the batch-processing or automatic tools that can speed this work in commercial packages, meaning that the main cost in time may derive from necessary step-by-step human interaction and interventions in the process. furthermore, while advancing technology does mean that computers with dedicated gpus, high levels of ram, and powerful processors are becoming cheaper in relative terms, the vcp was not always able to update to the cutting-edge and had to make do with once excellent, but now aging, hardware (see above desktop system). the end result is that the actual effect of sfm-based recording in the field was to transfer time costs from the field to the computer lab, and, given the amount of time spent after the fact, it is not entirely clear whether there has been a net savings in time. no doubt most researchers would quite happily maximize the use of expensive time in the field, at the cost of additional time spent in cheaper and perhaps easier environments at home. over time however, this phenomenon can easily produce an extensive backlog of unprocessed data that might require years of postprocessing to finalize, especially if provisions of time for post-processing were not included in the original plan of operations. upon returning home at the completion of each field season to full-time university instruction, it has rarely been possible to devote as much time as was needed to see sfm datasets to their final conclusion. as a result, small yearly accumulations have gradually built up into a substantial amount of needed post-processing. structure from motion and archaeological excavation: experiences of the via consolare project in pompeii 1:101 studies in digital heritage, vol. 2, no. 4, publication date: december 2020 challenges of archival storage and metadata similarly, the storage requirements for such a large number of images have been found to be extensive. as an example, the work of the via consolare project, having recorded every stratigraphic deposit and feature in excavation since 2012, as of 2020 had produced 139,101 image files requiring more than 1.5 tb of disk space, and this will only grow as more of these images are processed into 3d models. a standard series of photos captured for a single ‘job’ is roughly 160 images (or 2.18 gb) of storage. processing these images into 3d point clouds and meshes adds a number of additional files (more than 800 in the case of a standard job), and a further 2.5 gb of storage. certainly, having produced the dense point cloud or mesh, one could delete the intermediate steps, but at the cost of the time required to reproduce them, should they be required in the future. the decimation that is necessary to make most meshes workable entails so considerable a loss of data resolution that many researchers will wish to retain the original as well. in practice, numerous versions of these processing files tend to accumulate, especially if a given set of images requires refinement or must be processed multiple times to reach a satisfactory result. it can be difficult to know what to do with older versions, even those superseded by higher-resolution outputs, since the results are rarely entirely comparable. simply organizing and keeping track of these data can be a considerable challenge, especially when processed in sporadic moments of limited free time. while personal storage of these data is relatively easy and cheap to acquire and therefore presents little difficulty, this is not so for plans for permanent archival storage or the provision of useful metadata. as has been highlighted by rabinowitz [2015], for these datasets to be useful archives for the future, a minimum of information is required, which, given the vast number of elements involved, can easily become an overwhelming task. the raw input photos themselves can hold great potential in light of advancing technologies and possible future reprocessing [rabinowitz 2015: 35; olson et al. 2013: 248; willis, et al. 2016: 30]. numerous photos taken of insula vii 6, for instance, were taken prior to the completion of extensive restoration works under the “grande progetto di pompei,” which served to fill in and occlude many details of wall stratigraphy in this area. despite their lower resolution, such images therefore present a valuable historic resource documenting details that are no longer visible and can be used to create 3d models of conditions that cannot be reproduced. while such challenges of archival storage and metadata are in common with all of the products of archaeological excavation, from bags of potsherds to elements of primary written documentation, the volume components and outputs in sfm processing means that significant organizational and financial preparation is necessary to ensure appropriate future curation. it would be unreasonable to expect such data to be stored by the directorate of the site of pompeii, the archives of which reasonably can only accept a handful of still images each year. alternative storage and curation strategies will need to be developed to deal with the 3d and 2d components of the sfm process by the projects that produce them to ensure that they are organized and accessible by future researchers as legacy data. recording complacency and the impact of processing delay finally, it should be noted that the impressive and powerful ability of sfm to record in great detail, with minimal effort, and at great speed, can also lead to complacency in the trench itself. even when such methods are used only to augment and complement traditional recording, there can be a disturbing tendency to conclude that 3d data capture will be able to resolve any deficiencies of field 1:102 m. a. anderson studies in digital heritage, vol. 4, no. 2, publication date: december 2020 documentation. this problem is intensified by the delay that normally exists between photographic capture and 3d product. except in cases where a project has particularly established systems and resources to ensure the timely delivery of 3d results [olson et al. 2013: 252-255], sfm suffers from the same temporal division between documentation process and end-result that previously plagued film cameras and development, when it was possible to discover weeks later that excavation photography had been lost due to camera malfunction or poor choices in exposure by an area supervisor. in the same way, differences between the excavator’s imagination of what the 3d point cloud will be, and the reality of the actual processed result, can lead to undesirable gaps in the archaeological record, which could easily be irrecoverable. while none of these difficulties serve to diminish the significant utility of sfm methodologies in field archaeology, they nevertheless present challenges that need to be overcome. 7. conclusions while the beneficial impacts of sfm are clearly felt most by projects that have sufficient resources for commercial software, cutting edge hardware, and dedicated archaeological staff, nevertheless, sfm technologies yet hold a wealth of diverse opportunities for all archaeological field projects, including those of small scale and limited means. ease of setup and the ability to use even non-ideal or multi-functional equipment, means that it can augment, speed, and improve traditional recording methods. while 10 years of sfm use by the vcp has revealed a number of obstacles and limitations, it has also confirmed the robust utility of this technology. this is true even in imperfect conditions and utilizing an open-source or free for academic use pipeline, though some reduction in the quality of result and overall net efficiency must also be expected. it is also clear that, in its use for exploration and investigation, to fill in for missing data, or extract further details from legacy records, sfm may yet have even more to provide to field archaeology. given this, it is surely right to echo others in urging every project of whatever scale to take sfm photographs of all excavations, for the future, if not for themselves [willis et al. 2016: 30]. sfm provides a valuable tool that can be employed in all stages of archaeological field research from investigation, to recording, to publication, and its use in in archaeological projects will surely soon become as universal as the trowel. urls for software employed/mentioned in this article: hugin http://hugin.sourceforge.net/ vlfeat http://www.vlfeat.org/ sift https://www.cs.ubc.ca/~lowe/keypoints/ visics, 2011. arc 3d webservice. http://homes.esat.kuleuven.be/wvisit3d/ agisoft’s photoscan https://www.agisoft.com/ visualsfm http://ccwu.me/vsfm/ clustering views for multi-view stereo (cmvs) 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funéraire et commercial, campagne 2015.” chronique des activités archéologiques de l’école française de rome. les cités vésuviennes 2016. sandra zanella, laetitia cavassa, nicolas laubry, nicolas monteix, guilhem chapelin, arnaud coutelas, audrey delvigne ryrko, mélanie errera, léa gerardin, bastien lemaire, raphael macario, florien ortis, vincenzo pellegrino and géraldine sachau-carcel. 2017. “pompéi, porta ercolano: organisation, gestion et transformations d’une zone suburbaine, campagne 2016.” chronique des activités archéologiques de l’école française de rome. les cités vésuviennes 2017. received may 2019; revised october 2020; accepted october 2020 1. introduction 2. the via consolare project 2.1 area of the villa delle colonne a mosaico 2.2 insula vii 6 3. from stitched orthophotography to 3d point clouds 4. from planned uses to experimental implementations 4.1 walls 4.2 full structures 4.3 geo-referencing and registration 4.4 recording stratigraphic excavation 5. the past 10 years of sfm: changes to field methodolgy on the vcp 5.1 changes in recording standing architecture 5.2 changes in recording excavation 5.3 unplanned implementations 6. the next 10 years of sfm: lessons learned 6.1 “time saving” is really “postponement” 6.2 challenges of archival storage and metadata 6.3 recording complacency and the impact of processing delay 7. conclusions 8. references microsoft word 27552_gg_v3.docx studies in digital heritage, vol. 3, no. 1, publication date: june 2019 a roadmap to applied digital heritage: introduction to the special issue on digital heritage technologies, applications and impacts laura k. harrison, university of south florida, usa the recent “digital turn” in archaeology has driven methodological advances and opened new research avenues, with wide ranging impacts at multiple scales. the proliferation of methods such as 3d imaging, remote sensing, laser scanning and photogrammetry has led to the datafication of archaeology [caraher 2016: 467, mayer-schönberger et al. 2013: 73]. this process is most evident in research on digital surveying, data visualization, digital archiving, mapping, and image processing, which prioritize the creation and manipulation of large digital datasets. these research avenues often generate more intellectual traffic than “slow archaeology” routes [caraher 2016], which adopt a reflexive approach to knowledge production, embrace the inherent complexity of digital datasets, emphasize craft modes of archaeological documentation [perry 2015], and “highlight the value of small and properly contextualized data” [kansa 2016: 466]. confronting the growing tension between big data and slow archaeology will be an iterative process. it will evolve as researchers and other stakeholder groups assess the value of digital approaches to preserving, communicating, and interpreting the past as it relates to the present. this special issue of studies in digital heritage is the outcome of a symposium at the 2018 society for american archaeology (saa) conference in washington, d.c., entitled “digital heritage technologies, applications, and impacts.” the articles within contribute to this dialogue by critically assessing the challenges and successes of recent digital heritage projects in museums, teaching and fieldwork contexts. key words: applied digital heritage, public engagement, digital archaeology, digital museology, community engagement sdh reference: laura k. harrison. 2018. a roadmap to applied digital heritage: introduction to the special issue on digital heritage technologies, applications and impacts. sdh, 3, 1, 40-45. doi: 10.14434/sdh.v3i1.27552 1. digital heritage in the 21st century advances in digital heritage practice are driven by technological breakthroughs that expand what is possible in terms of recordkeeping, analysis, education, outreach and community engagement. powerful digital tools, ranging from hardware and software to open data archives and interactive apps, catalyze public interest and understanding of archaeology [economou 2015]. these new author's address: laura k. harrison, access 3d lab, university of south florida, 4202 east fowler avenue, cmc 342, tampa, fl 33620; email: harrisonl@usf.edu © [2019] by the author; licensee studies in digital heritage, iu, bloomington (in), usa. this article is an open access article distributed under the terms and conditions of the creative commons attribution license (cc by-nc). https://dx.doi.org/10.14434/sdh.v3i1.27552 a roadmap to applied digital heritage 2:41 studies in digital heritage, vol. 3, no. 1, publication date: june 2019 technologies encourage comparative research and transparency, close the loop on data lifecycles [kansa and kansa 2018], streamline data collection in the field [roosevelt et al. 2015], and increase multisensory engagement with the archaeological record [jamil et al. 2018]. in short, they propel innovative, digitally-driven research. the promising future of digital heritage does not render it immune to critique, however. as the field matures, it will be important to consider how current research impacts future directions. while it is critical to keep pace with technological advancements in digital tools, an avalanche of big data can distract from higher-level interpretive and analytical tasks [huggett 2015: 91, petrovic et. al. 2011]. just as expensive imaging equipment, powerful graphics-enabled computers, and virtual reality setups will expand capabilities for many, they will also exist as barriers to access for others. in turn, this creates tension in a field that often explicitly frames heritage as a human right and promotes virtualization as a globally beneficial endeavor. how are we to combat critiques of technological fetishism? is it possible to build open digital databases that favor the democratization of science, rather than implicitly reinforcing divisions between developed and less-developed nations, researchers and other stakeholder communities? there is no singular solution to these challenges. as digital heritage continues to evolve in the 21st century, novel scenarios that challenge the ethics, practice, and intellectual value of this work will emerge. these changes are occurring at a time when archaeology is more public than ever. the information revolution has vastly increased the public reach of archaeology, so that everything from routine fieldwork activities to fully realized interactive vr and ar experiences are reaching global audiences. with this widening network of archaeological communication, heritage professionals are engaging with issues of how the past relates to the present on a larger scale than ever before [moshenska 2009]. social media platforms and open access heritage databases create spaces for fresh conversation around the meaning and value of both tangible and intangible heritage. while these platforms often amplify marginalized voices and groups, such as women, minorities, indigenous, descendant communities, and lgbtqia+, they can also reinforce established modes of archaeological authority that undermine the democratization of science [walker 2014]. as online tribes form, they become venues for new heritage movements and controversies to arise [richardson 2013, richardson and lindgren 2017]. a recent example is the public outcry over the dakota access pipeline construction on native american lands [smith and van ierland 2018]. the conversation around what’s next in the field of digital heritage is thus not a question of technology, but rather one of impact. what are the outcomes of going digital, and what will digital heritage look like 5, 50 or 100 years from now? the concept of applied digital heritage offers a route forward. like applied anthropology, this type of community focused practice emphasizes participatory engagement with heritage resources. its focus is on putting research to good use and solving practical problems. in addition, immersive vr and ar applications for heritage sites draw in new audiences and expand knowledge and appreciation of archaeology by increasing stakeholder engagement. online story maps and virtual tours also offer a means of digital storytelling, which enlivens archaeological knowledge production by combining rich multimedia experiences with nonlinear narratives. these approaches employ digital tools as signposts that direct heritage conversations and interpretations to novel destinations. 2:42 l. k. harrison studies in digital heritage, vol. 3, no. 1, publication date: june 2019 2. saa session and the special issue the society for american archaeology 2018 symposium in washington, d.c. provided the impetus for this special issue. the symposium aimed to catalyze critical discourse about the applications and impacts of digital heritage. while discussion about technical aspects of heritage documentation and open data frameworks were critical elements of many papers, the focus of the symposium was not to simply celebrate the achievements of big data approaches in archaeology. rather, discussion centered on the thorny issues of how virtualization impacts data use and reuse, archaeological interpretation and analysis, outreach efforts and community engagement, among others. this reflects a realization among participants that digital tools and techniques are a new standard in the field and the lab – the initial forays into the digital realm are giving way to a more mature digital heritage practice. as we arrive at this juncture, it is critical to unpack the goals, problems and prospects of this “digital turn.” participants in the 2018 society for american archaeology symposium author three of the articles in this special issue: katherine cook and geneveive hill; davide tanasi, ilenia gradante and stephan hassam; and adam rabinowitz. the article by kevin gartski, chris larkee and john ladisa was solicited to add expertise and case studies in relevant areas to the central focus of this issue. each article in this special issue discusses the broader theoretical foundation and intellectual goals of our growing discipline with reference to one or more specific examples. an emergent theme in digital heritage is the importance of digital heritage as a process: a series of digital and analog steps that collectively result in scientific insight, community engagement, or another desired outcome. in their article, katherine cook and genevieve hill explore this idea of “hybrid digital heritage” by emphasizing the collaborative experience of making a digital application in a museum. students from the university of victoria collaborated with the royal british columbia museum to produce a pop-up exhibit that combined community-engaged archaeological research and digital heritage resources, with the goal of increasing access to archaeological collections, building upon existing permanent museum exhibits, and creating a more inclusive history of place. in doing so, participants engaged with difficult issues surrounding conflict and colonial legacies, while also gaining valuable professional skills pertaining to pedagogy, digital applications and technology, and logistics. an analysis of student perspectives on the project, and a candid evaluation of project successes and shortcomings by the authors is eye-opening. while there is recognized value in establishing long-term collaborative processes through co-creation, the structural complexities of supporting these longitudinal projects in universities, museums, and communities is a major challenge for the future. a frequently overlooked element of digital heritage dissemination is how the end user experience with the digital dataset impacts scientific and public consumption. adam rabinowitz’s article offers a critical appraisal of the communicative potential of archaeological data by investigating how multiple audiences respond to 2d and 3d archaeological datasets of varying resolution. the qualitative study investigates five different audiences, including an archaeozoologist, historic preservationist, and undergraduate students in classical archaeology, among others. an unexpected outcome is the realization that end users are not very interested in paradata: they exhibit a high degree of trust that model makers are truthful in disclosing the accuracy and precision of their a roadmap to applied digital heritage 2:43 studies in digital heritage, vol. 3, no. 1, publication date: june 2019 models. rabinowitz notes that this finding is concerning, and that it may be worthwhile to investigate better ways of communicating technical details of models, so that users better understand and appreciate the process by which the models are created. this qualitative study also elucidates a preference among scholarly and general audiences for a continuous path between low and high-resolution models that progresses from 2d photographs to increasingly large and complex 3d models, with thoughtful signposting along the way. overall, the article offers a valuable thought experiment in assessing the often-unexpected impacts of digital heritage datasets on public, academic, and specialist audiences. one of the most the many pressing questions shaping today’s digital heritage practice is whether digital tools bring us closer or further away from the trowel’s edge. as kevin gartski, chris larkee and john ladisa point out in their article, immersive 3d visualizations have been underutilized in the classroom. a key reason for this is that digital applications improve student understanding of the complex spatial and visual aspects of excavation, which are often available only by traveling to an archaeological site or museum. the article details how 3d models of archaeological sites and artifacts are projected in the marvl lab at marquette university, and incorporated into interactive course instruction in an introductory anthropology course. faculty members guide students through the processes of interpreting stratigraphy and explain archaeological field methods. viewing and manipulating excavation trenches in this way allows students to improve their spatial understanding of archaeological sites and offers insight into the mechanisms by which archaeologists draw conclusions about past peoples from material culture remains. although the immersive visualization lacks the haptic experience of an actual excavation, it conveys fundamentals of archaeological knowledge production that are useful in the absence of a firsthand experience. one of the key discussions at the 2018 saa symposium was a conversation about how 3d documentation methods, which surpass 2d methods in many ways, enhance archaeological recording, and may even come to replace it. in this context, davide tanasi, ilenia gradante and stephan hassam discuss their experience scanning the catacombs of st. lucy in sicily – a highly inaccessible archaeological context in which much of the existing graphic documentation is outdated and incomplete. the team used multiple 3d imaging techniques to collect data from multiple dimly lit underground contexts, which are in a poor state of preservation and are prone to flooding. the open dissemination of such collections advances academic scholarship by enhancing accessibility, and the 3d scanning and data processing was incorporated into an instructional context in which students learned low-cost methods of digital archaeology data collection and processing. the multiscalar approach outlined here is a representation of best practices in 3d digital recording and dissemination that mobilizes low-cost documentation methods to reach multiple stakeholder groups. 3. conclusion the papers in the saa symposium entitled “digital heritage technologies, applications, and impacts” explored the transformative role of digitization on archaeological practice in the 21st century, and offered insight into topics such as reflexivity in digital archaeology, knowledge production in the 2:44 l. k. harrison studies in digital heritage, vol. 3, no. 1, publication date: june 2019 digital age, the ethical and political issues surrounding open data, the importance of data curation, contextualization and dissemination, and the slow data critique. similarly, the papers in this special issue highlight key issues at the forefront of discussions about contemporary digital heritage practice. each of these articles engages with the concept of applied digital heritage, and together they envision a roadmap to a participatory and reflexive future for archaeology in the digital age. 5. acknowledgements i would like to thank the 2018 society for american archaeology symposium participants for their contributions to a grounded and critical discussion about the current state of digital heritage as a field. the discussion was instrumental in shaping the ideas laid out in this article. 6. references william caraher. 2016. slow archaeology: technology, efficiency, and archaeological work. in mobilizing the past for a digital future, erin walcek averett, jody michael gordon and derek b counts, eds. the digital press @ the university of north dakota, grand forks, 421–441. maria economou. 2015. heritage in the digital age. a companion to herit. stud. september (2015), 215–228. doi: 10.1002/9781118486634.ch15 jeremy huggett. 2015. challenging digital archaeology. open archaeol. 1, 1 (2015), 79–85. doi: 10.1515/opar-2015-0003 muhammad hassan jamil, prince steven annor, jonathan sharfman, robert parthesius, isabelle garachon, and mohamad eid. 2018. the role of haptics in digital archaeology and heritage recording processes. have 2018 ieee int. symp. haptic, audio-v. environ. games, proc. (2018), 51–56. doi: 10.1109/have.2018.8547505 sarah whitcher kansa and eric c. kansa. 2018. data beyond the archive in digital archaeology: an introduction to the special section. adv. archaeol. pract. 6, 2 (2018), 89–92. doi: 10.1017/aap.2018.7 eric c. kansa. 2016. click here to save the past. in mobilizing the past for a digital future: the potential of digital archaeo, erin walcek averett, jody michael gordon and derek b counts, eds. the digital press @ the university of north dakota, grand forks, 443–472. mayer-schönberger, viktor and kenneth cukier. 2013. big data: a revolution that will transform how we live, work, and think. houghton mifflin harcourt, boston. g. moshenska. 2009. introduction: public archaeology as practice and scholarship where archaeology meets the world. in key concepts in public archaeology, gabriel moshenska, ed. ucl press, london, 1–13. sara perry. 2015. crafting knowledge with (digital) visual media in archaeology. in material evidence. learning from archaeological practice., robert chapman and alison wylie, eds. routledge, london, 189–210. v petrovic, a gidding, t wypych, f kuester, t defanti, and t levy. 2011. dealing with archaeology’s data avalanche. computer (long. beach. calif). 44, 7 (2011), 56–60. doi: 10.1109/mc.2011.161 lorna richardson. 2013. a digital public archaeology? pap. from inst. archaeol. 23, 1 (2013), 1–12. doi: 10.5334/pia.431 a roadmap to applied digital heritage 2:45 studies in digital heritage, vol. 3, no. 1, publication date: june 2019 lorna-jane richardson and simon lindgren. 2017. online tribes and digital authority: what can social theory bring to digital archaeology? open archaeol. 3, 1 (2017), 139–148. doi: 10.1515/opar2017-0008 christopher h. roosevelt, peter cobb, emanuel moss, brandon r. olson, and sinan ünlüsoy. 2015. excavation is destruction digitization: advances in archaeological practice. j. f. archaeol. 40, 3 (2015), 2042458215y.000. doi: 10.1179/2042458215y.0000000004 jessica m. smith and tom van ierland. 2018. framing controversy on social media: #nodapl and the debate about the dakota access pipeline on twitter. ieee trans. prof. commun. 61, 3 (2018), 226–241. doi: 10.1109/tpc.2018.2833753 dominic walker. 2014. antisocial media in archaeology? archaeol. dialogues 21, 02 (2014), 217–235. doi: 10.1017/s1380203814000221 received march 2019; revised april 2019; accepted may 2019. microsoft word 27441_gg_v2.docx studies in digital heritage, vol. 3, no. 2, publication date: december 2019 the digital platform of d.i.r.a.a.s. (unige): an informatic application for the history of art criticism and photography martina massarente, university of genoa, italy this project studies photography as an instrument for artistic and historical teaching in relation to the didactic traditions of the humanities at the university of genoa. this research was initially based on an analysis of the corpus of glass diapositives and phototypes mostly owned by giusta nicco fasola, genoa’s first art history professor, and currently stored by d.i.r.a.a.s. (dipartimento di italianistica, romanistica, antichistica, arti e spettacolo). the corpus contextualizes fasola's scientific and didactic interests in relation to her complex biography as a woman, professor, and political combatant in the resistance in fiesole and florence. the central element of this analysis is the project for a prototype of a digital art history photo library, intended as a place of study and research and as a virtual communication platform. the overall goal of this work is to investigate the relationship between photography, history, and art critique. key words: photography, history of art, digital archives, digital humanities. sdh reference: martina massarente. 2019. the digital platform of d.i.r.a.a.s. (unige): an informatic application for the history of art criticism and photography. sdh, 3, 2, 156-169. doi: 10.14434/sdh.v3i1.27441 1. introduction this project studies photography as an instrument for artistic and historical teaching in relation to the didactic traditions of the humanities at the university of genoa. this research was initially based on an analysis of the corpus of glass diapositives and phototypes mostly owned by giusta nicco fasola, genoa’s first art history professor, and currently stored by d.i.r.a.a.s. (dipartimento di italianistica, romanistica, antichistica, arti e spettacolo). the corpus contextualizes fasola's scientific and didactic interests in relation to her complex biography as a woman, professor, and political combatant in the resistance in fiesole and florence. the central element of this analysis is the project for a prototype of a digital art history photo library, intended as a place of study and research and as a virtual communication platform. the overall goal of this work is to investigate the relationship between photography, history, and art critique. this article is a synthesis of the doctoral dissertation in digital humanities, presented at the university of genoa (may 2018) with the title: giusta nicco fasola and photography as a tool for art history in genoa. the project for a d.i.r.a.a.s photo library. author's address: martina massarente, university of genoa, via balbi 5, 16126, genova, italy; email: marty.massarente@yahoo.it © 2019 by the author; licensee studies in digital heritage, iu, bloomington (in), usa. this article is an open access article distributed under the terms and conditions of the creative commons attribution license (cc by-nc). https://doi.org/10.14434/sdh.v3i2.27441 an application for the history of art criticism and photography 3:157 studies in digital heritage, vol. 3, no. 2, publication date: december 2019 this analysis opened up a new art historical challenge, for the phototypes and documents connected to a broad range of art historical sources, as well as renowned italian photography studios. in addition, this research caused us to reflect on approaches to the photographic materials. photography is a modern cultural tool. in the first place, phototypes bear witness to events involving works of art, archaeological sites, and buildings. they are also mostly reproductions, and their distortions and selectivity are evidence of the professor's methods of art historical pedagogy. unfortunately, many documents pertaining to the photographic materials have been lost, and it has not been possible to find their historic inventories or the initial documentation of their earliest rearrangement (in the library of the faculty of literature and philosophy in genoa). however, through direct observation of the phototypes, research in other photo archives, and discussion with professionals in the industry, it has been possible to propose a technical and formal analysis of each object retracing fasola’s approach to photography and the camera. by relating the camera to the professor’s didactic approach to her research topics, this work also affords photo archives and libraries a central role as guardians of research methods and historical pedagogy. although university photo libraries are a largely unexplored field of study, new research attests to the historical value of such places. in 2017, two conferences hosted by the universities of udine and naples clarified the contributions of photo archives and libraries in institutional and academic contexts. the conferences built upon a wide range of discussions, including the relationship between analog and digital media, the digitization of phototypes, the creation of inventories and catalogs, and the elaboration of historical research methods and practices. the methodological conversation has proved necessary to the present effort of understanding the lives of particular photographs and their later representations, as well as their relationships with the teaching methods of professors. the aim here is to understand the strategies academic institutions have used to study the photo archives of art history, focusing on their processes of digitization and preservation, as well as the theories at the basis of the different study methods. this research can be a means of communication with other existing photo archives and libraries within italian universities that aim to advance the goal of sharing research and information, by reactivating the role of the photo library as a physical place of study on par with similar organizations at the international level. the initial phase of artistic historical research was followed by practical research in information technologies, with the goal of creating a prototype of a digital academic photo gallery. we ultimately proposed to expand the d.i.r.a.a.s photo gallery into a university-wide digital library. in creating our proposal, we generated a survey, which helped us hone our model for a shared project between different departments and museums, each with their own academic structures and cultures. as outlined above, art history photo libraries, intended as places of research and study as well as the everyday practice of art history, have been, at least up until the 1990s, active environments and essential points of reference for students and teachers alike. throughout the 1990s, as digital photography and new didactic methodologies in the humanities emerged, art history photo libraries underwent a crisis. the new trends in historiography and the explosion of online images made photo libraries appear obsolete and no longer able to fulfil their academic purposes. however, 1999, the year of a conference in memory of paolo costantini, saw the awakening of interest in the photographic heritage of academic institutions. this occasion marked a significant moment of reflection, in which 3:158 m. massarente studies in digital heritage, vol. 3, no. 2, publication date: december 2019 art historians and other experts were able to address the state of national photographic heritage. relatedly, digital humanities research can exploit new technologies to support cultural heritage, especially tools, software, and research instruments that can classify, catalog, and archive artworks as digital resources. the digital humanities have contributed to the development of strategies, practices, and working methods in various disciplines. d.i.r.a.a.s. analyzes how art historians and it specialists use communicative strategies to link various skills and professions, implementing useful tools for the documentation and valorization of photographic heritage on the internet. since the early 2000s debates have persisted regarding the digitization of archives (photographic or other) and the advantages and problems introduced by the new technologies of documentation. new needs and practices involving photographs and photo libraries have developed following a number of significant nation-wide initiatives regarding digital documents, including the plan devised by minister dario franceschini to create an italian digital library. also worth mentioning is the creation of the europeana photography archive, which stores two million digital photographs [tanni 2017]. such initiatives have triggered debates and discussions of new aspects of photography, in relation to both the object depicted and its digital reproduction. in recent years, the dissemination of new information technologies has led to discussions of the “digitization rush” of materials (documents and photographs), a discourse that some scholars call “an archaeology of disciplines” [edwards 2011]. with the growth of digital technology, institutions have had to face the question of whether to make their materials accessible on online platforms. this issue encouraged the necessary renewal and updating of the tools needed to implement and regulate digitization, while also motivating representatives of different disciplines to join forces in establishing common, shared procedures using the new it systems. as museums and other institutions have gradually implemented standard practices for the digitization of documents, they have developed databases, platforms, and sites exhibiting digital resources and objects. at the same time, this fast growth has raised problems of storing and preserving digital materials, such as the question of how to implement these resources, transform the analog originals into electronic media, and act without a support structure for the necessary scholarly theory and criticism. the question of digitization has incited a new wave of research that has also involved professionals in the cataloging, conservation, and restoration of cultural heritage. many of these professionals are also currently engaged as interpretive “mediators,” investigating cultural as well as technical questions. this newfound awareness, however, does not seem to find a full realization in practice because the pace of digitization has outstripped the communication of the critical discourse beyond the individual or regional level. this has created a both fragmentary and fragmented context, further complicated by the cyclical obsolescence of it media and of the guidelines for digitization. this article thus briefly examines the working model used in the project for a d.i.r.a.a.s. photo library. in the future, this project may extend to the whole university of genoa in order to unearth forgotten didactic material that would otherwise be doomed to oblivion. an application for the history of art criticism and photography 3:159 studies in digital heritage, vol. 3, no. 2, publication date: december 2019 2. cataloging and archiving: new technologies for digital archives cataloging cultural heritage is a complex process which requires the cooperation of most humanistic disciplines. these fields are beginning to harness the wider scope of applied computer science. the diffusion of new technologies has created new, hybrid professionals, whose main task is to catalog and archive cultural heritage by linking large amounts of data and information about artistic objects. professionals must be able to navigate new areas, moving beyond the specific knowledge of their discipline and embracing the new technical solutions of information technology. over the past few years, museums, archives, and libraries have turned their attention towards these types of practices, creating interactive online repositories with swift and accurate web design. managing such information can be challenging, as the platforms are created using various languages and structures, posing problems of compatibility. in addition, each institution applies the standards of inventory and cataloging that are particular to their field: librarians follow the rules laid out by library sciences, and archivists those of archival description. this raises the problem of how photography is considered from an ontological and epistemological point of view. in order to systematize objects that have been cataloged separately, museums and other institutions have invested in new multimedia digitization projects, while also making them available and accessible to a broader audience and not only specialists. the inventory goals established by previous institutions can be understood and maintained by cross-analyzing the variations of the stored objects and their means of documentation. some of the most significant aspects that a digital humanities study should consider when studying documents include: management systems for digital collections; digital storage systems; research tools and instruments; the means of presentation and visualization of the system. when developing a digital platform for the d.i.r.a.a.s. photo library, we have thus considered many factors in choosing descriptive typologies appropriate to the complexity of the stored photographic materials. consistent with debates of the recent past concerning academic art history photo libraries, our aim is to question the marginal role to which photography has been relegated, and thereby draw the attention of various kinds of professionals, who are invited to reconsider their role in the light of new research directions. starting from the reorganization of the analog photo library and the study of giusta nicco fasola’s didactic material, doctoral research has laid the foundations for reconsidering the possibilities offered by new technologies, especially for the organization of information and the display of the university of genoa’s photographic material in a new web space. 3. the d.i.r.a.a.s. virtual photo library project the d.i.r.a.a.s. photo library intends to encompass the storage, inventory, digitization and valorization of the nuclei of images identified in the department’s photographic collection. it also follows the theoretical notion that photography is a documentary source, to be considered alongside contextual documents that help to retrace the biographies of the professors of artistic and historical 3:160 m. massarente studies in digital heritage, vol. 3, no. 2, publication date: december 2019 subjects at the university of genoa. after evaluating cataloging methods and the existing online photo libraries in collaboration with professor marina ribaudo at dibris, we have assessed the software considered most suitable to the university of genoa’s requirements (fig. 1). figure 1. d.i.r.a.a.s. virtual photo library. collective access database platform. our software was available through collective access and was selected based on several key criteria:1 suitability for cataloging photographs and collective access (with the fields and sub-fields of the cataloging sheet starting from the linked open data made available by open iccd) ease of use long-term software maintenance compatibility with the main archival standards 1 http://www.collectiveaccess.org/configuration; http://docs.collectiveaccess.org/wiki/metadata_standards. an application for the history of art criticism and photography 3:161 studies in digital heritage, vol. 3, no. 2, publication date: december 2019 minimum system requirements (hardware and software) license our model, studied in collaboration with dibris, employs the open-source software collective access as a foundation on which improvements have been implemented to enhance the exhibition of photographic materials, such as interactive timelines, network graphs charting the relationships between key players of art history in genoa, maps and georeferences, files related to the digital objects, and digital reproductions in .jpg format.2 the platform's ability to create internal connections and relationships between information is useful, especially considering the potential for collaboration across art historical subfields. moreover, it served our main goal of creating new means for the online exploration of photographs and documents of potential interest to the university, starting with existing photographs, mostly teaching aids. the portal, the result of several years of research, can be a tool for non-experts and professionals alike, the latter contributing to the implementation of new search categories through a crowdsourcing micro-blog application. the platform makes it possible to view data and geo-data, zoom in on each image, understand the location of the objects through gis and webgis technologies, and superimpose various layers to enable users to navigate the map and the locations where objects are found. among the other operations guaranteed by the platform are: database searches and queries user-friendly content searches starting from the main menu a micro-blogging function that allows scholars and other users to participate the creation of a web space directly accessible from the university’s website is essential in order to make the university’s resources accessible to a wider public and create synergy between different skill sets. collective access was chosen for the short-term goal of managing the photographic materials as well as the long-term goal of enriching the platform with diverse digital items, as in the phaidra website. collective access makes it possible to manage archives and documents as well as process cataloging sheets according to the most up-to-date international models. the software guarantees the quick updating of data, separately for each user, and is also linked to a wordpress content management system. the graphic interface of the gallery also uses wordpress, and thanks to dr. nunzi’s programming, the user experiences a smooth transition from the wordpress home page to the cataloging system without noticing the change of platform. version 1.7.5 of collective access, the latest update as of august 2017, is used for the prototype. the system is open-source and easily updatable; the text and information within the pages can be modified or hidden from the public depending on the privacy settings. the database can be customized by adding or deleting fields and subfields. also, the files allow direct access to google maps for the georeferencing of locations. finally, it is possible to structure photo galleries so that the files are related and connected to each other. this especially serves the didactic goal of the project to ensure a broader comprehension of the role of art historians and the sources they use (fig. 2). 2 http://www.aspi.unimib.it/centro-aspi/il-portale-web/. 3:162 m. massarente studies in digital heritage, vol. 3, no. 2, publication date: december 2019 collective access boasts an active community, and the system is continuously developing and evolving. the software has a gnu free software license. the basic user interface complies with current web standards, and its content viewer is flexible and rich in features. it is even possible to view content in detail directly from the web app and to download versions of the desired content at a range of resolutions. figure 2. the d.i.r.a.a.s virtual photo library. data entry system showing linking capabilities between files. an application for the history of art criticism and photography 3:163 studies in digital heritage, vol. 3, no. 2, publication date: december 2019 collective access currently guarantees great flexibility and can handle changes and new implementations; however, the cataloging model scheda f has not yet been integrated according to iccd standards. to guarantee software updates as the first usable function during the installation, we elaborated a support program for the programming language python in collaboration with dr. simone nunzi, taking as an input the xml standard provided by open iccd. following the approach used by xdams, we integrated isad(g) and ead files. collective access uses models with supplementary information in order to maximize the compatibility of the cataloged objects with other platforms, guaranteeing the interoperability of the data. figure 3. the d.i.r.a.a.s. virtual photo library. biographical page for giusta nicola fasola. 3:164 m. massarente studies in digital heritage, vol. 3, no. 2, publication date: december 2019 for the most part, glams (galleries, libraries, archives, and museums) lack an approach to data interoperability that makes materials accessible to specific disciplines and fully exploits the potential of digitization. at the same time, these institutions have opened up to a wider and more diversified audience, which has made it all the more important to consider models for documenting heritage that provide the correct context and directly involve users, exploiting, for example, virtual exhibits of digital objects. there exist effective open-source tools that institutions use to create a network of digital objects and resources, but they are often difficult to navigate and use. let us therefore shift our focus from exhibition methods to the audience's ability to interact and participate. digital archives are fertile ground for experimentation with innovative access models, making full use of digitized heritage. in the light of such considerations, our research has focused on the modalities of exploration, research, selection, and display of the digital material in order to present contexts, characters, and locations involving the university of genoa. to this end, the platform was implemented with a system that maps the relationships between art history professors, using a javascript app that represents relational data according to conceptual map models. the javascript data extractor and the functions connected to the visualization of the data allow for users to navigate and discover information within the portal. this type of application makes it possible to input the personal data of the art history faculty in a search bar, and call up their conceptual relationships, such as their relocations between places, research and study activities, academic experiences, and teaching traditions (figs. 3, 4). figure 4. the d.i.r.a.a.s. virtual photo library. a map of biographical networks among art historians. thanks to this application, implemented and modified to make data input simple and intuitive, it will be possible to visualize how certain theoretical positions have spread in italy and abroad. in short, the program creates a georeferenced conceptual map of the history of art critique. an application for the history of art criticism and photography 3:165 studies in digital heritage, vol. 3, no. 2, publication date: december 2019 we have also made technical improvements to simplify the user's process of inputting data. for example, when filling in the “f file,” the program suggests to the cataloger the correct compilation procedure, marking the mandatory fields and the free text ones. by logging into the back end, accessible by signing in under the heading “galleries,” the cataloger can easily compile the file while simultaneously working with the physical object. we have facilitated the task of describing complex items, especially photographs, by introducing in the left sidebar a series of categories structuring the fields of object description. thanks to the linked open data system made available by open iccd, it was possible to implement collective access’s cataloging system for all the data in the “f file.” the software makes it possible to save at every step during the compiling and enables a pdf export at the end. it was also considered necessary to expand the closed vocabularies for inputting data in the cataloging file, as collective access, despite providing many international ontologies and thesauruses, did not contain all the necessary references for a correct object description according to iccd’s standards. as for graphic appearance, collective access, combined with wordpress, provides a great number of standard and customizable templates. while developing the graphic design, we kept in mind the institutional value of this initiative. after verifying the data-harvesting possibilities of the primo system (managed by the university of genoa library system), we ultimately chose graphics and colors that preserved the university's brand identity and satisfied its requirements for communicative clarity.3 the virtual photo library is organized according to a menu bar with the following sections: “home” (main home page with direct access to the particular elements of the digital photo library); “the project” (explains the ongoing project and the interdisciplinary collaborators who are involved); “the photo library” (provides a short description of the photo library, its structure and the heritage objects stored within); “the collection” (presents the photographic collections); “departments” (a ‘work in progress space hosting all the departments that intend to take part in the university’s digital library); and “events and activities” (sharing activities carried out by scholars who use the photo library). in addition, the blog is devised as a space for open discussion available to junior and senior scholars alike, as well as a bridge between the university and outside users. this space also enables the continuous updating of information, with news regarding projects and activities, research on specific photographic collections, and workshops. the gallery allows direct navigation of photographic material and includes a space dedicated to insiders (art historians and catalogers) that is directly linked to the catalog files (temporarily limited to diapositives on glass). a final section contains contacts and our location. in order to facilitate the use of the platform as a working tool and research laboratory, we equipped it with a micro-blogging system, separate from collective access, making both systems independent and specialized. due to its simple and versatile features, we used a wordpress system for data entry, the front end, and active blogging by users. 3 the term harvesting refers to the operations of collection, interchange and interaction between data repositories (database) adopting, in this case, the open protocol oai pmh (https://www.openarchives.org/pmh/). 3:166 m. massarente studies in digital heritage, vol. 3, no. 2, publication date: december 2019 we our currently devising, in collaboration with prof. annalisa barla and dr. giancarlo gasparini of dibris (unige), an application that allows the use of gis to navigate repositories of photographic heritage. webgis can be accessed via a web browser and allows the online floor-by-floor navigation of the structures. the spatial subdivision into floors and rooms will allow users to access data on the collections and images, as well as the building’s blueprints and the locations of the individual works. 4. later developments: a census of the athenaeum's collections during the years of my doctorate, the idea of creating of a larger online space that may spread awareness of the d.i.r.a.a.s. collections has raised the interest of other interlocutors, especially from the fields of science, medicine, ethnography and anthropology, and mathematics. we relished the opportunity to study a wide-ranging project that could involve many disciplines. in order to analyze the needs of the university and stakeholders, we set up an online survey in collaboration with dr. federica imperiale (cedia) and dr. ludovico sassarini (perform – unige). the purpose of the survey was to create a proposal for a multi-annual project on the management of the university’s digital heritage, promoted by cedia and sba (sistema delle biblioteche di ateneo) and currently still in progress. the project has involved many people and institutions, especially the libraries, departments, and museums connected with the university. the goals of the investigation were organized into a survey in order to coordinate a network of people interested in developing the project for a university digital library. on one hand, the survey aimed to identify the university’s collections of digital material (or material to be digitized). on the other hand, it aimed to assess the existence of laboratories and enough equipment to start up digitization campaigns. for example, we specified whether there were pre-existing inventory and cataloging procedures for the collections. the questionnaire on the management of digital material has shed light on the presence of analog and digital material throughout the university. for this reason, a section of the questionnaire was devoted to the material that needs to be digitized, with questions seeking to identify the types of materials and objects stored by different departments as well as their value, quantity, and variety. the survey on the presence of laboratories equipped for digitization practices and the specific equipment stored at the facilities also played an essential role. of particular interest during this initial investigation was the existence of operational plans for the conservation and restoration of the assets owned, as well as inventory and cataloging plans already being implemented or developed. a second phase of the survey was devoted to the collections of already digitized material. we collected information about cataloging operations, acquisition types, data storage practices and solutions, and chosen standards. in conclusion, we observed, from the analysis of the survey data, that scientific sectors expressed the clearest interest. these sectors have large and heterogeneous collections of photographs, books, drawings, models, films, and dissertations. no humanities departments, apart from d.i.r.a.a.s., showed comparable interest in the digital library. there was also a marked lack of appropriate equipment for the digitization of materials among humanities departments. some responses to the questionnaire showed an interest in the digitization of materials and the need to transfer videos and an application for the history of art criticism and photography 3:167 studies in digital heritage, vol. 3, no. 2, publication date: december 2019 images currently stored on analog media (disfor) to a digital format, while another set of responses highlighted the presence of appropriate equipment for setting up initial inventory surveys through information management and cataloging software, management systems for audio recordings, and 3-d models. the problem of non-differentiation of material also arose. the results of our survey highlighted several difficulties that are still widespread within universities, which are often not aware of their heritage objects and their value. in particular, the humanities fields are still somewhat isolated and separated from digitization and online validation practices. this is especially clear in the case of photographs, which are often considered as purposeless acquisitions or as additional and “ancillary” material alongside books and manuscripts, and therefore relegated to dusty shelves and boxes. the strong interest shown by scientific departments is encouraging our group to broaden its views. the initial project for an art history photo library that could preserve photographic material and make it accessible in analog and digital form has developed into a flexible platform system that can integrate a wide range of collections. each department will thus have access to a dedicated area for their specific activities, with its own procedures for cataloging items and presenting analytical data, all the while elaborating shared criteria that link the analytical requirements of each field of study. finally, the survey has highlighted the scarceness of existing experience in digital technologies. thus far, the level of experience in the digital acquisition, sharing, and communication of collections, as well as in the acknowledgment and mapping of assets, has been low. many inventories no longer exist or have been replaced over time, while others have been created in computer formats that are no longer accessible. 5. conclusions the history of photo libraries and of the scholars who created them (and developed them over time) is multifaceted. this history includes the individuals and their publications and the relationships between scholars, photographers and publishers. nowadays, it is enriched by new technologies and the innovations of information science, fields which are now extensively involved in humanistic research. ever since 1865, when hermann grimm wrote an essay on the need to own a photo library, launching a tradition of art history pedagogy based on diapositives and photographic collections, humanists have taken on new and diversified tasks as their profession has evolved in line with the emergence of new instruments. the discovery of the photographic material stored in d.i.r.a.a.s. opened new opportunities to study and retrace this tradition, as carried on by important art historians in genoa [caraffa 2011]. the work on this photographic material made it possible for the university of genoa to form part of a research discourse that has expanded in recent years to highlight several organizations attentive to the history of their universities and of the scholars who have worked there. in addition to valuing the opportunity to study the photographic heritage, these organizations share the goal of forging an online presence, in order to make their collections available to the non-specialized public. most of the universities state the existence of their photo libraries on their own institutional websites but have not yet provided historical information about themselves or uploaded their material online. for 3:168 m. massarente studies in digital heritage, vol. 3, no. 2, publication date: december 2019 example, this is the case with the university of florence, whose library holds photographs by art historians such as mario salmi and roberto longhi. this raises critical issues concerning the visibility of the information and the still widespread mindset that photography (and the photo library as a physical place) has a merely instrumental function, meanwhile new technologies are revolutionizing and hybridizing the way we “do” art history. this mindset blinds us to the important role that the photographic instrument has played for professors who have used it to establish new collaborations with contemporary scholars and photographers. for these reasons, our work has tried to link two different discourses: the historical-critical study of the role of the first art history professor in genoa and her photographic material, and the model of a digital gallery, which may in the future host a platform for the university’s heritage. it was also necessary to address the matter of the publication and exhibition of said material in the light of recent studies on the use of new technologies in the digital humanities, which is contributing in a major way to the analysis, archiving, cataloging, conservation, and dissemination of the photographic heritage held in archives and universities. the photo library can bring to light the pedagogical methods of the university faculty by making it possible for students and users to freely explore it, and thereby learn the interdisciplinary and documentary references that help to contextualize the works, as well as to compare images and retrace the formation of each professor. collective access allows the creation of virtual exhibition spaces, and the project aims to stage exhibits highlighting the research of professors and their students. in this way, we may give new value and vigor to the research of genoese art history culture. the web projects made possible by this software may, in the future, be developed in the following ways: analytical filing and cataloging, exploring paths for in-depth studies, recreating lectures from the past, and delving deeper into the research conducted by giusta nicco fasola and her contribution not only to the university, but to the whole city of genoa. by contextualizing works from a wide artistic range, we can underline the methodological peculiarities of individual protagonists of the university of genoa. by presenting the material online, with the images front and center, it is possible to create transversal paths that interact dynamically across disciplines and fulfil the educational purposes of the photographs stored on the d.i.r.a.a.s. premises. the hope is that this long-term project may continue naturally in the years to come, opening the university to the public and thereby spreading the knowledge of an immense heritage that is still unpublished. an application for the history of art criticism and photography 3:169 studies in digital heritage, vol. 3, no. 2, publication date: december 2019 6. references andreas witt and pavel kamocki. 2016. when dh meets law: problems, solutions, perspectives. in m. eder and j. rybicki, eds. digital humanities 2016, dh 2016: conference abstracts (jagiellonian university & pedagogical university, kraków, 11-16 july 2016). kraków: alliance of digital humanities organizations (adho), 104-8. aspi – archivio storico della psicologia italiana. le scienze della mente on-line. retrieved may 10, 2018 from http://www.aspi.unimib.it/centro-aspi/il-portale-web/ costanza caraffa. 2011. photo archives and the photographic memory of art history. monaco: deutscher kunstverlag. costanza caraffa and tiziana serena. 2012. pensavo fosse una fototeca, invece è un archivio fotografico. ricerche di storia dell’arte archivi fotografici. spazi del sapere, luoghi della ricerca. 106 (2012), 37-50. catalogo dei beni culturali – open data. retrieved may 10, 2018 from http://www.catalogo.beniculturali.it/opendata/ collective access. retrieved may 10, 2018 from http://www.collectiveaccess.org/configuration and http://docs.collectiveaccess.org/wiki/metadata_standards elizabeth edwards. 2011. photographs: material form and the dynamic archive. in costanza caraffa, photo archives and the photographic memory of art history. monaco: deutscher kunstverlag, 49. protocollo open source per l’interoperabilità. retrieved may 10, 2018 from https://www.openarchives.org/pmh/ received january 2019; revised july 2019; accepted august 2019. microsoft word 27720_gg_v3.docx studies in digital heritage, vol. 3, no. 2, publication date: december 2019 between light and shade – the present and future of the collection of old lithography of fbaul alberto faria, university of lisbon, portugal the faculty of fine arts of the university of lisbon (fbaul) holds a collection of lithographs, dated between 1840 and 1911, related to the memory of teaching drawing in the nineteenth century. lithographs after works of italian old masters like raphael sanzio and pompeo batoni, respectively, drawing courses of french artists of the second half of the nineteenth century like charles bargue, auguste allongé among others, relate this collection with its european counterpart of the nineteenth century. the fbaul virtual print room is a bilingual (portuguese/english) website project to enable users in future to have access to the inventory and knowledge of the collection and build connections with other archives worldwide. key words: digital humanities, lithography, university collections sdh reference: alberto faria. 2019. between light and shade – the present and future of the collection of old lithography of fbaul. sdh, 3, 2, 122-127. doi: 10.14434/sdh.v3i2.27720 1. introduction the fbaul virtual print room is a project currently in progress as part of my ph.d. thesis in heritage sciences at the university of lisbon, faculty of fine arts (fbaul), under the supervision of prof. luísa arruda, prof. fernando antónio baptista pereira (university of lisbon) and prof. joão brigola (university of évora). the project intends to present online the inventory and study of the fbaul collection of old lithography. the lisbon’s faculty of fine arts is housed in the former convent of são francisco da cidade, a thirteenth-century building, where in 1836 the lisbon’s academy of fine arts was established [calado, 2000, 2018]. the building of the convent was also chosen to lodge several institutions and their collections, which later gave origin to several important museums in lisbon [alves et al., 2018]. direct heir of the former academia and its heritage, the fbaul encompasses collections which are mostly related to teaching models and academic exercises; an historical archive, books, and legacies of the portuguese sculptor lagoa henriques (1923-2009), and the architect miguel ventura terra (1866-1919) [pereira, 2011]. the work for this article has benefited from the support of a phd grant from the fundação para a ciência e tecnologia. the author is a researcher affiliated to the universidade de lisboa, faculdade de belas-artes, centro de investigação e de estudos em belas-artes (cieba) | cidehus/ué. author's address: alberto faria, faculty of fine arts, university of lisbon, largo da academia nacional de belas-artes, 1249058, lisbon, portugal; email: albfaria@gmail.com © [2019] by the author; licensee studies in digital heritage, iu, bloomington (in), usa. this article is an open access article distributed under the terms and conditions of the creative commons attribution license (cc by-nc). https://doi.org/10.14434/sdh.v3i2.27720 between light and shade 3:123 studies in digital heritage, vol. 3, no. 2, publication date: december 2019 although there have been efforts to study and disclose it well as underline its relationship with the method of learning drawing at the former academia; the collection of old lithography of fbaul is only partially known [arruda 2012, 2016]. the collection comprises over five hundred lithographs, dated between 1840 and 1911. the lithographs display the drawings of the italian old masters like raffaello sanzio (1483-1520) and pompeo batoni (1708 1787), by artists, such as vincenzo camuccini (1771-1844); drawing courses of professors of the academia, like joaquim rafael (1783-1864), and french artists: auguste allongé (1833-1898), charles bargue (1826/27–1883), jean-léon gérôme (1824-1904), jules carot (1877-?) and josephine ducollet (1846-1876; active). these lithographs played a major role in the apprenticeship of drawing at the former academia/escola de belas-artes de lisboa, which followed the example of its european counterparts [arruda, 2012, 2016]. 2. website: fbaul | virtual print room in europe there are institutions that have their print rooms online: the herzog august bibliothek (germany); the college of optometrists (england); victoria & albert (england), ashmolean museum of art and archeology of the university of oxford (england). the initiative to present part of the collections of the fbaul online started with the virtual museum of fbaul in 2011, an idea outlined in the scope of my master’s thesis [faria 2009]. this museum set online the complete inventory of the fbaul old drawing collection [arruda & faria 2011; faria 2016]. in 2014 an expanded version was outlined and later developed which is currently online and includes besides the collection of old drawing of fbaul, the collection of etching and a virtual tour to the building of the fbaul [cardeira 2014, 2015]. the fbaul virtual print room is a bilingual (portuguese/english) website (still under construction) that presents the collection of old lithography. its main aim is to allow users to have access online to the inventory and study of the collection. the website is divided into three main sections: 1) catalogue; 2) study room; 3) mapping (figure 1). figure 1. homepage of fbaul virtual print room. 3:124 a. faria studies in digital heritage, vol. 3, no. 2, publication date: december 2019 catalogue the catalogue tab refers to the section where the database of the collection is presented. this database is a search engine with fixed criteria, which allows the users to find works that exist in the collection. the search can be performed using one of the following fields: inventory number/ author/artist, drawing, lithographer or subject after the search is validated, the results convey information of the lithograph(s) regarding the identification of the inventory number, author/artist of the drawing or lithograph, subject, title, dimensions, date, and a brief description of the work. all records presented give access to the inventory record in pdf format (figs. 2 and 3). figure 2. catalogue page. figure 3. catalogue page. view of the search result. between light and shade 3:125 studies in digital heritage, vol. 3, no. 2, publication date: december 2019 study room study room is a section of the fbaul virtual print room, where the lithographs are analyzed following a comparative approach comparative study. the users have access to a selective group of lithographs, organized according to the subject or artist. the lithographs are compared with examples taken out from art treatises, or originals that served as working references, but also drawings done after the lithographs, namely from the collection of old drawings of the fbaul. this last approach identifies the relation between the lithographs and the study of drawing, mainly with collection of old drawing of the fbaul [arruda 2010; faria 2008, 2011]. all comparative studies are accompanied with a brief explanatory text and hyperlinks to selective bibliographical references (fig. 4). figure 4. view of the study room page. mapping this section considers a geolocation approach, using google maps to view the whereabouts of lithographs from the collection in archives of institutions in portugal and other parts of the world. the view identifies the work, location, archive and url’s (if applicable) in a pop-up window. (fig. 5). 3. conclusions the fbaul virtual print room is a specific website that presents online, the study and research of the collection of old lithography of fbaul. this project intends to heighten the collection of lithography on the map of university art collections and by this way relaunch its museological identity as part of the artistic heritage of the fbaul. my aim is to contribute to support the understanding of portuguese academic drawing, regarding the methods and models which were 3:126 a. faria studies in digital heritage, vol. 3, no. 2, publication date: december 2019 followed in the nineteenth century and the first decade of the twentieth century and finally, bring this collection to light. figure 5. view of mapping page. 4. acknowledgements the author gratefully acknowledges the web developer, joão santos. 5. references alves, alice nogueira, arruda, luísa, fragoso, diana. 2018. o convento de são francisco da cidade de lisboa – uma casa de coleções. dinâmicas do património artístico. circulação, transformações e diálogos: 215-223. lisboa: artis, instituto de história da arte da faculdade de letras da universidade de lisboa. arruda, luísa, coord.; faria, alberto. 2010. desenho antigo: na colecção da faculdade de belas-artes da universidade de lisboa, lisboa: faculdade de belas artes da universidade de lisboa. arruda, luísa & faria, alberto. 2011. museu virtual da fbaul. retrieved on december 23, 2019 from http://hdl.handle.net/10451/4280 arruda, luísa. 2012. imagens do corpo na academia de belas-artes: método de aprender o desenho. in tavares, cristina azevedo (org.), representações do corpo na ciência e na arte: lisboa: fim de século, 139-151. calado, margarida 2000. o convento de s. francisco da cidade. subsídios para uma monografia. between light and shade 3:127 studies in digital heritage, vol. 3, no. 2, publication date: december 2019 biblioteca d’artes, lisboa: faculdade de belas artes de lisboa/ universidade de lisboa. calado, margarida. 2018. o convento de s. francisco da cidade= s. francisco da cidade convent. faculdade de belas artes da universidade de lisboa, lisboa. cardeira, ana mafalda. 2014. museu virtual fbaul: work in progress para a coleção de pintura. in semedo, alice, nascimento, elisa noronha, centeno, rui (coord), atas do seminário internacional «o futuro dos museus universitários em perspetiva»: 101-106. porto: universidade do porto. cardeira, ana mafalda. 2016. new virtual museum of the faculty of fine arts of lisbon: collections and virtual tour. in connecting collections. xvii universeum network meeting. amesterdam. faria, alberto cláudio rodrigues. 2009. a colecção de desenho antigo da faculdade de belas-artes de lisboa 1830-1935: tradição, formação e gosto. 4 v. lisboa: [s.n], universidade de lisboa, faculdade de belas-artes. faria, alberto 2011. a colecção de desenho antigo da faculdade belasartes de lisboa 1830-1935: tradição, formação e gosto. lisboa: fim de século. faria, alberto. 2016. the virtual museum of faculty of fine arts, university of lisbon. in wolfschmidt g. ed. enhancing university heritage-based research: hamburg: tradition gmbh, 223-227. pereira, fernando antónio baptista. 2011. o património artístico da faculdade de belas-artes: o edifício e as suas memórias, as colecções, o arquivo, os legados, um projeto de museu. in lourenço, marta, neto, maria joão. coord. património da universidade de lisboa: ciência e arte, lisboa: tinta-da-china, 157-172. received july 2019; revised november 2019; accepted december 2019 microsoft word intro_specialissue_revbf.docx studies in digital heritage, vol. 2, no. 1, publication date: september 2018 perceiving cultural heritage massimo bergamasco, scuola superiore sant'anna, pisa, italy perla gianni falvo, art perception, florence, italy giovanni valeri manera, art perception, florence, italy over the years, we have undertaken research projects in the field of cultural heritage perception, trying to analyze the response of the human cognitive system when immersed in virtual reality, augmented reality or other multimedia supports. our goal has been to study how to improve design exhibition, utilizing these technologies in museums and cultural heritage sites and to study alternative ways to promote human development through a deeper contact with art. key words: aesthetic perception, neurosciences, transmission of cultural heritage. sdh reference: massimo bergamasco, perla gianni falvo, giovanni valeri manera. 2018. perceiving cultural heritage. sdh, 2, 1, ii-v. doi: 10.14434/sdh.v2i1.27979 perceiving cultural heritage means coming into contact with a special condensate that represents the human being himself, his relationship with his own identity and the outside world. “man, in fact, is the only animal that leaves testimonies behind him, since he is the only one whose artefacts bring to mind an idea different from that of their material existence” [panofsky 1955]. the traces of this human capacity, which shows the need to outsource one's identity and to extend one's presence in space and time, are further away from us than we imagine: between 430,000 and 540,000 years ago, when a homo erectus at trinil in java used shells for tool production and engraving [joordens et al. 2014]. “the term humanitas has had two very distinct meanings. the first results from the comparison between man and what is less than man; the second from the comparison with man and what is more than man. in the first case, with humanitas we mean a quality, in the second a limit.” thus, wrote erwin panofsky, expressing thereby the basis of humanism and the renaissance. the renaissance admirably condenses its vision of man in the world with the invention of perspective representation that canonizes the point of view of a human observer. the image of the human being and its centrality, promulgated through the various multimedia means of communication of the time – painting, sculpture, architecture, the scenography of great events and sacred representations designed by artists of the caliber of michelangelo and brunelleschi [olschki 2001], as well as philosophy and the nascent scientific revolution– led to the cultural awakening of the renaissance, which is at the root of contemporary western culture. ergonomics derives from the same impulse authors’ addresses: massimo bergamasco, perceptual robotics laboratory (percro), sant'anna school of advanced studies, via g. moruzzi 1, 56124, pisa, italy; email: massimo.bergamasco@santannapisa.it; perla gianni falvo and giovanni valeri manera, art perception international, via orcagna, 53, 50121 florence, italy; emails: perla@artperception.org; giovanni@artperception.org. © [2018] by the authors; licensee studies in digital heritage, iu, bloomington (in), usa. this article is an open access article distributed under the terms and conditions of the creative commons attribution license (cc by-nc). http://dx.doi.org/10.14434/sdh.v2i1.27979 perceiving cultural heritage 1:iii studies in digital heritage, vol. 2, no. 1, publication date: september 2018 that gave birth to perspective: it takes its point of departure from the assumption that things must be dimensioned in conformity with the characteristics of the human body, and that they are at the service of the body’s extension. the topics related to the users experience (ux) further deepen and specialize this vision with the support of cognitive neuroscience that “allows us to formulate a new model of perception in which action, perception and cognition are closely integrated, and in which multimodal integration, modelled on the bodily experience we make of the world, shapes how our brain through the body maps our being in the world” [gallese and guerra 2015]. a) b) figure 1. art perception: a) lucio fontana's cuts on canvas. in studying the neurophysiological effects these works of art it was experimentally verified the activation of the motor areas assigned to the cutting activity; b) benozzo gozzoli chapel, palazzo medici riccardi, florence (italy). detail of the fresco. art condenses human activity in a coherent and meaningful form, surprising us, adding elements to our sense of humanity, in both the way we perceive ourselves internally and relative to the external world [gardner 1993]. art represents man and his actions in a living form, able to relate to other human beings overcoming space-time barriers [cassirer 1923; cassirer 1925; cassirer 1929], suggesting resonances with individual experience and reflections on human existence. it offers the aesthetic expression of the meaning of life, the bearer of emotions and messages that take the form of a language. “every man is capable of feeling all human feelings, while not every man knows how to express them all,” wrote leo tolstoy in “what is art?” this insight foreshadowed what cognitive sciences show us more clearly today [tolstoy 1904]. the recent discovery of mirror neurons sheds new light on the phenomenon of the relation between the subject and the object [gallese et al. 2002; freedberg and gallese, 2007]. mirror neurons confirm in an experimental way the presence of automatic cognitive abilities that all human beings share. other studies have also shown that cultural transmission concerns a learning phenomenon that includes sensorimotor channels (which are prelinguistic) [gallese 2009], symbolic and conceptual 1:iv m. bergamasco et al. studies in digital heritage, vol. 2, no. 1, publication date: september 2018 channels [antinucci 2011]. this scientific research should guide museum exhibition designers to set perceptual events in space bearing in mind what factors “are relevant to someone going to an art exhibit ... making people more focused, better able to concentrate and ignore distractions, which you must do if you are going to stand in front of a painting and have a rapport with what that painting is telling you about the world” [gianni falvo et al. 2018]. the identity formation of a person, community, or nation has a foundation in its cultural production and is strengthened by the relationship with the contents of the cultural heritage productions. in this context, carlo ludovico ragghianti wrote: “therefore the results of a good and adequate reading of poetry, or painting, far from transporting or confining us in a gratuitous aestheticism, can therefore be, as far as education is concerned, and therefore the individual liberation, much more fruitful and profound than a book, for example, of sociology!” in his latest essay he added that “it is necessary to widen the space for art. it is necessary to increase the circulation of the values and problems of art, which are essential factors of civilization. it is necessary to make possible a broad and continuous participation of the public, of society” [ragghianti 1965]. it follows that the way in which the experience of cultural heritage is designed is crucial for the creation of a context in which everyone can elaborate their meaning, connect it to their personal history and establish a relationship with the work of art. to study the exciting phenomenon of aesthetic perception in its complexity requires the simultaneous input of the sciences of nature and of culture. once again, we would like to thank the publishers and all those who in various ways have contributed to this special issue dedicated to aesthetic perception and to the emergence of reference elements for museum design. we hope that the vision offered by these interventions will promote the progressive definition of a shared research protocol on the effects of aesthetic perception. acknowledgment we thank the editors-in-chief for giving us the opportunity to publish this special issue as well as all the authors who agreed to contribute to it. references antinucci f. 2011. parola e immagine, storia di due tecnologie, editori laterza, bari, italy. arnheim, rudolf. 2004. art and visual perception, a psychology of the creative eye. university of california press, oakland (ca), usa. cassirer, ernst. 1923. philosophie der symbolischen formen. erster teil: die sprache. berlin: bruno cassirer. translated as the philosophy of symbolic forms. volume one: language. new haven: yale university press, 1955. cassirer, ernst. 1925. philosophie der symbolischen formen. zweiter teil: das mythische denken. berlin: bruno cassirer. translated as the philosophy of symbolic forms. volume two: mythical thought. new haven: yale university press, 1955. cassirer, ernst. 1929. philosophie der symbolischen formen. dritter teil: phänomenologie der erkenntnis. berlin: bruno cassirer. translated as the philosophy of symbolic forms. volume perceiving cultural heritage 1:v studies in digital heritage, vol. 2, no. 1, publication date: september 2018 three: the phenomenology of knowledge. new haven: yale university press, 1957. freedberg d. and gallese v. 2007. motion, emotion and empathy in esthetic experience. trends in cognitive sciences, 11, 197-203. gallese v. 2009. neuroscienze e fenomenologia in enciclopedia treccani terzo millennio, institute of the italian encyclopedia, rome, italy. gallese v. and guerra m. 2015. lo schermo empatico. cinema e neuroscienze. p.218. raffaello cortina. milano, italy. gallese, v., fadiga, l., fogassi, l., and rizzolatti, g. 2002. action representation and the inferior parietal lobule. in prinz, w., and hommel, b. (eds.) common mechanisms in perception and action: attention and performance, vol. xix. oxford: oxford university press, 247-266. garbero zorzi e. and sperenzi m. 2001. teatro e spettacolo nella firenze dei medici. olschki, florence, italy. gianni falvo p, valeri manera g and zoss j. 2018. conversation with daniel goleman about the relationship between the person viewing art and the art itself. studies in digital heritage, 2(1), xxv. https://doi.org/10.14434/sdh.v2i1.26872 howard, gardner. 1993. multiple intelligences: the theory in practice, basic books, isbn 9780465018222. joordens, j.c.a., d’errico, f., wesselingh, f.p., munro, s., de vos, j., wallinga, j., ankjærgaard, c., reimann, t., wijbrans, j.r., kuiper, k.f., mücher, h.j., coqueugniot, h., prié, v., joosten, i., van os, b., schulp, a.s., panuel, m., van der haas, v., lustenhouwer, w., reijmer, j.j.g., roebroeks. w. 2014. homo erectus at trinil on java used shells for tool production and engraving. nature. 518, 228-231. panofsky e. 1955. meaning in the visual arts. the university of chicago press, chicago (il), usa. ragghianti c.l. 1961. divulgazione, sele arte, 54, p. 45. tolstoj, lev. 1904. che cosa è l'arte? traslation from russian to italian authorized by the author. fratelli treves editori, milan, italy. accepted: september 2018. microsoft word 24590_gg_v3.docx studies in digital heritage, vol. 2, no. 1, publication date: september 2018 the problem with printing palmyra: exploring the ethics of using 3d printing technology to reconstruct heritage roshni khunti, university of cambridge, united kingdom the use of 3d printing technology to reconstruct the arch of triumph in palmyra has opened a pandora’s box of ethical issues relating to the use of digital technology to preserve heritage represented by historical objects and sites. the author investigates the ethical implications of the three replicas of the arch made by ida in new york, london, and dubai after the original was destroyed in the syrian civil war. the ethics of digital reconstructions of heritage are not yet coded by unesco or icomos, but it is important to hold reconstructed heritage to the same ethical expectations as other types of heritage. this paper concludes that the reconstructed arch failed to meet these expectations in four key ways. first, it does not address the human loss in palmyra and the contribution of the assad regime to its destruction. second, despite an ostensible commitment to reproduction, the reconstructed arch is inaccurate in material and scale. third, the arch is patented by the ida and has had limited public and digital access. finally, the reconstruction promotes a potentially irresponsible culture of quickly reconstructing destroyed heritage without respect for the context or current needs of the respective people. through delving into pandora’s box, this article aims to highlight ethical issues specific to digital reconstructions of heritage that need to be addressed in formal codes of ethics concerning the preservation of heritage represented by historical objects and sites. key words: digital reconstruction, photogrammetry, 3d printing, palmyra. sdh reference: roshni khunti. 2018. the problem with printing palmyra: exploring the ethics of using 3d printing technology to reconstruct heritage. sdh, 2, 1, 1-12. doi: 10.14434/sdh.v2i1.24590 1. introduction after the islamic state of iraq and syria (isis) seized control of palmyra in 2015, the terrorist group destroyed the roman-era ruins of the ancient syrian city. amongst the casualties was the arch of triumph, which was built during the third century to commemorate the victory of the roman empire over the parthians. in response to the destruction and loss of palmyra’s historic ruins, the institute of digital archaeology (ida) used 3d printing technology to create a physical reconstruction of the arch. roger michel, the executive director of the ida, stated that “[t]he ida is undertaking reconstructions of the lost monuments of the middle east out of respect for the history and heritage author's address: roshni khunti, department of archaeology, downing street, cambridge, cb2 3dz, uk; email: roshnikhunti@gmail.com © [2018] by the author; licensee studies in digital heritage, iu, bloomington (in), usa. this article is an open access article distributed under the terms and conditions of the creative commons attribution license (cc by-nc). http://dx.doi.org/10.14434/sdh.v2i1.24590 2:2 r. khunti studies in digital heritage, vol. 2, no. 1, publication date: september 2018 these objects represent” [the institute for digital archaeology 2016]. original artifacts in museums and heritage sites are similarly preserved for, and presented to, the public because of the history and heritage that they represent. accordingly, the reconstructed arch created using 3d printing technology should obey the basic ethical principles applied to preservation and presentation of original artifacts and heritage sites. these ethical principles include honest accounts of the history, ownership(s) and rights to heritage; ensuring an authentic presentation and experience of the heritage; and guaranteeing that the public has accessibility to the heritage as well as maintaining the ethical standards within the heritage sector. despite the rapid development and use of digital technology in the heritage sector, heritage organizations such as unesco and icomos have not drafted formal codes of ethics relating to digitally generated reconstructions of historical objects and sites. consequently, the staff of the ida was neither advised nor obliged to comply with basic ethical responsibilities when they reconstructed palmyra’s arch of triumph. nevertheless, the ida provoked controversy for failing to address these ethical issues in their reconstruction of the arch. the arch of triumph was the first large-scale monument recreated using 3d printing technology, and it is therefore illustrative of a need to set ethical standards for future 3d reconstructions of heritage. through exploring the ethical controversies provoked by the ida’s reconstruction of the arch of triumph, this essay aims to illustrate why the basic ethical standards applied to the display of original objects and sites should also apply to digitally generated reconstructions of heritage. 2. ethical responsibilities for organizations during their ten-month occupation of palmyra, isis simultaneously attacked the heritage and people of the city. over 400 citizens were beheaded by isis, including khaled al-asaad, the archaeologist charged with the care of ancient heritage in palmyra [agencies in beirut, 2015]. after al-asaad refused to reveal the locations of palmyra’s most value artifacts under torture, isis executed him and hung his mutilated corpse on a remaining roman column amongst the debris of the arch. in addition to prompting worldwide outrage and concern for the heritage and people of syria, photographs of alasaad’s headless body strapped to the ruins also firmly associated the loss of heritage with the loss of lives. nevertheless, the ida abstained from using their reconstruction of the arch to highlight the devastating human loss that accompanied the destruction of heritage in palmyra. the ida’s failure to recognize the human loss that occurred in palmyra contravenes the unesco declaration concerning the intentional destruction of cultural heritage drafted in 2003. the declaration stipulates that “[s]tates [must] recognize the need to respect international rules related to the criminalization of gross violations of human rights… in particular, when intentional destruction of cultural heritage is linked to those violations” [unesco, 2003]. while publicizing and unveiling the reconstructed arches in london, new york and dubai, both the ida and representatives of these nations refrained from explicitly referring to the devastating human plight in syria. roger michel, the executive director of the ida, stated that by reconstructing the arch “we [the ida] are restoring dignity to people” [gayle 2015]. boris johnson, the mayor of london, proclaimed that the arch was reconstructed “in solidarity with the people of syria...in defiance of the barbarians who destroyed the original” [brown 2016]. alicia glen, the deputy mayor of new york, the problem with printing palmyra 2:3 studies in digital heritage, vol. 2, no. 1, publication date: september 2018 echoed johnson’s speech when stating that the exhibition of the arch in city hall park was “first and foremost, an act of solidarity with the people of syria” [voon 2016]. the executive director of the ida, as well as the mayors of london and new york, presented the reconstructed arch as a response to the suffering in syria, which detracts from the fact that none of them actually pledged to actively improve the lives of the people in conflict. the three countries in which arches were reconstructed were countries that accepted a minimal number of refugees. these countries presented reconstructed arches as a token response to the palmyra offensive, which in turn prevented an escalation of public pressure to increase refugee intake. the human loss that was incurred in the invasion of palmyra was further downplayed by the celebration of the technological advances and creative talents that enabled the ida to reconstruct the arch. during the unveiling of the arch in london, johnson stated that the reconstruction represented “technology and determination.” similarly, the deputy mayor of new york said “[w]e’re here today to celebrate hope, to celebrate how technology gives us hope for the future” [voon 2016]. michel said that the exhibition of the reconstructed arch was “proof of our competency to do these things” [richardson 2016]. the celebration of technology was also at the heart of the exhibition of the arch in new york. claire voon, a journalist in new york, remarked that “ [w]hat the park display did make clear was that the occasion presents an opportunity to show off technology. the only on-site supplement to the arch was [a] mobile, augmented reality experience” [voon 2016]. when voon enquired if the app included information about the arch, the developer said “no — people could just easily google palmyra’s history or read about it on its wikipedia page” [voon 2016]. although technology can provide an engaging means of communicating the syrian crisis, the technology presented during the exhibition was more of a display of the accomplishments and talents of british and american organizations than a real effort to aid syrians. furthermore, the ida received criticism for not confronting or acknowledging the actions of the assad regime that also inflicted harm on people and heritage of palmyra. under the control of assad’s forces, palmyra was the home of the one of the regime’s most brutal prisons for political dissenters [taylor 2016]. assad also ordered several strikes with russian assistance over palmyra during isis’s occupation, which inflicted damage on the ancient ruins in the city [taylor 2016]. the ida framed isis as the sole threat to syrian people and heritage, and in doing so they neglected the brutality of the assad regime, which one resident of palmyra described as “no better than isis” [alkhateb and broomfield 2016]. in this way, the ida has stood accused of condoning and even supporting the action of the assad regime. the head of the council for arab-british understanding stated that “assad did not need a pr company as the arch was unveiled, because it appeared to many to be another example of the refashioning of the “not so bad” and “not as evil as isis’ syrian regime” [willits 2017]. a month before the reconstructed arch was unveiled in london, the assad regime had recaptured palmyra from isis. the reconstruction of the arch creates a censored narrative of recent history, in which isis is the sole culprit in the destruction of palmyra’s heritage. this censored narrative is not only unethical for not honestly condemning all groups involved in the destruction of palmyra’s heritage, but also enables the assad regime to reinforce their oppressive regime in palmyra without international intervention. many articles criticizing the ida’s reconstructed arch have argued that the syrian people themselves should have made the decision of when and how to reconstruct the arch. karima bennoune, the un 2:4 r. khunti studies in digital heritage, vol. 2, no. 1, publication date: september 2018 special rapporteur on cultural rights, presented a report to the un general assembly stating that organizations should be “consulting the people who have particular connections with heritage when seeking to determine whether they wish to rebuild or reconstruct such heritage, and if so, how and when” [bevan 2017]. journalist robert bevan summarized the conflict between the local and the international stakeholders for the ancient heritage when he stated that “while palmyra may hold great significance to the world, the final decision should belong to those who have lived alongside it… the syrian people” [bevan 2016]. reports of the reconstruction of the arch feature the support from maamoun abdulkarim, the director general of antiquities and museums in syria, who is quoted as calling isis “barbarians” [black 2015]. the articles featuring abdulkarim’s support for the arch portray him as a spokesperson for the syrian people, despite his position as an employee of the assad government. without reflecting on the barbarity of the regime that he serves, abdulkarim demonizes isis as the sole destroyer of palmyra. abdulkarim’s employment compromises his capacity to serve or represent the interests of the syrian people; therefore, the ida appears not to have sufficiently consulted the syrian people before reconstructing their heritage. 3. authenticity nicholas stanley-price, the director-general of the international centre for the study of the preservation and restoration of cultural property (iccrom), identified a list of arguments against reconstruction [stanley-price 2009, p. 37]. one of the most prominent arguments was “[t]he ethical issue of conveying erroneous information. inaccurate reconstructions can mislead the professional and lay public unless identified as such” [stanley-price 2009, p. 39]. the ida used photographs taken by tourists before the start of the syrian war to reconstruct the arch. unfortunately, archaeologist kay kohlmeyer explains that “[f]or anyone who is familiar with the palmyra arch, this so-called replica has nothing to do with the original…in photogrammetry there is much room for error” [garaev 2016]. the factum foundation, an organization that uses 3d scanning technology to create replicas of historical objects and art, posted an entry on their website to illustrate the inaccuracies produced through the use of photogrammetry [factum foundation 2016]. this organization used photographic comparisons of the original and the reconstructed arch to illustrate that the use of low-resolution photogrammetry to create the reconstructed arch meant that “[t]he stonework ha[d] been simplified [and] the capitals have entirely lost their sense and meaning” (figg. 1 and 2), [factum foundation 2016]. with this photographic evidence, the factum foundation refuted michel’s claim that the reconstructed arch was “completely indistinguishable from the original” as “misleading and irresponsible” [factum foundation 2016]. through refuting michel’s claim of the authentic likeness of the reconstructed arch, the factum foundation demonstrates an awareness and commitment to maintaining the ethical ideal of authenticity within the heritage sector. the ethical commitment statement for icomos members emphasizes authenticity as an integral principle in the conversation about and presentation of monuments and sites. this statement stipulated that “[t]he fundamental obligation of an icomos member is to advocate the conservation of monuments, sites and places so that their cultural significance is retained as reliable evidence of the past…. this requires a comprehensive, holistic, dynamic and often multidisciplinary approach to guarantee authenticity and integrity.” the problem with printing palmyra 2:5 studies in digital heritage, vol. 2, no. 1, publication date: september 2018 figure 1: the top of the replica of the arch of triumph, london (photograph from the official website of the factum foundation, 2015) <http://www.factumfoundation.org/pag/236/> [accessed 20 april 2017]. figure 2: image of a section of the original arch of triumph, palmyra (photograph by daniel demeter for syriaphotoguide.com and taken from the official website of the factum foundation, 2015) <http://www.factumfoundation.org/pag/236/> [accessed 20 april 2017]. 2:6 r. khunti studies in digital heritage, vol. 2, no. 1, publication date: september 2018 the first statement is that “authenticity judgements may be linked to the worth of a great variety of sources of information…[that] may include form and design, materials and substance, use and function, traditions and techniques.” nevertheless, the choice of stone contributes to the inauthenticity of the entire reconstruction. the ida used marble quarried in italy, which was criticized by archaeologist michal gawlikowski, who stated that “historic accuracy demands only original stones are used to salvage a monument” [bacchi 2016]. the yellow color of the marble visually distinguishes the reconstructed arch from the original. journalist sam kriss, who visited the reconstructed arch in london, wrote that “the marble is smooth, bright and plasticky; it looks as much like a roman ruin as the disneyland castle looks like an actual medieval fortress” [kriss 2016]. if the cultural significance of the original arch is to be maintained and conserved in the reconstructed arch, the ida should have aimed to recreate the authenticity and integrity of the original arch in their reconstruction. in addition to the color of the arch, the small scale of the reconstruction also contributed to the “disneyfication” of syrian heritage that kriss insinuated in his description of the arch. the term “disneyfication” refers in this case to heritage being presented as a theme park attraction. cunliffe explains that “3d printing fails to capture the authenticity of the original structures, amounting to little more than the disneyfication of heritage” [cunliffe 2016]. the reconstructed arch is two-thirds the size of the original arch, which contributed to many historical inaccuracies in the reconstruction. the size and color fail to provide the public with the authentic experience of the monumentality and unique appearance that led the original arch of triumph to be given the status as a world heritage site by unesco. through failing to provide onlookers with an authentic experience of the culturally significant architecture, the reconstruction is less likely to provoke a serious mediation of the loss of syrian heritage. another important dimension for ensuring the authenticity of digital heritage is context. the exhibition of the reconstructed arch is decontextualized by the absence of written explanations accompanying the display. without written notices to communicate the significance of the reconstructed arch as an “act of solidary” and “defiance”, some of the public have misappropriated the reconstruction as a novelty attraction. voon remarks that during the exhibition of the arch in new york “[s]elfies were quick to occur, but many people remained baffled about why exactly a copy of an 1,800-year-old arch from western asia was standing in downtown manhattan” [voon 2016]. the arch was also used as a background for a beauty pageant, which prompted one iraqi twitter-user to write: “[a]ngered to see ‘miss america’ model under replica of arch of palmyra… reduces significance of loss in syria” [al-oraibi 2016). the decontextualization of the arch thus reduces the impression of the arch being an authentic symbol of solidarity or defiance, which renders the reconstruction to be less effective as a means of raising awareness of the loss of syrian heritage. 4. accessibility neumüller et al. [2014, p. 119] argued that 3d printing provided “multi-sensorial forms of experiencing culture [that] have a great benefit for the accessibility of cultural heritage, especially for persons with learning difficulties, for children, the elderly, for blind or visually impaired visitors.” however, the exhibition did not allow the public to walk between, touch, or engage with the arch in a “multithe problem with printing palmyra 2:7 studies in digital heritage, vol. 2, no. 1, publication date: september 2018 sensorial experience.” social anthropologist michal murawski described the arch as “flanked by burly, square-jawed security men with earpieces” in london, and the monument was no more accessible in new york [murawski 2016]. voon observed in new york “an invited group of two dozen guests in suits who watched from their reserved seating [and] received a better view of the arch than any members of the general public” [voon 2016]. consequently, the reconstructed arch defied the ethical responsibility to provide a widely accessible experience of heritage for the public. while the reconstructed arch was not accessible for most syrian people because of the locations where it was exhibited, the language used to describe the arch further distanced syrian claims to their own heritage. when asked why the reconstructed arch would be displayed in london, michel replied “our past is their past” [richardson 2016]. the deputy mayor of new york described the reconstructed arch as “an expression of our shared history” [bond 2016]. likewise, the minister of cabinet affairs of the uae stated that the arch presents a way in which “aspects of shared human history” can be presevered [al gergawi 2017]. despite these statements declaring common humanity uniting these countries to syria, these statements appear tokenistic because of the reluctance to share their countries with syrian refugees. the uae had over 250,000 syrians living in the county in 2016; however, most of these people were educated professionals who had to obtain work visas because the uae did not accept people with refugee status [mcfarlane 2016]. international and public pressure compelled the uk government to house 20,000 syrian refugees by 2020 [lyons 2016]. unfortunately, a report by the local government association has found that the uk will not achieve this target, because a third of local councils have refused to accept syrian refugees [lyons 2016]. the usa aimed to take in 10,000 refugees, a small number considering its size and wealth [the washington post editorial board 2016]. consequently, the claims of shared humanity and history suggest that these nations appropriate syrian culture rather than genuinely empathizing with the syrian people. digital heritage also has an ethical responsibility to increase its accessibility by being available online. bond explains that “[i]f these artifacts truly belong to the public, all 3d models and images should be openly accessible and downloadable for replication” [bond 2016]. through not making their arch data available online, the ida had been accused of “digital colonialism,” whereby an organization had seized a patent of a historical object or site [bond 2016]. by withholding the patent of the reconstructed arch, the ida’s act of “digital colonialism” does not allow syrian people access to their own heritage. in 2011, farida shaheed, a special reporter on cultural rights for the office of the united nations high commission for human rights, argued that access to cultural heritage was a fundamental human right [office of the united nations high commissioner for human rights 2011]. accordingly, restricting online availability of digital heritage is unethical because it denies people access to cultural heritage. 5. the ethical implications of physical 3d reconstructions the reconstruction of heritage that was targeted by terrorist organizations creates ethical issues concerning human safety. for example, it was feared that the exhibition of the reconstructed arch might provoke an act of terror. journalist damien gayle reported that alexy karenowska, the ida’s director of technology, ‘downplayed’ the security risks and stated “[a] building like the national 2:8 r. khunti studies in digital heritage, vol. 2, no. 1, publication date: september 2018 gallery or trafalgar square, these are major targets by virtue of what they are.” the ida has a similarly blasé attitude to the safety of people participating in their million image database project, which provides volunteers with 3d cameras to capture photographs of endangered heritage in order to create more physical reconstructions [the institute for digital archaeology 2017]. kohlmeyer stated that “[w]e also need to think about the fact that we are sending these people into a dangerous situation. imagine there's a monument in is territory and somebody comes with a camera – certainly he will be killed” [garaev 2016]. while stressing the need to protect heritage, the acts of the ida could potentially endanger lives. the reconstruction of the arch has prompted an ethos for quickly reconstructing destroyed heritage, which creates ethical issues concerning political agendas. michel reportedly offered “the syrians two printers, that he claims can operate at a speed that “should enable us to rebuild what has been destroyed inside six months” [jenkins 2016]. unesco had initiated plans to reconstruct the ruins of palmyra with russian financial support; however, these plans were abandoned due to pressure from a petition by the avaaz organization against the hasty reconstruction. the online petition protested against “the protection and future of syrian heritage [being] discussed with and decided by russian president vladimir putin, an active player in this gruesome conflict and a perpetrator of human and cultural rights violations” [avaaz 2017]. although the ida’s involvement with the reconstruction of palmyra would not involve the russian government, the ida did not acknowledge russia’s contribution to the destruction of palmyra. consequently, a quick reconstruction of the ruins of palmyra may cover up the atrocities committed by the russian government. some critics of the arch argued that it should have shown the damage inflicted on the ruins at the hands of isis, which would highlight the destruction of palmyra to the international community. dr. emma cunliffe, from the blue shield, a charity working to protect archaeological sites from conflict and natural disaster, stated that “[i]f we do rebuild something, we can also incorporate what has happened to that site, and how it has affected people” [clammer 2016]. cunliffe’s statement also implies the wider intrinsic ethical issue with reconstructions: whether reconstructions of heritage erase the trauma of loss and the suffering of the source community. debate concerning this issue halted any efforts to reconstruct the buddhas of bamiyan in afghanistan, which were destroyed by the taliban in 2001. the enclaves where the buddhas once stood remain empty; however, a chinese couple did use 3d laser light projection technology to temporarily project a holographic image of the buddhas into the enclaves in 2015 [russon 2015]. the semi-transparent projections effectively communicated the loss of the monuments. in this way, the ida should have considered in what ways the memory of destruction could be communicated through the reconstruction of the arch. furthermore, the reconstruction of heritage using 3d printing also contravenes guidelines issued by unesco to ensure that the reconstructions remain authentic. the charter of venice advises that “[a]ll reconstruction work should be ruled out a priori. only anastylosis, that is to say, the reassembling of existing but dismembered parts can be permitted” [icomos 1964, p. 4]. as previously mentioned, the 3d printing technology used by the ida did not produce a reconstruction that closely resembled the original. consequently, this technology would produce a reconstruction in which the 3d printed components used to reassemble the arch are clearly distinguishable. the new additions to the reconstruction may cause the structure to lose the significance it once held for the people of palmyra. philippe de montebello, the former director of the metropolitan museum of art, referred to the problem with printing palmyra 2:9 studies in digital heritage, vol. 2, no. 1, publication date: september 2018 the potential reconstruction of the bamiyan buddhas as “an egregious betrayal of authenticity [that]… will have betrayed public trust.” an inauthentic reconstruction of the arch of triumph will not only betray the syrian people but also the international stakeholders in the ancient heritage that the arch presented. within the heritage sector, there is consensus that heritage organizations have an ethical responsibility to serve the interests of and be a benefit to the public [silberman and bauer 2012, p. 493]. inaccurate reconstructions of heritage that fail to meet public expectation would ultimately defeat this key ethical responsibility. 6. conclusion 3d printing technology essentially reproduces historical objects and sites, which has challenged the conventional application of ethics to heritage. as previously discussed, established ethical principles and responsibilities concerning heritage typically refer to the perseveration and presentation of original objects and sites. the absence of explicit references to digital heritage creates a loophole for organizations producing this type of heritage, whereby they are able to disregard basic ethical considerations in their recreation of historical objects and sites. the fundamental issue with exploiting this loophole was demonstrated in the controversy surrounding the reconstructed arch of triumph. the controversy surrounding the reconstructed arch was largely centered on four key ethical issues. first, the ida failed to explicitly address the devastating human loss in palmyra and the assad regime’s contribution to the destruction of syrian heritage. second, the reconstructed arch appears inauthentic due to the material and methods used to recreate the structure. third, the three cities chose to display the reconstructed arch in a way that limits public accessibility to the reconstruction. finally, the reconstruction of the arch also encourages an ethos of quickly reconstructing destroyed heritage regardless of the current situation and needs within the concerned country. these four issues concern the value of honesty, authenticity, accessibility and long-term consideration for the heritage sector respectively, which are all values that are emphasized in existing guidance and advice regarding the ethical preservation and presentation of heritage. ultimately, the controversy surrounding the reconstruction of the arch of triumph resulted from a perceived disregard for basic ethical principles customarily applied to heritage. despite the fact that 3d printing technology produces replicas of historical objects and sites, criticism of the reconstructed arch of triumph indicates an expectation that reconstructions should abide by the same ethical principles as the original object or site. in addition, digital reconstructions also aim to preserve and present the heritage in the same manner as the original objects or sites they are based on. consequently, current ethical guidelines for heritage should be amended to include ethical standards for digital reconstructions of heritage. 7. acknowledgements the author would like to express her utmost gratitude to brandon fathy for all of his invaluable support and advice. 2:10 r. khunti studies in digital heritage, vol. 2, no. 1, publication date: september 2018 8. references agencies in beirut, 2015. 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"arch of history: what the ruins of palmyra reveal about conflicting visions of the east and the west." [online] the calvert journal. available at: http://calvertjournal.com/features/show/6145/power-and-architecture-palmyra-boris-johnson [accessed 14 apr. 2017]. neumüller, m., reichinger, a., rist, f. and kern, c. 2014. "3d printing for cultural heritage: preservation, accessibility, research and education." in m. ioannides and e. quak, eds., 3d research challenges in cultural heritage, lecture notes in computer science. [online] berlin heidelberg: springer, 119–134. available at: http://link.springer.com/chapter/10.1007/978-3-66244630-0_9 [accessed 14 apr. 2017]. office of the united nations high commissioner for human rights, 2011. access to cultural heritage as a human right. 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"the reconstruction of ruins: principles and practice.: in a. richmond and a. l. bracker, eds., conservation: principles, dilemmas and uncomfortable truths. [online] london: routledge, pp. 32–46. available at: https://www.archaeological.org/pdfs/sitepreservation/n_s-p_article_dec_2009.pdf taylor, a., 2016. "the problem with rebuilding a palmyra ruin destroyed by isis – does it simply help assad?" washington post. [online] 20 apr. available at: https://www.washingtonpost.com/news/worldviews/wp/2016/04/20/the-problem-withrebuilding-a-roman-ruin-destroyed-by-isis-does-it-simply-help-assad/ [accessed 10 apr. 2017]. the institute for digital archaeology, 2016. the triumphal arch. [online] the institute for digital archaeology. available at: http://digitalarchaeology.org.uk/the-triumphal-arch/ [accessed 27 apr. 2017]. the institute for digital archaeology, 2017. imaging projects. [online] the institute for digital archaeology. available at: http://digitalarchaeology.org.uk/projects/ [accessed 27 apr. 2017]. unesco, 2003. declaration concerning the intentional destruction of cultural heritage. [online] available at: http://portal.unesco.org/en/ev.phpurl_id=17718&url_do=do_topic&url_section=201.html [accessed 25 apr. 2017]. voon, c., 2016. "slick replica of palmyra’s triumphal arch arrives in new york, prompting questions." [online] hyperallergic. available at: https://hyperallergic.com/323978/slick-replicaof-palmyras-triumphal-arch-arrives-in-new-york-prompting-questions/ [accessed 14 apr. 2017]. willits, j., 2017. "syria’s human losses and london’s replica of palmyra’s arch." [online] alaraby. available at: https://www.alaraby.co.uk/english/comment/2016/4/22/syrias-human-losses-andlondons-replica-of-palmyras-arch [accessed 18 apr. 2017]. received february 2018; revised september 2018; accepted september 2018. introduction to the special issue on 3d methodologies in mediterranean archaeology studies in digital heritage, vol. 4, no. 2, publication date: december 2020 introduction to the special issue on 3d methodologies in mediterranean archaeology matthew f. notarian, hiram college, oh, usa this issue brings together several papers originally presented at the 2019 annual meeting of the archaeological institute of america in a panel entitled, “three-dimensional archaeology comes of age.” this collection takes stock of a decade’s worth of groundbreaking transformation in archaeological practices with a focus on the ancient mediterranean. over this time, a subtle transition has occurred in which contentious debates over the value and practicality of 3d tools, such as photogrammetry, 3d scanning, 3d reconstruction, and virtual reality (vr), have given way to an emergent consensus that these constitute a new and important class of recording and heuristic instruments. rather than seek to cover this fundamental shift in a comprehensive matter, this issue presents a characteristic cross-section of current archaeological research based in three-dimensional computational methodologies. the content cuts across some 3000 years of mediterranean archaeology, from the aegean bronze age to the later roman empire, underlining the discipline-wide impact of this methodological revolution. it seeks to shed light on how digital tools are transforming not just the ways we record data, but the very questions archaeologists ask of this information and how this will shape methodological and analytical trends in the next decade and beyond. key words: digital archaeology, field practices, photogrammetry, 3d recording, archaeological illustration, 3d reconstruction, virtual reality. sdh reference: matthew f. notarian. 2020. introduction the special issue on 3d methodologies in mediterranean archaeology. sdh, 4, 2, 75-77. https://doi.org/10.14434/sdh.v4i2.32095 1. introduction this issue brings together several papers originally presented at a colloquium of the 2019 annual meeting of the archaeological institute of america in san diego, ca, entitled, “three-dimensional archaeology comes of age.” the goal of that panel was to take stock of about a decade’s worth of groundbreaking transformation in archaeological practices with a focus on the ancient mediterranean. over the course of the previous decade, a subtle transition has occurred in which contentious debates over the value and practicality of 3d tools, such as photogrammetry, 3d scanning, 3d recording, and author's address: matthew notarian, department of modern languages and classics, hiram college, p.o. box 67, hiram, oh, 44234, usa; email: mnotarian@gmail.com © [2020] by the authors; licensee studies in digital heritage, iu, bloomington (in), usa. this article is an open access article distributed under the terms and conditions of the creative commons attribution license (cc by-nc) https://doi.org/10.14434/sdh.v4i2.32095 mailto:mnotarian@gmail.com 4:76 m. notarian studies in digital heritage, vol. 4, no. 2, publication date: december 2020 virtual reality (vr), have given way to an emergent consensus that these constitute a new and important class of recording and heuristic instruments [e.g. olson and caraher 2015; averett, gordon and counts 2016; koenig et al. 2017; landeschi 2019]. furthermore, technological improvements in software and hardware continue to drive costs downwards, leading to their adoption by an almost exponentially increasing number of projects each year. similar advances in unmanned aerial vehicle (uav) technology have also made aerial photography commonplace. open-source and economically priced 3d modeling software let even non-specialists create sophisticated 3d reconstructions of ancient architecture, artifacts, and art, opening new avenues of both qualitative and quantitative data analysis. in short, 3d approaches to archaeological recording, analysis, reconstruction, and publishing have shifted from specialist niches to mainstream methodology. at the same time, experts have continued to push boundaries with groundbreaking forms of documentation and inquiry, driving innovation at a broader level. these rapid and exciting changes led roosevelt et. al [2015] to boldly revise the adage “archaeology is destruction” to “archaeology is digitization” in an already seminal article. nevertheless, archaeological epistemology is still catching up to this new three-dimensional reality, often compacting 3d data down to theoretical questions grounded in more familiar 2d thinking. the articles collected in this issue each explore how new technologies are pushing research closer to a true “3d turn” as envisioned by campana [2014]. given the scope of the digital revolution in archaeology, this selection of papers cannot possibly cover the fundamental shift in a comprehensive manner (see garstki [2020] for a recent overview). it instead represents a characteristic cross-section of current archaeological research based in threedimensional computational methodologies and adds to a growing body of research on this possible paradigm shifting moment in archaeological thought. anderson and notarian each offer reflective examinations of the impacts, benefits, and challenges of photogrammetry in recording excavation from the perspective of early and late adopters, respectively. sapirstein’s article contributes an important study to the ongoing debate over the consequences of a shift from measured hand drawing to computer-based techniques in fieldwork. finally, the contributions by clinton and fredrick and vennarucci offer early data on novel approaches to understanding human navigation of architectural spaces by analyzing crowd sourced data from 3d reconstructions inside gaming environments. the original aia session also included presentations by two authors not represented in this collection. justin leidwanger spoke about measuring and quantifying the standardization of late antique transport amphorae using photogrammetry and structured light-scanning. matthew brennan presented the use of vr as a tool for researchers to interact with archaeological stratigraphy in an immersive environment far from the field. philip sapirstein’s presentation differed from the paper published here, instead examining the challenges of disseminating resource-intensive data from a highly accurate photogrammetric survey of the heraion at olympia. as a whole, the content of this issue cuts across some 3,000 years of mediterranean archaeology, from the aegean bronze age to the later roman empire, underlining the discipline-wide impact of this methodological revolution. it seeks to shed light on how digital tools are transforming not just the ways we record data, but the very questions archaeologists ask of this information and how this will shape methodological and analytical trends in the next decade and beyond. introduction to the special issue on 3d methodologies in mediterranean archaeology 1:77 studies in digital heritage, vol. 4, no. 2, publication date: december 2020 2. acknowledgements i give my sincere thanks to the participants of the original aia colloquium and especially the authors whose contributions herein provide timely and valuable insight into this exciting moment in archaeological research. david fredrick, in particular, offered early encouragement and suggestions for conference participants. matthew brennan was instrumental in the early efforts to bring this issue to publication. 3. references erin walcek averett, jody gordon, and derek counts, eds. mobilizing the past: recent approaches to archaeological fieldwork in a digital age. grand forks: the digital press at the university of north dakota. stefano campana. 2014. 3d modeling in archaeology and cultural heritage–theory and best practice. in fabio remondino and stefano campana, eds. 3d recording and modelling in archaeology and cultural heritage. oxford: bar international series 2598, 7-12 kevin garstki. 2020. digital innovations in european archaeology. elements in the archaeology of europe. cambridge: cambridge university press. https://doi.org/10.1017/9781108881425 charles w. koenig, mark d. willis, stephen l. black. 2017. beyond the square hole: application of structure from motion photogrammetry to archaeological excavation. advances in archaeological practice 5, 1 (2017), 54–70. https://doi.org/10.1017/aap.2016.8 giacomo landeschi. 2019. rethinking gis, three-dimensionality and space perception in archaeology. world archaeology 51,1 (2019), 17-32. https://doi.org/10.1080/00438243.2018.1463171 brandon r. olson and william r. caraher eds. 2015. visions of substance: 3d imaging in mediterranean archaeology. grand forks: the digital press at the university of north dakota. christopher h. roosevelt, peter cobb, emanuel moss, brandon r. olson, and sinan ünlüsoy. 2015. excavation is destruction digitization: advances in archaeological practice. journal of field archaeology 40 (2015), 325–346. http://dx.doi.org/10.1179/2042458215y.0000000004 received june 2020; revised december 2020; accepted december 2020. https://doi.org/10.1017/9781108881425 https://doi.org/10.1017/aap.2016.8 https://doi.org/10.1080/00438243.2018.1463171 http://dx.doi.org/10.1179/2042458215y.0000000004 1. introduction 2. acknowledgements 3. references microsoft word 31442_gg3.docx studies in digital heritage, vol. 5, no. 1, publication date: june 2021 the flexibility of dense 3d data capture: rapid documentation of monumental fountains in rome martina attenni, marika griffo, carlo inglese, and alfonso ippolito, sapienza university of rome, italy eric lo and dominique rissolo, university of california, san diego, usa the knowledge and study of built heritage is now deeply connected to methodologies associated with the measure of surface details by recording point cloud coordinates. these methodologies enable researchers to gather a wider range of information, which is increasingly connected to technological advances. such approaches influence the management of data, and these data are often redundant due to the ways in which they are captured. massive or raw data capture does not include preliminary selection based on metric, geometric, and material features of the object. a multi-scalar approach, in which the criteria for data capture depends on the goals of the survey, is needed to optimize the relationship between information and the scale of the models to be built. this case study involving a selection of fountains in rome aims to apply these principles to urban contexts defined by a strong spatial connection between architectural and sculptural elements. survey can express this distinctiveness through complex, dynamic, and effective digital models. keywords: 3d data capture, integrated survey, fountains, rome. sdh reference: martina attenni et al. 2021. the flexibility of massive data capture: rapid 3d documentation and the fountains of rome. sdh 5, 1, 62-74 https://doi.org/10.14434/sdh.v5i1.31442 1. introduction the interpretation of architecture uses a deconstruction and subsequent organized reconstruction of both quantitative and qualitative information. this is possible because of the on-site “experience” of the object as well as the researcher’s related knowledge and domain expertise. this modality is related mainly to a heuristic approach that enables one to extract the meaningful characteristics of the object from the “whole indistinct.” the work for this article was carried out under project c26v17tsaf, which was funded by sapienza university of rome. authors’ addresses: martina attenni, marika griffo, carlo inglese, alfonso ippolito, department of history, representation and restoration of architecture, sapienza university of rome, piazza borghese 9, 000186, rome, italy; email: (martina.attenni, marika.griffo, carlo.inglese, alfonso.ippolito)@uniroma1.it; eric lo, dominique rissolo, qualcomm institute, university of california, san diego, 9500 gilman drive, la jolla, california, 92093-0436, usa; email: (eklo, drissolo)@ucsd.edu © 2021 by the authors; licensee studies in digital heritage, iu, bloomington (in), usa. this article is an open access article distributed under the terms and conditions of the creative commons attribution license (cc by-nc) rapid documentation of monumental fountains in rome 1:63 studies in digital heritage, vol. 5, no. 1, publication date: june 2021 in the field of architectural heritage, the concept of “whole indistinct” refers to the amount of information derived from the tools and techniques of massive data capture performed by optical imaging or 3d scanning, which is anything but a selective approach. data related to superficial qualities of the object are acquired uncritically and objectively without semantic distinction or hierarchy among the millions of points captured. even though this stage of the process seems to be completely automated due to its connection to tools and devices, one must make several choices related to how such devices should be used. this confirms the importance of the survey project, in the traditional sense, even in an era in which tools and technologies are increasingly sophisticated and automated [bianchini et al. 2017b]. on the other hand, massive data capture implies placing trust in processing operations to define concepts, theories, and thematic and semantic connections in addition to geometrical and physical features. the construction of a complete digital copy of the object results in a manifestation – temporal and physical – that is unique to virtual space. the model is therefore disconnected from the limits of our perception of the physical world and assumes an absolute value. this modalità di lettura (way of reading) is not a substitute for experiencing the object, in a physical sense, but is nonetheless empowering and rich in possibilities. the experimentation presented here intends to evaluate the relationship between the data capture stage of quantitative data production and the qualitative data extraction by emphasizing to what extent the first affects the second [bianchini et al. 2017a]. the present study has been conducted on a selection of fountains (and their urban context) in rome and is considered meaningful from a morphological, symbolic and – concerning the fountains – a decorative point of view. the research project applied structure-from-motion (sfm) / image matching (im) photogrammetric processes with the long-term objective of obtaining multi-scalar numerical models. the goal is to further develop analysis on a global level – studying the urban context of architectural and sculptural elements – and on a detailed level, by focusing on the deconstruction of the sculptural artifact into its own elementary parts [centofanti et al. 2012]. this process emphasizes the management of an increasing amount of data (attributable to the use of technology). the sheer quantity of data results in significant geometrical overlap (with respect to numeric models) and produces a redundancy of data (prompting some level of intervention). for this reason, a pre-dimensioning of the data-capture stage – according to the objectives of the study and the scale of the final model – can reduce or limit disorder in the virtual world. 2. methodology these concepts guided the study of the fountains in piazza mattei, piazza santa maria in trastevere, and the twin fountains of piazza farnese (fig. 1). the fountains are essentially analogous in function, with each one exhibiting a unique morphology and a range of sculptural or decorative details. from a formal point of view, the axis of each fountain is connected to the geometrical layout of the squares in which they are located. their urban background or context is composed of historical buildings with high architectural value. from a dimensional point of view, the perpendicular axes of the water basins vary from 11 m for the piazza farnese fountains to 5 m for the fountain of the turtles in piazza mattei (with their heights being 6 m and 2 m, respectively). finally, from a typological point of view, there are pronounced differences in the historical sequence of events with respect to the architectonic construction and the related urban space. 1:64 attenni et al. studies in digital heritage, vol. 5, no. 1, publication date: june 2021 figure 1. fountains in rome; an overview of the objects of study in the urban context. rapid documentation of monumental fountains in rome 1:65 studies in digital heritage, vol. 5, no. 1, publication date: june 2021 the sixteenth-century fountain of the turtles, which was constructed in 1581 as part of a giacomo della porta project, is the barycenter of the square. its sculptural layout is rich and elaborated and was realized by taddeo landini. in combination with the limited size of the square, it becomes, from a perceptual point of view, the focal point of an open-air “room.” the piazza santa maria in trastevere offers the wider perception of an empty urban space. it is set up on a quadrangular plan with the fountain in an eccentric or off-center position. the location of a fountain in this area is documented as early as roman times. there were several restoration interventions that changed its position and configuration, and the main interventions are celebrated in engravings located at the base of the fountain. in piazza farnese, the twin fountains are the focal points of a rectangular structure. the basins were originally located in piazza venezia and then moved to piazza farnese as a decoration. they were turned into fountains in 1626 by gerolamo rainaldi. the architect decided to not only change their function, but also their configuration by adding basins at the base and at the top of each fountain [delli 1985]. in each of the presented case studies, the architectural and sculptural elements are evocative of their era. the spatial and symbolic connection with urban façades gives them an urban role that is characteristic of the identity of rome as well (fig. 2). the process approaches the study of typologically comparable elements by identifying a procedure that can be adopted in all contexts in which basic documentation is required and the methods of data acquisition and processing are explicit and reliable. the efficacy of the documentation of the forms and sculptural elements of the fountains is tied to the potential to survey (with a high level of detail) the characteristic elements of the typology. the data acquisition, therefore, concerned all parts of the objects that were visually and physically accessible, with the aim of producing numerical models that could be easily explored and via which further contextual analyses could be conducted. figure 2. urban interpretation: single image rectification and photo stitching of façades of piazza santa maria in trastevere. this analysis has been performed to contextualize the fountain of the piazza. 1:66 attenni et al. studies in digital heritage, vol. 5, no. 1, publication date: june 2021 a primary consideration is the scale of the selected object. in the case of the fountains, the sfm process is more controllable and, to a certain extent, independent from other data capture techniques (making integration with other modalities not always essential). the opposite is true with respect to architectural and urban scales, where it is considered necessary to integrate different data capture methodologies (including survey) to achieve metric and geometric accuracies and to accommodate heterogeneous data gathered from different sources. finally, on the diametrically opposite side, is the detailed relief of objects with dimensions on the centimeter scale. in this case the acquisition strategy cannot ignore the use of pre-arranged instrumentation and photographic settings, the effectiveness of which strongly determine or condition the obtained result (fig. 3). figure 3. the scale of survey, integrated data capture. rapid documentation of monumental fountains in rome 1:67 studies in digital heritage, vol. 5, no. 1, publication date: june 2021 even though this distinction highlights differences in the documentation approach used for heterogeneous elements, the process presented here demonstrates the added benefit of using a level of computational power that does not impose practical limits on data capture. for the analysis of the artifact from an architectural and compositional point of view, the reading of the detail and of the chromatic features of surfaces plays an important role. the nature of the documentation project – defined by a strategy that fits the objectives of the research – determines the methods and tools for data capture and data processing. in this case, the process is not linked to limits imposed on the number of images (and the level of resolution) that can be acquired. this makes it possible to obtain three-dimensional numerical models, with high point density, that better enables the user to “experience” the object. these models play a fundamental role in the documentation of the object as well as the dissemination of digital data (fig. 4). the numerical model, meant as a product of a scientifically reproducible process, is well suited to sharing and implementation among researchers in all fields connected to the investigation of the object. the organization of a digital database open to users with different levels of specific knowledge about the object would allow continued systematic documentation would provide analytical tools for scientific research [apollonio et al. 2018]. figure 4. architectural interpretation: the portico of church of santa maria in trastevere. from left to right: numeric model derived from laser scanner 3d data capture, 2d ortho image extracted from structure-frommotion numeric model, and 2d geometric representation of the main construction lines from architectural reading of the portico. 1:68 attenni et al. studies in digital heritage, vol. 5, no. 1, publication date: june 2021 figure 5. fountain of the turtles, piazza mattei. rapid documentation of monumental fountains in rome 1:69 studies in digital heritage, vol. 5, no. 1, publication date: june 2021 figure 6. southeast fountain, piazza farnese. 1:70 attenni et al. studies in digital heritage, vol. 5, no. 1, publication date: june 2021 figure 7. northwest fountain, piazza farnese. rapid documentation of monumental fountains in rome 1:71 studies in digital heritage, vol. 5, no. 1, publication date: june 2021 3. workflow a consistent image acquisition strategy for sfm photogrammetry was applied to each fountain. the cameras and lens used were a sony a7riii 42.4 mp full-frame mirrorless camera with a 16-35 mm lens (shot at 16 mm) and a sony qx1 20.1 mp lens-style camera (aps-c type cmos sensor) with a 20 mm lens. the a7riii was hand-held and afforded the field technician between 0-2.0 m of vertical range. the compact qx1 was mounted on a 1.24 m telescopic prism pole that extended to 2.15 m. this allowed the qx1 to reach approximately 4 m above the piazza floor. the qx1 camera was controlled via a smartphone using the sony playmemories mobile app. attempts were made to achieve comprehensive coverage of each fountain (with approximately 6080% overlap between photographs) using a systematic convergent approach while following a circular to rising “dome-shaped” path (switching from hand-held to pole-mounted camera when appropriate). once the “dome” of images was accomplished at a consistent distance from the fountain, the technician would then shoot their way towards the fountain to increase the degree of coverage and level of detail necessary for accurate geometric reconstruction and higher point density. photo scales (1-m rods with 10 cm increments) were used, and each imaging run began and ended with a photo of a color calibration chart with 12 reference colors and 6-step grayscale (dgk color tools). a manageable number of images were acquired for each fountain. the numbers are as follows: piazza mattei: 436; santa maria in trastevere: 399; piazza farnese east: 348; piazza farnese west: 249. the quantity of images (or poses) proved more than adequate to realize the desired result, though an increased level of detail could be achieved with additional imaging (figs. 5-7). numerous challenges were encountered in each piazza. chief among them was pedestrian traffic as well as parked and moving cars, trucks, motorbikes, and bicycles. these resulted in line-of-sight occlusions and dynamic scenes (the latter being more manageable in pre-processing and processing phases). railings and fences also created line-of-sight issues as well as practical access challenges. both water and wet surfaces can also prove problematic, though in the case of the fountains, did not inhibit 3d reconstruction. given the height of the fountains, a significant limitation turned out to be the height of the pole (for the qx1 camera). a longer pole (perhaps 3-5 m in length) would have afforded the camera additional perspectives and would have resulted in greater coverage overall. the noise along the upper edges of the fountain (in the unmeshed models) is partly the result of this limited range. sunny, cloudless skies persisted during the acquisition period. ideally, the fountains would have been imaged in overcast conditions (providing diffused and even lighting). bright sunlight can result in erroneous feature-matching (as a result of hard shadow boundaries), inaccurate rgb values, and exposure challenges. without proper metering, for example, the fountains would tend to be underexposed due to the sun-lit building façades behind them. it should be noted that we can take advantage of the 15 stops of dynamic range offered by the camera’s sensor to mitigate the potential loss of detail within the underexposed regions of each composition. following the field acquisition, the images are pre-processed for image quality, and then processed through agisoft photoscan 1.4.2 to create the 3d digital surrogate. pre-processing consists of a 1:72 attenni et al. studies in digital heritage, vol. 5, no. 1, publication date: june 2021 number of steps to ensure the quality of the images to be used in the reconstruction. first, any superfluous images containing notes, beginning/end of acquisition markers are removed, along with any imagery of obviously poor quality, such as those with poor focus or exposure settings. if color accuracy is a requirement, and particularly if multiple cameras are used, a color calibration target can be used to correct the white balance to make the cameras more consistent. while it is ideal to acquire well-exposed images, field conditions do not always permit ideal lighting, and exposure correction and tone mapping can be applied to the imagery in the form of decreasing contrast, reducing highlights, and brightening shadows or darker areas. if necessary, noise reduction can also be applied before exporting the images for use in the 3d reconstruction. for each area, all images from relevant cameras were combined in the reconstruction project. the first stage of processing generates a sparse point cloud and an estimate of the location and orientation from where each image was taken. after a visual inspection of the point cloud and estimated camera positions, an appropriate bounding box is defined to maximize resolution on the area of interest. next, we generate a dense point cloud, which is our primary 3d representation of the site. finally, we define the scale of the model using multiple measurements from scale bars in the imagery. this scaled dense point cloud is then exported into viscore (a proprietary point cloud renderer and point-based visual analytics software), for analysis (https://chei.ucsd.edu/viscore/). if the sparse point cloud reconstruction does not align well, and only a minority of the cameras are misaligned, we reset their alignment and try to align again, or simply remove the cameras if they are redundant. when a significant number of the cameras are misaligned, it is likely that there is either an issue with image quality or there may be inadequate overlap to robustly cover the area. if possible, these issues should be reviewed, and new imagery acquired, but when this is not possible, there are strategies for dealing with marginally reconstructible imagery. first, reducing the resolution on the imagery can allow blurry or poorly focused imagery to align. this is facilitated by changing the sparse reconstruction quality in the photogrammetry software. another option is to reconstruct chunks which do align individually, and manually align those chunks visually. these "remediated" reconstructions should be assumed not to have the same geometric fidelity as those that reconstruct well (though they can still yield a visual result). in cases where sites of interest, such as in piazza farnese, are adjoining and may have overlapping coverage, the two sites (fountains) can be combined into one project in order to provide context and a common coordinate system. to preserve detail on each area of interest, we duplicate the project and use a bounding box for each individual area of interest, though an additional copy can be processed with a bounding box including the entire area for context. with respect to image acquisition in piazza farnese, the accurate geometric reconstruction of each of the two individual fountains was given priority over the spatial accuracy of the two fountains with respect to each other, the piazza, and the surrounding buildings. the 3d models turned out to be extraordinarily accurate, with only a 2-3 cm difference between the hand-measured physical widths of the lower basins and the corresponding measurements taken off the scaled models. in general, the fountain in piazza di santa maria in trastevere presented the fewest number of image acquisition challenges and yielded a good overall result. rapid documentation of monumental fountains in rome 1:73 studies in digital heritage, vol. 5, no. 1, publication date: june 2021 to represent the building façades associated with each piazza, 2d orthophotos were extracted from the 3d point clouds in autodesk recap, then imported into autocad to produce 2d architectural drawings (e.g., fig. 4). an additional interpretive approach involves the use of rectified photomosaics of building façades to contextualize the fountains and the elements of the piazzas (e.g., fig. 2). the original data assets (images and point clouds) as well as all derivative products (3d and 2d) can be archived and interactively viewed within viscore as a multimodal digital twin. 4. conclusion the numerical model produced with photogrammetric imaging constitutes an effective form of basic documentation. the level of detail achieved enables one to identify and characterize materials and structural elements, evidence of degradation or weathering, and the proportional relationships of the parts to the whole. indeed, the possibility of obtaining a very high level of detail allows for the evaluation of the consistency of an object. shifting different scales or “ways of reading” within the same model is a way to validate the data capture and processing methodologies concerning typologically similar objects. moreover, it permits one to evaluate and study the design and construction rules that connect the smaller scale of the fountains to the urban scale of the piazzas and the architectural façades. the numerical models are placed in continuity with the current logic of dissemination and use, constituting a fundamental element in the knowledge of architectural and urban heritage, while imposing a new definition for the relationship between the scale of the model and its informative content. in this context, further phases of the research will be related to the integration of data, metadata, and 3d models into a 3d database to enable further typological studies, to archive existing documentation, and to share contents among the research community. 5. acknowledgements research was supported by sapienza university of rome. the authors would like to thank the students, staff, and faculty of the department of history, representation and restoration of architecture, especially carlo bianchini. at the university of california, san diego, the authors thank michelle hermas, falko kuster, crystal liu, christopher mcfarland, dominique meyer, vid petrovic, and ramesh rao. 6. references fabrizio ivan apollonio, vilma basilissi, marco callieri, matteo dellepiane, marco gaiani, federico ponchio, francesca rizzo, angelo raffaele rubino, roberto scopigno, and giorgio sobra. 2018. a 3d-centered information system for the documentation of a complex restoration intervention. j. of cult. herit. 29 (2018), 89-99. carlo bianchini, michael hess, carlo inglese, and alfonso ippolito. 2017a. quality or quantity: the role of representation in archaeological architecture. in marco ceccarelli, michela cigola, and giuseppe recinto, eds. new activities for cultural heritage. proceedings of the international 1:74 attenni et al. studies in digital heritage, vol. 5, no. 1, publication date: june 2021 conference heritagebot 2017. cassino (italy) 21-22 september 2017. springer international publishing ag, 150-157. doi 10.1007/978-3-319-67026-3 carlo bianchini, carlo inglese, and alfonso ippolito. 2017b. i teatri del mediterraneo come esperienza di rilevamento integrato. the theatres of the mediterranean as integrated survey experience. rome: sapienza università editrice. mario centofanti, stefano brusaporci, and vittorio lucchese. 2012. architectural heritage and 3d models. in p. giamberardio, d. iacoviello, r. natal, and r.s tavares, eds. computational modeling of objects presented in images: fundamentals, methods and applications. switzerland: springer international publishing, 31-49. sergio delli. 1985. le fontane di roma. rome: schwarz & meyer. received september 2020; revised april 2021; accepted may 2021. studies in digital heritage, vol. 6, no. 2, publication date: december 2022 digital approaches for a public art collection between conservation and public outreach: the “mastroianni experience” laura baratin, università degli studi di urbino, italia giovanni checcucci, università degli studi di urbino, italia francesca gasparetto, università degli studi di urbino, italia digital tools for artworks can offer new opportunities and design new approaches for conservation and public outreach. this paper presents the experience carried out by the school of conservation and restoration of the university of urbino to preserve a public collection of wooden artistic models assembled by umberto mastroianni and used as a project of original bronze and steel sculptures. the digital documentation supported the maintenance protocol and helped design the restoration work. moreover, thanks to cutting-edge technologies, a virtual exhibition was created, testing an ar application that allows the public to better appreciate the results of the interventions. digital storytelling about artistic meaning connected the models to original sculptures placed in various italian landscapes, offering the public an artistic journey into urbino’s architecture. keywords: conservation, documentation, 3d models, ar, public art. sdh reference: laura baratin, giovanni checcucci, and francesca gasparetto, digital approaches for a public art collection between conservation and public outreach: the “mastroianni experience”. sdh, 6, 2, 51-70. https://doi.org/10.14434/sdh.v6i2.33914 1. introduction and cultural context umberto mastroianni was an italian abstract sculptor who died in 1998. his art started from futurism and cubism, was inspired by the plasticity of john arp and henry moore, and focused on studying and rendering dynamic values. umberto mastroianni's works can be found in over 280 of the most prestigious museums in the world. the mastroianni experience project began in 2014 as a collaboration between the municipality of urbino (pu), italy, and the school of conservation and restoration of its university. specifically, the project was developed in the context of an educational workshop about contemporary restoration techniques. during the classes, students worked to perform correct interventions on wooden artistic models that the city of urbino has owned since 1977. some of these models were showcased at the authors’ address: laura baratin, giovanni checcucci, francesca gasparetto: dipartimento di scienze pure e applicate (dispea), piazza della repubblica 13, urbino, pu, italy; email: (laura.baratin, giovanni.checcucci, francesca.gasparetto)@uniurb.it © 2022 by the authors; licensee studies in digital heritage, iu, bloomington (in), usa. this article is an open access article distributed under the terms and conditions of the creative commons attribution license (cc by -nc) https://doi.org/10.14434/sdh.v6i2.33914 2:52 l. baratin, et al. studies in digital heritage, vol. 6, no. 2, publication date: december 2022 “museo della città” (“museum of the city,” today closed), and the larger ones were stored in hangars outside the city. at that time, the purpose was to imagine a new arrangement for the collection that could bring back to light mastroianni’s legacy, linking the wooden objects to the bronze monument made by the artist for the city of urbino and placed in fortezza albornoz. the research followed a general interpretation of mastroianni objects starting from the rediscovered and restored artistic models. the main subject for the project's first phase was the study of the collection of models, focusing on different technical problems: techniques of execution, conservation conditions, and environmental parameters of the storage spaces. the educational program stressed interesting and original research topics that compared wooden models and original artworks placed in open spaces. the study began with an analysis of images and historical documents. next, the application of the 3d systems was crucial in recording precise geometries and volumes of such complex shapes. finally, a methodological proposal was carried out to classify each part and establish its location. the resulting guidelines supported the general maintenance for correct preservation, considering the relationship between the artwork and the museum environment/urban space. figure 1. umberto mastroianni, “monumento alla pace” (monument to peace), 1987, cassino. as the project progressed, it was necessary to imagine how best to promote public understanding of the restored models. moreover, the opportunity to receive european funding led us to explore the the “mastroianni experience” 2:53 studies in digital heritage, vol. 6, no. 2, publication date: december 2022 possibility of setting up a public art museum inside francesco di giorgio martini's helicoidal ramp, a walkway connecting two parts of the city. the museum could remain open to the public and develop an "artistic promenade" without interfering with the usual use of the famous ramp as a link between the piazza del mercatale and the highest part of the palazzo ducale. for this purpose, a scientific committee was organized to discuss proposed solutions to different conservation problems presented by mastroianni’s legacy and its public communication. the committee contacted many public institutions with mastroianni heritage materials. the project encountered several setbacks. for example, the dimensions of the collection did not allow for a correct balance between the artworks and the architecture. the lack of funds sometimes slowed down progress toward the project’s final goal. 2. research aim: the conservation of mastroianni’s legacy the goals of the project evolved over several phases: digital documentation of the individual elements; the restoration and assembly of the models stored in the hangar; designing handbooks for assembling the works using 3d models; the development of a work plan for placing the models in a suitable location for their conservation and public communication; the preparation of environmental assessment protocols for the new exhibition sites; the preparation of a public communication approach using ar systems. what all the various goals had in common was the use of digital data throughout the process, up to and including the design of the virtual museum. the exhibition project of the museum of the ramp involved a small number of wooden models. the remaining pieces will be included in a proposed new exhibition that adds some historical buildings – property of the university of urbino – redesigned by giancarlo de carlo during the 1970s. an innovative dialogue between modern architecture and contemporary sculpture was framed, which could increase cultural tourism. at the same time, the original solution opened and transformed important urban spaces, including the university buildings, as a structural part of the urban and social fabric. 3. the collection of wooden models: mastroianni and urbino a brief art-historical overview umberto mastroianni (1910-1998) is considered a prestigious and brilliant artist, among the most significant of contemporary italian sculptors. he was born in fontana di liri, near frosinone, italy. at the age of fourteen, he moved to rome, where he attended his uncle domenico's studio and drawing courses at the san marcello academy. two years later, having arrived in turin with his family, he honed his sculpting skills in michele guerrisi's studio. called up for military service during the war, he took part in the resistance with a commitment to issues such as freedom that were later reflected in his artistic work. he received praise from national critics after his brilliant debut as a young figurative artist. his sculptures moved through an informal phase and finally to a mature plastic expression toward the end of the 1960s. 2:54 l. baratin, et al. studies in digital heritage, vol. 6, no. 2, publication date: december 2022 referring to mastroianni's post-war sculptural work, giulio carlo argan wrote of a “poetics of resistance” that increasingly took on the monumental value of a cultural rebirth [argan 1971; argan, 1980]. his eclecticism led him to experiment with a wide variety of techniques on different materials, but he is known as the author of monuments to the resistance scattered throughout italy, including the “monumento alla resistenza italiana in cuneo” (monument to the italian resistance in cuneo, 1969), which he himself acknowledged to be his masterpiece; the “monumento alla pace in montecassino” (monument to peace in montecassino, 1971-1977, fig. 1); and the “monumento alla lotta partigiana” (monument to the partisan struggle, 1975-1980), located in cuneo’s resistance park. in 1951, his first solo exhibition was organized at the galerie de france in paris, one of the most important galleries in europe at that time. in the following decades, the artist’s work evolved to plasticism, addressing a total geometric, chaotic, and angular spatiality [barbero 2005]. the mastroianni foundation was established in the early 1990s in arpino (fr), italy. the situation in urbino was different. here, the museum of wooden sketches was planned: a collection of fifteen monumental wooden works preceding bronze or steel casting donated by mastroianni to the city in 1977. this came after an exhibition of "chromatic reliefs," drawings, wooden sketches, and engravings curated by floriano de santi, highlighting a creative expression seldom investigated by scholars [de santi 2002]. mastroianni died in his house museum in marino in 1998. in october 1998, another exhibition of seventy-one unpublished works on paper was held in the palazzo ducale in urbino. it displayed the multiplicity and complexity of this famous artist’s rich artistic production [de santi 1998]. the artistic value of mastroianni's wooden models the city of urbino preserves a substantial number of umberto mastroianni’s wooden models and one original artwork, the “monumento alla resistenza” (monument to the resistance.), located in the garden of fortezza albornoz. fifteen models were offered by mastroianni to the city, but in the absence of suitable spaces for their display, the wooden objects were the subject of a troubled and complex story. in 1998, the municipality, in cooperation with the provincial government, launched a recovery project to enhance mastroianni’s heritage. each model was thoroughly studied to perform the intervention, and fifteen artworks were assembled. the important result was an exhibition named "fucina mastroianni," set up in 2002 in a large space outside the city. this temporary museum was dismantled in 2007. some models were moved to a new museum, the museum of the city, which had been re-opened for the occasion. noting the current artifact conditions, the temperature and relative humidity were monitored to maintain the correct conditions in the new exhibition space. the rest of the pieces, constituting the biggest models, was disassembled and stored in a warehouse to await a new arrangement. the “mastroianni experience” 2:55 studies in digital heritage, vol. 6, no. 2, publication date: december 2022 a) b) figure 2. examples of umberto mastroianni’s sculptures: a) “oeil intèrieur” (interior eye), 1970, size: 182 x 155 x 58 cm; b) “ritmi plurimi n.2” (multiple rhythms n. 2), 1976, size 175 x 216 x 90 cm. the collection is an example of public art, a distinctive product of an art-historical period, and an emblem of a harmonious relationship between the artist and the city that held his last important exhibition (fig. 2). the models, and the design sketches, represent a guide for the artist and his collaborators to create larger steel artworks. “[…] almost all the medium-size and large woods worked by the artist are models for foundry forming, or for the preliminary verification of the assembly of steel elements, or even for measurements of the ‘lifting’ in the marble technique." (de santi, 1998) the models have their own artistic autonomy. in fact, they present various structural modifications and some aesthetic changes with respect to the final full-size metal sculptures, which were executed with modifications as independent artworks. a factor of the wooden sketches’ autonomy is reinforced by the large number of exhibitions in which they have participated, not for their function as "purely interim elaborations" but for the completeness of their forms and their strong, autonomous artistic message. the wooden models, therefore, represent a decisive moment in mastroianni's creative phase, maintaining an autonomous artistic character that makes them an important group of works representative of the artist's artistic development and maturation. 4. the applied research methodology of the school of conservation from the beginning of the program presented in june 2012 and on the basis of a public agreement with the municipality, the school of conservation proposed a practical intervention focused on different research topics: technical issues about the assembled method, material preservation aspects, and physical and microclimate conditions for setting up future exhibitions. 2:56 l. baratin, et al. studies in digital heritage, vol. 6, no. 2, publication date: december 2022 figure 3. summary of the different project phases. the “mastroianni experience” 2:57 studies in digital heritage, vol. 6, no. 2, publication date: december 2022 our approach, pictorially summarized in fig. 3, was to find a data integration method using a digital tool. our research was not focused on technological aspects; our interest was rather on methodological issues. we used well-known technologies that had already been assessed in the scientific field with the aim of exploring a new method of data integration. the innovation of our research liess not in the technology but in the aim of ensuring that no aspect of the preservation process was neglected. the mastroianni collection needed to be analyzed from a scientific point of view. in an effort to fully understand their construction and assembly systems, especially the mechanisms of deterioration, the conservators and the students examined each technical aspect of the models starting from the research on the typology of wood. moreover, a deep archival investigation was carried out to discover the different objectives of the artist and to find possible old restoration works that could have compromised the artworks’ originality. during the investigation, we identified some microbiological attacks on the models showcased in the museum of the city. therefore, samples were prepared to obtain specific indications of biological deterioration. moreover, the wooden surfaces were deeply studied to define better the point of oxidation caused by several metal nails. in addition, the students monitored the temperature, relative humidity, and intensity of the lighting over the artwork surface to support exhibition design choices for future presentations. the analytic process was different for the models stored in the hangar. in this case, the research focused on the artworks’ assembly systems and the exhibition space design owing to the models’ larger size. the goals pursued in different classes were presented in two master theses focused on different schematic phases: • documentation and detailed mapping of single works using three-dimensional systems capable of high accuracy in recording objects with complex and articulated volumes; • digital storage and maintenance; • creation of assembly manuals for individual artworks using three-dimensional surveys; • preparation of environmental assessment protocols for the new sites identified for their definitive location through a study of the climatic conditions of the likely exhibition environments; • guidelines, specific to each work, fundamental for conservation purposes and in view of possible movements, always considering the general relationship between the work of art and the environment • reassembly of the works located in the sheds, the first example of which was the installation of the sketch at the peace monument in cassino. the “mastroianni experience” project can be considered the general result. the program envisages the reunification of the elements of the general collection, providing the restoration and designing a 2:58 l. baratin, et al. studies in digital heritage, vol. 6, no. 2, publication date: december 2022 new approach for their fruition. the project focuses on a specific issue that considers conservation activities a way to open up the collection to a wider public. we planned to create a museum that would be situated in the access area of the ramp designed by francesco di giorgio martini. moreover, the exhibition continues with a city tour throughout the university buildings redesigned by architect giancarlo de carlo, encouraging visitors to explore the city’s modern features. the successful proposal of a museum open to citizens all these conservation activities helped us achieve our goal: reinstall wooden models in an innovative exhibition space. the idea was to transform the legacy of mastroianni into a public art collection that could connect city architecture with the artistic value of the objects. as the first exhibition plan was developed, the initial thought was that the characteristics of the ramp should be emphasized because of its architectural peculiarity. but, as a part of a specialist conservation institution, we were concerned that the conservation parameters for artistic objects should be correct and adequate to support a real conservation plan and not solely an exhibition plan. in fact, we considered various issues, such as how close people could safely walk past the artworks. the project has moved beyond traditional gallery concepts to give mastroianni’s wooden models a new artistic life. this has been achieved by studying and developing new access to this heritage. the research was engaged with several questions: how can the work of mastroianni be installed in a new context? what are the conservation challenges presented by these objects? to provide a functional process, the research for the new exhibition area followed three general rules: conserving, installing, and using. according to this flow, the results obtained from the intervention were the starting point. the opportunity to give conservation data a vital role led us to explore a new approach to documentation as an operative tool to share important decisions and to define solutions. emerging digital tools helped us to study the complex interrelation of layers of conservative documentation. structuring a new and digital acquisition process, we could distinguish two different layers: one technical for archiving data from intervention, and one more empirical for describing the value evolution. the museum of the ramp was installed as a public open space in 2015. the overall mission of this first project output was to preserve the mastroianni collection through preventive care and open access to its enjoyment. during the next few years, the project grew in scope. from this first exhibition experience, new research evolved with new opportunities for digital documentation. the “mastroianni experience” 2:59 studies in digital heritage, vol. 6, no. 2, publication date: december 2022 figure 4. digital survey of a mastroianni’s sculpture performed with a laser scanner. 5. digital tools for conservation the museum of ramp was the first attempt to display the mastroianni legacy as a whole. it was the first conservation effort in terms of the general collection. designing the museum, we hoped visitors and citizens would walk away with an appreciation of the general significance of mastroianni’s work, observing his studies and wooden models together in one location. the specific conditions established inside the museum of ramp allowed the objects to function as if they were real original artworks. this installation implied the presence of a specific conservation standard which had evolved based on contemporary digital technologies. in fact, the rapid rise in new digital technologies has revolutionized the practice of recording artistic objects [marra et al. 2021]. in the last five years, several tools and applications for conservation have been developed to help the monitoring process [acke et al. 2021; apollonio et al. 2018; abate et al. 2014]. however, before evaluating the functionality of the technology at our disposal, a clear documentation process had to be set up. in fact, the importance of documentation plays a central role in collection care (fig. 4). the challenging aspect of this project was creating digital content for conserving peculiar art collections like the one shown here that could transform documentation tools into effective and sustainable knowledge systems. the collected data were deployed over the years: from a 3d model of the object to an integrated digital schedule to control the conservative parameters. 2:60 l. baratin, et al. studies in digital heritage, vol. 6, no. 2, publication date: december 2022 using digital documentation tools, the general acquisition of data for conservation is changing from an empirical model of linear narrative description to incorporating diverse media and creating 3d objects, visualizations, and simulations [cameron and robinson 2007; kalay et al. 2008]. taking account of new technological potentialities [willot et al. 2022], we could revise traditional documentation by recognizing a new poly-systemic model that considers each aspect of the object. in this sense, we could transform the intrinsic characteristics of conservation, extending its significance. for example, the way digital databases are structured today enables users to link information, store data, search information, and share technical meanings. this access sets the stage for a possible revolution of documentation for conservation. certainly, the use of technology has implications for the historical evolution and transformation of language and culture. in the same way, this can shift the general definition of conservation through a new approach to digital documentation. in our case, the work of documenting mastroianni’s models has evolved into two principal steps: the first focused on a technical approach to conservation, and the second centered on communicative aspects. the assembly manual designed for each object ”the graphic or photographic capturing of information describes the physical configuration, evolution, and condition of heritage sites at known points in time” [letellier 2007]. letellier argued that technical documentation is a significant part of the conservation process because it can virtually freeze and transmit a specific situation. he referred to heritage sites, but we can use the same method for movable assets such as works of art. for the mastroianni project, we strictly worked with graphical documentation obtained through many survey campaigns. [letellier 2007]. the surveys were undertaken manually and digitally, as best practice dictates. new digital technologies are simply part of a larger kit of tools available to conservators. regarding digital surveys, the acquisition of three-dimensional data was conducted using laser scanner technology and photogrammetry. the geometric results obtained from these devices constituted an indispensable reference for any further analysis and study of the documented object [marra et al. 2021]. our goal was to obtain technical instructions to re-assemble each artifact. at the time when the work started, most of the individual pieces of the models were disassembled and stored in different hangars. to better understand the internal structure of each dismantled model, virtual 3d reconstructions were developoed using the dimensional data acquired from different types of surveys. the conscious distinction between 3d recording and 3d modeling was our general guideline in this context. in fact, interactive procedures to acquire and elaborate 3d data are preferred, since they provide more accurate metric results [santana quintero and vileikis, 2011]. the “mastroianni experience” 2:61 studies in digital heritage, vol. 6, no. 2, publication date: december 2022 figure 5. abacus of elements of the “monumento alla pace” (monument to peace). this integrated way of proceeding analytic/digital; 2d/3d; automatic/interactive was a great opportunity to correctly collect all the dimensional data. throughout the course of the technical study, conservators of the school of conservation and restoration devised a method to identify the single elements of the original wooden sculptures from their virtual reconstructions. first, an abacus of elements was composed in order to know every single part of the object (fig. 5). the second step was to design the sequential phases of physical assembly (fig. 6). finally, the digital 3d model was processed. underlining the importance of a systematic documentation process to pinpoint conservation needs, we obtained a technical handbook for describing the correct assembly process of each part. overall, the reassembly activities following the technical handbook were a great success. one of the key factors contributing to the correct setup of artworks was the support of digital reconstructions. conservators collaborated actively to draft the booklet because they instantly recognized the usefulness of digital systems to achieve the required result. 2:62 l. baratin, et al. studies in digital heritage, vol. 6, no. 2, publication date: december 2022 figure 6. representation of the assembly process for the “monumento alla pace” (monument to peace). the monitoring process this section draws on the findings of a monitoring process capable of transforming the simple collection of environmental data into effective knowledge useful for correct conservation activities. the study explores this issue across the breadth of the documentation methodology and led us to a new interpretation of a documentation schedule. the general aim, in fact, was to digitally create a knowledge base able to store, explain, and narrate the conservation data of the art collection using only one web-based management tool. we needed a flexible method in an open context, such as the museum of the ramp. the traditional approach to monitoring was inadequate, since it tends to register only the technical data and use them to evaluate the state of conservation. the collection of mastroianni models in its new interpretation has multiple dimensions, often incorporating a public dimension. the museum conservators must consider this issue and accept that the significance of preservation is not fixed for each object but rather is a product of its life [konsa 2015]. today, this also means opening up knowledge about collections through digital processes and digital channels [gasparetto and devecchi, 2020]. from this perspective, the monitoring of collections must be viewed in a new way, in that the value of technical data about environmental and physical conservation must always be accessible to a wider public composed of the general population. generally, digital technologies create greater public participation in all types of art collections [schonfield et al. 2021; king et al. 2016]. however, they are also effective as support for conservation activities. in this case, we experimented with a website that presents the technical details of the artwork in an organized framework, allowing us to generate an easy-readable report for non-experts. furthermore, thanks to its flexible structure, the digital tool efficiently manages different types of data, from the description of the state of conservation to the project of intervention. the “mastroianni experience” 2:63 studies in digital heritage, vol. 6, no. 2, publication date: december 2022 figure 7. table of links, “parabola umana” (human parable). in this sense, the digital approach changes traditional monitoring activities. although the digital approach was previously insufficient compared to the needs associated with diagnosis, exhibition, preservation, and public outreach, today, digital tools are helping us to work interactively. 6. a new digital method for conservation monika jadzinska, conservator-restorer and member of the faculty of academy of fine arts in warsaw writes: “only after having accumulated such knowledge can one create strategies for the active and preventive care and conservation for given object” [jadzinska, 2016]. why is it so important to focus on knowledge and documentation? and why are we talking about the importance of knowledge communication and transmission? using digital technologies and applications has an impact on contemporary conservation.. to design a correct process of art preservation, we need to start from a set of data and transform them into possible courses of action. the conservator employing digital tools acts as an expert in data analysis who selects and defines all possible links between art, its conservation, and its relationship with users/visitors. the digitization of useum collections affects both conservation and public understanding. conservators should skillfully distinguish between these two things. contemporary icts extend far 2:64 l. baratin, et al. studies in digital heritage, vol. 6, no. 2, publication date: december 2022 beyond the recent and famous applications for public outreach and appreciation of ch [fernandes vaz et. al 2017; king et al. 2016]. conservation also depends on ict systems for recording, monitoring, and transmitting information. conservators today are engaged in the new activities of digital conservation as an integrated approach. these kinds of innovative perspectives open creative ways of connecting conservation efforts and communication with the general public. when new technologies are designed and applied as real tools for conservators, they can correctly display the work beyond laboratory walls and engage museum visitors in the preservation process. 7. from conservation to public outreach: a virtual open tour to visit the mastroianni models since the museum of the ramp opened, the mastroianni legacy has been connected to the city of urbino. even though the idea of a public museum open to the citizens and tourists was a great opportunity for public outreach, the difficulties of exhibiting the artworks in the space were greater than expected. after almost two years of research and many experiments, our work had not fully started. by using the assembly handbook, we have been able to put together no more than two models. in fact, virtual reconstructions showed us we had little chance of actually seeing the museum inside the ramp due to its narrow space. so, to achieve our goal of public outreach, we came to the conclusion that in designing the mastroianni museum we would also be open to virtual heritage solutions. following the contemporary idea of a pop culture open to modernity and able to dialogue with digital tools, the new project proposes a mixture of physical and digital artifacts [giannini and bowen 2021; lupo 2021; giannini et al. 2019; vermeeren et al. 2018]. this possibility allowed increasing the number of models on display, overcoming the problem of the limited ramp size. moreover, this made possible a new interpretation of museum collections as an explicit attempt to produce cultural experiences through a digital approach and icts. the new proposal had to meet two specific challenges: to support free access to the enjoyment of the different mastroianni wooden models and to integrate the virtual and real as part of the visit. starting from an analysis of the digital material collected during the preservation process, we began to develop this new hybrid solution. the principal goal was to use conservation results to achieve a public story we could share with visitors. although this is not currently something easy to achieve, we planned to mix physical results with digital visualizations. before finding suggestions on how to make virtual information tangible, we started to research the attempts to apply digital 3d models of artworks. these models were used to realize the maintenance booklet. for these reasons, we designed a possible evolution in an application for 3d data using ar technology. our first motivation in adopting an ar solution was to engage the public through a digital application [verhulst et al. 2021]. for this reason, we envisioned an application named mastroapp. the development of the project is still in progress. the technical part is already developed, but implementation of the digital solution, which depends on a collaboration with the municipality, is not yet planned. the “mastroianni experience” 2:65 studies in digital heritage, vol. 6, no. 2, publication date: december 2022 the development of the contents of the app followed a precise technical workflow. the geometric starting point was the result of a laser scanner survey that provided exhaustive documentation of the general morphology of mastroianni's works. homogeneous models were post-processed using dedicated software devices such as autodesk recap and gexcel's reconstructor. the resulting point clouds were imported into autocad to generate the geometric primitives of each constitutive element. later, the 3d models were imported into autodesk 3d studio max by loading the ar-media plugin. as a result of the autodesk system, the inglobe technologies augmented reality (an augmented reality platform) platform can be accessed directly on the cloud. in this digital environment, once the upload is completed on the cloud through the inglobe technologies ar-media account, we could prepare the model for its final use. figure 8. data post-processing in 3d studio max. trying to address an application problem, we developed a stunning digital representation of objects, and this raised the issue of creating a virtual environment for the exhibition. the centrality of the location of the museum remained an important aspect of the project. the space in which we use the virtual heritage is not neutral ground. the application of digital media to cultural heritage must maintain a dialogue with the context and create a strong cultural link. the proposal for mastroianni's virtual heritage reconstruction exploits the city of urbino. as in the first solution of the museum of the ramp, characterized by a special focus on historical architecture, mastroapp sets the important buildings of the university of urbino as a backdrop in both physical and virtual terms. in recognition of the countless opportunities that digital solutions offer to open all kinds of heritage, we thought of a cultural promenade as a new idea of integrated experience. walking through the 2:66 l. baratin, et al. studies in digital heritage, vol. 6, no. 2, publication date: december 2022 narrow street of the renaissance historical center and entering the principal courtyards of the university, users will interface with the art and architecture of urbino. by using a code located on a wall, the users will be able to view on their devices the architectural environment with the digital models of the artworks that can be separated into all their constituent elements. in order to employ all data about preservation interventions, another mastroapp solution was designed. in the few cases where models are present, mastroapp provides ar information about the morphology and mounting system of the structure. figure 9. ar content delivered with the mastroapp, on a smartphone in front of the wooden model “oeil interieur” located inside the ramp museum. the “mastroianni experience” 2:67 studies in digital heritage, vol. 6, no. 2, publication date: december 2022 the mastroapp project manages to bring together digital content with physical spaces in a unique experiential solution. in this way, visitors and citizens will be invited to tour the city, discovering the most important places for its university, which will also offer an opportunity to explore virtually mastroianni’s collection of models. the finished project will provide a dynamic public outreach tool for mastroianni’s work and the city of urbino. moreover, it can promote the public’s appreciation of original wooden models virtually placed in different urban historical areas. mastroapp is now a beta version, and it is not yet used by tourists and visitors to urbino. different concepts will be applied to measure and evaluate the user’s experience of this research project, including engagement and enjoyment as well. in this context, engagement could be principally focused on technical aspects to demonstrate ict's importance in the global conservation process. 8. conclusions our research has confirmed that the digital approach entails additional challenges in conservation and public outreach projects. the main research results led us to an integrated method for digital documentation in the cultural heritage field, which can help technical staff in its everyday conservation activities and visitors during their cultural tours. the principal target audience for research is contemporary restorers engaging with digital issues in order to support their work. the paper raises awareness about the use of digital technologies in the field of conservation as an operational tool, improving a standardized approach to the preservation of all kinds of artistic objects. the conservation field faces new challenges as a new digital reality dominates the artistic world. looking at these challenges from within the laboratories, professionals are thinking about what their interventions should become. this means finding new solutions to help the ongoing transformation without losing a scientific approach. in this sense, the paper demonstrates that the contents of technical documentation could transform the traditional appreciation of a museum collection. in our work, conservators had the possibility to digitize technical data and organize them in a sustainable knowledge environment open to the general public as well. as the conservators collaborated on this project, they changed their goals and created a digital ecosystem that democratizes conservation data both for experts and the general public alike. we also came to understand the potential of ar for its experiential value and as a technical solution that could be used to tell engaging stories about the art and its conservation. as noted, our ar solution, mastroapp, is still in development and assessment, and so this part of our study has not yet been brought to a conclusion. in summary, the general aim of our research was to defend a rich public art collection that could no longer be displayed owing to administrative circumstances and the most disparate sets of problems. the conservation program proposed by the school of conservation and restoration developed a 2:68 l. baratin, et al. studies in digital heritage, vol. 6, no. 2, publication date: december 2022 documentation method and underlined the potential of digital technologies to create 3d objects, easy visualizations, narrative descriptions, and conservation indications using recorded data. our work on the mastroianni experience project helped us to rethink the role of this public collection of wooden models, and it enabled us to make publicly accessible an important part of urbino’s cultural heritage using technical data we originally collected purely for purposes of conservation. 9. acknowledgments we want to thank mrs. arch. luana alessandrini and mr. assessor massimo guidi for their support. we also thank the conservators and professors (school of conservation and restoration of the university of urbino) for their assistance and support in developing the project within their classes and in collaboration with their students. this work was supported by the municipality of urbino. 10. references daniele abate, fabio menna, fabio remondino, gattari. 2014. 3d painting documentation: evaluation of conservation conditions with 3d imaging and ranging techniques. in: the international archives of the photogrammetry, remote sensing and spatial information sciences. 2014. volume xl-5. proceeding of isprs technical commission v symposium. italia, riva del garda. violette abergel, kévin jacquot, livio de luca, philippe veron. 2021. combining on-site and off-site analysis: towards a new paradigm for cultural heritage surveys. in: disegnarecon, 2021, 14 (26), https://doi.org/10.20365/disegnarecon.26.2021.13 lien acke, kristel de vis, stijn verwulgen, and jouke verlinden. 2021. survey and literature study to provide insights on the application of 3d technologies in objects conservation and restoration. in: journal of cultural heritage 49, 272–288. fabrizio apollonio, valentina basilissi, marco callieri, matteo dellepiane, marco gaiani, federico ponchio, rizzo, rubino, roberto scopigno, giorgio sobrà. 2018. a 3d-centered information system for the documentation of a complex restoration intervention. in: journal of cultural heritage, 29, 89-99. giulio carlo argan.1971. mastroianni. cassa di risparmio di cuneo, cuneo. giulio carlo argan, cesare brandi. 1980. la simbologia delle forme, edizioni dedalo, bari. giovanna barbero. 2005. umberto mastroianni. i legni per i monumenti alla resistenza. verso l’arte, roma. dusan barok, julia noordegraaf, arjen p. de vries. 2019. from collection management to content management in art documentation: the conservator as an editor, in: studies in conservation, 64:8, pp. 472-489. fiona cameron, helena robinson. 2007. digital knowledgedscapes: cultural, theoretical, practical, and usage issues facing museum collection databases in digital epoch, in: f. cameron, s. kenderdine (eds.) theorizing digital cultural heritage. a critical discourse, mit press, london, cambridge, pp.165-192. lucio tommaso de paolis, antonio mongelli. 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https://doi.org/10.3390/s21175956 2:70 l. baratin, et al. studies in digital heritage, vol. 6, no. 2, publication date: december 2022 in human behavior. 2021. 125. laura willot, d vodislav, l de luca, valérie gouet-brunet. 2022. automatic structuring of photographic collections for spatio-temporal monitoring of restoration sites: problem statement and challenges. in: isprs wg ii/8 9th international workshop 3d-arch ”3d virtual reconstruction and visualization of complex architectures”, mar 2022, mantua, italy. pp.521 528, https://doi.org/10.5194/isprs-archives-xlvi-2-w1-2022-521-2022 received jan 2022; revised jun 2022; accepted jun 2022. https://doi.org/10.5194/isprs-archives-xlvi-2-w1-2022-521-2022 2. research aim: the conservation of mastroianni’s legacy 3. the collection of wooden models: mastroianni and urbino 3.1 a brief art-historical overview 3.2 the artistic value of mastroianni's wooden models 4. the applied research methodology of the school of conservation 4.1 the successful proposal of a museum open to citizens 5. digital tools for conservation 5.1 the assembly manual designed for each object 5.2 the monitoring process 6. a new digital method for conservation 7. from conservation to public outreach: a virtual open tour to visit the mastroianni models 8. conclusions 9. acknowledgments 10. references new light on the relationship between the montecitorio obelisk and ara pacis of augustus bernard frischer, indiana university, usa john pollini with nicholas cipolla, university of southern california, usa giuseppina capriotti, centro archeologico italiano, cairo jackie murray, university of kentucky, usa molly swetnam-burland, william and mary college, usa karl galinsky, university of texas, usa chrystina häuber, ludwig-maximilians-universität münchen, germany john miller, university of virginia, usa michele r. salzman, university of california, riverside, usa john fillwalk, ball state university, usa matthew r. brennan, indiana university, usa the article takes as its point of departure recent work [frischer forthcoming] critiquing the theory of edmund buchner about the relationship of the gnomonical instrument known as the horologium augusti and the ara pacis augustae. as a result of this critique, the montecitorio obelisk could be situated with greater precision on the map of the city. a computer simulation showed that buchner erred in positing that the shadow of the montecitorio obelisk went into the center of the ara pacis on augustus’ birthday. in this article, computer simulations are used to develop a post-buchnerian interpretation of the relationship of the obelisk and altar. over 230 hitherto unrecognized solar and shadow alignments are reported. the first part of the article defines four zones around the monuments where the solar and shadows observations were made. in the second part of the article, specialists interpret the significance of the annual solar and shadow spectacle from various points of view. the conclusion synthesizes the results, arguing that the monuments were intentionally aligned and situated in order to propagate the same message as the one inscribed on two sides of the montecitorio obelisk[cil 6.702 = ils 91]: that augustus was a devoted worshipper of the sun god (sol), who brings rome victory in time of war, and prosperity in time of peace through his earthly representative, the emperor. key words: horologium augusti, montecitorio obelisk, ara pacis augustae, unity, stellarium, archaeoastronomy sdh reference: bernard frischer et al. 2017. new light on the relationship of the montecitorio obelisk and the ara pacis of augustus. studies in digital heritage 1, no. 1 (may 2017), 18-119. https:doi.org/10.14434/sdh.v1i1.23331 first author's address: bernard frischer, department of informatics, indiana university, 901 e. 10th st., bloomington, in, usa 47408; email: bernard.d.frischer@gmail.com permission to make digital or hardcopies of part or all of this work is granted without fee according to the open access policy of sdh. © 2017 sdh open access journal the relationship between the montecitorio obelisk and the ara pacis     1:19 1. introduction bernard frischer1 lucem redde tuae, dux bone, patriae: / instar veris enim voltus ubi tuus / adfulsit populo, gratior it dies / et soles melius nitent.... (horace, odes 4.5.5-8) from 13 to 9 bc augustus initiated projects in the northern campus martius to erect the ara pacis, montecitorio obelisk, and the gnomonical device generally known as the horologium augusti.2 the projects had two motivations closely related to the two ways we can couple the monuments: obelisk–gnomonical device and obelisk–ara pacis. the obelisk–gnomonical device pair is functionally bound, serving the purposes of accurate time-keeping. the obelisk supported a sphere on a rod attached to the top of its pyramidion, and the shadow of the gnomon hit a crosshatch inscribed on the meridian line at local noon each day of the year. the obelisk–ara pacis pair appears to have served the purpose of expressing the symbolism of imperial ideology, since the two monuments are visually bound but have no functional connection. they have a similar orientation (rotated counterclockwise ca. 15-18 degrees west of north), and the obelisk stands athwart an extension westward of the altar's axis of symmetry. in recent years, the attention of scholars has been concentrated more on the first than on the second pair. this paper shifts the focus to the second pair and its motivation. it has two goals: to present a series of recently discovered solar and shadow axial alignments between the sun, the ara pacis, and the montecitorio obelisk that could be seen in the campus martius and campus agrippae during the reign of augustus and beyond (for the location of these monuments, see the map on figure 1), and to interpret these alignments from various, 1 i am pleased to acknowledge that the research project on which i report in this paper was supported by the following: zukunftskolleg, university of konstanz; school of informatics and computing, indiana university; the netherlands institute for advanced study in the humanities and social sciences; the national science foundation (grant #iis-1014956). i take this opportunity to thank francesco prosperetti, superintendent of the soprintendenza speciale per il colosseo, il mnr e l’area archeologica di roma, for permission to take geological cores and to pursue campaigns of ground penetrating radar in the area of the campus martius where the horologium augusti is suspected to have extended. for her support and cooperation, i am grateful to marta baumgartner, the superintendency’s official responsible for the area in question. i am indebted to marina sapelli ragni and anna maria reggiani, the members of the scientific advisory committee for this project, for giving so generously of their time, advice, and insights. i wish to thank the following for their indispensable help in researching this article: paolo albèri auber, maria elena bertoldi, heinz beste, michele bilancia, ralf bill, matthew r. brennan, jane crawford, david dearborn, stefano floris, egbert friedrich, guido giordano, chrystina häuber, robert hannah, lothar haselberger, paul humphreys, günter leonhardt, paolo liverani, frans maes, ismini miliaresis, adalberto ottati, alberto pichardo, marco ricci, pietro roccasecca, rosella roccasecca, orietta rossini, michael schütz, claudio soccodato, magda la torre, giuseppe tosti, vance tiede, ursula vedder, and georg zotti. i express my deep appreciation to sig. giuseppe brunelli for permission to visit, survey, and take a core through the section of the meridian located in the basement of the building he owns at via di campo marzio 48, rome. i thank sig. brunelli’s staff, especially carla coglitore and giuseppe cantiello, for their help and cooperation in arranging many visits to the site. i am grateful to christof schuler, director of the kommission für alte geschichte und epigraphik of the german archaeological institute, munich, for permission to consult the edmund buchner archive and to publish the archival materials used in this article; and to ortwin daly, director of the german archaeological institute, rome, for permission to consult edmund buchner’s geological cores as well as documents in the friedrich rakob archive. finally, i am happy to acknowledge the contributions made by the three anonymous referees of this paper. they are clearly highly informed, qualified, and perceptive readers, and their input has improved this paper in numerous ways. peer review works! 2 hereafter also called the “gnomonical instrument,” “gnomonical device,” or “calendrical device”. the latin nomenclature used for the device is either horologium or solarium. all these terms are used interchangeably in this article. the relationship between the montecitorio obelisk and the ara pacis     1:20 mutually reinforcing points of view. we shall argue that the major motivation in erecting the monuments and siting them as they were was to create a recurrent sun and shadow spectacle that would have impressed the ancient viewer with the emperor’s learning, power, and religious commitment to sol, the god to whom he explicitly dedicated the obelisk [cil 6.702 = ils 91; for the text, see n. 56 and the end of this article]. figure 1. map of the northern campus martius, ca. 9 bc, showing monuments discussed in this article. scale in meters. source: matthew r. brennan, virtual world heritage laboratory, indiana university. the background of our study is the theory of edmund buchner about the horologium augusti and its reception by scholars since the first version of the theory was published in 1976. in a recent publication [frischer forthcoming], we have traced the development of buchner’s theory and have brought to bear new evidence (partly found among the unpublished materials in buchner’s archive now available for consultation in the commission for ancient history and epigraphy in munich) casting doubt on its validity. in this article, we take our conclusions in that paper as the point of departure for a new, post-buchnerian approach to the problem. given the central role played by buchner’s ideas since his first publication on the problem in 1976, it will be useful to begin by giving a summary of buchner’s theory and our stance toward it. buchner’s theory had three elements: (a) the siting of the ara pacis, montecitorio obelisk, and the gnomonical instrument; (b) the environmental effect caused by the siting; (c) the ideological message implicit in the environmental effect. regarding element (a), bucher 1976 proposed that the gnomonical instrument was a horizontal sundial the relationship between the montecitorio obelisk and the ara pacis     1:21 inscribed on a monumental pavement; in the 1980s and 1990s, buchner’s thinking about the exact design of the instrument evolved. several of buchner’s critics in the past ten years have interpreted the gnomonical instrument as a meridian [heslin 2007; albèri auber 2011-2012; albèri auber 2014]. at present, all we may safely say is that new fieldwork is required to resolve the debate about this matter. buchner thought that the environmental effect (element b) was the projection of the shadow of the obelisk into3 the center of the ara pacis on augustus’ birthday (september 23). we have shown elsewhere that, once we correct buchner’s errors about the siting and phasing of the gnomonic device, the obelisk’s shadow does not penetrate into the center of the ara pacis on that date. we also mooted the possibility that what was as relevant as the projection of the obelisk’s shadow onto the altar was the appearance of the sun’s disk centered on the top of the obelisk. we preliminarily reported that we had observed a single solar axial alignment observed east of the ara pacis on october 9 each year, and we suggested that this alignment might have been decisive in the siting of the monuments [frischer and fillwalk 2014: 88]. in a more recent article, we noted that further research has revealed that similar alignments occur on at least 224 days of the year, making it unlikely that a single date such as october 9 was driving the arrangement of the monuments. we promised to follow up in a subsequent article with the details and a new interpretation, which we hereby do. we will also propose a new interpretation of the environmental effect based on the idea that what was significant was the cumulative effect of the sun and shadow spectacle staged by augustus each year in the new public parks in the northern campus martius and the adjacent campus agrippae. in an earlier publication, we also noted that attributing this role to the sun’s disk should not be ruled out of consideration for the simple reason that “everyone knows you shouldn’t look at the sun.” in fact, the modern understanding of the risk of solar retinitis caused by looking at the sun was not something known to medical science before 1894;4 and that naked eye observation of the sun is attested for millennia [vázquez and vaquero 2009]. here we also note that we have evidence of such observation from ancient rome: in the period of ca. 450 to 260 bc, an attendant of the consuls had the duty of observing the sun prior to publicly declaring the noon hour and last hour of business in the roman forum [pliny, hn 7.60]. aulus gellius [7.4] recounts the story of the torture of marcus atilius regulus by the carthaginians during the first punic war. we are told that regulus, who served as a famous exemplum virtutis to generations of roman schoolchildren, was imprisoned in a dark dungeon and then, as part of the regimen of torture to which he was subjected, he was brought outside and forced to gaze directly at the sun with his eyelids forced apart and sewn open. we are not, however, told that, as a result of this mistreatment, regulus lost his vision.5 in other words, we have no evidence that the romans connected gazing at the sun with blindness. so there is no obvious reason that would have prevented the augustan designer from basing the alignment of the ara pacis and obelisk on the sun’s disk as well as on the obelisk’s shadow projected onto the altar. buchner thought that the message transmitted by the effect (element c) was that augustus was natus ad pacem. in this article, we work out the interpretative consequences of the numerous solar and shadow alignments we have discovered and propose a new message. we should note at this point that, although we clearly do not 3 recently, there has been some debate about whether buchner’s theory was that the shadow would go “into” the center of the ara pacis on augustus’ birthday or merely “toward” the center. for the latter view, see haselberger 2014a: 179. we have presented clear evidence from buchner (†2011) himself that he meant the former (frischer forthcoming: section 2). 4 mackay 1894; note especially the following on the article’s first page: “...one is surprised to find how few cases of ocular injury from such exposure have been recorded.” see frischer and fillwalk 2014: 88. 5 i thank chris johanson for bringing this passage to my attention. on tubero, the late-republic historian, as gellius’ source, see hosius 1903: xxxvii. the relationship between the montecitorio obelisk and the ara pacis     1:22 agree with some details of edmund buchner’s theory, we acknowledge his undisputed importance in both defining the problem and undertaking the fieldwork that, among other things, brought to light part of the meridian under the building at via di campo marzio 48 and also produced evidence about where the obelisk stood beneath the building at piazza del parlamento 3. this paper has three main sections: (1) a description of the computer simulations, including their archaeological and astronomical basis, and the solar and shadow alignments they revealed; (2) interpretations of the newly discovered alignments from various points of view; and (3) a final section with a summary and a conclusion in which we propose a new message implicit in the environmental effects. 2. the computer simulations and solar alignments bernard frischer the research reported here was undertaken with the aid of computer simulations of the northern campus martius in the period 9 bc to ad 40.6 we therefore begin with a description of the simulations and the related archaeological and celestial data incorporated in them. 2.1 archaeological data the simulations incorporate 3d digital reconstruction models of the augustan campus martius between the via flaminia on the east and the mausoleum of augustus on the northwest and the pantheon on the southwest. also included is the portion of the campus agrippae across the via flaminia from the ara pacis. the features of the pantheon,7 mausoleum, and via flaminia still exist and thus can be put into the computer simulation with great confidence in the right place and at the right quota level.8 the ara pacis was surveyed by moretti, who published a plan showing its footprint superimposed over the modern palazzo fiano-almagià [moretti 1948: vol. 2, fig. 36]. it can thus also be accurately situated in the simulation in terms of quota level and location. the final component of the simulation is the montecitorio obelisk. this monument was excavated in 1748 and restored and re-erected ca. 220 m to the south in 1792.9 the mid-eighteenth century interventions were well described in bandini 1750 but, unfortunately, they were not sufficiently documented cartographically to allow us to know exactly where the obelisk stood in terms of the modern city. what is certain is that the base, rotated 15o 10’ off the cardinal points,10 was found beneath the modern building at piazza del parlamento 3, a building whose footprint is ca. 22.6 x 23.5 meters. precise positioning of the obelisk within the building’s perimeter thus requires an inferential method, whose results can be controlled by the data produced by unpublished corings undertaken by edmund buchner. the fact that a gnomon must be positioned due south (in the northern hemisphere) of a meridian allows us to infer with precision the east-west position (longitude) of the obelisk, since we know the longitude of the part of the meridian found by buchner under the modern building at via 6 the time period reflects the fact that the ara pacis and montecitorio obelisk were completed by 9 bc and, according to pliny [hn 36.73] the gnomonical device ceased to render accurate time by ca. 40 ad. 7 for the temple’s design in the augustan period, we have followed the indications of virgili and battistelli 1999; virgili 2006: 167. 8 for the footprint and orientation of the augustan pantheon, see virgili and battistelli 1999: 137-154. 9 ciampini 2004: 143. for the measurement, we relied on google earth. on the high accuracy of google earth for surveys in the city of rome, see pulighe, baiocchi, and lupia 2015. 10 see stuart in bandini 1750: lxxiii; n. 110 in frischer forthcoming. the relationship between the montecitorio obelisk and the ara pacis     1:23 di campo marzio 48.11 the obelisk's north-south position (latitude) is less certain. in principle, it could be calculated if we knew the exact height of the gnomon above the quota level of the meridian, but we do not. recent estimates vary from 29.6/30.0 meters [albèri auber 2014: 73; albè auber 2016] to 30.7 meters [schütz 2014: 44]. the difference in height of ca. 1.0 meter results in a corresponding difference of ca. 1.0 meter in the placement of the obelisk on the extension of the meridian line. if the shorter measurement is accepted, then the obelisk is about one meter farther north than if the higher measurement is used.12 additional evidence about the location of the obelisk derivable from buchner's unpublished corings in the basement of the building at piazza del parlamento 3 is presented in frischer forthcoming, section 9. the corings support our placement of the base of the obelisk. settling these matters is critical for understanding the timepiece, but, as our stress tests will show (see section 2.5), it is not so for defining the alignments between the ara pacis, obelisk, and the sun. regarding the controversial matter of whether novius facundus’ project to use the obelisk as the support for the sphere was planned right from the start or was a later idea,13 we are agnostic for two reasons. first, even if the sphere (or, finial) was part of the original plan, its umbral shadow could not reach as far as the ara pacis, only its much fainter penumbral shadow. secondly, the shadow that concerns us is the umbral shadow of the trunk of the obelisk, which, without doubt, would have reached as far as the ara pacis. thus, the answer to the question of whether or not, right from the beginning, there was a finial atop the obelisk has no bearing on the new theory we develop in this article. finally, we note that there is no archaeological evidence that the western extension of the axis of symmetry of the ara pacis, running from the altar toward the obelisk and beyond, was ever paved.14 we base this statement on the absence of finds of ancient paving in the carta archeologica di roma. the simulations we created have a pathway which is hypothetically restored; our theory does not depend on the validity of the hypothesis, only on the absence of any structure obstructing the movement or the the sightline from the ara pacis to the obelisk and beyond. as we will see, this is the case. from the east entrance of the ara pacis to the via flaminia, we do have evidence that the axial line was paved.15 farther east, across the via flaminia in the campus agrippae, we have no evidence of a paved road or of obstructions along our axial line for some distance. the first known obstruction occurred ca. 450 meters east of the ara pacis, when the axial line crossed the aqua virgo, which is 11 see frischer forthcoming, where two independent surveys are reported, both of which agree with the surveys by bill and leonhardt found in the buchner archive. so the exact position on the modern map of the meridian discovered by buchner is not in dispute. we note here that ottati’s survey, reported in frischer forthcoming, and bill’s survey (unpublished document, buchner archive) agree in finding that the meridian line excavated by buchner runs almost exactly due north: any error is less than one-half a degree. valerio baiocchi is presently engaged in research trying to define the deviation from geographic north with even more precision; he agrees that the error is under one-half degree (personal communication to b. frischer, november 5, 2016), an amount which gnomonist paolo albèri auber describes as trivial and having no bearing on the ability of the gnomonical device to operate reliably (personal communication to b. frischer, july 2015). 12 the reader can confirm this observation by positioning himself just south of the equinoctial line, setting the time for march 22, 9 bc, at 11.30 (i.e., 11:18 am gmt/uht), and using the sliders on model 1 labeled obelisk height adjust and obelisk north/south to change the height of the obelisk by +1.1 m and its position -.90 m. 13 on the basis of the obelisk’s orientation, rotated 15 degrees countercloswise from true north, stuart 1750: lxxiv first proposed the two-phase theory, which bandini 1750: 72 accepted. this theory has been revived in modern times by schütz 2011: 82-83 (=schütz 2014: 47-48), albèri auber 2014: 69; heslin forthcoming: 14. in contrast, buchner assumed that the gnomon was planned from the beginning and the project was unitary, a position recently argued by pollini and cipolla 2014: 54 and also below in this article. other co-authors disagree, but the matter is tangential to our main argument and so will left in abeyance here. 14 there has been speculation to the effect that it was, e.g., in the physical model of the area on display in the museum of the ara pacis in rome. 15 carta archeologica di roma: no. 85 on the map. the relationship between the montecitorio obelisk and the ara pacis     1:24 reported by the carta archeologica di roma to have been running above ground at that point.16 the intersection is farther to the east than the area we studied and hence has no impact on our results. in general, we argue that elements (b) and (c) of buchner’s theory are in logical and practical terms independent of element (a). whether the gnomonical device was a horizontal sundial or a meridian has no necessary relationship to the nature and purpose of the alignment between the ara pacis and the obelisk. as long as the issues of the exact height and position of the obelisk are settled within the current range under debate, the alignments that we report here will remain valid. 2.2 computer simulations using these archaeological data, we created a number of simulations of the northern campus martius in the time of augustus. what may be called the “base simulation” differed from the others in that it has a gnomon that is 29.6 m off the level of the meridian. we have one version of the base simulation in the game engine unity, first created in 2012 (see model 1), and a second in the planetarium software stellarium, created in 2015.17 besides our base simulation in stellarium, we also used that software to create variants to support empirical studies necessitated by research: in one, the gnomon is set at 30.7 m off the level of the meridian, and the obelisk is accordingly moved ca. 1 m to the south. in another, we add to the base stellarium simulation the ara providentiae in the position hypothesized by coarelli 1983 (referencing the work of scheid and broise 1980). all of these simulations allow the user freely to explore the scene, the northern campus martius in the augustan age, and to change the position of the sun on a minute-by-minute basis for the period 9 bc to 40 ad. each sets the camera at approximately average adult eye level—the unity simulation at 1.58 m off the virtual ground, the stellarium simulation at 1.65 m.18 the unity simulation published here as “model 1” supports various views of the scene. in “ground view,” the user can freely explore the entire area contained within the model. in “ara pacis view”, the user is locked on the line of axial symmetry of the ara pacis, and the camera is positioned at 1.58 m off the ground to approximate adult human vision. this facilitated studies of alignments involving the sun’s disk, since it was found in “ground view” that the observer could easily deceive himself and create false alignments by moving even as little as a meter off axis. “top view” facilitates studies of the obelisk’s shadow, since the viewer can easily see the entire sweep of the shadow cast by the obelisk within the zone modeled. the clock in the unity simulation works in units of one minute of equinoctial time. the unity simulation also includes various resources that can be superimposed over the top view, including a contemporary aerial photograph of the zone, the city’s cadastral map, a drawing of the segment of the meridian found by buchner under the building at via di campo marzio 48, and the plan of the foundations of the ara pacis published by moretti. finally, the unity simulation supports research on the impact that a change in the height and position of the obelisk would have on the environmental effects of the obelisk’s shadow and the position of the sun in the sky. the obelisk can be raised or lowered from its default value of 29.6 m by as much as 2.0 m. it can similarly be moved as much as 2.0 m north or south from its default position on an extension of the line of axial symmetry of the ara pacis. we used these features to support various experiments, or “stress tests,” to understand if changes in the height or position of the obelisk would affect our results. this matter is discussed below in section 2.5. here 16 in the modern city, the aqueduct ran between the via due macelli and the via gregoriana. the distance from the east entrance of the ara pacis given above is based on using the measurement tool in google maps. 17 http://stellarium.org/ our stellarium model can be downloaded here; for instructions on how to use it, see: http://www.stellarium.org/wiki/index.php/3d_sceneries_plugin 18 see http://www.ergotron.com/portals/0/reserved/resources/6369777d096d4b0fa344c38eb3e750bd-orig.pdf the relationship between the montecitorio obelisk and the ara pacis     1:25 we may note that the ability of simulations to support such empirical work is a powerful new tool in the toolkit of archaeology [cf. frischer forthcoming, section 15]. model 1. the unity version of the virtual meridian of augustus (may take time to load). click here to view full screen version. for instructions on how to use the model, see appendix i. source: institute for intermedia arts, ball state university, in collaboration with the virtual world heritage laboratory, indiana university. the stellarium simulation was a resource whose main purpose was to offer independent confirmation of the alignments uncovered by the unity simulation while also improving precision. it, too, supports free movement through the area modeled. it has one advantage and one disadvantage as compared to the unity simulation. on the positive side, stellarium prints to the screen the camera’s current coordinates and calculates time to the second (features lacking in the unity simulation), and this increases the precision with which terrestrial positional data for a given alignment can be defined and reported. in contrast, it is not currently possible in stellarium to lock the camera to a fixed path, such as the line running between the midpoints of the ara pacis and obelisk, as we did in the unity version. thus, although stellarium reports our position with greater accuracy than is the case with unity, we are less certain that we are exactly on the line tying together the midpoints. a final advantage of stellarium was not directly relevant to our study but should be mentioned: it has a correctly rendered dynamic night sky, which is a feature not currently available in the unity simulation. we plan to use this affordance to investigate possible alignments of the monuments with the visible planets, the moon, and the constellations. the two simulations provided independent confirmation of each other’s solar alignments because each uses a different method in calculating the earth’s ephemerides (or, if you will, the sun’s apparent movement across the the relationship between the montecitorio obelisk and the ara pacis     1:26 sky over time). stellarium uses the method known as vsop87;19 unity uses the jpl development ephemeris (jpl de431).20 thus, in using the same archaeological data to find solar alignments calculated in two different ways, we were able to replicate our results before accepting them as valid and reporting them here. 2.3 rules of investigation before reporting the solar alignments we observed in both simulations, we make explicit the rules of investigation we applied. rules are useful for two reasons: in the area studied, there are almost twelve billion possible solar observations one can make during the course of a year.21 so having rules was useful, first of all, to quantify the scope of the problem and to reduce the number of possible solutions to something more manageable. secondly, it is not clear from an ancient source whether the alignments reported here were ever noticed and, if so, what, exactly, constituted the preconditions to be fulfilled before an alignment could be said to have occurred. where did you have to stand? what were you supposed to see? thus, the second use of rules was to define as clearly as we can what we consider to be an alignment. this allowed us to be consistent and also to invite our readers to judge whether or not they consider our approach reasonable. regarding the absence of an ancient source explicitly discussing an alignment, we should simply note that the surviving documentation is scarce. in fact, the most informative source—pliny hn 36.71-73—does not treat the obelisk-ara pacis alignment, only the obelisk in relation to the gnomonical instrument. thus, the absence of explicit attestation that the alignments reported here were noticed and considered important in antiquity cannot fairly be taken as evidence against the project, initiated by buchner 1976 and continued by other scholars, to find and interpret alignments between the altar and obelisk. it is not as if we have many ancient reports about the ara pacis and obelisk, none of which mention their alignment. in fact, we have no ancient source at all discussing one monument in reference to the other, and we have precious few about either monument taken alone.22 the rules we use derive, in part, from those implicitly observed by earlier scholars writing about the buchner thesis, starting with edmund buchner himself. for buchner, the rule was that the shadow of the obelisk had to enter into the middle of the ara pacis. this was a rather vague definition: he did not state what the length of the shadow would be, whether he was referring to the umbral or penumbral shadow (or both), where, exactly, the shadow entered and how far it penetrated into the interior of the altar. he also did not specify where the ancient viewer should, ideally, have stood to watch this spectacle. in pointing out these issues, we are not necessarily making a criticism: clearly, the shadow effect is quite subjective, and scientific measurements are not to be expected. in the case of the solar alignments of interest to us, this is all the more the case in that no one can look at the sun for more than a few seconds (of course, today we know that you should never look at the sun so readers are urged not to try doing this), and this does not allow enough time for more than a vague impression to form in the observer’s mind. moreover, the eyes tend to blur when looking at the sun high in the sky, and this also works against 19 see http://www.stellarium.org/wiki/index.php/precision 20 https://en.wikipedia.org/wiki/jet_propulsion_laboratory_development_ephemeris 21 here is how the above estimate was calculated. the area of interest is 150 m in a n-s direction and 600 m in an e-w direction. consider that one’s view of the scene defined by the sun in the sky and the monuments on the ground noticeably shifts every time one moves out of a zone that measures 1 x 1 meter. let us call such a zone an “observational unit.” then there are 90,000 such units in the area of interest (i.e., 600 * 150). next, consider that the sun appears to be moving through the sky at a rate of 1 solar diameter every 2.1 minutes. let us call two minutes a “solar unit.” each movement of the sun by one unit perceptibly changes the scene. there are ca. 263,000 minutes of daylight each year, or 131,500 solar units. so the total number of possible observations in our area of interest is: (number of observational units) * (number of solar units) = 90,000 * 131,500 = 11.835 billion. 22 for a collection of ancient sources mentioning the ara pacis, see centanni and cianni 2007. the relationship between the montecitorio obelisk and the ara pacis     1:27 precise observation. it should be noted that the finial atop the obelisk eclipsed the sun, at least in part,23 and this would have helped protect the eyes and reduced the blurring. that said, in this study we have striven to make our observations as precise as possible, even if the degree of precision we achieved was in excess of what was required. this was motivated less by a pedantic desire for accuracy than by the desire to give exact times and geocoordinates so that the reader can use the simulations we publish here to attempt to replicate any or all of the hundreds of observations found in our tables in the appendix. when the results of our simulations are checked by readers, we claim an accuracy of ±30 minutes and ±10 meters. greater precision than this is not possible given the tools available, the remaining uncertainties about the archaeological facts on the ground, and the enormous passage of time. moreover, greater precision (however desirable as a scientific end in itself) is not pertinent to our argument. we are interested here in the fact that on a certain day, there was a solar alignment vieweable by someone standing somewhere along the axial line at some moment in time. the spatio-temporal coordinates we give have the purpose of facilitating the reader’s ability to control the results we report by consulting the tables and harmonizing the simulation on their screens to our settings. with this background in mind, let us now state the rules of investigation that we used. the first rule is axiality. the observer must stand on an extension of the line of axial symmetry of the ara pacis, whether to the east or to the west. the monuments as well as the obelisk’s shadow or the sun must also appear to be in axial alignment. applying this rule sharply reduces the area of interest (from 600 x 150 m to 600 x 1 m) and thereby reduces the number of possible observations from the intial ca. 12 billion to ca. 79 million. we note here that axiality has long been recognized to be a hallmark of roman architectural design.24 next, there is the rule of superimposition. the environmental effect (whether, in this case, the obelisk’s shadow or the sun’s disk) must appear to be superimposed over or behind one of the monuments of interest. superimposition was stressed by buchner: the shadow of the obelisk was only significant when it was projected into the middle of the ara pacis. in terms of a sun-obelisk alignment, our report is based on the assumption that the desired effect was the obelisk’s pyramidion centered on the sun’s disk (for a photograph of how this appears today, see figure 2).25 that such an effect was considered by the egyptians as particularly relevant to the sun cult is clear from the determinative of the sun tangent to the top of an obelisk (figure 3), which is found in some fifth dynasty texts and is used in connection with sun temples [schäfer 1929; bonnet 1952: 539; ricke 165: 5]. we do not claim that knowledge of this determinative was available after the fifth dynasty, only that the sign is evidence of an early conception behind the symbolism of the obelisk. later egyptian and, indeed, roman texts make it clear that the obelisk was thought to represent a sun beam [quirke 2001; see also section 4 below]. it is a short step from that conception to the notion that the hierophany of the sun occurs when the 23 we do not know the diameter of the finial, so we cannot tell whether it entirely or only partially eclipsed the sun (for how this appears today in the modern restoration see figure 2). either way, because of atmospheric refraction, which (as can be seen in model 1) greatly increases the sun’s apparent diameter, the viewer could easily tell when he had achieved the maximum alignment of the sun with the top of the obelisk. 24 axiality, along with symmetry and frontality, is a hallmark of roman architectural design. see, for example, in the older literature: von gerkan 1924: 146-148, 160-161; kaschnitz von weinberg 1944: 89-128; boethius 1935: 184f.; boethius 1948; von blanckenhagen 1954: 21; brown 1967: 20, 27; castagnoli 1971: 121; cf. the perceptive remark in clarke 1991: 4: “strangely, vitruvius and other writers on the domus are silent on the subject of the fauces-atrium-tablinum axis, probably because it was such an obvious and invariant feature.” 25 the alternatives to the finial-gnomon are: (1) the base of the sun’s disk tangent to the top of the obelisk. this relationship will, however, vary according to the atmospheric refraction, something that does not affect the juxtaposition of the finial or tip of the obelisk and the center of the solar disk. (2) the tip of the pyramidion of the obelisk. while certainly possible, we consider this less likely since at the design stage, the height to the finial-gnomon was an exactly known quantity, whereas that to the top of the pyramidion may have been less certain. the relationship between the montecitorio obelisk and the ara pacis     1:28 sun is directly over its symbolic sun beam. that is a notion that was always implicit and which could be spontaneously reactivated from time to time, even if the fifth dynasty explicit association had long since been forgotten. for the sun–ara pacis alignment, we assume that the desired effect was the appearance of the sun centered behind the ara pacis at some point after sunrise, as seen by someone standing to the west of the altar with the obelisk at his back. in egypt, this recalls the hieroglyph known as the akhet, which is associated with sunrise over the horizon (see below, section 3.2). for the shadow alignment, we follow buchner in looking for the shadow of the obelisk (not of the sphere, whose umbral shadow would not have been salient to the distance of the west façade of the ara pacis) projected onto the center of the west façade of the altar. as we will see, application of this rule effects a further reduction of possible observations from approximately 79 million to under three hundred. figure 2 (left). sun atop and centered over montecitorio obelisk. source: photograph by bernard frischer. figure 3 (right). determinative in old egyptian for a solar cult. source: bernard frischer after schäfer 1929: 721. the third rule is spatial relatedness. since the problem under study is the relationship of the obelisk and the altar, the obvious and most convincing explanations are those that put both monuments in a direct line of sight with each other, or else that require the observer to be positioned between both monuments. as an example of the latter, one may cite buchner’s interest in the obelisk’s shadow projected onto the west façade of the ara pacis. this is something best seen by someone standing with the obelisk to his back in the area between the obelisk and the west façade. the first variant of spatial relatedness is called intervisibility; the second, interpositionality, or to use the geometric term, betweenness.26 in what follows, if a view is said to be intervisible, that means that it includes both the obelisk and the ara pacis; if it is called interpositional, that implies that the viewer must stand between the two monuments while looking at one of them. this rule has no impact on the statistical analysis of possible observations since it is, in effect, another way of formulating the first rule of axiality with reference to where the human observer is standing and gazing. finally, there is the fourth rule of frequency. the rule is also applied in two ways. if the environmental effect happens relatively infrequently throughout the year, then, when it occurs, it can strike observers as particularly 26 cf. scholander 1952: 372: “betweenness. we now consider a set s of elements a, b, c, in which, for each ordered set of three elements a, b, and c, there holds or fails to hold a relation denoted by abc and read “b is between a and c.” the relationship between the montecitorio obelisk and the ara pacis     1:29 compelling and worthy of note. this is clearly the case if the occurrence coincides with an appropriate cultural custom or event, such as a religious holiday or, as buchner assumed, the emperor’s birthday. contrariwise, an effect that occurs very frequently can imply that the general phenomenon, apart from the specific cultural event(s) with which it may be associated, is the point that is being emphasized. once again, application of this rule does not affect the number of possible observations; it pertains to how we interpret our observations. granted, there is a subjective factor in deciding what should be considered “rare” or “very frequent” and what not. in weighing the matter, we must bear in mind that, except for the solstices, the sun is in the same position in the sky on two days of the year, given the fact that it retraces its apparent path through the sky between one solstice and the other. this means that most alignments are likely to occur, at a minimum, not once per year but at least twice or, depending on the amount of space where the observer could conceivably have stood, some multiple of two. as we have seen, buchner assumed that rareness was the way this rule should be applied: he focused exclusively on augustus’ birthday, september 23. in doing so, he did not point out that the sun is in the same position on a corresponding date of the year, viz., march 23. the same can be said of an early critic of buchner, schütz, who proposed april 21 (parilia) as the key date driving the alignment of the ara pacis, but who does not note that the sun is in the same position on august 27.27 both buchner and schütz ought to have pointed out the second date and explained why they preferred the member of the date-pair they chose to emphasize. finally, neither buchner nor schütz gave any indication that they considered the scope of the problem and how many solutions were possible. each appears to have seized on some particular date and time of alignment solely because it seemed, a priori, the logical solution to the problem they were addressing. a sounder approach, we argue, is empirical: making all possible observations first and only later deciding which, if any, were significant. this raises the issue of when one might expect that the point of an environmental effect is its rareness and when its high frequency. here the built environment can be suggestive. if the space is small and delimited by a wall, then the number of possible celestial observations is reduced as compared to a large, open space with its ample sightlines and viewsheds. so, in the case of a small built environment closed off from its surroundings by walls, we would expect—all things being equal—that the rare variant of the frequency rule is operative.28 of course, there are exceptions. if, for example, there are observational markers in a large area, then, clearly, the ancient viewer was interested primarily in those environmental effects perceptible from the markers. the best evidence of a marker is physical: we expect a built feature with the right orientation and with an alignment occurring on a date with cultural significance. in prehistoric cultures, this was typically a solar event such as a solstice or an equinox. in historical cultures, the range of culturally significant dates known to us, typically through literary remains, is much broader. if there are no physical remains of such a marker, then, at least in the case of a literate culture, there may be written or inscriptional evidence that survives, referencing the fact that there once was a marker. hence, in the case of a large, open space, it is possible in principle that the rare variant of the rule could be applied. on the other hand, absent special markers (or at least textual attestation of lost markers), it is not unreasonable to find that a large space exemplifies the high-frequency variant of the rule. 27 see schütz 2011: 85. note that the critique in frischer and fillwalk 2014: 85-85 should be modified to say that schütz ought to have specified whether his april 21 alignment was based on the sun’s first gleam while bisecting the horizon line, or the moment when the solar disk is tangent to the horizon. on these two possibilities, see hawkins 1966: 5. we assumed (perhaps unfairly) he meant the latter. on the former possibility see tiede 2016, who at p. 270 reports that the sun bisects the horizon on axis with the ara pacis on both april 21 and august 27. using our model 1 we confirmed this observation. 28 for an example, see frischer and fillwalk 2012 on the alignment occurring on the summer solstice in the lower sanctuary of roccabruna at hadrian’s villa. the relationship between the montecitorio obelisk and the ara pacis     1:30 of course, it is possible to imagine a tertium quid in which there are both solar markers used on specific dates and also other—and more frequent—alignments seen in a variety of spots in a large, open area. in fact, we will see that this final possibility offers a plausible explanation for our findings about the augustan solar program in the northern campus martius and campus agrippae. figure 4. map showing area where solar and shadow alignments were investigated. source: matthew r. brennan, virtual world heritage laboratory, indiana university. the area in which the ara pacis and obelisk were sited was quite large. we cannot specify the exact dimensions, but we can say that there is no evidence of augustan urban development in at least a 600 m (ne-sw) x 150 m (nw-se) rectangle around these monuments (figure 4), which could, indeed, have extended much farther, especially in the east-west direction. as part of the public parks of the campus martius and campus agrippae, this area was not enclosed by walls. no augustan solar markers have been found, nor are any mentioned in the surviving ancient texts. hence, in principle, we would not expect the single alignment theory such as that proposed by buchner to be valid. rather, we would expect there to be so many alignments that focusing on just one can only be termed arbitrary and a case of selective observation. at any rate, we have limited our study to just this area of ca. 600 m x 150 m because it was, as far as we know, free of buildings that could have interfered with the intervisibility of the monuments of interest to us. in particular, within this zone we investigated the area 295 m west of the obelisk and 190 m east of the ara pacis (=290 m east of the obelisk) all along the extension of the axis of symmetry of the ara pacis. the relationship between the montecitorio obelisk and the ara pacis     1:31 2.4 the solar alignments there are two purely intervisible zones (figure 4) where alignments were observed such that, from the point of view of someone stationed on the axis formed by connecting the mid-points of the ara pacis and the obelisk, the mid-point of the obelisk’s finial overlapped the middle of the solar disk: zone 1 west of the obelisk (appendix table 1; figure 5) and zone 4 to the east of the ara pacis (appendix table 4; model 1). the areas studied could be extended farther in both directions. assuming there were no buildings obstructing the way,29 the tiber, ca. 1.2 km from the obelisk, would have provided the natural limit for zone 1 to the west. figure 5. zone 1: the sun is centered over the obelisk as observed by someone standing ca. 100 m west of the obelisk. the ara pacis is seen in the background. source: institute for intermedia arts, ball state university, in collaboration with the virtual world heritage laboratory, indiana university. similarly, the area studied in zone 4 to the east of the ara pacis across the via flaminia is not known to have offered obstructions and formed part of the public park known as the campus agrippae, the exact bounds of which are not known but which certainly reached even farther north than the ara pacis.30 the first known potential obstruction of the axial sightline was the raised section of the aqua virgo ca. 475 m east of the ara pacis.31 this falls well outside the area we studied. another potential obstacle (the tiberian ara providentiae) will be discussed below (section 11). 29 dumser 2002 has no other augustan features in this area. see also the related digital augustan rome: http://digitalaugustanrome.org 30 as indicated on the digital augustan rome map; http://digitalaugustanrome.org. that the area across the via flaminia from the ara pacis belonged to the campus agrippae is suggested by the fact that the temple of the sun in campo agrippae was built in this general area under aurelian; see liverani 2006-2007. before aurelian’s temple—of obvious significance for our theme in this study (see salzman’s contribution below in section 12)—there is no definite evidence that this section of the campus agrippae was occupied by any buildings (on the possibility that the ara providentiae stood in the area, see below, section 11). 31 frontinus 1.22 tells us that “the arches of the virgo begin below the horti lucullani,” i.e., in an area in or near the northeast part of the campus agrippae. thus the arches will have intersected our axial line. for the location, see the map in dumser 2002. the relationship between the montecitorio obelisk and the ara pacis     1:32 zone 3, the ca. 90 meters from the base of the obelisk to the west entrance of the ara pacis, is purely interpositional (figure 6). when one stood somewhere between the obelisk to one’s back and the west façade of the ara pacis, it afforded views of the rising sun east on axis behind the ara pacis (appendix table 3). finally, one area is both interpositional and intervisible: zone 2, in the 100-m area between the west entrance of the ara pacis and the obelisk (appendix table 2; figure 7). the interpositional part of this zone falls inside the western precinct of the ara pacis from which, on several dates, one can see the sun over the obelisk to the west; on most dates, however, one must stand somewhere west of the ara pacis to see this effect. on these dates, the zone is characterized by interpositionality. figure 6. sunrise seen in zone 3. source: institute for intermedia arts, ball state university, in collaboration with the virtual world heritage laboratory, indiana university. the four zones provided optimal viewsheds for seeing the axial alignments: zones 1, 2 (except for the interior of the ara pacis) and 3 are flat; at its eastern extreme zone 4 encountered a rise up the southern extension of the pincian, which, however, only increased the visibility of the obelisk. as far as we know, there were no obstructions to the sightlines in the augustan age all the way in zone 1 to the tiber, 1.2 km from the obelisk, although the validity of this claim is not important for our argument, which, as noted, is limited to the area 295 m west of the obelisk: it provides alignments enough to prove our point. to the east, in the augustan period, there are no securely known obstructions in zone 4 for the ca. 585 m east of the obelisk until, as already noted, the superstructure of the aqua virgo was reached.32 viewshed analysis shows that, absent obstructions, an obelisk with a height of 29.6 m could potentially33 be seen as far as 19 km in all directions, so its visibility in the limited area we studied is beyond question. the ara pacis, whose exact height is not known since the 32 that the ara providentiae stood on the axial line of the ara pacis about 30 m east of the via flaminia is merely speculation and, if true, does not contradict the interpretation we offer here. see below, section 11. 33 “potentially” means that atmospheric refraction was at a minimum. the relationship between the montecitorio obelisk and the ara pacis     1:33 superstructure does not survive but which can be estimated to have stood 4.5 to 5.0 m high, was potentially visible for 7.6 to 8.0 km.34 hence, it, too, was certainly visible within the area we studied. figure 7. zone 2. source: institute for intermedia arts, ball state university, in collaboration with the virtual world heritage laboratory, indiana university. we may conclude that, barring other unknown obstructions, the two monuments were readily visible along their axial line in the area we studied. in zone 1 (appendix table 1), we found forty-seven pairs of dates with intervisible alignments of the sun’s disk seen over the obelisk, to which can be added the summer solstice, giving us 95 individual alignments in all. the dates in the area studied range from may 8 to august 10 and occur in the early morning not long after sunrise. if the zone is extended all the way to the river, then the range of dates is increased by about two weeks into mid-april and another two weeks to late august.35 the ara pacis is located ca. 90 m from the obelisk. in zone 2, running westward from the west entrance of the altar to the obelisk, there are 189 alignments of the sun over the obelisk seen from the altar to a point ca. 23.5 m from the obelisk, when the summer solstice is reached; after the solstice, one slowly retraces one’s steps back toward the altar to see the alignments. in addition to the summer solstice, there are the two groups of dates running from march 19 to june 23 and from june 25 to september 27 (see appendix table 2). the solar alignments occur in the midto late afternoon. the first two pairs of alignments occur inside the western part 34 the formula for calculating the visibility of an object on a flat landscape is the square root of 13h, where h is the height of the object [see magli 2017: 7]. assuming good atmospheric conditions and barring any physical obstructions, neil devadasan, lead systems engineer and technology manager of the polis center of indiana university-purdue university indianapolis, calculates that the visibility of the obelisk could have extended for 19.43 km. applying the same formula to the ara pacis, the results are 7.576 km for a façade that was 4.5 m high and 7.986 km for a façade that was 5.0 m high. buchner 1976: 33, figure 11 reports the surviving portion of the ara pacis’ west facade to be 4.01 m. bernard frischer thanks dr. devadasan and prof. david bodenhamer, executive director of the polis center, for their help in making this determination. 35 noreña 2013 speculated that the ustrinum of augustus stood at the intersection of our axial line with the line from the mid-point of the pantheon and mausoleum. according to our measurements, the two lines do not, in fact, intersect at this point but ca. 8 meters north of the midpoint of the pantheon–mausoleum line. the relationship between the montecitorio obelisk and the ara pacis     1:34 of the ara pacis and hence entail intervisibility. for the other pairs, only the obelisk is visible in front of the observer while the ara pacis is to his back. so these alignments exemplify interpositionality. in zone 3, exemplifying interpositionality, we found 111 dates on which a person standing on the axial line with the obelisk to his back and facing the ara pacis would have seen the sun rise on axis with the ara pacis (appendix table 3). zone 4 is characterized by intervisibility, and in the area studied alignments of the sun seen over the obelisk were found in the mid to late afternoon for the period from february 28 to march 13 and from october 3 to october 17 (appendix table 4). the first pair of alignments is visible at ca. 14 meters east of the east entrance of the ara pacis. while standing any closer to the altar, the observer’s view of the obelisk is blocked by the east façade of the ara pacis. since, as far as we know, there was no building occupying the land immediately to the east of the via flaminia in this area,36 the ancient observer might have continued several hundred meters farther east into the campus agrippae, finding ever new alignments into mid february and late october. we explored in detail as far as 190 m from the ara pacis (=ca. 290 m east of the obelisk). to summarize, the dates when solar alignments were found range from february 28 to october 17. had we continued our study beyond 290 m to the east of the obelisk and 295 m to its west, we could have extended the range of dates from at least mid-february to late october. but limiting ourselves only to the alignments we recorded, there were solar alignments on a minimum of 224 days of the year along the line connecting the middle of the ara pacis and the montecitorio obelisk, as documented on appendix tables 1-4 and summarized on appendix table 6. a second environmental effect of equal interest to us is the shadow cast by the obelisk into the interior of the ara pacis. this effect is clearly also solar in the sense that only sunlight striking the obelisk could cause it to cast its shadow across the campus martius. as noted above, buchner’s theory held that the shadow reached the mid-point of the altar on september 23, augustus’ birthday, so he was already thinking in terms of this effect. our simulations show that buchner’s hypothesized shadow did not travel, as he imagined, into the west entrance of the altar on that date, so his theory is not valid [frischer forthcoming, section 12]. but we found that what buchner imagined might happen on one date actually did occur at many other times, viz., on twenty-four pairs of dates (appendix table 5). these occur in the late afternoon and cover the periods from february 25 to march 21 and from september 27 to october 21. to conclude this section, adding the dates of shadow alignments to those of solar allows us to report with certainty that there was at least one solar or solar-shadow event in this part of rome every day during 239 days in the period from february 25 to october 21. some dates had more than one alignment event. for an overview of all the alignments throughout the year, see appendix table 6. finally, we note that in this section we are simply reporting the facts as observed using the new virtual simulation; we are not yet interpreting the phenomena. we should, however, clarify here that, in our interpretation to follow, we will claim no specific significance for the individual dates in the period running from february 25 to october 21. our point is that significance arises from the dates in the aggregate. taking this approach to its logical conclusion, one might ask why we do not find solar alignments every day of the year. the reason is clear: the ara pacis was oriented to the pre-existing via flaminia, which is rotated 18° 37’ west of north. to obtain solar alignments every day of the year, the axial line joining the ara pacis and obelisk 36 for the so-called arco di portogallo and the ara providentiae, see below section 11. the relationship between the montecitorio obelisk and the ara pacis     1:35 would have to have been aimed at sunset on the winter solstice, i.e., rotated 23° 30’ west of north. the need for the ara pacis to respect the orientation of the pre-existing via flaminia was apparently a given of the design program. of course, the altar could have been erected elsewhere, and/or it could have been given a different orientation. so it is intriguing to speculate that, in addition to purely aesthetic considerations of creating a parallelism between the eastern façade and the nearby thoroughfare, the augustan planner was motivated to give the ara pacis this particular orientation in order to facilitate an alignment of the altar with the first gleam of the sun on the parilia, april 21 [tiede 2016, confirmed by our model 1 on april 21, 9 bc, at 4:15 utc]. following this line of reasoning, the project to construct the ara pacis off the via flaminia (securely datable on the basis of ancient sources to 13 bc) will have preceded that to site the obelisk ca. 90 meters down the line of symmetry of the ara pacis. the obelisk, dedicated in 10/9 bc on the basis of still extant dedicatory inscription (see n. 56), will have been added as a compatible, secondary elaboration of the original plan. it related the ara pacis to the sun, as before, but now on a great many days of the year, no longer on a single festival day, and it also tethered the altar to a monument symbolic of the sun to its west, instead of simply to a single sunrise on the horizon to the east. 2.5 stress tests of the alignments it is important to discuss two possible factors that could potentially affect the results thus far reported: the cycle of four years from one leap year to the next; and the matter of the height of the obelisk. to begin with the first factor, we have noted that appendix tables 1a-4a report on observations for the year 9 bc. appendix tables 1b-4b take a random sample of two dates from 1a-4a and report the observations for them during the following two years of the four-year cycle from one leap year to the next (in the fourth year, the sun returns to its position in the first year, so it is not included). as will be seen, none of the alignments is invalidated, though the exact position where one must stand as well as the time of day changes slightly (in some cases by as much as 24 hours). as noted above, there is a scholarly debate about the height of the obelisk with sphere. under consideration are heights of 29.6 m [albèri auber 2014: 72] and 30.7 m [schütz 2011: 78-79]. the higher value requires that we move the obelisk 0.90 m farther south with reference to the lower. so the current range of values under consideration is ca. 1.00 m in height and 0.90 m in latitude. our unity and stellarium simulations make it possible to raise or lower the obelisk ±2 m.37 we can also move the obelisk along the southern extension of the meridian by the same amount. using these two simulations, we performed “stress tests” to see if the solar alignments reported above could survive if we change the height used in the simulation from 29.6 m to 30.7 m with a related shift southward by 0.90 m of the obelisk. the results are presented on appendix tables 1c-4c. because of the sun’s apparent angular motion through the sky, we found that generally these changes did not invalidate any of the alignments reported here: all one needs to do is slightly adjust one’s position and/or the time of day to compensate for the obelisk’s altered position (figure 8). there were exceptions: the shadow alignments of march 20 and 21 seen with the 29.6 m obelisk do not occur with the 30.7 m obelisk. in compensation, though, with the taller obelisk we observed fifteen alignments that did not occur with the shorter 37 even though a flexibility of height and position of ± 1 m would have sufficed in the light of the current state of scholarship, we designed the simulation to support changes of ± 2 m in case future discoveries require greater adjustments. the relationship between the montecitorio obelisk and the ara pacis     1:36 obelisk (see appendix table 4d). so the taller obelisk—far from invalidating our results—would give us a net gain of thirteen new shadow alignments. figure 8. stress test in zone 2 at same date and time seen in figure 7, with obelisk raised to 30.7 m and moved south by 1 m. source: institute for intermedia arts, ball state university, in collaboration with the virtual world heritage laboratory, indiana university. to summarize, the northern campus martius and adjacent campus agrippae were the stage for a recurrent light and shadow show of alignments between the sun, obelisk, and ara pacis. at a minimum, alignments of sun or shadow took place 239 days each year in the period from february 25 to october 21 (appendix table 6). the details of exact time and place change slightly in the second and third years of the leap-year cycle. even if the height of the obelisk is increased to 30.7 m, and the position of the obelisk is adjusted accordingly, essentially the same series of alignments is attested, and, indeed, the number of dates increases to 254 in the period from february 17 to october 28. it is for this reason that we stated earlier that the debate about the exact nature and design of the augustan timepiece is not pertinent to our study of the relationship of the ara pacis and montecitorio obelisk. we turn next to our interpretation of this new information revealed by the computer simulations about the augustan solar program in the northern campus martius and campus agrippae. we will show that the solar program is appropriate in view of the dedication of the montecitorio obelisk to sol, augustus’ role as king of egypt, and augustan propaganda which closely linked augustus to apollo, a god with a strong solar aspect. we will also show that later emperors protected the augustan solar program and in at least two cases may even have enhanced it with new features. finally, in the conclusion (section 13.2), we consider the issue of whether the recurrent annual light and shadow spectacle was likely to be intentional or accidental. we begin with the egyptian background and in this connection flag the highly pertinent remarks in herklotz 2007: 209-229 about augustus’ relationship to the sun god. the relationship between the montecitorio obelisk and the ara pacis     1:37 3. egyptological reflections on the ara pacis giuseppina capriotti vittozzi the position of the ara pacis and its newly discovered relationship with the montecitorio obelisk of augustus suggest an egyptological approach to the monument.38 such an approach will look to the presence of egypt in rome in forms that are sometimes explicit, sometimes mediated, and are expressions of that mediterranean koiné to which egypt offered a notable contribution. the obelisk is definitely a product of egypt, while the ara pacis at first glance incorporates classical forms. researchers of the altar have properly sought possible models in the greek and italic context while recognizing unique elements of its design [trimble 2007]. trimble noted that on account of the great variety of potential models, none exactly replicated in the ara pacis, “in the current view the ara pacis is understood to embody a multi-layered appropriation of the past, recombined in sophisticated and innovative ways to meet the needs of the present” [trimble 2007: 11]. the hypothesis that is presented here springs from the observation of the monument not from a stylistic or iconographic point of view but from that of its function in relation to a topography that included the obelisk. this study has been made possible thanks to the simulations conducted by bernard frischer, who has brought to light special visual relationships at specific times of the year between the sun, the obelisk, and the ara pacis. thus, we present here an hypothesis which looks at the possible function as the construction of a sacred landscape inspired by analogous sacred areas of a different tradition. the appropriation of foreign motifs [see trimble 2007] and, in particular, those from pharaonic egypt, had various intensities and nuances at rome, characterized by the romans’ ability to adapt, translate and attribute new meanings to foreign cultural traditions [capriotti vittozzi 2013]. in the ara pacis one may thus imagine an ambiguity of architectonic language which can at once express a creative bond with traditions like those of greece and italy while at the same time charging them with new meaning by alluding to different and important traditions that entered at a later date into the cultural sphere of rome. augustus’ decision to bring to rome the obelisk of psametik ii to serve as the support for the gnomon of a monumental meridian in the campus martius may be read in the light of what ammianus marcellinus (17.4.12-15) recounts about the desire of the princeps to transport to rome the “unique obelisk” of karnak, a monolith and the object of cult. augustus abandoned this project, and the obelisk reached rome much later and today stands before st. john lateran (hence its alternative name, the “lateran obelisk”).39 the obelisk, originally located in the eastern area of the great temple complex of karnak [barguet 1950], dedicated to the solar cult, was associated with the solar god and, by projecting its shadow onto the earth, it rendered the god present and indicated his passage through the sky [bell 2002: 23; capriotti vittozzi 2013: 160]. the construction of augustus’ solar park, as frischer calls it above, must have represented a variation on ancient themes and new functions, yet it still referred to egyptian models, albeit reinterpreted. 38 see capriotti vittozzi 2013 and for egyptianizing decorative elements of the ara pacis, see p. j. e. davies 2011: 360. 39 capriotti vittozzi 2013: 158-160, with earlier bibliography. the relationship between the montecitorio obelisk and the ara pacis     1:38 3.1 the ara pacis and the “horned altar” the peculiar external architectural design of the ara pacis as a cubic structure crowned on the corners by acroteria40 (figure 9) evokes, at least to an egyptologist, the monumentalized form of the so-called “altar with horns.” its origin is debated, 41 but in the hellenistic period it imposed itself, in particular in explicit association with greco-roman cults. figure 9. bronze as coined at lugdunum, ca. 64-67 ad, reverse illustrating the ara pacis. note the volutes atop the façade. source: courtesy of helios numismatik. the oldest horned altar known in egypt is found near the temple-tomb of petosiris near hermopolis magna (figure 10), a strongly international site dated between the end of the fourth and beginning of the third century bc. during the hellenistic period, the type spread both as an architectural structure used in temples and also as portable furniture, including in funerary contexts [soukassian 1983]. the type is found again in isiac contexts, for example in the temple of the egyptian divinities on delos [deonna 1938: 387; soukassian 1983: 331-332]. the case of delos appears particularly instructive for the relationship which has been suggested between this kind of cult structure and the so-called horned altar of phoebus [deonna 1938: 436; quaegebeur 1970: 195], cited in callimachus’ second hymn to apollo [bruneau 1995]. on faience oionochoai (figure 11), the ptolemaic queens depicted with cornucopias execute a rite before this kind of altar [burr thompson 1973]. 40 the acroteria are seen on coins of nero and domitian. the excavator noted that “one unrecoverable loss must be lamented: that of the crown with the obligatory frieze and probable acroteria.” see moretti 1938: 490 (translation by b. frischer). for the coins, see calandra di roccolino 2007. 41 it is attested from very ancient times in the middle east and has been placed into a minoan context; see, for example, quaegebeur 1970: 195; hitchcock 2002. the relationship between the montecitorio obelisk and the ara pacis     1:39 figure 10 (left). horned altar (red arrow), in front of the temple-tomb of petosiris near hermopolis magna. source: courtesy of gerhard huber, copyright 2009. figure 11 (right). faience oinochoe, ca. 243-221 bc, showing berenike ii holding a cornucopia while standing before a horned altar (red arrow). j. paul getty museum, inventory 96 ai 58. source: used with kind permission of the j. paul getty museum. one may also imagine that the altar had a solar function:42 on it fire consumed the sacrifice.43 as soukassian emphasizes, the holocaust could be offered to various divinities; however it was intended to destroy the enemies of both the solar god [quaegebeur 1993] and the king himself, evoking the battle between the sun and his enemies which was renewed each morning near the eastern horizon.44 a great structure of this kind is present right in the eastern area of the temple of karnak,45 and it has been related by klotz to the “unique obelisk” and with the so-called “contra temple” decorated in the reign of domitian [klotz 2008]. according to klotz, the situation of the horned altar in the area of the solar cult of karnak has a precise meaning in relation to the topography of karnak as “a projection of the solar cycle, and the contra temple represents the eastern horizon…the location of the . . . ‘place of destruction,’ where the enemies of re are ultimately destroyed by the newborn and recharged solar disk in a fiery bloodbath, the cause of the red sky immediately before sunrise” [klotz 2008: 75]. in myth, the god is reborn every day on the eastern horizon after the bloodbath of battle, inaugurating a new era. 3.2 the horned altar as the eastern horizon this function of the horned altar and its particular history in greco-roman egypt leads to a further thought. soukassian has emphasized that it is difficult to trace in the egyptian tradition a comparable structure, and thus we might well be faced with an emprunt [soukassian 1983: 328]: such a loan, however, was evidently acquired and reinterpreted in accordance with tradition, given its broad use in temple contexts thousands of years old. 42 this did not seem obvious to soukassian [1983: 320]. 43 according to deonna 1938, just the perfumes; for another view see quaegebeur 1970: 19-197; soukassian 1983: 330-331; quaegebeur 1993. see, recently, nachtergael 1998; klotz 2008: 71, with earlier bibliography. 44 on the various traditions and in particular the heliopoitan, see yoyotte 1978; yoyotte 1981: 84-90. 45 chevrier 1949; http://dlib.etc.ucla.edu/projects/karnak/resource/contratemple/428 the relationship between the montecitorio obelisk and the ara pacis     1:40 quaegebeur [1970: 196 n. 4] has noted that the horned altar may have been at the root of a new kind of altar attested in the ptolemaic period which is also seen in a hieroglyphic sign (figure 12): it is made up of a strut, already known from the egyptian tradition, surmounted by a kind of table with raised sides, which resembles precisely the sign for the horizon (figure 13).46 figure 12 (left). horned altar as hieroglyph in ptolemaic inscriptions; see quaegebeur 1970:196n4. figure 13 (right). the akhet hieroglyph. cf. frischer’s zone 3 (figure 6). in the egyptian tradition, such a sign represents the two mountains framing the reborn sun, that is to say, the place, par excellence, of the divine epiphany. in ptolemaic and roman times, it is attested in this sense as an indicator of the temple itself.47 the connection made by klotz between the eastern horizon and the horned altar, as well as the dependence of the altars formed by the sign of the horizon on the pedestal emphasized by quaegebeur, seem to reveal the egyptian interpretatio of the horned altar as a model capable of making present the place of battle between the solar god and his enemies at the moment of his rebirth. the loan assumed from the egyptian tradition becomes particularly suggestive when we consider an image preserved in the book of the dead, in which the tomb is represented as the solar horizon and thus as a place of rebirth [chapter 192, figure 7]. furthermore, research conducted by lehner and others on the giza plateau underlines a very ancient tradition regarding the monumental construction of the akhet sign in order to focus the sunlight at the horizon. indeed, the pyramids of khufu and kafra provide the frame for sunset on the summer solstice.48 augustus’ interest in karnak and, in particular, in the eastern area and the unique obelisk make particularly appropriate the vision of the ara pacis out of which the sun seems to rise on axis, as demonstrated above by frischer for his zone 3 (figure 6, and see appendix table 3 for the dates). such a choice inevitably imposed a precise meaning, and it poses, yet again—but in a new way—the old problem of the princeps’ employment of egyptian experts [capriotti vittozzi 2013: 85-87]. 46 see also soukassian 1983: 323, 325 figs. 12-13. 47 wörterbuch der ägyptische sprache, vol. 1, 17-19. 48 in this case the sunset is consistent with the funerary purpose of the area; see lehner 1985; dash 2011. that the effect waas intentional was argued by shaltout et al. 2007, magli 2009, magli 2011. the relationship between the montecitorio obelisk and the ara pacis     1:41 4. the montecitorio obelisk as solar symbol molly swetnam-burland understood as a functional monument—that is, as the support of the meridian’s gnomon—the montecitorio obelisk (figures 2, 14) has long stood at the center of debate about meaning-making in advertising the power of the new regime. it reminded viewers of augustus’ co-option of the new province, and its transportation from egypt and re-erection in rome were technological marvels. yet most scholarly discussion has focused on the movement of its shadow, forging ideological connections in the campus martius as it traversed the pavement. roman understandings of the symbolism and history of egyptian obelisks, as dedications to the sun and embodiments of its rays, also enhanced the relationship between the montecitorio obelisk and the other structures situated in close proximity.49 the montecitorio obelisk was already centuries old when it was brought to rome in 10/9 bc, and had a long history and rich symbolism in its own right. it was commissioned by the second and third kings of the 26th dynasty, necho ii and his son psametik ii (r. 610–595 bc and r. 594–589 bc). it is the first extant obelisk from the late period, a time of intense construction in egypt that witnessed a deliberate return to language and monumental forms of the past. it was most likely one of a pair, as were most egyptian obelisks, erected in the city of heliopolis [swetnam-burland 2010: 139 – 141]. generally speaking, in egyptian culture the form of the obelisk symbolized the sun’s benefits to the lands of egypt, and even distributed the sun’s regenerative powers. the rose granite material of which most were fashioned was reflective when polished, and some obelisks were faced with gleaming precious metals [iversen 1968; d’onofrio 1967; habachi and van siclen 1974; curran et al. 2009]. the egyptian inscription on the monument—though only partially preserved, for the obelisk was heavily repaired when moved to stand in front of the palazzo montecitorio—states that this obelisk honored the sun god re-harakhti, an incarnation of the sun god that celebrated his rise at dawn.50 the text of the montecitiorio obelisk affirms his role in granting the king life, happiness, and power; and it praises psametik as the ruler of heliopolis and recently reunited upper and lower egypt.51 certainly, in its original context, the obelisk celebrated the divine rights of the king and honored the sun god. as a monument, it was also efficacious: it both embodied the sun’s rays, and reflected its benefits upon the land and people. its removal for use in the augustan campus martius, however, abrogated this context and altered siteand culture-specific interpretations of its significance. in considering what this egyptian monument “meant” in its augustan context, therefore, it is important to keep in mind that what romans knew of egyptian history, culture, and religion as well as the way they constituted that knowledge differ in many ways from our own understandings.52 49 what follows draws upon my previous work on this monument, swetnam-burland 2010 and swetnam-burland 2015. i have been particularly inspired by new approaches to obelisks that investigate their biographies, diachronic history, and meaning in roman contexts. for new approaches, collins 2000; parker 2003, 2007; safran 1993; schneider 2004, 2005; sorek 2010. i am grateful to bernard frischer for the invitation to contribute to this exciting project. 50 on the place of re-harakhti in egyptian religion, assman 1983: 21-143; leitz 2002, iv: 630-632, s.v. re-harachte, an the encyclopedia entry listing all known titles and monuments associated with re-harakhti. 51 for transcription and translation into italian, ciampini 2004: 143-149. 52 scholars often interpret the evidence for egyptian influence on roman culture in different ways, according to their training (that is, as romanists or egyptologists). for an egyptological perspective this case, see gregory 2012; capriotti, above, section 3. the relationship between the montecitorio obelisk and the ara pacis     1:42 figure 14. montecitorio obelisk, rome. source: photograph by bernard frischer. pliny the elder, our best ancient source for the montecitorio obelisk and the manner of its display, refers to the king who commissioned it as psemetnepserphreus. the name appears to derive from a transliteration of the name psametik and the king’s “good” name, neferibre. this name suggests that pliny’s information did not come from the greek historiographical tradition, and it is possible that his source for this unusual name may have been the obelisk itself [swetnam-burland 2010: 143]. a few monuments from the imperial period show that there were some people in italy able to compose meaningful texts in hieroglyphic script, and thus presumably able to translate their texts.53 but this was a rare skill, associated chiefly with religious contexts. hermapion’s “translation” of the piazza del popolo obelisk is the only such document preserved by the literary tradition. the translation does not offer a word-for-word key to the text but rather interprets it, at once rendering the hieroglyphic script into greek and making its content more understandable to readers of a different culture [lambrecht 2001]. it is clear that roman audiences did not interpret obelisks as would scholars today, or as would have egyptians – either those of the past, when the obelisk was commissioned, or of the roman-period. even so, the “egyptian” symbolism of the monuments was important to italian audiences, and it appears that some members of the elite, like pliny, had access to specialized, albeit partial, sources of information about their content. how, then, might contemporary audiences have understood this symbolism? in addition to recording the name of the egyptian king who commissioned the montecitorio obelisk, pliny the elder transmitted detailed 53 on egyptians in rome, see noy 2004; swetnam-burland 2011; swetnam-burland 2015. the relationship between the montecitorio obelisk and the ara pacis     1:43 information about its role as the gnomon in the meridian (also noting that, in his own lifetime, it had ceased to function accurately [pliny hn 36.72-73]). for present purposes, however, his general description of obelisks takes precedence. though pliny offers many anecdotes about the commissioning and quarrying of these monuments, he attributes the same generalized function to all: “kings fashioned slabs of it [i.e., aswan granite], in a certain kind of rivalry, calling them obelisks, sacred to the divine power of the sun. their motif is in the representation of its rays, and is so signified by the egyptian name. . . for truly, those carvings and representations which we see are egyptian letters.”54 writing centuries later, ammianus marcellinus [17.4.6] similarly stressed that obelisks transmitted egyptian wisdom, and that their shape emulated the rays of the sun. he also quoted a long section of a book about obelisks by hermapion. though the translation belongs to augustus’ other obelisk, set in the circus maximus and standing today in the piazza del popolo, this text also serves as confirmation of the solar properties of obelisks more generally, revealing an association between apollo and helios, the sun. the text repeatedly invokes apollo as the child of the sun and, in places, conflates him with the earthly king, ramestes; it casts apollo as the recipient of the sun’s benefits, and the intermediary who transmits this power to the world, by conquest and various acts of dedication and benefaction [ammianus marcellinus 17.4.17-23]. for romans, then, obelisks, as a category of monument, were seen to bear meaningful texts that transmitted wisdom; they were religious in purpose, honoring the gods and commemorating prayers; and their form was believed to refer to the sun’s rays, the engine by which the sun transmitted energy and light to the earth. though all of these sources post-date the augustan period, there is contemporary evidence to suggest that early imperial audiences may have viewed obelisks’ symbolism similarly. first, there is significant debate about the date of hermapion’s book, of which the preserved section is just one part; some believe that it may belong to the early first century ad [benaissa 2013]. thus, it is possible that contemporary audiences had access, in some form, to information about the egyptian language on augustus’ obelisks. though this must remain a matter of speculation, it is also clear that there was popular interest in their inscriptions. two extant cameo-glass vessels, a type of luxury-ware that was produced in italy only during the early empire, depicted obelisks. one of them, today in the getty villa, included characters that were carefully modeled on egyptian hierolgyphs—all ‘real’, though they do not preserve a word in its entirety (figure 15). this vessel, too, included a depiction of an egyptian king making offerings at an altar with the obelisk in the background, confirmation of their seemingly religious function.55 above all, augustus re-dedicated both obelisks to the roman god sol, or sol indiges, as evidenced by the inscriptions on their bases—deliberately playing upon their solar associations and known function as dedications, according to roman understandings of their “egyptian” symbolism.56 54 plin. hn 36.64: trabes ex eo fecere reges quodam certamine, obeliscos vocantes solis numini sacratos. radiorum eius argumentum in effigie est, et ita sigificatur nomine aegypto. . . . etenim scalpturae illae effigiesque quas videmus aegyptiae sunt litterae. 55 on the getty flask, see wight and swetnam-burland 2010; swetnam-burland 2015, and sources cited. for discussion of other fragments of cameo class, including one that shows an obelisk featuring ‘fantastic’ hieroglyphs, see van aerde 2013. 56 cil 6.701, 6.702: imp(erator) caesar divi f(ilius) / augustus / pontifex maximus / imp(erator) xii co(n)s(ul) xi trib(unicia) pot(estate) xiv / aegupto in potestatem / populi romani redacta / soli donum dedit. the relationship between the montecitorio obelisk and the ara pacis     1:44 figure 15. roman glass flask, ca. 25 bc–25 ad; j. paul getty museum inv. 85.af.84. source: j. paul getty museum. sol indiges was the latin version of the sun god, and a deity featured prominently in the religious renaissance of augustan rome. there was a shrine to sol in the circus maximus (which, in part, explains the dedication of the obelisk in that context), and the augustan calendars reveal that rituals were performed in sol’s honor on august 9 on the quirinal hill, in commemoration of julius caesar’s victory at pharsalus.57 in addition, horace invoked sol in the carmen saeculare, performed in 17 bc. he addressed him as a god of rejuvenation (“reviving sol, you who in your gleaming chariot bring forth and hide the day, are born again and the same, may you be able to see nothing greater than the city of rome”) and equated him with augustus’ patron apollo, echoing a religious association between the deities attested in italy as early as the fourth century bc.58 the solar symbolism of the monument, combined with the close relationship between sol and apollo it suggested, resonated with themes prevalent throughout the art and literature of the period: agricultural fertility, healing, and rebirth and regeneration, much needed in the city’s recovery after a long and bloody conflict. that sol was honored in association with julius caesar’s victories in civil war, too, reinforces this interpretation. better awareness of the montecitorio obelisk as a monument with multiple and complex symbolic associations will enable deeper inquiries, considering its relationship with the other monuments of the augustan campus martius afresh—as it related to the egyptianizing elements incorporated in the mausoleum, for instance, and to the lower friezes of the ara pacis, with their image of controlled but abundant natural landscape.59 on many 57 inscr. ital. 13. 2.191 9: e v np soli indigeti in colle | quirinale fer(iae) q(uod) e(o) die | c. caes(ar) c. f. pharsali devicit, “to sol indiges on the quirinal hill. feriae, because on that day c. caesar was victorious at pharsalus.” see also the fasti allifani, inscr. ital. 13 2.181; fasti antiates, inscr. ital. 13 2.208. 58 hor. carm. saec. 9–12: alme sol, curru nitido diem qui | promis et celas aliusque et idem | nasceris, possis nihil urbe roma | visere maius. see on the role of sol here miller 2009: 279–81. for the early association of usil (the etruscan deity assimilated with sol) and apollo in italy, see de grummond and simon 2006: 61. 59 for illustration of the atef crown incorporated into the sculptural decoration of the mausoleum, see de vos 1980, frontispiece; for discussion, sö̈ldner 2000; schneider 2004, n. 76 for bibliography. for the alexandrian-inspired construction of the mausoleum, see the relationship between the montecitorio obelisk and the ara pacis     1:45 levels, the egyptian symbolism of the montecitorio obelisk, as it was understood in augustan rome, enriched its function in the meridian. because its form was understood as a representation of the sun’s rays, the path the monolith traced on the pavement served as an ever-changing, yet perpetual, reminder of the sun’s might. it made visible in shadow what could not be viewed directly by human eyes. as a symbol of sol/apollo, it echoed and reinforced an emerging augustan ideology. and, as a symbol of egypt’s history and traditions, it proclaimed augustus the new governor of the territory and the inheritor of its riches and wisdom. 5. ptolemaic background jackie murray although possible, as we have just seen in swetland-burland’s contribution above, it remains hard to prove that romans in the first century bc would have had direct access to egyptian religious ideas from the pharaonic period about the sun and about how they informed monumental building. on the other hand, it is difficult to deny that augustus and his contemporaries had direct access to the ptolemaic version of these ideas and how they applied to contemporary monumental building in egypt. accordingly, it is worth coming to grips with certain fixed associations in ptolemaic royal ideology, namely the fusion of apollo and horus and astronomical alignment, in order to make sense of why the montecitorio obelisk was dedicated to sol.60 it is well known that as early as the fifth century greeks identified their gods with those of the egyptians, notably, for our purposes, apollo with the egyptian horus [hdt.2.144; 2.166.5]. on what grounds this equation was made is unclear, since greeks in herodotus’ day probably did not understand the egyptian religion of the time well enough to know all of the attributes of horus, who was simultaneously the sun, the protector of the pharaoh and the living pharaoh himself. what concerns us is that the ptolemies, who did have access to egyptian religious ideas, promoted the integration of apollo and horus in egypt and exploited the longstanding co-existence of greek and egyptian cults in cyrene. there the syncretism of apollo, the patron of the state, with horus the divine pharaoh began early in its history as a greek kingdom under the battiad dynasty. small votive horus-falcons dating from the sixth century on into the hellenistic age have been found in the extramural precinct of the sanctuary of demeter [warden 1990: 3-13], whom the greeks identified with isis. in the fourth century, a temple to isis was built adjacent to the temple of apollo in the center of the city, and beginning in the ptolemaic period statues of isis nursing horus-the-child were set up in the sanctuary of apollo [paribeni 1959: no. 409-20]. the evidence of continuous worship of horus from the archaic period into the ptolemaic suggests that the ptolemies were building on well-established foundations. in egypt, from ptolemy soter to ptolemy caesar, all the ptolemies identified themselves with horus and took on the five titles that the egyptian religious conception of kingship demanded: horus, two ladies, golden horus, throne, and son of re. the ptolemies also used the pre-existing apollo-horus as a cornerstone of their royal ideology. in cyrene, philadelphus’ half-brother, magas, was certainly exploiting the local apollo-horus syncretism when he took on the position as priest of apollo in order to legitimate his position as king [seg 18:743]. the youthfulness of the two gods seems to have provided important ground on which to merge them. whereas soter took a horus name that emphasized his military prowess, “horus whose might is great, the valorous ruler” (wr-phti nsw-qnj [naville 1890:62]), he did introduce from sinope the syncretic cult of serapis in davies 2000: 51–60. on the floral friezes of the ara pacis, which made reference in several ways to deities including apollo and dionysus, see castriota 1995. for further dicussion of their role in the architectural program, see pollini, section 8. 60 on the relationship of theory and practice of augustan and ptolemaic rule in egypt, see herklotz 2007: 402-411. the relationship between the montecitorio obelisk and the ara pacis     1:46 which harpocrates, horus-the-child, was prominent. accordingly, when philadelphus took his horus name, he chose one that could link him to harpocrates: “child triumphant” (hwnw qnj [lepsius 1849: vol. iv, plate 7g, qus pyl]). the court poets helped articulate this fusion to the greek-reading intelligentsia. callimachus’ hymn to delos [160-195] expresses the ideas behind philadelphus’ horus name by associating the king closely with triumphant youthful apollo [koenen 1983: 174-190; mineur 1984; hölbl 2001: 111]. callimachus’ hymn to apollo also links the reigning ptolemy to apollo as the protector of kings: “whoever fights with my king, also fights with apollo” (ὅστις ἐμῷ βασιλῇ, καὶ ὰπόλλωνι μάχοιτο, 25) [williams 1978; koenen 1983; bing 1988; cameron 1995: 407-409; stephen 2003; and, especially, selden 1998]. as selden 1998: 387 points out, outside of the ptolemaic orbit, the presentation of apollo as the protector of kings would have been an alien notion to a greek audience. it was all the more alien when hesiod’s pronouncement on the matter is brought to mind contrasting apollo’s authority over poets with zeus’ authority over kings [hes. th. 94-96]. the innovative conjunction of kingship and apollo’s power in the apolline hymns of callimachus (who, not coincidentally, grew up in cyrene) was introduced in a milieu where apollo had long been assimilated to horus [selden 1998: 391-392]. by the reign of ptolemy iii euergetes, people made very little distinction between harpocrates, horus-the-child and apollo.61 the identification of the reigning ptolemy with harpocrates/horus-the-child persisted into augustus’ day. cleopatra’s father ptolemy xii’s elaborate horus name reads: the perfect youth, pleasant in his popularity, whose ka distinguishes the two ladies with the people, who the wonderful khnum praises so that he receives the crown as king, who unites himself with the works (of his father) in joy like that which his father protects, who is shining at birth on the throne of his father like horus, the strong bull, the lord who lights up egypt like the living apis, to whom many great sed festivals will be given through ptah-tennen, the father of the gods.62 caesarion’s horus name, “perfect youth, pleasant in his popularity” (hwnw-nfr bnr-mrwt),63 and his connection to harpocrates was reinforced by cleopatra, who, on monumental images, styled herself as isis suckling him.64 apollo also starts to take on horus’ solar attributes under the early ptolemies, both in literature and in the public perception. in apollonius’ argonautica, apollo makes two epiphanies to the argonauts. in the first, after the argonauts come through the clashing rocks and are safely resting on a tiny deserted island reminiscent of delos in the black sea, apollo, whose youthfulness is stressed by the narrator, appears to them just before sunrise. following orpheus’ instructions, they build an altar and worship the god as “the lord appearing at dawn,” ἑώιος. they dance as orpheus sings a hymn echoing the content of the homeric hymn to apollo, all as if they were at delphi [2.687-719]. similarly, in an episode on their return voyage, apollo appears again in response to jason’s prayers, and he brings the dawn back for the argonauts after a sudden chaotic darkness endangers them [4.1690-1718].65 around the same time that this poem was produced, an inscription was set up in the precinct of the serapeum to apollo with the epithet bladoui (απόλλωνι βλάδουι). selden argues convincingly that this otherwise unattested epithet of apollo, βλάδουιι, is most likely “a deformation of an 61 ogis 89 where the dedication is made to isis, sarapis and apollo. see selden 1998: 389-390. 62 c. bennett’s translation 2001-2012 [http://www.tyndalehouse.com/egypt/ptolemies/ptolemy_xii_fr.htm] based on the transliteration from lepsius 1849: iv, plate 49b: hwnw-nfr bnr-mrwt tnj-sw-nbt-rxyt-hna-ka.fdwa.n.f-xnmw-sps-r-szp-n.f-xa(t)-m-nsw snsn.n-shnw-m-haaw-mj-nd-jt.f thn-msw(t)-hr-nst-jt.f-mj-hr-ka-nxt jty-psd-m-tamrj-mj-hpw-anx rdj-n.f-habw-sd-asaw-wrw-mj-pth-tatnnjt-ntrw. 63 lepsius 1849: iv, plate 61a. 64 cleopatra vii struck coins on cyprus some time after caesarion’s birth depicting him at her breast with the double cornucopia on the reverse and with the legend “cleopatra the queen”; for the images see poole 1883: ix-xxiii (pl. xxx,6), walker and higgs 2001: 178 (cat. no. 186). for discussion of the monuments depicting cleopatra as isis suckling osiris, see tyldesley 2008: 118-122. 65 on the date of the argonautica see murray 2014: 247-284. the relationship between the montecitorio obelisk and the ara pacis     1:47 epithet of horus, perhaps bl-dwɜy, ‘eyes of the dawn,’” which has a parallel in the ritual texts on the walls of the temple of horus at edfu, which was begun under ptolemy iii and completed by ptolemy xi, cleopatra vii and her brothers [breccia 1911: no. 168; selden 1998: 389-390]. the edfu texts refer to “horus the behdetite, the great god of the sky, who ascends on the horizon of the east ... his eyes illuminate the circle of the lands, he mounts the distant sky at dawn” [selden 1998: 390; alliot 1949-1954: vol. 1, 414]. monumental building was an important way in which the egyptian king demonstrated his right to rule. from pre-dynastic times on, horus was the god of monumental architecture, and building temples to the gods was thought to be a reenactment of the primeval creation of the world [hornung 1992]. for greeks, however, apollo was not really a god of architecture or primeval creation in the same way prometheus or hephaestus was. he was, however, the god of creation in poetry and music, and in poetry apollo is associated with building. in the iliad, homer says that apollo and poseidon built the walls of troy [il. 7.452-53]; in the elegies of theognis, apollo built the walls of megara [773-74]; and, most significantly, in the homeric hymn to apollo, the god himself lays the foundations for his own temple at delphi [287-95]. in support of the early ptolemies’ promotion of the synthesis of apollo and horus as primeval architect, callimachus and apollonius highlighted apollo’s connection to the construction of the temple at delphi. in his hymn to apollo, callimachus alludes to the image of apollo building his temple at delphi in the homeric hymn in his own description of apollo weaving the altar for himself and artemis on delos. callimachus sets this event prior to apollo’s foundation of cyrene in libya, which in turn precedes his slaying of the snake pytho. in effect, in callimachus’ hymn apollo’s building activity antedates his building of the temple in delphi, making the altar on delos and the laying the foundations of cyrene the first acts of construction in the world [selden 1998]. as noted above, apollonius also uses the homeric hymn to apollo as the primary intertext for the first epiphany of apollo in his argonautica. after celebrating apollo ‘εώιος, the argonauts are inspired to swear an oath to protect one another forever and to build a shrine to the goddess ὁμονοία, concord to commemorate the oath. and according to the narrator the shrine was still standing in his day [2.685-719]. this picture apollonius paints frames all the monumental building of the ptolemies in terms of pious devotion to the gods that has its model in the heroic age. the ptolemies pursued a policy of active temple building to make their rule consonant with ancient pharaonic ideology about the king’s role. this led to a proliferation of temple architecture, especially in the south [hölbl 2000: 257-285]. here it is worth focusing on the temple of horus at edfu, because of its connection to apollo. it is the best preserved of all ptolemaic temples and its building inscriptions provide details from every phase of construction [cauville and devauchelle 1984]. it was started at the high point of the dynasty by ptolemy iii euergetes in 237 bc, the year following his jubilee and his introduction of the first calendar with 365 and one-quarter days, the basis of the julian calendar [pfeiffer 2004]. the inscription describes the initial act of foundation, i.e. the stretching of the cord to determine the proper cosmic alignment. what is interesting in this inscription is that ptolemy iii claims to have observed the egyptian constellation meskhet(yu), which corresponds to our big dipper, while carrying out the stretching of the cord ceremony with the goddess seshat [chassinat and cauville 1990: 31, 2ff; wainwright 1932: 373]. this claim is repeated by his son philopator 25 years later in 212 bc [furth et al. 2004: 44, 7 ff]. the inscription preserves the earliest explicit statement that astronomical observation was involved in aligning temples in egypt [belmonte et al. 2009]. egyptologists are not completely in agreement about exactly how observation of this constellation determined the alignment, but there is general consensus that astronomical observation best explains the near perfect north-south axis of the temple, which is significantly different from the earlier pharaonic era birth-house, the axis of which is roughly east-west [zaba 1953: 58-73; shaltout and belmonte 2005: 273-298; leitz 1989; waitkus 1983]. regardless of exactly how observation of the the constellation factored into the physical orientation of the temple, it certainly the relationship between the montecitorio obelisk and the ara pacis     1:48 was consistent with contemporary ptolemaic royal ideology. it can hardly be coincidental that the same king who brought order to the heavens by introducing a new calendar is also the king who initiated the building of the temple to apollo by aligning its foundations to the heavens. the final phase of construction was finished by ptolemy xi auletes in 57 bc, leaving the decorations and statuary to cleopatra vii and her brothers. ptolemy xiii is depicted on the pylons in the traditional pharaonic smiting scene, whereas in front of these pylons cleopatra added the large horus falcons protecting an almost life-size caesarion. these images express ptolemaic kingship and imperial ambition in traditional egyptian terms. let us return now to rome, to the campus martius where we observe the triple alignment of the sun-obeliskara pacis on many days of the year. the obelisk, in its original egyptian context in heliopolis, was a symbol of pharaonic conquests and egyptian empire. thus, its transportation and re-erection in rome enacted the conquest it commemorates as well as the reorientation of the imperial center of the world from egypt to rome. the ara pacis commemorates all of augustus’ conquests, which amount to an end of all wars, an end to the succession of empires. bringing to bear the aspects of ptolemaic royal ideology we have been discussing sheds some light on how these three monuments work together. first, roman apollo, was not the archaic or classical apollo of the greeks. roman apollo was born in the hellenistic era. roman apollo was a sun god and as argued above, it was under the influence of ptolemaic royal ideology that apollo became a sun god. in other words, the apollo augustus identifies with was closely related to the ptolemaic apollo-horus. that being the case, dundas' observations about the changes that augustus made to the traditional pharaonic titulary gain significance in relation to the conjunction of the sun, obelisk, and the ara pacis. whereas the ptolemies maintained the traditional five-part protocol, augustus reduced it to one, the horus name. the short version of his horus name is usually simply autokrator, but the longer version ends with this remarkable phrase: "...whose power is incomparable in the city par excellence that he loves, rome" [translation by dundas 2002:445; see grenier 1995]. as dundas points out, augustus' horus name is a declaration that rome has been chosen by the god over egypt as the new center of the world. hence, we might be tempted to read the conjunction of the sun, obelisk, and ara pacis as an expression of augustus' horus name in monumental terms. 6. augustus’ rôle as pharaoh of egypt—pax augusta—golden age—felicitas temporum—ara pacis67 chrystina häuber in 30 bc, octavian/augustus became the pharaoh of egypt and, as such, was believed by the egyptians to be the son of the sun god re.68 the claim, “i, augustus, am the son of the sun god (apollo/re),”69 is made visible by the ara pacis, and no other augustan building would better qualify to convey this message. in particular, the iconography of the ara pacis, of course, shows the achievements of augustus' reign, but those blessings are exactly the same that the king of egypt in pharaonic times had long been expected to bestow upon his 66 to be sure, there are earlier attestations of the association of apollo with helios (e.g., euripides, phaethon fr. 781.11-12, a reference i owe to an anonymous referee of this article, who justly writes, “ptolemaic ideology presumably built upon this association rather than inventing it”). 67 the ideas presented here are discussed in more detail in häuber 2016. 68 hölbl 2004; herklotz 2007: 209-220 with n. 589, and passim, p. 209; häuber 2014: 735 with n. 68. 69 herklotz 2007: 209-211 with nn. 519, 520; pp. 218-219, 220 with n. 589; pp. 227-228. the relationship between the montecitorio obelisk and the ara pacis     1:49 people. the sun god re was (among other things) the force that enabled the pharaoh to provide his subjects with these benefits. therefore, the pharaoh was the bringer of prosperity because his most important duty—to be realized by actions and rituals he had to perform on a daily basis or on special occasions—was to establish maat (“world order”) [assmann 2006]. the pharaoh’s establishment of maat resulted in justice and peace on earth and in the sphere of the gods [herklotz 2014: 221 with n. 595], resulting in universal prosperity for his people.70 precisely these positive results of the monarch’s reign were represented on a marble altar at praeneste, which was dedicated posthumously to the deified augustus (figure 16). on it augustus is seen wearing a radiate crown, the (lost) metallic parts of which, representing the rays of the sun, were inserted into holes drilled into the marble. the cornucopiae on this altar symbolize, according to zanker, the universal prosperity brought about by augustus. in his discussion of this altar, zanker also mentions the ara pacis as “symbol of peace and of universal well-being”71 because both monuments express basically the same meaning.72 clearly, the ara pacis is the building par excellence celebrating augustan peace and prosperity. the message of the marble altar in praeneste turns out to be that augustus73 was the founder of a new golden age—hence the cornucopiae—and thus the guarantor of prosperity and of temporum felicitas (“felicity of the times”). needless to say, the prerequisite of all this was peace. berges has observed that the iconography of the altar’s fruit-laden cornucupiae. with globular lower end resembles the famous ptolemaic dikeras74 (two parallel cornucopiae). according to rice, “the dikeras, filled to overflowing ... obviously emphasizes the role of the monarchs [of egypt, king ptolemaios ii and his wife arsinoe ii] as the joint source of blessings and abundance to the kingdom.”75 it was to develop into the attribute par excellence of the wealth and tryphe (“opulence”) of ptolemaic rulers, and hence of egypt. 70 goyon 1988: 29-30; goyon 1989: 33-34; häuber 2014: 733-735; assmann 2006: 226-228. 71 zanker 2006: 325, caption of fig. 240: “... il ritratto di augusto era munito di una corona di raggi. le cornucopie indicano in lui l'artefice della prosperità universale.” 72 cf. häuber 2014: 716 n. 240, quoting zanker 2006: 325, caption of fig. 240 (on the altar, here figure 16); cf. p. 334, caption of fig. 247: “altare da un santuario per la gens augusta, eretto a cartagine dal liberto p. perellio edulo. roma con la vittoria davanti a un monumento che celebra la pace e la prosperità universale. prima età imperiale;” pp. 333-334 on the same relief of this altar: “... la composizione va intesa come una versione semplificata di quelle che è, sull'ara pacis, la coppia roma-pax ... simbolo della pace e del benessere universale;” cf. zanker 1987: 304, fig. 240. 73 for “... zwei antithetisch aufgestellte füllhörner als zeichen des goldenen zeitalters [in the augustan period].” see also schneider 1997: 103; pollini and cipolla, in section 7 below: “an implied sexual connection between the obelisk and the ara pacis would have highlighted augustus' bringing to the world felicitas (good fortune), with its attendant fertility and prosperity, requisite for the rebirth of the golden age.” 74 berges 1995: 103; häuber 2014: 714 with n. 223 and 603 with n. 15. 75 rice 1983: 203, 204; häuber 2014: 604 with n. 24. the relationship between the montecitorio obelisk and the ara pacis     1:50 figure 16. marble altar dedicated to divus augustus. museo archeologico nazionale, palestrina. thus berges notes “the tangible promise of prosperity, which is expressed by the cornucopia,” and further interprets the “unusual altar” in praeneste in this way: “it is certainly no accident that this motif [scil., of the cornucopia] appears on a monument which was dedicated to augustus, the founder of imperial rule in rome, who at the same time inherited power from the ptolemies, and whose domestic program strove to communicate through the concept of pax augusta the same promise of prosperity which long before him the ptolemies had expressed through the imagery of the dikeras.”76 the praeneste altar was dedicated to divus augustus posthumously, but we can nevertheless be sure that he himself was quite familiar with the meaning of the iconography. on one of the first coins that he minted in alexandria (before 9/10 ad) a portrait of his wife livia appears on the obverse with the legend livia sebastou (“livia, the wife of augustus”). on the reverse, we see the legend patros patridos (referring to augustus’ title pater patriae bestowed upon him in 2 bc77) as well as the ptolemaic dikeras (two parallel cornucopiae), which contain, as usual, poppies and ears of wheat and are wound about with a tainia (the royal diadem of the ptolemies). at about the same time augustus issued coins in alexandria with a portrait of himself on the obverse with the legend pater patridos and on the reverse the dikeras with the legend sebastos (“augustus”) [häuber 2014, 715, n. 234]. he could not have chosen better iconographic motifs to proclaim that now the imperial couple guaranteed “prosperity” (“wohlfahrt,” berges) in exactly the same fashion as the ptolemaic rulers had done. considering what was said above, we may ask ourselves whether or not the ideological basis for augustus’ claim to good leadership is actually indicated in the iconography of the praeneste altar, viz., the radiate crown worn by augustus (figure 16). we know that he was the first roman emperor to wear a radiate crown [bergmann 1998]. the hypothesis proposed here can only be true if the sun-rays must be explained by the fact that augustus was also the first roman leader who was the pharaoh of egypt and thus believed by the egyptians 76 berges 1995: 95 with n. 25, p. 103 with n. 64, taf. 26,3, which quotes zanker 1987: 304. german passages translated above by b. frischer. 77 cf. r. hanslik, s.v. augustus, der kleine pauly, vol. 1, 1979, col. 752; häuber 2014: 715 with n. 232. the relationship between the montecitorio obelisk and the ara pacis     1:51 to be the son of the sun god re.78 here, again, as with the cornucopia, augustus’ precedent came from ptolemaic royal imagery [bergmann 1998: 112-115]. as observed by musso, the roman emperor was regarded as “parens mundi, producer of good governance and in turn governor of fate. in the official terminology, the quality of guarantor of the cosmic order is transmuted into imperial virtue.”79 la rocca writes under the rubric “augustus' political vision” that “augustus was born for the welfare of mankind” [la rocca 2014, 157]. all this sounds exactly like the theological construction of the image of the egyptian pharaoh, as discussed above. in a relief at the temple of esna in egypt, the emperor caracalla is shown as pharaoh in the act of harvesting wheat, and the inscription calls him “guarantor of fertility and nourisher of the people.”80 the inscription on the antinous obelisk at rome even reads: “hadrian, supported by the nile god, is the guarantor of fertility for the entire world.”81 7. the birth of augustus, the solarium augusti, and the life-giving aspects of apollo and sol in augustan visual culture john pollini82 with nicholas cipolla in 12 bc, augustus became pontifex maximus, a position that gave him control of the roman calendar and thereby also, in a sense, control of time itself. one of his first and most important tasks as supreme pontiff was to correct the julian calendar following an error introduced by the pontifices shortly after julius caesar’s death.83 to correct this mistake, which may have involved the inclusive roman method of counting intercalary days, and to check the roman calendar on a daily basis throughout the year, augustus made plans for a great calendrical meridian line, to be laid out in the open space of the campus martius [cf. macrobius, sat. 1.14.13-15]. the meridian made use of an egyptian obelisk for its pointer, or gnomon. the meridian line and gnomon functioned together as a calendrical “solar device,” or calculator.84 for the pointer of this special type of solarium, an obelisk originally set up by the pharaoh psametik ii (594-589 bc) at heliopolis, egypt was erected in the 78 for other interpretations, cf. musso 2000: 378; frischer, below section 11, on the ara providentiae. 79 musso 2000: 378 with nn. 64, 65; cf. häuber 2014: 715 with n. 231. italian translated by b. frischer. 80 hölbl 2004: 529 with n. 14, fig. 7; häuber 2014: 736 with n. 71. 81 hölbl 2004: 529; häuber 2014: 736 n. 72. 82 i would like to thank bernard frischer, paolo albèri auber, david dearborn, and matthew brennan for information and discussions about various aspects of the solarium–ara pacis complex and the new frischer-fillwalk virtual meridian simulation. special thanks are also owed to nicholas cipolla, who collaborated on the models for my book (pollini 2012), and for discussion and comments on both of my essays published in this series of contributions. in addition, i thank lothar haselberger for inviting me to participate in recent scholarly discussions regarding the solarium (horologium) augusti and to contribute an article in a collection of essays published in jra suppl. 99 (2014) 53-61. to reduce the bibliography to a minimum, i have cited where applicable my recent book (pollini 2012), in which a number of these themes have been explored at greater length and with further bibliography. new ideas and observations are also incorporated here. see also in general galinsky 1996. 83 see stern 2012: 214-216, nn. 163-164. 84 a scholarly debate has arisen on the use of the correct terminology to describe both the meridian and the colossal obelisk used as its gnomon, since objections have been raised to referring to these two objects together by the synonymous terms horologium and solarium, both of which are commonly used to mean a “sundial” in the sense of a diurnal clock. for this debate, see most recently haselberger 2014: 171-73. in fact, neither term was used in the ancient sources to describe augustus’ meridian with its obelisk gnomon-pointer. since the word horologium puts emphasis on the horae, or hours of the day, we prefer to use the term solarium in describing this gnomon-meridian device for no other reason than the term solarium places emphasis on the “sun,” and therefore literally means in latin a “sun thing/device.” consequently, we employ the modern term “solarium augusti” to describe the gnomon-meridian in the sense that it was a calendrical solar device. for a discussion of the various types of solaria, see varro (ling. 6.4) and pliny (hn 7.214). see also cicero (nat. d. 2.87) for the seemingly odd use of the term solarium ex aqua for a water clock. the relationship between the montecitorio obelisk and the ara pacis     1:52 campus martius in rome.85 the very transporting of such granite behemoths on specially constructed ships was itself considered a wondrous feat of roman engineering that was credited to augustus.86 to immortalize his victory over cleopatra (and antony), which also marked the end of the roman civil war period, this obelisk in its new context was made roughly 100 roman feet high, a number that had great symbolic value, since the roman numeral c (= 100) was closely associated with the concept of immortality and eternity.87 in order to achieve this height (ca. 29.60 m),88 a granite base and a once gilded bronze finial, or top ornament, were added to the obelisk’s shaft, which originally stood only 21.79 m high.89 the shadow cast by the obelisk with its finial would have fallen along the long bronze meridian line with short bronze cross-bar markers (regulae), which was laid out on large white travertine flagstones with markings indicating the path of the sun at noon each day over the course of a year, probably from about 9/8 bc on.90 bronze letters in greek for the signs of the zodiac and the winds were also set into the travertine pavement of the meridian to indicate the periods and seasons of the year. as pliny tells us [hn 36.72], the gilded sphere that formed part of the finial was attached to the pyramidion, the pyramid-shaped capstone of the obelisk, to give greater clarity or definition to the shadow cast on the meridian line, an arrangement inspired by the shadow cast by the head of a human body. as with augustus’ other great urban projects in rome, his calendrical solarium would serve both a practical and an ideological function. besides its use as the gnomon for the meridian, there were a number of important symbolic and ideological aspects to augustus’ obelisk, especially in connection with the nearby ara pacis augustae and more distant mausoleum augusti. in egyptian religion, rose-colored granite obelisks are sacred to the sun god re, and their pyramidion-shaped capstones, probably gilded, are symbolic of the triangle that 85 for this obelisk, see swetnam-burland 2010: 53. another colossal obelisk imported by augustus was that of seti i, later erected by his son rameses ii. this obelisk was set up originally on the spina of the circus maximus, but was re-erected in modern times in the piazza del popolo. pliny (hn 36.71) confuses these two obelisks and their original locations. 86 for a description of the transportation of such colossal obelisks, the ships used to carry them, and the obelisk that augustus set up on the spina of the circus maximus, see pliny (hn 36.70). 87 this is implied by the predilection for propitious hundred-foot monuments among both the greeks (e.g., hekatompedon temples) and the romans (e.g., the colossus of the god sol set up by nero, as well as the columns of trajan and of marcus aurelius). also relevant is the anecdote recounted by cassius dio (56.29.4) that a thunderbolt (a divine sign) struck a statue of augustus on the capitoline and obliterated the “c” in his (inscribed) name “caesar.” this led seers to conclude that 100 days hence augustus would attain divine status, thus becoming a god (divus), as he did, since the word “caesar” is composed of the letter “c,” signifying 100 among the latins (romans), while the rest of the name “aesar.” signified “god” among the etruscans. secondarily, roman architects liked even numbers, especially multiples of 10 units. it was also well known that the greek philosopher pythagoras had established 10 as the perfect number, since it contained in itself the first four integers—one, two, three, and four [1 + 2 + 3 + 4 = 10]. the isosceles triangular figure (tetractys), produced when ten points are arranged in four rows with one, two, three, and four points in each row, became a mystical symbol. the number 100 (i.e., 10 x 10) might be thought to be beyond a human concept of perfection and thus came to be associated with the divine, as well as with immortality and eternity. 88 the roman pes (“foot”) as used in various monuments and buildings varies from ca. 29.40 to 29.60 cm. we thank robert cohon for discussions on this matter and permitting us to read his article before it was published. see now cohon 2015, especially 80-81. 89 we are skeptical about the two separate phases proposed by p. albèri auber 2011-12: 469, 501; 2014: 68-69; namely, that the meridian and the spherical finial which were added to the obelisk were part of some practical “afterthought” or secondary plan after the obelisk had been set up to serve only an ideological need (i.e., as a victory monument). in our opinion, the obelisk and the meridian would have been planned together from the outset shortly after augustus became pontifex maximus, when he then had the right and duty to rectify problems with the calendar. this “unitary project” was proposed by e. buchner and l. haselberger: see haselberger 2011: 53-55, and his recent criticism of albèri auber on this matter, 2014: 193-94. there are too many unknowns to be definitive on this matter. nevertheless, this problem deserves further study. in any case, even if there were two distinct phases, the meridian would most likely have been in place very soon after the setting up of the obelisk, probably at the latest by 8 bc, several years after the julian calendar was recognized to have been in error. if it were a two-step process, the addition of the finial would have given even greater meaning to the relationship of the monuments. 90 the year 8 bc was the final year that an incorrect intercalary day was inserted into the julian calendar. after that year augustus suspended all leap years until ad 4 in order to correct the calendar. see stern 2012: 214-15 with nn. 161-62. the relationship between the montecitorio obelisk and the ara pacis     1:53 the sun’s rays form, especially when seen on a cloudy day as they break through clouds. in fact, as pliny [hn 36.64] tells us, the egyptian word tekhen is the same for “sunbeam” and “obelisk.” rose-colored granite used for obelisks was emblematic of the fiery sun itself and was understood as such even in roman times, as suggested by the greek word pyrrhopoekilos (“red-spotted”) for this type of bespeckled rose-colored stone [pliny hn 36.64]. in discussions about the significance of the sun and the obelisk of augustus, it has been generally overlooked that engraved in negative relief at the very pinnacle of the four sides of the pyramidion of this obelisk is the sacred egyptian scarab, symbolic of the creator god khepri, pushing the solar disc across the heavens over the course of the day. figure 17. james stuart’s engraving of the pyramidion of the montecitorio obelisk; bandini 1750: plate iii. this engraved image, drawn by stuart in the mid-18th century from the fallen obelisk (figure 17), finds an analogue in the movement of the obelisk’s shadow over the course of the day.91 though generally also not commented on, the gilded sphere affixed to the top of the pyramidion of augustus’ obelisk suggested the very form of the sun in all its golden brilliance and was symbolic of the sun god re, who in this new augustan context was to be thought of as the roman sun god sol (or helios, as he was known to the greeks). the pertinent part of the latin inscription on the base of the obelisk makes clear that it was to be understood as a roman victory monument dedicated to sol: augustus... aegypto in potestatem populi romani redacta soli donum dedit (“... with egypt restored to the power of the roman people, augustus dedicated [this] to sol”) [cil 6.702 = ils 91]. with egypt again under roman sway, augustus had now become the direct successor of the ptolemies and the official upholder of ancient egyptian religious traditions.92 91 because of the height of the obelisk and the slope of the pyramidion, this feature is almost imperceptible from the ground. for this illustration, see stuart 1750, pl. iii. for the hieroglyphs on the obelisk, see ciampini 2004: 142-49 (no. 6). 92 prior to octavian’s conquest of egypt in 30 bc, the country under the ptolemies had become so weakened that it became de facto a protectorate of rome—hence caesar’s intervention on the matter of who would rule egypt. this is why the specific verb redacta (“having been restored/brought back”) is used with aegyptus (f.) in the dedicatory inscription. importantly, julius caesar was probably first introduced to the egyptian solar calendar when he was in alexandria in 48 bc. he is also said to have planned to improve on the calendar of eudoxos of cnidus (fourth century bc): see luc.10.186-187. pliny (hn 18. 211-212) mentions that sosigenes of alexandria assisted caesar in the implementation of the new julian calendar. the relationship between the montecitorio obelisk and the ara pacis     1:54 but victory was only one of the two principal pillars of augustus’ verbal and visual ideology; the other was peace. the roman concept of “peace through victory” was, in fact, one of the fundamental ideological messages of augustus’ great urban projects, or as augustus himself expressed it more fully in his res gestae (13): per totum imperium populi romani terra marique ... parta victoriis pax (“throughout the entire empire of the roman people, both on land and sea peace [was] brought forth by victories”).93 for this reason, the base of augustus’ obelisk was set in near axial alignment with the ara pacis augustae (“altar of augustan peace”), a pendant monument voted by the senate in 13 bc. the ara pacis was located just under 90 m to the east of the obelisk. at a distance of about 35 to 36 m to the east of the ara pacis and running parallel to it was the via flaminia (via lata), the roughly north-south main thoroughfare leading out of rome which augustus himself had recently restored [rg 20]. in order for the calendrical solarium to function, the meridian had to be placed in north-south alignment at an angle of about 15° to the axis of the obelisk. together, the solarium, with its obelisk/gnomon celebrating victory, and the ara pacis, heralding augustan peace, would convey augustus’ principal ideological concept of “peace through victory.” of all his achievements, peace through victory was his most important and the one that would eventually lead to his apotheosis after death, as even ovid recognized in his metamorphoses [15.868-70]. augustus’ birth and accomplishments in life were connected symbolically with his death and future deification through the axial alignment of the obelisk and his great dynastic mausoleum to the northwest. as testimony to his right to apotheosis, augustus indicated in his will his desire that his achievements be engraved on bronze tablets flanking the entrance to his mausoleum [suet. aug. 101.4].94 at the heading of this posthumous public record of his official accomplishments were the words res gestae divi augusti [see also suet. aug. 101.2]. in this way, the solarium-ara pacis complex was brought into an intimate relationship with the mausoleum augusti, which had been finished around 25 bc. from the optimum viewing angle of these three monuments, an observer could synoptically appreciate the concept of peace through victory leading to the apotheosis of augustus, whose image atop his mausoleum most likely represented him in a triumphal chariot (in quadrigis) to celebrate his triple triumph in rome in 29 bc, just after construction had commenced on his great dynastic tomb. with such a quadrigate image towering over the campus martius at a height of about 150 roman feet, augustus would have appeared to an approaching viewer (especially from the south) as though he were ascending to heaven like romulus in the chariot of his father mars, an event which is said to have occurred to the south near where the agrippan pantheon was built.95 as in the case of dedications of roman temples, association with imperial birthdays and anniversaries also played an important role in the solarium-ara pacis complex.96 the ara pacis itself was dedicated on january 30 in 9 bc, the 50th birthday of augustus’ wife livia. as for the obelisk, the inscription on its base indicating offices held by augustus makes it clear that the obelisk was dedicated around the same time, between june of 10 and june of 9 bc. in my view, the specific date is likely to have been the birthday (dies natalis) of augustus, on september 23 in 10 bc. that year marked the vicennalia (20th anniversary) of augustus’ great military success 93 for the roman concept of “peace through victory,” see pollini 2012, especially 178-190. 94 buchner discovered the foundations of these two pillars: buchner 1996: 161-68; pollini 2012: 251, pl. xxviii. 95 for these ideas, including new models of the mausoleum augusti and the circumstantial evidence for the image of augustus atop his mausoleum being of the quadriagate form rather than the assumed statua pedestris (on foot) type, see pollini 2012: 248-56 with further bibliography. 96 for the six roman temples that we know were rededicated on augustus’ birthday (sept. 23) after restoration, see gros 1976: 33-34. although the ara pacis was not an aedes (a “temple” in the modern sense of the word), it was a templum in latin terminology, in that it was a sacred inaugurated precinct, marked out on the ground by augurs: pollini (2012) 227. this was also true in the case of the majority of roman aedes. the relationship between the montecitorio obelisk and the ara pacis     1:55 over cleopatra. it is also noteworthy that augustus’ 50th birthday fell in the year 13 bc, when the ara pacis was constituted (constitutio) by the roman senate.97 even in the roman provinces, augustus’ birthday was a significant occasion; for example, at the time of the construction of the solarium-ara pacis project in rome, the koinon of the hellenes in asia (minor) voted that their new year begin on augustus’ birthday. recognizing the importance of that date, buchner, who excavated a section of the augustan meridian, concluded that the shadow cast by the obelisk pointed directly toward the center of the ara pacis in the afternoon of augustus’ birthday on september 23, indicating that augustus was born to bring peace to the world ("natus ad pacem").98 the new simulations published here are based on frischer’s forthcoming correction of buchner’s positioning of the meridian fragment and obelisk on the map of contemporary rome, and they also update the position of the shadow in relation to the ara pacis on augustus’ birthday. they show that at that time the shadow of the obelisk with its finial fell on the western staircase of the altar (figure 18). the inscription of the koinon of the hellenes also noted the felicitous and momentous near-coincidence of his birthday with a cosmic event, namely, the autumnal equinox.99 augustus’ birthday would in all probability have been highlighted with a sacrifice at the altar in the afternoon, when priests and spectators would have witnessed the penumbral shadow of the obelisk falling on the staircase leading to the entrance.100 although the shadow pointed toward the ara pacis on other days as well, the birthday sacrifice would have given special meaning then to the location and orientation of the shadow of the obelisk with its finial.101 to be sure, the shadow would have been somewhat diffused by the time it reached the ara pacis’ western (front) entrance at around 4:22 pm (=16:22 cet).102 nevertheless, it would still have been clearly visible, especially on the white marble stairs, as calculations of the penumbra of the obelisk’s sphere and comparative studies of the shadows of other obelisks have shown.103 the shadow of the obelisk’s finial would have fallen near the top of the staircase (figure 18), or may have just pierced the western entrance of the ara pacis on september 23 and september 24 (figure 19),104 while on september 26, the darker, umbral shadow of the shaft of the obelisk itself would have pierced this entrance. this phenomenon would have had great visual symbolism, as we shall see.105 we may note here that augustus’ 97 for a discussion of the constitutio in relation to the inauguratio of the ara pacis and the event represented on the two processional friezes of the altar, as well as its dedicatio and consecratio, see pollini 1978: 95-99. 98 for this neologism, see buchner 1982: 37. 99 haselberger 2011, no. 12 and 2014: 34-35 with further references. 100 sacrifices were made to augustus’ genius on many occasions and in many places by vote of the senate starting in 30 bc: cassius dio, 51.19.7. see also taylor 1931: 151-52; pollini 2012, especially 330-31 et passim. 101 it is important to remember that such an alignment happens twice a year, once in the fall and once in the spring. we thank bernard frischer for emphasizing this point. the alignment in the fall (september 23) is clearly the more important one, since that was the birthday of augustus, when a crowd would have gathered for the birthday sacrifice, as noted above. 102 the shadow shown in some simulations is slightly darker than it would have been in reality because the simulation does not represent penumbral (soft) shadows accurately. see here, however, figures 18-19, which show more accurately the penumbral shadow of the finial. 103 we thank astrophysicist dr. david dearborn of nasa ames research center for calculating the degree of saliency of the penumbral shadow at a distance of ca. 90 m (only 32% as bright as the surrounding sunlit area) and corroborating that the shadow of the obelisk with its sphere-and-spike finial could indeed be seen at that distance. for an approximation of the diffusion of this penumbral shadow based on the shadows cast by actual obelisks, cf. pollini 2012: 215, figure v.7e, and especially pollini 2014: 55-56, 59-60, figs. 2-5. 104 from the perspective of a viewer standing on the ground the shadow would have appeared at the top of the stairs. see the following note. 105 how high on the staircase or how near the western entrance of the ara pacis the shadow of the finial fell cannot be determined exactly because the true height of the obelisk with its finial is only a close approximation to the roughly 100 roman feet already discussed. see pollini 2014: 54-55. the relationship between the montecitorio obelisk and the ara pacis     1:56 birthday was actually celebrated formally on both september 23 and 24—a biduum (“double-day”) celebration.106 it is therefore quite possible that on these two days, birthday sacrifices would have been performed in front of the ara pacis at the time the shadow of the finial first approached (sept. 23) and then approached even closer to the entrance (sept. 24), as suggested here in figures 18 and 19. equally important, as the new simulations reveal, if one looked west from the customary place of sacrifice in front of the ara pacis’ staircase, the sun’s disk would have appeared to hover directly over the top of the obelisk, as recreated in figure 7 (september 23) and reported by frischer in appendix table 2. this phenomenon, which we observed and note here for the first time, would have also underscored the importance of augustus’ birth in connecting the obelisk with the ara pacis. indeed, the alignment seen at the bottom of the staircase was repeated each day for the next five days. each day, the best vantage point was ca. 1 m farther east along the axial line running up the staircase until reaching the interior of the ara pacis on september 26 (see appendix table 2 for that date). figure 18 (left). frischer-fillwalk simulation showing shadow of finial hitting front stairs of the western façade of the ara pacis at 16:22 cet on september 23, 9 bc. note that unity does not render the penumbral shadow, so the shadow of the finial has been lightened in photoshop to suggest how it might have actually appeared. figure 19 (right). frischer-fillwalk simulation showing shadow of finial hitting front stairs of the western façade of the ara pacis at 16:23 cet on september 24, 9 bc. note that unity does not render the penumbral shadow, so the shadow of the finial has been lightened in photoshop to suggest how it might have actually appeared. in this context, we should recall that the obelisk was an egyptian phallic symbol stressing the life-giving force of re, reborn into the world of man each day at heliopolis, where his sacred obelisk-like bnbn stone was enshrined and revered [quirke 2001:135]. in a graphic representation of re-harakhti (“re-horus of the horizon”) on the painted funerary stele of tapéret in the louvre (ca. 1000 bc), rays emanating from the solar disc take the form of rows of lotus blossoms.107 the ancient egyptians regarded the lotus as the primordial symbol of creation, out of which the newly born sun was said to have arisen. the “penetration” of the stairs of the ara pacis and likely also its west entrance by the solar alignment, as well as by the shadow of the sphere atop the obelisk, would have great symbolic value in terms of cosmic birth or rebirth, especially since the 106 see degrassi 1963: 514 for sept. 24 in the fasti. on this day, the arvals also sacrificed. cf. pollini 2012: 213-16, with fig. v.7e, where in our first published computer simulation of the solarium/ara pacis complex we had already recreated this phenomenon, although the actual piercing of the doorway (with its symbolic significance) may have occurred on the second day of the biduum of augustus’ birthday instead of the first. 107 louvre, inventory e 52. for an illustration, see http://www.louvre.fr/oeuvre-notices/stele-de-la-dame-taperet the relationship between the montecitorio obelisk and the ara pacis     1:57 egyptian word for “obelisk” (tekhen) derives from the verb “to pierce,” which can have sexual overtones in terms of regeneration, or rebirth, as a result of piercing or penetration.108 moreover, the latin word obeliscus derives from the greek obeliskos, meaning “small spit,” or “skewer,” which undoubtedly also had sexual overtones, given its obviously phallic shape. sexual overtones in the context of cosmic birth and rebirth are to be found, after all, in augustus’ own expression in his res gestae [13], parta victoriis pax (“peace brought forth by victories”), since the latin perfect passive participle parta is from parīre, that is, “to bring forth” in the sense of procreation, or “to give birth to.” the notion of birth and rebirth are also symbolized in the floral scroll reliefs of the ara pacis, as we shall see below. an implied sexual connection between the obelisk and the ara pacis would have highlighted augustus’ bringing to the world felicitas (“good fortune”), with its attendant fertility and prosperity, requisite for the rebirth of the golden age. augustus’ birthday was also linked to felicitas, as evidenced by the contemporary decree of the koinon of hellenes of asia (minor), noted above, and a letter of its proconsular governor paulus fabius maximus, especially the phrase “his birthday heralds the beginning of life and real living” (ἀρχὴν τοῦ βίου καὶ τῆς ζωῆς γεγονέναι).109 in roman thought, felicitas was one of the key elements resulting from victory, as expressed in the triumphal formula, auspicio, imperio, felicitate, ductuque (“through auspices, legal authority, good fortune, and military leadership”).110 it is worth noting as well that the temple of felicitas in rome was one of the six temples associated with augustus and rededicated on his birthday [gros 1976; degrassi 1963: 512]. figure 20. fragment of a relief from vienne showing sol rising from the sea. musée lapidaire, vienne. source: john pollini. all these blessings and fruits of peace, birth, and regeneration as a result of victories were possible because augustus was the charismatic leader chosen by the gods to govern on earth. 108 see swetnam-burland 2010: 139 with n. 27. see also her section 4 above. 109 for the preserved greek and latin texts with commentary, see sherk 1969: 328-37 (no. 65); for the quotation from the epis. pauli fabii maximi 10, see 329. 110 see, e.g., livy 40.52.5. for a discussion of the meaning of the words in this roman triumphal formula, see versnel 1970: 356-371. the relationship between the montecitorio obelisk and the ara pacis     1:58 the messages of peace and prosperity and the prophesied return of the golden age under augustus and apollo/sol were all given verbal and visual expression in augustan private literature and art, as discussed by miller below. in non-official arts, such as a relief from vienne in southern france representing sol rising out of the sea (figure 20),111 the god looks somewhat like augustus because of the strongly idealized facial features of augustus in some of his portraits. private or non-official sentiments such as these find close parallels in other private works of art of the augustan age, most notably in the gemma augustea.112 on this large, magnificent sardonyx cameo augustus is presented jupiter-like, holding a ruler’s staff and augural lituus. to the left of the head of augustus is represented a solar disc (nimbus) with the rays of the sun inscribed within it. overlaying this is capricorn, augustus’ natal sign [suet. aug. 94.12]. together, the sun and capricorn allude to augustus’ birth and future apotheosis, for, in hellenistic solar theology, it was believed that divine monarchs descended to earth from the sun, king of the stars, and that after death they would return to the sun to dwell as gods in the heavens [vell. pat. 2.123.2; man. astron. 1.799-804]. stories were also told that augustus’ father octavius dreamt that before the birth of his son, the sun rose from the womb of augustus’ mother atia and that augustus himself was the product of a virgin birth, in that apollo had come to atia in the form of a snake (that is, a genius, or divine spirit) [suet. aug. 94.4]. on another occasion his father dreamt that his son appeared to him wearing the sun’s radiant crown, dressed like jupiter and with the god’s insignia [suet. aug. 94.6]. it was also said that augustus himself took special pride in thinking that the glance of his eyes was like the radiance of the sun [suet. aug. 79.2]. the co-numinous workings of augustus’ patron god apollo-sol are underscored in the ara pacis augustae, a premier example of augustan official art.113 although there are no exact equivalents in greek and roman religion to the egyptian sun god re, apollo and sol overlap in relation to the physical sun and its life-giving powers. as a god of regeneration and of light—clearly attested in his epithets “phoibos” and “lykios”—apollo is intimately associated with the personified sun, sol (helios).114 so closely related were phoibos apollo and helios/sol in greek and roman times that they were considered a numen mixtum, or mixed divine entity. even though the two were separate divine forces, many ancients considered them to be the same [plut. mor. 386b, 393d, 1130a]. their close tie was also visually attested in other forms of augustan art. in the imperially commissioned statue of augustus from prima porta, helios/sol is represented driving his solar chariot across the heavens at the top of augustus’ breastplate, while lower down on the left appears apollo, playing his lyre and seated on his sacred griffin, a fabled animal long associated with the sun.115 both gods are likewise found in close association with augustus and his temple of apollo palatinus, since the statue of helios/sol riding a chariot once served as the central acroterium of this temple [prop. 2.31.11]. 111 musée lapidaire, vienne: pollini 1993a: 282, figure 85. a statue of apollo in the library of augustus’ house on the palatine is also said to have borne the features of augustus. if so, it was probably set up after his death and deification; if set up by augustus himself, it is highly unlikely that the features of the god apollo would have been assimilated to his own, given his propriety in such matters. this would not, of course, have prevented someone from reading into the idealized facial features of the god a portrait of augustus. for problems associated with the appearance of this statue, see pollini 2012: 70-71; for the differences between official and non-official art, see pollini 2012: 69-161. 112 for the gemma augustea and the complexity of its visual language, see pollini 1993a. it should also be noted that ideas expressed in this private work of art differ radically from those expressed in augustus’ official public arts after the founding of the principate in 27 bc. see also previous note. 113 for the ara pacis, see pollini 2012: 204-308. 114 for the many aspects of apollo and helios/sol, see pollini 2012: 271-308. 115 see pollini 1995, with further bibliography. the relationship between the montecitorio obelisk and the ara pacis     1:59 specifically, in connection with the notion of rebirth in nature, helios/sol is found represented in art rising out of an acanthus, itself a symbol of regeneration. in hellenistic egypt this motif was apparently adapted from earlier egyptian works showing the sun god re rising for the first time out of the primeval lotus blossom. because of the acanthus’ symbolic importance, especially in connecting apollo and dionysos as gods of fertility in the cycle of life, death, and regeneration, it is the dominant plant form in the floral scroll reliefs of the ara pacis.116 out of its many lituoid, or lituus-like, convoluted vines grow other plant forms in a fantastic manner intended to recall the return of the golden age, when nature is renewed by the life-giving forces of the sun, as alluded to by the numinous presence and workings of sol and apollo. among the various animal forms on the ara pacis that herald this new golden age dawning under augustus are the reiterated augural swans, which grace the tops of the candelabrum-like acanthus stalks. swans were said to have attended the birth of apollo and to have borne the god in a chariot to his oracular shrine at delphi. on the ara pacis they underscore the altar’s augural aspects because swans were given the gift of prophecy by apollo [cic. tusc. 1.30.73], the augur god of mighty jupiter [verg. aen. 4.376-378].117 with widespread wings they are represented enframed on the ara pacis by another apolline emblem, the palm, which takes the form of sickle-shaped split palmettes that resemble the wings of a bird. these split palmettes are the most frequently appearing floral forms on the ara pacis after the acanthus. they also are very similar to the acroteria on the corners of the ara pacis, as represented on the reverses of roman coins such as the one illustrated above by capriotti (figure 9). palm (phoinix), too, is a symbol of victory. in greek, it is the same word (φοῖνιξ) for the fabled phoinix (lat. phoenix), the solar bird of arabia, or the east, where the sun rises. it also symbolizes regeneration and rebirth, as it periodically and victoriously arose from its own ashes on widespread wings to live again. the many alignments reported above in the first part of this article also associate the gods sol and apollo with the obelisk of augustus and the ara pacis. as already noted, the base of the obelisk and the ara pacis are in near axial alignment. and, as we know from other monuments, roman architects and urban planners were obsessed with axial alignments and with the “linear manipulation” of viewers to create specific visual and symbolic effects.118 through these new computer simulations, it was discovered that when one stood on an extension of the axial line joining the ara pacis and the obelisk, there were several hundred days on which a solar alignment could be seen, whether in the early morning, when viewed from the west (frischer’s zone 1), or in the afternoon, when viewed from the east (frischer’s zone 4). moreover, there were many days on which the ancient viewer could see the sun rising on axis behind the ara pacis (frischer’s zone 3), and others on which the obelisk’s shadow pointed toward the direct center of the ara pacis, as frischer shows in appendix table 5. these solar alignments bring to mind augustus’ special relationship with apollo, especially apollo palatinus, with his strong solar aspect, which is discussed below by galinsky (section 9). this phenomenon also played off augustus’ birth, since another very important temple of apollo, that in circo flaminio (also known as the temple of apollo 116 for the divine associations and meaning of acanthus, especially in connection with the ara pacis, see pollini 2012: 278-96. 117 for the augural aspects of the ara pacis’ scroll reliefs, see pollini 2012: 296-99. for the importance of augury in the figural friezes of the ara pacis in general, see also pollini 2012: 204-308, et passim, and in my other essay, “aeneas, augury, and dynasty and destiny in the ideology of augustan visual culture,” below, section 8. 118 cf. above n. 24. on the sight lines, linking various monuments associated with augustus in the campus martius, especially the optimum viewing angle of the mausoleum of augustus, the solarium’s obelisk, and the ara pacis augustae, as well as their ideological significance see pollini 2012: 210-11, figs. v.5 & v.9, pl. xx. for roman architects’ use of sight lines and reading urban structures in context, see, in general, favro 1996. the relationship between the montecitorio obelisk and the ara pacis     1:60 sosianus), was rededicated on augustus’ birthday. it was in this temple that the senate met to deliberate on the awarding of triumphs, which soon only members of the imperial family were to be granted.119 thus, important dates of dedication involving augustus, his birth, his patron god apollo, and the roman sun god sol were given visual form and great ideological significance in some of the greatest urban monuments in the iconosphere of augustan rome. 8. aeneas, augury, and dynasty and destiny in the ideology of augustan visual culture john pollini the concept of “peace through victory,” (parta victoriis pax) emphasized by augustus himself in his res gestae [13],120 found visual form in the obelisk of augustus (celebrating his victory over egypt) and the ara pacis (heralding augustan peace). these two monuments were axially aligned. as demonstrated by the new frischer-fillwalk virtual meridian simulation of the obelisk and the ara pacis, after the shadow of the top of the pyramidion with its sphere-and-spike finial fell near the top of the western staircase or just into the entrance of the ara pacis on the biduum of september 23 (figure 18) and september 24 (figure 19),121 the shadow veered south and passed to the right of the entrance of the ara pacis, climbing up the right side of the precinct wall until, at ca. 16:33 cet the shadow of the finial first fell upon the figure of aeneas in the “aeneas panel” (figure 21) and then, moving a little further to the right, fell upon the figure of aeneas’ son iulus at ca. 16:35.122 in this way, a visual link was established not only between aeneas and augustus but also with iulus, the founder of the julian house. the narrative of dynasty and destiny, underscored by the many augural aspects of the ara pacis, was thereby extended. the cycle of time from aeneas to augustus was now completed, and an auspicious future was to be expected to continue under the future leaders of the julian house, who appear with augustus in the processional friezes of the ara pacis augustae. trojan aeneas held a special place in the ideology of augustus, figuring prominently both in augustan public and private arts and in the literature of the augustan age, most notably in vergil’s epic poem the aeneid.123 in official augustan art, best exemplified in the related representational programs of the forum of augustus and the ara pacis, aeneas played a particularly significant role in promoting the augustan concepts of dynasty and destiny.124 aeneas was considered the father-founder of the roman race (gens romana) and the archetypal ancestor of the julian house through his son iulus, the homonymous progenitor of the gens iulia. already uniquely positioned in the state as the son of divus iulius, augustus, by virtue of his adoption into the julian house,125 could claim direct descent not only from aeneas but also from the immortal gods, in that venus was 119 for sources, see richardson 1992: 12-13, s.v. “apollo, aedes.” 120 for the augustan/roman concept of “peace,” see especially pollini 2012: 178-190. 121 see section 7 above with nn. 105 and 106. 122 some years ago, in the 1980s, i had asked edmund buchner if the shadow of the obelisk would have fallen on the figure of aeneas on some day during the year. his reply was “no.” however, in viewing the new simulation of the solarium with bernard frischer, orietta rossini noticed that the shadow indeed pointed toward aeneas on the birthday of augustus. i thank bernard frischer for passing on her observation to me. 123 to reduce the bibliography to a minimum, i have cited where relevant my recent book (pollini 2012), in which most of these themes have been explored at greater length and with further bibliography. see also in general galinsky 1996. 124 for the creation of dynastic narratives in augustan art and thought, see pollini 2012: 204-270. 125 for julius caesar in augustan visual culture and rhetoric, see pollini, 2012: 133-161. koortbojian 2013 has also recently published on the divinization of caesar and augustus. the relationship between the montecitorio obelisk and the ara pacis     1:61 the mother of aeneas by his father anchises. augustus’ birthright served, too, to validate further his status in the state as princeps, or “first citizen” of rome, as well as highlight his superior auctoritas. figure 21. shadow of frischer-fillwalk simulation added to pollini’s slightly altered photorealistic reconstruction of the ara pacis (see n. 132). date: september 23, 9 bc at 16:33 cet. note that to suggest the penumbral shadow of the sphere, it has been lightened in photoshop. source: bernard frischer. one of the most important visual expressions of these ancestral and ideological connections was the over life-size sculptural group of pius aeneas, with his aged father anchises (alluding to the past) on his shoulders and his small son iulus (referencing the future) by his side, in the center of the left hemicycle of the forum of augustus in rome.126 dominating this forum was the great temple of the roman war-god mars, the father of the city’s founding hero romulus, who became a god himself and was worshiped under the name quirinus in his own temple on the quirinal hill. his statue, representing him in armor and shouldering a military trophy, was located in the center of the right hemicycle of the augustan forum, as a pendant to the aeneas group in the left hemicycle. these two state heroes, aeneas and romulus, were also linked through parental love, expressed in the union between aeneas’ mother venus and romulus’ father mars. as augustus had brought mars, the god of war, within the sacred pomerium of the city, where peace was to reside, so too he “planted” the ara pacis augustae in the northern campus martius. many of the same underlying ideological concepts and the emphasis on dynasty and destiny, going back to rome’s founding heroes aeneas and romulus, also find expression in the visual program of the ara pacis, which the senate voted to augustus in 13 bc for his safe return from rome’s western provinces. this altar was set up in the northern sector of the city. several years earlier, in 19 bc, the senate had voted him another altar, the ara fortunae reducis (“altar of fortuna [patroness of] returning”), set up in the southern sector of the city for 126 this famous lost sculptural group, alluding to aeneas’ flight from troy, was also reflected elsewhere in rome, italy, and the provinces in different artistic media. for this statue group and the statue of romulus in the opposite hemicycle, as well as for the forum augustum itself, see pollini 2012: 22-25, pl. ii, especially with n. 58 for further bibliography. the relationship between the montecitorio obelisk and the ara pacis     1:62 his safe return from the eastern provinces.127 it has not been previously noted that the four cardinal points of the compass are thus symbolically referenced in these two n. and s. augustan altars for his safe return from the w. and e. respectively. in this way, the safety of augustus, wherever he found himself, became increasingly equated with the safety of the state itself. the panel to the right of the entrance of the ara pacis depicts the archetypal ancestral hero aeneas sacrificing over a rustic altar to his household gods, the youthful penates, who appear in the porch of their temple.128 these gods are highly significant, since they are connected with jupiter in augury, a point stressed by the two augural litui that appear in the pediment of their temple. guided by the penates and apollo through augural signs, aeneas had made his way to italy, which he had learned through prophecy was the true ancestral home of the trojans [aen. 3.250-257].129 to the right in the panel is a partially preserved figure wearing distinctive trojan dress, most likely aeneas’ son iulus, who, as noted, was regarded as the founder of the julian house. also represented in this panel are two attendants leading to sacrifice the famous “sow of lavinium,” which, as was also prophesied, would lead aeneas to the site of the future city of lavinium.130 it is significant that aeneas appears here no longer as youthful and beardless, attended by the child iulus in the flight from troy, but rather as the elderly, bearded pater aeneas. having been “much buffeted on land and sea,” aeneas was destined to come to italy, where he would “build a city [lavinium] and bring his [household] gods to latium, from which would spring the latin race, the lords of alba, and the lofty walls of rome” (verg. aen. 1.1-7). having left troy years earlier, iulus was now a young man (iuvenis), represented in this panel on the ara pacis carrying a cornel-wood spear.131 aeneas is posed in a way that is very similar to that of augustus in the south frieze of the ara pacis, though they perform different ritualistic acts. both aeneas and his descendant augustus have their heads veiled and wreathed with laurel, the crown that also signifies victory. like a visual simile, these two figures could be seen at one and the same time by those approaching the ara pacis on its southwest side, an optimum viewing angle (figure 21), which explains in part why the figures of aeneas and augustus are positioned on contiguous sides at this corner of this monumental altar.132 there is, moreover, another implied comparison and sense of emulation: in bringing peace and prosperity to the roman world, which had been torn apart by more than a hundred years of civil wars and foreign conflicts, augustus has even outstripped the achievement of his great ancestor aeneas. on the ara pacis the themes of foreordained peace and prosperity are also figuratively underscored in the magical scroll-reliefs, with vegetation of different seasons growing out of the dominant acanthus plant and vines, which themselves signify rebirth and regeneration of the prophesied golden age now dawning under 127 richardson 1992: 157, s.v. “fortuna redux, ara.” 128 more than a decade ago rehak 2001, following in part an interpretation of his mentor lawrence richardson, jr., identified the stately figure not as aeneas but as the second king of rome, numa pompilius, sacrificing not to the penates but to jupiter and dis. for a rebuttal of this view, see pollini 2012: 242-247. 129 that is, the original home of dardanus, from whom the trojans also take the name dardani (“dardanians”). 130 that this is a sow can be determined from her teats. one of her offspring might have been represented in the broken section behind her as a token figure for her brood of 30 piglets, see pollini 2012: 221 with figure v11c. 131 for the cornel-wood spears borne by iulus and other trojan youth: verg. aen. 5.557. for an older, bearded aeneas and a grown iulus still wearing trojan dress to remind romans of their trojan origin, see pollini 2012: 242-244, figures v.31a-c. 132 for the three-quarter optimum view from the sw corner and its significance, see pollini 2012: 239 with figure v.5 and pl. xx. note that in my pl. xx, i altered slightly the colorized original published image in order to represent augustus and the two figures flanking him wearing the crimson trabea of the augurs with its distinctive scarlet stripes. i have also added the augural lituus to augustus’ right hand. figure 21 above was modified to reflect the same changes. the relationship between the montecitorio obelisk and the ara pacis     1:63 augustus.133 this fantastic floral scrollwork garden is inhabited by various creatures through whose sounds and movements the gods made their will known to man by augury. beneath the great acanthus plant a snake slithers up to a nest of fledglings. this imagery recalls the omen foreshadowing the fate of troy in homer’s iliad [2.311320]. however, the homeric portent of a doomed troy is transformed on the ara pacis into a good omen: one of the fledglings flees the nest to safety, undoubtedly an oblique allusion to aeneas’ fleeing troy and becoming the father-founder of the roman race, the aeneadae (“descendants of aeneas”), who are represented directly above in the processional frieze [pollini, 1993b: 214-15, idem. 2012: 296-298]. without the fall of troy, there could have been no rome [cf. prop. 4.1.87; verg. aen. 1.206].134 the enormous, curling, lituus-like acanthus vines literally surround and bind together all of the figural reliefs of the altar’s outer precinct walls. the message of the entire sculptural program of the ara pacis is clear: an auspicious future is to be expected under the guidance of augustus, appearing in the exterior friezes with his family and the pious leaders of the state. with their assistance, augustus has achieved the correct relationship with the gods, what the romans called the pax deorum (“peace of the gods”), which was essential to the realization of the pax augusta, the very concept embodied in the ara pacis augustae. 9. apollo palatinus, sol/helios, and augustus karl galinsky the solar and shadow alignments of the montecitorio obelisk with the ara pacis on over two hundred days of the year provide a splendid example of augustan sophistication and make excellent sense. buchner’s hypothesis privileged a rather one-dimensional message: september 23 is the birthday of the man who was natus ad pacem. the new hypothesis proposed here that sees significance in the aggregated annually recurrent sun and shadow spectacle, by contrast, opens up wider horizons, including a closer connection with the obelisk and its dedication to sol/helios. in this connection, it is useful to delve into the solar aspect of augustus’ tutelary deity and putative father, apollo. the close association between augustus and apollo thrived especially in the mythology of his life and in augustan poetry [zanker 1987: 149]. it powerfully influenced interpretations of the archaeological evidence on the palatine, especially carettoni’s finding that the “house of augustus” was connected to the temple of apollo palatinus by a ramp [carettoni 1983: 9 and 45 with plan 1]. that hypothesis is the palatine equivalent to buchner’s, and the analogy continues as recent excavations have shown that claim to be unsubstantiated [iacopi 2007: 7-14]. the house in question was lavish indeed, featuring two peristyles, but it was destroyed, still unfinished, for the building of the complex of the temple of apollo; what is shown today as augustus’ house on the upper level cannot be proved to be his [wiseman 2014a; wiseman 2014b; häuber 2015: 7 n. 30]. the essential point is that neither the connecting ramp nor the “house of augustus” are necessary for consolidating the overall picture: the temple of apollo was a cynosure placed next to the augustan compound, the domus augustana. vowed to commemorate the hugely important victory over sextus pompey at naulochus 133 for acanthus as a symbol of rebirth and regeneration, as well as this magical scroll-work garden with its animal life, see pollini 2012: 271-308 with further bibliography, as well as section 7 above. for the flora represented in the scroll friezes, see also caneva 2010. 134 this was undoubtedly how the romans could understand troy’s defeat at the hands of the greeks and how that would be avenged. this would also explain the otherwise seemingly odd (to a modern audience) representation of achilles killing trojan troilos on the breastplate of the magnificent bronze statue of germanicus in the archaeological museum of amelia: see pollini 2017. the relationship between the montecitorio obelisk and the ara pacis     1:64 in 36 bc, its siting grew ever more extensive, leading to the teardown of the aristocratic residence under construction to make room for a greek and a roman library and for a large portico with statues of the danaids. instead of being revetted with marble, the structure was built of solid marble blocks and sent its solar reflection over a large part of the city, including the circus maximus; an argument has been made that its front was facing that way instead of toward the palatine.135 thus, there is no question but that augustus made a statement here with a visual impact second to none. to turn to the connections with the obelisk on the campus martius and the ara pacis, we can begin by noting that the fastigium of the temple was crowned with the chariot driven by sol/helios, the sun god,136 which may have been oriented to the rising sun, the east; the representation recurs on the cuirass of the prima porta statue. it also looked down, as we have noted, on the circus maximus and the obelisk there, also imported from heliopolis and with the identical inscription as that in the campus: aegypto in potestatem populi romani redacta soli donum dedit. sol/helios was, of course, identified with apollo and a second quadriga, guided by apollo and diana, was placed on the arch, also on the palatine [pliny hn 36.26], which augustus built in honor of his father, octavius [kleiner 1988]. customarily, a statue of that honoree should have occupied the top of the arch. here we come, of course, to a central point: the version, parallel to zeus’ fatherhood of alexander, that apollo was the real father of octavian/augustus. and sol had yet another relevant dimension: he was the ancestor of the latins (helios was the father of circe and latinus was her son) and that may be part of the function in which he is invoked, after separate earlier invocation of apollo, in horace’s carmen saeculare (alme sol, 9), which was performed on the palatine [galinsky 1967]. further, apollo palatinus also stood for victory, first at naulochus and then at actium, a dimension that was further enhanced by the proximity of the temple to the two palatine shrines of victoria and by the shared anniversary date with that of venus victrix on the capitoline.137 besides these multiple aspects, the significance of the temple was based on its high-profile uses, such as the repository of the sibylline books (transferred from the capitoline) and frequent meetings of the senate in its libraries [suetonius, aug. 29.3]. in light of all this, the decision to create hundreds of annually recurring alignments of the sun, the obelisk and the ara pacis in the campus martius and nearby campus agrippae is extraordinarily full of meanings. one is the association of apollo with victory, which is the precondition for pax: parta victoriis pax, as augustus put it succinctly in res gestae 13. several years before the construction of both obelisk and altar, vergil depicted augustus as surveying the triumphal procession, and the triumph over egypt specifically, from in front of the temple of apollo palatinus: sedens niveo candentis limine phoebi [aen. 8.720] and as affixing the gifts (dona) from the subject peoples to the temple’s doors. compare again the inscription on the obelisk: egypt has been conquered and augustus presents the obelisk as a donum to the sun god, who on the palatine is explicitly identified with apollo. as the frischer-fillwalk simulations show, the shadow of the obelisk would point to the panel with the julian ancestor, aeneas, on september 23 (figure 21). likewise, the impressive annually recurring solar spectacle in this part of the city recalls palatine sol, who was hymned, at least in part, as ancestor of the latins in the revised celebration of the secular games that highlighted the increased role of the palatine in general. 135 most recently, zink 2012; doubted, e.g., by claridge 2010: 142-143. 136 barchiesi 2009 ingeniously connects the palatine helios and the circus maximus with the phaethon episode in ovid’s metamorphoses (1.747-2.339); additional observations by galinsky 2013: 36-38. 137 fasti amiterni on vii id. oct. the relationship between the montecitorio obelisk and the ara pacis     1:65 in sum, the recurrent spectacle of solar and shadow alignments reported in the beginning of this article has many dimensions—going far beyond a single date, however significant, such as september 23—and this kind of richness of evocations and polysemous associations is quintessentially augustan. 10. horace, odes 4.5 john miller the thematic linkage between the montecitorio obelisk and the ara pacis augustae finds parallel expression in contemporary poetry. in odes 4.5, horace urges augustus to return to rome after his long absence, since peace, prosperity, and the virtue of the nation depend upon his safety. the absence in question would be augustus’ campaigning in gaul, whence on july 4, 13 bc he would formally enter the city accompanied by an elaborate set of ceremonies that included the inauguration of the site (the constitutio) of the ara pacis.138 horace imagines rome’s plenitude and tranquility not unlike the tellus/pax panel on the altar—tutus bos etenim rura perambulat, / nutrit rura ceres almaque faustitas, ‘for the ox roams safely over the fields, and ceres and kindly prosperity nurture the crops’ [17–18].139 romulus, too, figures prominently in both the ode140 and the altar’s iconography. perhaps most striking of all in this connection, given the role of the obelisk dedicated to sol in the campus complex, is the powerful, salutary solar effect, that, in the opening of the poem, horace predicts at augustus’ return [5–8]: lucem redde tuae, dux bone, patriae: / instar veris enim voltus ubi tuus / adfulsit populo, gratior it dies / et soles melius nitent, ‘restore the light, good leader, to your country: for when your face shines like spring upon the people, the day proceeds more pleasantly, and the sun shines more brightly.’ augustus, ‘descended from kindly gods’ (divis orte bonis, 1), is here addressed as a quasi-sun god himself. the ode closes with the sun’s movement marking day’s progress as the romans continually beseech and honor the princeps, now directly called a god [deum, 32; tuum . . . numen, 34-35].141 from these correspondences du quesnay has argued that odes 4.5 was “intended for publication and performance” at the grand celebration for augustus’ return from gaul in july of 13 bc [du quesnay 1995: 182]. not just the dramatic date, but the actual time of composition, will have antedated the emperor’s return, not to mention the completion of the obelisk—ara pacis complex in the campus during the years following 13 (the most commonly accepted date, too, for the publication of odes 4142). but, suggests du quesnay, “horace was well aware of what was being planned for the return of augustus” [du quesnay 1995: 186]. while this interpretation finds support [la rocca 1999: 155], in the absence of fuller evidence one understands the skepticism registered towards du quesnay’s speculation that horace’s appeal for augustus to come back was actually performed at the ceremonies for his return in 13 [thomas 2011: 7 n. 13 and 152]. it may be safer to follow du quesnay’s alternative formulation that odes 4.5 was “intended to evoke the carmina that formed a 138 dio 54.25 with i. du quesnay 1995: 135–38. for the senate’s formal decision to erect the altar, the constitutio, made a feast day also for two other augustan altars, see aug. rg 12.2 and the calendars as reported in degrassi 1963: 476; also wissowa 1912: 475 and welin 1939. 139 e.g., benario 1960: 342, whose article traces parallels with the ara pacis throughout odes 4; syndikus 1973: vol. 2, 340. 140 4.5.1–2: optime romulae / custos gentis, which triggers awareness of an ennian passage on romulus (ann. 105–9 sk.) that permeates the ode. 141 4.5.37–40: ‘longas o utinam, dux bone, ferias / praestes hesperiae!’ dicimus integro / sicco mane die, dicimus uvidi, / cum sol oceano, a claim set up by the scene of the rustic opening condidit quisque diem (29), from which phrase emanate thoughts of the sun via its virgilian intertexts, ecl. 9.51–2, longos . . . condere soles and g. 1.458 [sol] referetque diem condetque relatum. 142 though there are those who argue for later dates—as late as 8 bc; for a good summary of opinions and the evidence, see thomas 2011: 5–7. the relationship between the montecitorio obelisk and the ara pacis     1:66 part of such ceremonies” [du quesnay 1995: 145]. likewise, the interval of three and a half years between the adventus and constitutio of the ara pacis in 13 and the altar’s dedication in 9, with the erection of the obelisk for sol in between–all this should perhaps encourage us to speak in terms of horace and the architect of the obelisk-ara pacis complex separately participating in the construction of augustan ideology at a particular point in time, rather than to argue that the poet is following the lead of the architectural plan in detail. it nonetheless remains remarkable that the same nexus of ideas–return of the princeps, sun god, peace and prosperity–recur in the two media in the same few years. whichever view we adopt, there emerges from the rich intertextuality of horace’s address to augustus in solar terms [4.5.5–8] an additional correspondence that is directly relevant to the central argument of this paper. commentators note that the image of the ruler as the sun has many precedents, and is often deployed in connection with a ruler’s return.143 the cluster of solar effects here in reference to augustus also continues the ode’s engagement with ennius’ treatment of rome longing for the deceased romulus: ‘you led us forth into the world of light’ [tu produxisti nos intra luminis oras, ann. fr. 109 sk.]. and we have suggested that horace’s verses anticipate the obelisk dedicated to sol in the obelisk–ara pacis complex. most powerfully of all, the verses summon to mind, via poetic allusion, another spectacular augustan monument that had captivated the imagination of romans for more than a decade, namely the palatine temple of apollo. odes 4.5.5–8 recall another horatian stanza addressed to the sun god himself near the start (as here) of the carmen saeculare [9-12]: alme sol, curru nitido diem qui / promis et celas aliusque et idem / nasceris, possis nihil urbe roma / visere maius, ‘nourishing sun, who in your chariot bring forth and hide the day, and are reborn new and yet the same, may you be able to see nothing greater than the city of rome.’ in both texts the sun brings day’s brightness [adfulsit, dies, soles nitent; cf. sol, nitido, diem] to rome [patriae, populo; cf. roma], and the two addresses are sealed with a wish or expectation marked by matching comparatives [melius; maius]. once again, this is but part of an extensive engagement of odes 4.5 with the carmen saeculare, an engagement signaled from the start (by a phrase, 4.5.1–2 romulae . . . gentis, which is otherwise found only at cs 47 romulae genti).144 in this case we know that a chorus did perform horace’s ode as a conspicuous part of the saecular games in 17 bc. and the first performance of horace’s carmen was in front of augustus’ new temple of apollo on the palatine hill, a cult with strong solar associations (see galinsky in section 9 above). the chorus’s address to sol, himself a by-form of apollo, gestures to the site of that original performance with mention of the sun god’s chariot, which adorned the roof of apollo’s palatine temple [propertius 2.31.11].145 in imaging the returning augustus as the sun around 13 bc, therefore, horace allusively evokes apollo palatinus in much the same way that the multiple solar alignments between the obelisk of augustus and the ara pacis augustae constructed in the years immediately following draw special attention to the solar cult installed by augustus in apollo’s palatine shrine and referenced by the dedication of the montecitorio obelisk in the northern campus martius. 143 du quesnay 1995: 157 with further bibliography. 144 other connections between the two odes: fertility of the land emblematized by ceres paired with another goddess (4.5.18 nutrit rura ceres almaque faustitas; cs 29–30 fertilis frugum pecorisque tellus / spicea donet cererem corona); the pairing of parthians and scythians as subdued foreign enemies, both with motifs of fear (4.5.25 quis parthum paveat, quis gelidum scythen; cs 54–55 medus albanasque timet secures, / iam scythae responsa petunt); law guaranteeing marital virtue (4.5.21–23 nullis polluitur casta domus stupris, / mos et lex maculosum edomuit nefas, / laudantur simili prole puerperae; cs 17–20 diva, producas subolem patrumque / prosperes decreta super iugandis / feminis prolisque novae feraci / lege marita). book 4 is otherwise preoccupied with the carmen saeculare; see, e.g., putnam 1986: 16–20 and passim. 145 miller 2009: 247–52. another obelisk, also dedicated by augustus to sol, was set up in the circus maximus (at about the same time as that in the campus martius, c. 10 bc) in a direct line of sight with apollo’s palatine temple. the relationship between the montecitorio obelisk and the ara pacis     1:67 11. the ara providentiae as solar marker? bernard frischer judging by the archaeological remains, for almost three centuries augustus’ successors protected both the monuments and the axial line supporting the solar and shadow alignments reported in the first section of this paper. as is well known, in the imperial period, the campus martius came to be filled with dynastic monuments and temples of various kinds. it is telling that this development stopped just south what we may call the augustan “solar park”. when the ara pacis was at risk from the periodic flooding of the tiber, hadrian protected it with a retaining wall [moretti 1948: vol. 1, 198]. when the triumphal arch of uncertain date known as the arco di portogallo [torelli 1993; liverani 2007] was erected across the via flaminia, it was sited just north of our axial line, which was therefore not obstructed (figure 22). on the apotheosis relief decorating the column of antoninus pius, the montecitorio obelisk is used as the attribute for the youth personifying the campus martius who holds it in his lap (figure 31 [vogel 1973:32-33]). this suggests that the obelisk had become by that time the identifying landmark of this entire area of the city. there is one tiberian monument, the ara providentiae, which might represent an exceptional interference with the axial line (figure 22). we shall see, however, that this was not the case. so let us next consider this monument. figure 22. map showing location of arco di portogallo (ap), which spans the via flaminia just north of the eastern extension of the axis of symmetry of the ara pacis. also seen along the axial line to the east of the via flaminia is the hypothetical position of the ara providentiae. the relationship between the montecitorio obelisk and the ara pacis     1:68 on the basis of good numismatic evidence,146 the ara providentiae is known to have resembled the ara pacis (figure 23). it is also known to have been erected in the campus agrippae.147 charlesworth argued in 1936 that the providentia honored at the altar was augustus’ foresight in choosing tiberius to be his successor [charlesworth 1936; béranger 1975]. as for date, a post quem of 13 ad is provided by augustus’ latest revision of the res gestae, where the monument is not mentioned. the latest possible ante quem of 20 ad is provided by the s.c. de cn. pisone patre, where at lines 82-84 piso’s name is ordered erased from a statue of germanicus near the ara providentiae.148 it is likely that the ante quem is several years earlier.149 once erected, the altar is recorded to have been used by the arval brethren on several occasions which happen to be memorialized in the preserved acta. under caligula in 38 ad, there was a sacrifice at the altar on june 26, probably to commemorate augustus’ adoption of tiberius on that date in 4 ad [scheid and broise 1980: 234]. figure 23. ae as; rome mint; 29mm/11g. left: obverse. divvs avgvstvs pater; radiate bust of augustus. right: reverse. provident. s. c. facade of ara providentiae augusti (sear 1789, ric i 81). photograph courtesy of philip grathwol. a second mention of a sacrifice at the altar, also under caligula, occurs in a fragment of the acta that is lacking information about the date. the immediately following text includes the date of october 24/26, making it likely that the sacrifice at the ara providentiae occurred on the occasion of the augustalia, held from october 3 to 12 each year.150 this festival celebrated augustus’ return from the east in 19 bc, the occasion on which the ara fortunae reducis near the porta capena was dedicated. after augustus’ death, the festival, held on just one day in his lifetime (october 12), was extended from october 3 to 12 and included public games [wissowa 1912: 263; degrassi 1963: 516 (oct. 3-12), 519 (oct. 12); lebek 1988]. the location of the monument in the campus agrippae is not known, but scheid and broise wrote in 1980 that “it is tempting to imagine that the architects structured the space in such a way that the view of someone looking at the altar of providence toward the west, for example when he participated in the annual sacrifice, 146 see scheid and broise 1980: 232 n. 26. 147 cf. scheid et al. 1998: 30 (c. césar [no 11-16]), line 56: in campo agrippae ad aram providentiae augustae. 148 for the text see eck et al. 1996, and see pp. 197-202 for commentary on the passage in question; potter and damon 1999. 149 on this matter see the discussion by fishwick 2010: 252. fishwick’s attempt to date the ara providentiae to before the death of augustus, despite augustus’ silence in the res gestae, is unconvincing; see ibid., 252, and cf. lott 2014-15: 149. 150 see scheid 1998: 38, note on fgh, l. 9-16. the relationship between the montecitorio obelisk and the ara pacis     1:69 encompassed at the same time the mausoleum of augustus and the ara pacis: the architectural perspectives would thus also confer a meaning to the sacrifice, the meaning intended by the imperial entourage, to grasp that the augustan peace was guaranteed by the wide-ranging ‘providence’ of divus augustus and the providential virtues of his heirs. urbanism and ideology thus cohere in this enormous garden, this sanctuary as big as a city quarter, in order to legitimate not only the choice of a successor and his action, but also the entire julio-claudian dynasty through a clearly sacred conjunction between the mausoleum, the ara pacis, and the ara providentiae, between augustus, the ruling dynasty, and peace.”151 several years later, coarelli converted these words into the more concise topographical proposal of considering the ara providentiae to be a pendant of the ara pacis with the same dimensions, orientation, and distance from the via flaminia (figure 22).152 the position indicated on coarelli’s map has been adopted by later scholars.153 if, for the sake of argument, one accepts the scheid-broise-coarelli hypothesis about the altar’s location (even if—and this should be stressed—the present author is skeptical about the hypothesis because in his experience archaeological reality seldom corresponds so neatly to our modern hypotheses), then the line of axial symmetry running east from the ara pacis bisects the ara providentiae. it is therefore important to gauge how this hypothetical location, if accepted, would impact the solar alignments we have been discussing. to do so, we created a version of the stellarium simulation in which the ara providentiae corresponds to the ara pacis in size and orientation and is positioned an equal distance off the via flaminia to the east. moving the date forward to ad 17, our finding was that placing the altar here caused minimal or no disruption to the pattern of solar alignments detected earlier, even though the altar would be directly on the axial line. the following table shows the dates, times, and positions of solar alignment as revealed by two variant reconstructions of the ara providentiae: the first, in which the interior exactly resembles that of the ara pacis, with a sacrificial table raised off the interior floor; the second, in which the interior was simply paved, and the sacrificial table, if present, was not raised. in both versions, the alignments on october 10 occur when the observer stood in front of the west entrance, and by october 14, the observer was well beyond the altar to the east. in table 1, the observer would have stood on the interior stairs before the sacrificial table on october 12 and 13. in table 2, the observer would have already been outside the altar to the east by october 12. the following table gives the relevant data: variant 1: with raised sacrificial table variant 2: date (ad 17) time (utc) coordinates date (ad 17) time (utc) coordinates oct. 11 15:45:22 172.27m, 71.36m, 0.23m oct. 11 15:45:22 172.27m, 71.36m, 0.23m oct.12 15:46:48 173.52m, 71.74m, 1.24m oct. 12 15:46:48 183.24m, 74.80m, 0.22m oct. 13 15:48:17 176.11m, 72.52m, 3.15m oct. 13 15:48:17 204.84m, 81.38m, 0.22m 151 scheid and broise 1980: 235-236 (translation by b. frischer). 152 coarelli 1983: 41-42, and see also the map on p. 43. scheid 1998: 35 (on c, 1. 54-57) cites this passage with approval. 153 coarelli’s view is accepted by torelli 1999a: 166. for the same arrangement see the map of bodel 1999: 54. the theory is repeated in coarelli 2007: 235. the relationship between the montecitorio obelisk and the ara pacis     1:70 the only less than perfect alignments are those of october 12 and october 13. in variant 1 on october 12 the view of an exact centering ofthe finial with the solar disk is blocked by the superstructure of the altar over the west doorway. however, at the time and position specified on the table, there is a good enough alignment for practical purposes. similarly, in variant 2 on october 13, a precise centering of finial and solar disk is blocked by the superstructure over the east doorway, but the alignment seen from this position is adequate. these results mean that not only would an ara providentiae located in this position not have interfered with the augustan scheme, but it could also lend credence to the scheid-broise-coarelli theory. zone 4 is rich in october alignments. if the ara providentiae really was located where the theory stipulates, then it occupies a spot when the october alignments coincide with the augustalia (october 5-12; [lebek 1988: 62]). some might be tempted to see this as not coincidental but evidence in favor of the scheid-broise-coarelli theory. in this connection we may note that, as bergmann pointed out, the biggest tiberian coin issue was the as showing the ara providentia on the reverse and a radiate head of augustus on the obverse. (figure 23; bergmann 1998: 106-107) the iconography of the radiate crown clearly links augustus—the first emperor shown this way—with jupiter and apollo-sol, as bergmann notes [bergmann 1998: 104]. here, again, the s.c. de cn. pisone patre and its mention of a statue of germanicus near the ara providentiae is relevant. since the inscription tells us the statue was erected by the sodales augustales [see hemelrijk 2007: 319], it ought to have been part of a portrait group that included augustus [rose 1997; boschung 2002]. one might imagine a radiate augustus standing somewhere near the ara providentiae [see pollini 2012: 355-357, fig. vii.39a-b]. such a statue would have provided a suitable prop for the celebration here of the augustalia by prestigious priesthoods such as the arvals and augustales in precisely the days when the zone 4 solar alignments are occurring nearby. the nexus of associations seen on the as may have their topographical correlative in the ara providentia set on the axial line of solar alignments just in the section coincident with the climactic days of the annual festival held to honor augustus. assuming the scheid-broise-coarelli theory is correct (and we again stress here that we do not claim that it is), then we will have to do with a solar marker analogous to the first marker at the western staircase to the ara pacis—yet another way the two altars will resemble each other. the fate of this monument is unknown; interestingly, one scholar has speculated that it was incorporated into aurelian’s temple of the sun, the subject of the next section [torelli 1999a: 166], while another scholar has suggested that a fragmentary julio-claudian relief preserved in the museo gregoriano profano of the musei vaticani may once have decorated the inner altar of the ara providentiae [pollini 2012: 324, fig. vii.15]. 12. aurelian’s temple of sol invictus in rome michele r. salzman aurelian dedicated a temple to sol invictus in rome in 274 as a sort of ex voto for his victories over zenobia in 272 and over tetricius in 274.154 considering how much has been written about the location of this temple, it is surprising how little consideration has been given to why aurelian built it where he did. the topographical associations of this temple will be the focus of this contribution, after a brief overview of the evidence. of particular relevance to this article is the association of aurelian’s temple to the solar monuments of the augustan age. but as we shall see, modern topographers concur that it can be identified with the temple to the 154 ha. aurelian 39.2 and 39.4; eutropius 9.15.1 repeat the notion of the temple being “most magnificient.” see hijmans 2010: 388, for bibliography for the dedication year of 274. the relationship between the montecitorio obelisk and the ara pacis     1:71 sun in the campus agrippae in a position across the axial line of solar alignments in zone 4 identified above by frischer.155 though the temple was described as “magnificentissimum” and “the precinct was endowed with wealthy gifts,”156 nothing of it remains today. scholars argued for some time about its exact location and its orientation.157 most scholars today, however, accept the textual evidence and agree that the temple ascribed to aurelian in honor of sol should be located in region vii of the city, as it is so described by the fourth-century origo gentis, which lists this emperor’s temple, together with a set of castra in the campus agrippae.158 the fourth century regionary catalogues similarly lists a templum solis and castra in this region.159 based on this evidence, the sixteenth century drawings by palladio that are identified with this temple on the site of san silvestro in capite have led most scholars to posit that the temple had an east-west orientation.160 this would be in accord with the orientation recommended by vitruvius for temples in general, and it would seem particularly apt for a temple to sol to have an east-west orientation.161 the sixteenth-century drawings also indicate that this temple included two buildings under whose porticoes, as noted in our fourth-century source, wine was stored; aurelian is said to have begun the state distribution of wine at reduced prices as a right of the plebs romana.162 an inscription (cil 6.1785 + 31931) records the transport of barrels from the area of the ciconiae to the temple; this inscription was discovered near san silvestro in capite and provides some additional evidence that the temple with its porticoes was the location for wine distribution. the nature of the temple precinct—which zosimus (1.61) mentions included statues of belos and helios—remains open to speculation. since no one has identified the remains of its cella or foundations, some posited that the porticoes were in an enclosed sacred space without a temple proper, and that the renaissance drawings are more fantasy than actual. 163 moreover, aurelius victor mentions that aurelius built a fanum (or, sacred precinct) without mentioning a temple.164 the mid-fourth century origo gentis, regionary catalogues, and the author of the historia augusta call the construction a templum, indicating a sacred precinct and perhaps a temple.165 if this sacred precinct acquired a proper temple, it is possible—but not at all certain—that eight porphyry columns reported by an eighth-century source to have been given in ca. 536 to the church of hagia 155 for possible locations of the temple, see liverani 2006-2007. 156 aurelius victor 35.7: his tot tantisque prospere gestis fanum romae soli magnificum constituit donariis ornans opulentis. 157 for more about the dispute on its location between lanciani, who wanted to locate the temple on the quirinal, and hülsen, see calzini gysens and coarelli 1999: 331-332. for the finds from the temple and recent literature see capanna 2013: 486-487. 158 origo gentis in the chronogr. a. 354 148 m: templum solis et castra in campo agrippae dedicavit [aurelian]. 159 regionary catalogues in valentini and zucchetti 1940: 111 and 219. 160 torelli 1992; calzini-gysens and coarelli 1999: 331-332. see too liverani 2006-7: 302-305; hijmans 2010: 385-390. 161 vitruvius 10.4.5.1. 162 hist. aug. aureliani 25: templum solis fundavit; 48.4: in porticibus templi solis fiscalia vina ponuntur. latin text here and later from lcl, ed. d. magie. for discussion, see calzini-gysens and coarelli 1999: 331-332 and liverani 2006-7: 302-305. 163 hijmans 2010: 388 suggests that there was no actual temple building within the enclosed space of the porticoes, but this does not square well with the testimony of zosimus. hijmans 2010: 388 is following earlier scholars who agree that “the round peripteros, drawn by palladio in the larger enclosure, is a renaissance fantasy.” 164 aurelius victor 35.7. 165 hist. aug. aurelian 25: sacerdotia composuit, templum solis fundavit et pontifices roboravit; chronogr. a. 354 148 m: templum solis et castra in campo agrippae dedicavit [aurelian]. the relationship between the montecitorio obelisk and the ara pacis     1:72 sophia in constantinople were from the aurelianic temple proper, or from one of the porticoes in the precinct.166 most important for our argument, aurelian chose to build his ex voto monument to sol in the campus agrippae. we do not know what was on the spot prior to this construction, but the area certainly had strong associations with augustus and sol for centuries. after his victory over cleopatra and antony, augustus had brought an obelisk from egypt as a gift to sol and placed it in the campus martius to be used as a gnomonic device. though the device was no longer functioning by the time of aurelian, the obelisk and the inscription would have remained visible to visitors in late antiquity. the third-century visitor to rome could see that augustus had given the obelisk to commemorate his conquest of egypt and as a “gift to sol.”167 so the memory of augustus’s victory in the east, the restoration of peace to the empire through military success as recalled by the ara pacis, and his subsequent offering to sol in the campus martius set a powerful precedent for aurelian.168 just as augustus sought to associate his victory over the egyptian queen cleopatra with the divine power of his defeated enemy, so, too, aurelian could associate his victory over the defeated eastern queen zenobia with the divine power of the palmyrene sol. military victory had been necessary to establish peace in the time of augustus; likewise, aurelian’s conquests would bring peace back to rome. although sol had been worshipped in rome before this date, aurelian’s reforms of the cult signaled that his particular version of solar worship would be distinctive. first, it is worth noting that several of the sour ces comment on the immense size of the precinct. second, in a clear effort to elevate this cult above others, aurelian instituted a new college of priests, pontifices (dei) solis, second in rank to the pontifices maiores, who now were known as pontifices deae vestae.169 third, aurelian celebrated his cult with new sorts of public games, such as the agon solis.170 moreover, as i have argued elsewhere, his new cult to sol invictus incorporated elaborate games with some thirty races in the circus on december 25th, a few days after the winter solstice. the association of this day’s games with aurelian requires further explanation, since the codex-calendar of 354 and an oration of julian provide the earliest textual evidence that december 25th was celebrated in honor of sol in rome. moreover, i would argue, as have many earlier scholars, that december 25th was most likely the dedication day of this emperor’s new temple in the city.171 the common assumption found in many publications is that the winter solstice was celebrated on december 25th, and hence it was this reason that prompted aurelian to dedicate his temple with games to sol invictus on this day. under christian rulers, this holiday was interpreted as the celebration of the birthday of the son of god, with metaphors, in later fourth and fifth century texts, about the light of christ’s justice abounding.172 this narrative is not quite correct, for the winter solstice in the 270s fell several days earlier. moreover, prior to aurelian there is no evidence that the winter solstice or december 25th was celebrated in honor of sol in 166 codrinus reports that the columns belonged to a widow, marcia, who gave them away; see codrinus, de antiquit. const. 4 p 65 (p. 131-2 bekker, corpus script. hist. byz.) and more recently, ps.-codrinus, narratio de structura templi s. sophiae, antiquitates constantinopolitane 4. 185 ed. prenger 1901, i, 75-76. however, this is a text of the eighth century, so not entirely reliable. on the other hand, we do have other instances of private donations of public monuments from rome from the fifth or sixth centuries; see liverani 2014. 167 cil 6. 702= ils 91: .../aegypto in potestatem/ populi romani redacta/soli donum dedit. 168 frischer and fillwalk 2014; and albéri auber 2014. 169 hist. aug. aurelian. 25: sacerdotia composuit, templum solis fundavit et pontifices roboravit. 170 origo gentis in the chronogr. a. 354 148 m: agonem solis instituit. 171 for the calendar of 354, see salzman 1990: 127-128; and julian or. 11.4.42-43. though there is no absolute evidence that the december 25th day noted as the natalis invicti was the dedication day of aurelian’s temple, it seems most likely since only recent imperial holidays were honored with so many circus games in the mid-fourth century. for an alternative view, see hijmans 2010. 172 this is the common view, as noted by hijmans 2010: 389. the relationship between the montecitorio obelisk and the ara pacis     1:73 rome. as i have argued more fully elsewhere, the only other source for december 25th as important for solar worshippers is an astronomical calendar from egypt attributed to antiochus of athens, a document that most probably dates to the third or fourth century.173 on december 25th in antiochus’s calendar we read: “birthday of the sun; light increases.”174 this egyptian calendar may, however, reflect a wider eastern understanding about the sun; only a few days after the solstice can one be certain of the sun’s rising, and so celebrate it accordingly. this notion was common in egypt, and presumably also in the east, as julian in antioch expressed it later. this widespread idea may explain why aurelian chose to honor sol invictus on december 25th. i am not the first scholar to propose that december 25th was the celebration of the dedication of aurelian’s temple to sol invictus in the campus martius, but the arguments for this dedication have not given sufficient weight to the egyptian calendar of antiochus that reflects earlier egyptian worship of the sun.175 moreover, there has been little appreciation of the topographical associations for aurelian’s choice of a location for his temple. as earlier sections of this article have demonstrated, augustus’s association of military victory in the east with sol led to the location of the montecitorio obelisk in association with the ara pacis. augustus set a powerful precedent for aurelian, who, similarly, was seeking to legitimate his rule through military victory. moreover, aurelian was, like augustus, planning on founding a new dynasty. the conscious echoes of augustus also emerge on aurelian’s coins, another way in which aurelian could tie his rule to that of the originator of the imperial system.176 finally, as an emperor seeking to unite the east and the west in a time of peace, aurelian, like augustus, was aware of the universal appeal of solar cults across the empire. if i am correct, the celebration of the dedication of aurelian’s temple on december 25th in the campus agrippae area follows augustan precedent by linking aurelian’s victory and solar worship with augustus’s victory and the egyptian sol. what better place to build his temple to sol than in an area already associated with augustus’s recurrent solar spectacle. aurelian’s precinct probably straddled the axial line of the solar alignments in frischer’s zone 4. in any event, it stood within the viewshed of the montecitorio obelisk, whose duplicate inscriptions recorded its celebration of imperial victory and its dedication to the sun god. 13. summary and conclusion bernard frischer 13.1 summary in this collection of essays we reported on new research utilizing computer simulations of the augustan northern campus martius and adjacent campus agrippae that showed a recurrent annual cycle of alignments between the sun, the obelisk, and the ara pacis. at a minimum, alignments of sun or shadow took place 238 days each year from february 25 to october 21. the details of exact time and place change slightly in the second and third years of the leap-year cycle. even if the height of the obelisk is increased to 30.7 m, and the position of the obelisk is adjusted accordingly, essentially the same series of alignments is attested, and, indeed, the number of dates increases to 251 from february 17 to october 28. two different visualization engines were used to run the simulations, each of which used a different method to calculate the solar ephemerides. the 173 i presented my ideas in a paper in 2015 and in print, salzman 2017. 174 lehoux 2007: 343. cf. wallrach 2001: 176 and n. 9. 175 for a full discussion of these arguments with bibliography, see hijmans 2003 and wallrach 2001. see now salzman, 2017. 176 watson 1999: 201-202. the relationship between the montecitorio obelisk and the ara pacis     1:74 results of the simulations were essentially the same, and this duplication of our observations added confidence to the validity of our observations. capriotti interpreted these findings in the light of hellenistic egypt. the central role played by the sun god suggested a relationship between the architectural design of the ara pacis and the egyptian “horned altar” found near temple tombs in several locations, including the temple of egyptian deities at delos and in the area of the east temple at karnak where—as in the northern campus martius—there was also a “unique obelisk.” a function of this altar type may well have been to support burnt sacrifices offered to various gods with the goal of destroying the enemies of the sun god and of the king. the design of the ara pacis reminds us of the hieroglyph akhet. the zone 3 solar alignments of the rising sun on axis behind the ara pacis is an apt illustration of capriotti’s interpretation. swetnam-burland shifted the focus to the montecitorio obelisk, whose original egyptian context is explained to provide the requisite background for understanding its adaptation in the augustan campus martius. erected by psametik ii, it honored the sun god re-harakhti, the incarnation of the sun god of the dawn. the praises recorded to him on the obelisk attribute to him the power to grant life, happiness, and power to the king. hence, in its original egyptian context the obelisk celebrated the divine rights of the king while honoring the sun god who bestowed those rights on him. she next discussed how the romans understood the obelisk, starting with the observation that they would not have had access to—or probably interest in—an exact, “scholarly” translation of its inscriptions. yet pliny’s discussion of obelisks shows that educated, elite romans had a basic understanding of their meaning and import. he also attests that the romans well understand the solar symbolism of obelisks. another relevant source is hermapion’s translation of the flaminian obelisk, which is preserved in ammianus marcellinus. hermapion may well have lived not in the time of ammianus but in the first century ad. at any rate, he continually invokes apollo as the child of the sun god and sometimes fuses him with king ramestes. apollo is the recipient of the sun’s benefits and the intermediary who makes them available to mankind through military victory and benefactions. augustus was clearly familiar with the solar significance of the montecitorio obelisk, which he dedicates to sol. this divinity was the subject of special cult honors in augustan rome and was assimilated to apollo. murray then picked up the theme of the ideology of kingship in hellenistic egypt, discussing the fusion of apollo and horus in relation to astronomical alignments. in apollonius of rhodes, apollo is the “lord appearing at dawn”, a concept very possibly also attested on an inscription from the precinct of the serapaeum and in ritual texts on walls of the temple of horus at edfu. another aspect of apollo stressed by the ptolemaic kings is his association with buildings, especially sacred buildings first reflecting astronomical alignments. augustus, too, linked his legitimacy to rule to his special relationship with apollo, notably in the palatine temple, which emphasized apollo’s solar aspect. this solar apollo derives from hellenistic egyptian and, ultimately, earlier fifth-century precedents. indeed, in his capacity as king of egypt, augustus amplified the importance of apollo-horus by keeping only the horus name and jettisoning the four other traditional regal names. murray concludes that the conjunction of the sun, the obelisk, and the ara pacis expressed augustus’ horus name “in monumental terms.” häuber also closely connected the ara pacis and the montecitorio obelisk to the egyptian ideology of kingship. her point of departure was different from murray’s: the close connection between the sun god re and the pharaoh, which established maat. she interpreted the ara pacis as the augustan monument par excellence expressive of this ideology of rulership. augustus’ appropriation of the radiate image and symbol of the cornucopia from his ptolemaic predecessors also reflects the concept of augustus as a ruler favored by the sun god who can therefore bestow peace and prosperity on his people. the relationship between the montecitorio obelisk and the ara pacis     1:75 pollini and cipolla focused on the ara pacis as an expression of the augustan ideology of peace through victory, a message reinforced by the montecitorio obelisk, whose dedication was explicitly motivated by the fact that egypt had come into the possession of the roman people. important in understanding the ara pacis is its association with imperial birthdays. it was dedicated on livia’s fiftieth birthday. one of the many solar alignments reported earlier in this article occurred on augustus’ birthday, as seen by someone standing in the architecturally strongly marked spot of the western entrance of the ara pacis. a study of the shadow alignments reported here shows that they moved up the staircase and pierced, or penetrated, the altar in an almost sexual way—another allusion to fertility and birth. this phallic association of the obelisk and its shadow suggested the message that augustus brought felicitas with its attendant fertility and prosperity to the roman world, themes richly featured in the iconography of the ara pacis. behind this iconography is the god apollo, a sol figure whose life-giving light and warmth is the basis of felicitas. beyond the ara pacis, the iconography of sol and apollo bulks large in augustan art, sometimes with the emperor himself assimilated to images of the gods in the non-official arts of the augustan age. pollini next interpreted an observation made by orietta rossini when bernard frischer showed her the virtual meridian: on augustus’ birthday (september 23), after the shadow of the obelisk fails to reach the western entrance of the ara pacis, it strikes the area to the right of the doorway, pointing at the aeneas relief. according to pollini, this may be intentional: the shadow suggests the strong tie between augustus and aeneas, the ancestor of the julian family into which augustus was adopted by julius caesar. galinsky treated the most important augustan monument dedicated to apollo, the great palatine temple. this temple has strong solar associations. in a manner reminiscent of the ptolemaic ideology of kingship, augustus, too, associated apollo with military victory, which is the precondition for the peace celebrated by the ara pacis. miller explored how the association of augustus with the sun and the solar god apollo were developed in several poems of horace which reflect augustan ideology. in odes 4.5, horace urges augustus to return to rome since the city’s security and prosperity depend on his presence. at the beginning of the poem, augustus is fused with the sun when the poet writes, “restore the light, good leader, to your country: for when your face shines like spring upon the people, the day proceeds more pleasantly, and the sun shines more brightly” (odes 4.5.5-8). it is remarkable that the nexus of augustus’ return from war, the sun god, peace and prosperity occur in a relatively short period of time in horace’s poem, the iconography of the ara pacis, and the dedicatory inscription on the obelisk. relevant in this connection is the fact that near the beginning of horace’s earlier poem, the phallic association of the obelisk and its shadow suggested the message that augustus brought carmen saeculare, the sun god is addressed as the deity bringing dawn and evening and looking down on rome in its unparalleled greatness. we know that a chorus first performed the poem in 17 bc in front of the temple of apollo palatinus. frischer then addressed a hypothetical obstruction of the axial line to the east: the possibility, mooted by several recent scholars, that the tiberian ara providentiae, often considered a twin of the ara pacis in design and dimensions, was erected ca. 30 m to the east of the via flaminia on an extension of the axis of the ara pacis. while stressing that this siting is purely speculative (and that he is skeptical that the speculation is correct), he suggested that, even if true, the ara providentiae would not so much have disturbed the solar spectacles along the axial line as added a new solar marker for a relevant annual festival, the augustalia. finally, salzman looked at the later topography of the campus agrippae in the general area where the ara providentiae is presumed to have stood, across the via flaminia from the ara pacis. she suggested that it is not a mere coincidence that the third-century emperor aurelian situated his temple of the sun in this area with its many earlier solar alignments and associations. aurelian exploited the area’s existing solar associations and the relationship between the montecitorio obelisk and the ara pacis     1:76 by building his solar shrine here—probably stretched across a section of the axial line in zone 4—he also explicitly linked his rule with that of augustus, whose reputation and prestige were undiminished with the passage of time. 13.2 conclusion at this point two key issues ought to be addressed: (1) why should we imagine that the solar alignments reported and interpreted here were intentional? (2) assuming the answer to the first question is affirmative, then was each of the alignments meant to be seen and by whom? regarding the first question, there are clearly three possibilities: (1) the solar alignments were the inevitable, if accidental, result of placing any two structures in fairly near proximity to each other anywhere on the ground at this latitude; (2) they were the inevitable result of intentionally creating one, key alignment (e.g., for the sake of argument, those around augustus’ birthday in zone 2); and (3) they were all intentional. in grappling with this issue we note that, first of all, the gnomonic instrument attests that solar alignment was part and parcel of the overall augustan design. it is true that we began by claiming that the design and operational details of the timepiece were irrelevant to our theme in this paper. that remains true. however, the instrument should be now recalled as proof positive that the augustan designers were thinking in conscious terms of coordinating the sun, the obelisk, and the meridian. the device was based on harmonizing the (apparently) moving sun and the stable obelisk in order to render the same time (local noon) each day in the same longitude (the meridian line). the focus of the viewer’s attention, if the effort was successful, was the gnomon’s shadow projected onto a crosshatch (regula) on the long meridian line. the meridian has rightly been called a scientific instrument. seeing it in operation appealed to the rational intellect more than to the viewer’s emotions. the purpose of the instrument was, moreover, purely practical. the axial system we have been studying reflects the opposite possibility: coordinating the (apparently) moving sun and the stable obelisk to create a vision of the sun, the obelisk and/or the ara pacis seen from different latitudes-longitudes at different times of the day on various days of the year. the effort, if successful, would not have conveyed scientific information about date and time, but would instead have both appealed to the viewer’s aesthetic sensibility and aroused his feeling of religious awe. the purpose was not practical—telling time—but symbolic: creating a recurrent hierophany of the sun god. it implicitly transmitted a message about the nature of the emperor who commissioned the complex and at the same time evoked reverential awe for the sun god to whom the emperor dedicated the obelisk, itself a well-understood solar token. achieving the scientific purpose required that the obelisk be sited near the meridian line with its perpendicular metal crosshatches. to effect the emotional response it was desirable to pair it with some evocative monument such as the ara pacis, which used symbolism to produce a range of positive aesthetic and emotional responses. in other words, had we only been interested in alignments of the sun’s disk over the obelisk without reference to the ara pacis, then the objection could justly have been made that once you had the obelisk and meridian, you willy-nilly got the obelisk’s solar alignments, so that attributing intentionality to such phenomena is purely arbitrary. indeed, without the ara pacis and its dual role of providing an axial line on which the observer had to stand as well as a sight for targeting the top of the obelisk and the obelisk’s shadow, there would have been many more—indeed, millions of—potential solar alignments associated with the obelisk. so, the presence of the ara pacis and its tethering role are crucial, and its decisive role in the augustan project is revealed by the telltale sign that the obelisk is aligned not to the meridian and cardinal points, as one might the relationship between the montecitorio obelisk and the ara pacis     1:77 well have expected,177 but to the altar 90 meters away, which is itself oriented to the via flaminia. at a minimum, this is telling us that the designers encouraged the ancient viewer to see the two monuments in close relationship. why did the designers establish such a close, visual connection between the ara pacis and the obelisk? at this point, the siting of each monument should be considered, a question not yet treated in previous scholarship about these monuments. if purely a visual relationship was desired, the designers could have put the two monuments somewhat closer or farther apart than they actually were. why are they sited ca. 90 m apart? the first point we can make is that the shadow alignments were not determining this choice. if they were, then the 90-m interval would represent the maximum possible number of shadow alignments available for monuments designed in this way and standing at these particular geographical coordinates. in actual fact, however, the closer the obelisk moves toward the ara pacis, the more shadow alignments one gets. for example, we made two simulations in stellarium which supported experiments in which the obelisk was moved 50 m east and west of its actual position. when the obelisk was 50 m closer to the ara pacis, there was a gain of seven pairs of dates before 2/25–10/21 and nineteen pairs after 3/21–9/27 for a net gain of 52 dates of alignment. contrariwise, in the version of stellarium in which the obelisk was moved 50 m west of its actual position, we observed a gain of 14 dates before the pair 2/25–10/21, but a loss of 26 dates from 3/9–10/9 to 3/21–9/27. we conclude that 90-m interval between the monuments was chosen for a reason other than maximizing the number of shadow alignments. so let us look at the solar alignments and see what they tell us. again, we can compare our findings with an obelisk hypothetically moved either 50 m farther west or 50 m farther east. the maximum number of solar alignments we found occurs in zones 2 and 3. both zones have the same spatially terminal date, the summer solstice. by “spatially terminal,” we mean that at this point along the line, the viewer must step back in the opposite direction to get the dates of alignment after the summer solstice. now, each starting point is on the two nodes—3/19–9/27 inside the ara pacis and 4/30–8/18 at the obelisk. had the two monuments been placed closer together, then their visual alignment might have been still clearer, but the starting pairs of alignment dates in each zone would have been lost. for example, we made a version of the stellarium simulation with the obelisk set 50 m to the east of its actual position (i.e., ca 40 m from the ara pacis). this simulation shows that the dates in the west entrance (i.e., zone 2) of the ara pacis become 4/14–9/2. hence, we lose all the alignments from 4/3 to 4/15 and from 9/3 to 9/27. standing at the obelisk and looking east at sunrise we find that the first dates of alignment in the reduced zone 3 is no longer 4/30 – 8/18 but 5/10–8/8. so, moving the obelisk 50 m closer to the ara pacis results in a loss of 46 days of alignment in zone 2 and 18 days in zone 3. this net loss of 54 dates of solar alignments more than cancels out the gain of 52 dates of shadow alignment. moving the obelisk 50 m to the west of its actual position adds eight pairs of alignments from 3/11–10/5 to 3/18–9/28 in zone 2. the first three of these pairs we already have at the beginning of zone 4, so they are not an real addition as compared to what we actually find. so putting the obelisk 50 m to the west nets five new pairs of dates. in zone 3, we gain one pair of dates at the very beginning of the sequence, which would start with 4/29–8/19 instead of 4/30–8/18. this total gain of twelve days in new solar alignments exactly balances the loss of twelve days of shadow alignments. thus, moving the obelisk 50 m to the west results no change to 177 and as was certainly expected by the 18c british surveyor, james stuart, who found the obelisk’s rotation so odd that he felt obliged to check the accuracy of his compass when it revealed the obelisk’s 15-degree counterclockwise rotation; see bandini 1750: 72. the relationship between the montecitorio obelisk and the ara pacis     1:78 the overall number of shadow and solar alignments, but with the additional 50 m of distance between the altar and obelisk, the purely visual relationship between them would have been attenuated. and this brings us back to our point of departure: the siting of the ara pacis and the montecitorio obelisk does not appear to be the result of chance but of an application of the “goldilocks” principle:178 with a separation of 90 m, the number of shadow and solar alignments is maximized while at the same time the visual relationship between the two monuments remains strong. one additional point that emerges from the foregoing analysis: the distillation of a solar marker from the general cloud of shadow and solar alignments along the axial line through our four zones. we have seen that the more the obelisk is moved closer to the ara pacis, the greater the loss of total alignments. we have also seen that moving the obelisk farther away would have provided no net gain in alignments while costing something in terms of the visual connection of the altar and the obelisk. there would have been another price to pay as well: if one moves the obelisk to the west, then one also shifts to the west all the dates of alignment we actually found. but this would mean that the specific alignment flagged by pollini—september 23rd at the foot of the western staircase to the ara pacis—would also be lost. to see this alignment, you would now have to stand 1 m to the west of the staircase for every 1 m the obelisk was moved to the west.179 this formula works in the opposite direction as well: every meter the obelisk is moved east from its current position toward the ara pacis causes the september 23 alignment to move one meter farther east along the axial line. the front of the western staircase fulfills our minimum conditions of a solar marker. if the alignment of september 23 is moved to the east or west along the axial line, this becomes just another date which, however marked in augustan culture and on its calendar, was not physically marked on the ground.180 it would thus be arbitrary to attribute any particular significance to it as opposed to the myriad other dates on the roman religious calendar for which we also found alignments (see appendix table 6 for the dates). the fact that the monuments are sited the way they are suggests that pollini-cipolla may be correct to see the foot of the western staircase as a solar/shadow marker.181 if so, then our research suggests that buchner’s most important point, while wrong in detail, was correct in general: the ara pacis and the montecitorio obelisk are connected in relation to augustus’ birthday. but now the connection is made by both a solar and a shadow alignment, and those alignments do not occur in the middle of the ara pacis and they have nothing to do with the (hypothetical) equinoctial line, of which buchner made so much. so we might grant that buchner was partially right for the wrong reason. this suggests that at a minimum, the second of our three theoretical possibilities regarding intentionality is operative. what about the third possibility—that all the alignments were intended, not just the one on september 23? this is more difficult to demonstrate because, clearly, granting that the monuments were sited 90 m apart in order to create the solar alignments in the period from september 23 to september 27, the other 179 for a definition of the “just right,” goldilocks principle, see https: //en.wikipedia.org/wiki/goldilocks_principle 179 the stellarium coordinates are: 37.38m, 29.80m, -1.50m. 180 note that the obelisk could have moved ca. 10 m east and still left the alignment on september 23 in a potentially marked position somewhere from the foot of the west staircase to the west entrance of the ara pacis. for about the next 20 m of eastward movement of the obelisk, the view is blocked of the top of the obelisk, hence no alignments would have been visible in this area. and, once we move more than ca. 16 m eastward from the foot of the west staircase, we are no longer inside the ara pacis and thus have lost our potential marker in any case. 181 we may note here that the stellarium simulation with an obelisk of 30.7 m shifted 1 m south still gives us an alignment on september 23 at the bottom of the western staircase. the relationship between the montecitorio obelisk and the ara pacis     1:79 alignments followed automatically: it was not within human power to turn the sun on and off or to vary its regular (apparent) movements through the sky. on the other hand, if we take our point of departure from augustus’ stated intention of bringing the obelisk to rome as a gift to the sun god, then self-celebration by the donor is too narrow a goal. we saw in our experiments moving the obelisk closer to and farther from the ara pacis that this did not significantly reduce the number of shadow and solar alignments. this means that augustus could have had it both ways: creating a specific small group of alignments associated with his birthday, while at the same time honoring the sun god with a much larger series of solar and shadow alignments stretching through much of the year. nothing prevented augustus from pursuing both goals. all he needed to do was site the two monuments at the right distance to set up the birthday alignments at a marked place, and create a strong visual relationship between the two monuments. this he accomplished through a shared orientation, by siting the obelisk almost exactly on the axis of the symmetry of the altar, and by guaranteeing an unobstructed view for hundreds of meters in either direction along the axial line. we know that all these conditions were, in fact, fulfilled, not only during the reign of augustus but for several centuries thereafter.182 here we may draw special attention to the arco di portogallo, the siting of which to the east of the ara pacis might well suggest that the zone 4 solar alignments were considered something to be respected. zone 4, of course, has nothing to do with augustus’ birthday and adds a new point favor of the importance of the motivation to honor the sun god. if we want to push further beyond the augustan phase, we can note that each of the later known or possible enhancements to this part of the city plays on the solar theme, as if something more than a handful of solar alignments aimed at honoring one individual was occurring here. as we have seen, the first possible addition was tiberius’ erection of the ara providentiae at a spot along the axial line where appropriate october alignments would occur on the augustalia, known to have been celebrated, in part, before this altar. the second-century conversion of the former meridian into a basin—reflecting, at once, the sky and the obelisk—has recently been interpreted in a way compatible with the solar theme we have been developing [heslin forthcoming]. the climactic enhancement was doubtless reached with aurelian’s temple of the sun in the campus agrippae, whose exact design and location are not known. although topographers have proposed different footprints for the sanctuary, there is general agreement in situating it in positions that would have put it athwart our axial line. to sum up, we have some grounds for suspecting that the third possibility was operative: the logic of the layout of the monuments made it possible to honor both the dedicator and the dedicatee. the evidence that the former was done is the ara pacis, which stands at the right spot to mark the emperor’s birthday. the evidence that the latter was also a goal is the orientation and siting of the obelisk and ara pacis as well as the lack of obstructions along the entire length of the axis of symmetry of the ara pacis for at least 300 m in either direction of the obelisk. we therefore conclude that the solar program created in the area of the campus martius and campus agrippae exemplifies the tertium quid theorized at the beginning of this article, in which hundreds of solar-shadow alignments throughout the year are combined with one or more marked alignments on a given date. since the reason for the former is to honor sol in the most appropriate way imaginable—using his very dedication as the “magic wand” to bring forth his hierophany—it is quite compatible with the point of the latter, which is to 182 an observation made earlier at moretti 1948: 115. the relationship between the montecitorio obelisk and the ara pacis     1:80 present augustus as both the devotee of sol and the man born as “the sun who arose from atia’s womb” (suet., augustus 94.4). this last point explains on an ideological level why the intention to honor the dedicatee alone would have been too narrow. in discussing the montecitorio obelisk, herklotz,183 citing grandet 1986, drew our attention to the same passage in suetonius, which we now quote in full: i have read the following story in the books of asclepias of mendes. when atia had come in the middle of the night to the solemn service of apollo, she ...fell asleep, while the rest of the matrons also slept. on a sudden a serpent glided up to her and shortly went away. when she awoke, she purified herself, as if after making love with her husband.... in the tenth month after that augustus was born and was therefore regarded as the son of apollo. atia too, before she gave him birth, dreamed that her vitals were borne up to the stars and spread over the whole extent of land and sea, while octavius dreamed that the sun rose from atia's womb. [suetonius, augustus, 94.4] she also noted that a similar story is reported by cassius dio 45.1.2-3: for caesar, being childless and basing great hopes upon him [i.e., augustus], loved and cherished him, intending to leave him as successor to his name, authority, and sovereignty. he was influenced largely by atia’s emphatic declaration that the youth had been engendered by apollo; for while sleeping once in his temple, she said, she thought she had intercourse with a serpent, and it was this that caused her at the end of the allotted time to bear a son. before he came to the light of day she saw in a dream her entrails lifted to the heavens and spreading out over all the earth; and the same night octavius thought that the sun rose from her womb. in both passages we have the story that a serpent impregnated augustus’ mother, atia, in a sanctuary of apollo and that she and her husband, octavius, had dreams associating the soon-to-be born augustus with the heavens and the sun. both versions agree in calling apollo the father of augustus. herklotz follows grandet in seeing an egyptian background behind the story of atia’s vision that her womb spread over the sky: the sky goddess nut devours the sun every evening so that he can be reborn the next morning.184 the pharaoh was the offspring of his goddess mother and his divine father, the sun god. as such, “the pharaoh is the earthly incarnation of the sun god,”185 just as apollo-sol is the father of augustus. at rome, this parentage bolstered augustus’ claim to power; in the greek world, it associated him with another divinely-engendered figure, alexander the great; and in egypt, it was consistent with augustus’ role as pharaoh.186 herklotz recalls the egyptian ideology of kingship in which the pharaoh is s3 re,” the “son of re,” something exemplified, as swetnam-burland noted above, on the montecitorio obelisk itself. moreover, this concept could also be behind the architectural design of the ara pacis, if capriotti’s suggestion is accepted that it derives from the horned altar associated in egypt with the rebirth of the sun and the related daily battle it fights at dawn against its enemies and the enemies of the pharaoh. so if the alignments at the ara pacis evoke augustus’ birth, then those along the entire axis can be related to the sun’s (re)birth. both involve epic battles against enemies: re is only reborn each morning after fighting victoriously over his enemies during the night. the ara pacis was built to celebrate augustus’ victories from one end of the empire to the other. in pursuing the double goal of celebrating himself and the sun god, 183 herklotz 2007: 209. 184 herklotz 2007: 219; grandet 1986: 370-373. 185 herklotz 2007: 219. 186 herklotz 2007: 219-220. the relationship between the montecitorio obelisk and the ara pacis     1:81 augustus was not simply sharing an honor with another; he was simultaneously emphasizing the strong bond that existed between himself and his putative father. of course, as capriotti vittozzi noted, the romans did not simply translate elements of egyptian culture in their pure, original form to rome but always adapted them to their own needs and traditions.187 our study presents a case in point. to mention only the major differences: apart from the unique obelisk of thutmose ii and iv in the amun-re-harakhty temple at karnak east (called a “striking exception” by bell),188 the egyptians generally used obelisks in pairs, not as singletons.189 we have no evidence that they created axes of solar alignment with obelisks in or around their sanctuaries. indeed, without the leap year in their 365-day calendar, they could not do this, since whatever date-specific alignment they chose would soon cease to be valid as time advanced through the 1,460 astronomical years of the sothic cycle. hence, one implication of the augustan program is connected, at a deep level, with the gnomonic device: like the operation of the latter, the solar spectacle of the obelisk-altar alignment demonstrated the advantage of the roman calendar: it was harmonized with the ephemeris of the sun such that it was possible to set up an alignment of the sun over the obelisk that would recur at more or less the same time and place each year—something the egyptians were never able to achieve, even if the fifth dynasty determinative (figure 3) suggests that they might have occasionally wished to do so. although we know that the gnomonic device ceased to render accurate time by ca. ad 40 (almost certainly because, as stuart discovered in the eighteenth century, the obelisk had subsided by 5 cm to the southwest), the computer simulations show that this slight shift—however fatal to the scientific instrument—would not have affected the sun’s alignment with the ara pacis and montecitorio obelisk (see appendix tables 1d-4d). augustus’ sun and shadow show was not stopped by any physical defect or astronomical miscalculation. this is why the third-century emperor aurelian found it worthwile to enhance the spectacle with the addition of an impressive solar sanctuary athwart the axial line. this brings us to the second question raised at the beginning of this section: was each of the solar alignments meant to be seen, and by whom? the only answer we can honestly give is that we simply do not know. all we can say is that an ex silentio argument against our interpretation based on the lack of an eyewitness account in the surviving ancient literary record would be unjustified. the literary notices of the monuments in question are too scanty to build a case along the lines, “surely if frischer et al. were correct, then roman author x would have mentioned these alignments.” it is worth noting, in the connection, that such an ex silentio argument was rarely, if ever, raised against the theory of edmund buchner, which our new interpretation would replace. this brings us to the matter of how, in conclusion, we would update buchner’s view that the obelisk-altar relationship implicitly propagated the message that augustus was natus ad pacem. if a new slogan is sought, one might emend buchner’s text to read: “augustus was natus ad pacem because of his devotion to sol-apollo.” that is, augustus’ ability to bring rome victory in war and prosperity in time of peace was made possible by the divine origin and sanction of his rule as well as by his own pietas. on an objective, scientific level, this meant that it was augustus who was the one to correctly implement julius caesar’s calendar. on a subjective, religious level, it meant that he felt a special relationship with apollo and sol, insofar as they were separable deities in 187 see also the survey of recent scholarship on this issue in versluys 2015. 188 bell 2002: 23. 189 mckenzie traces this roman habit to the single obelisk erected by ptolemy ii philadelphus in the arsinoeion; see mckenzie 2007: 33. the determinative of the sun atop the obelisk discussed above suggests that the egyptians would have liked to achieve what augustus did, but because their calendar lacked the leap year, they were unable to coordinate the solar ephemeris with a fixed time and date. cf. schäfer 1929: 723: “die religiöse vorstellung, dass der gott auf dem obelisken ruhe, war in den schreibern so lebendig, dass sie wieder einmal, wie so oft, eine in ihrer bildhaften schrift gegebene möglichkeit zur symbolik hübsch benutzt haben.” the relationship between the montecitorio obelisk and the ara pacis     1:82 his mind. the solar alignments discussed in this paper provided unmistakable evidence of the emperor’s piety toward sol-apollo. in terms of power, the obelisk-altar project showed that the emperor had the massive human and material resources required to bring an obelisk from egypt to rome and to have it erected with great precision both to serve the needs of a great scientific instrument, the gnomonic device, and to express his deep religious devotion through the recurrent sun and shadow spectacle he created in the campus martius and nearby campus agrippae. in short, our new interpretation views the relationship of the ara pacis and montecitorio obelisk as an expression in the language of monuments and astronomy of the still-extant words inscribed on two sides of the plinth of the obelisk [cil 6.702 = ils 91]: imp caesar divi f emperor caesar augustus, avgvstvs son of the deity, pontifex maximvs chief priest, imp xii cos xi trib pot xiv serving with imperial power twelve times, as consul aegypto in potestatem eleven times, and with tribunician power fourteen times, popvli romani redacta because egypt had been brought under the soli donvm dedit power of the roman people, gave this as a gift to the sun god. the relationship between the montecitorio obelisk and the ara pacis     1:83 14. appendix i – tables bernard frischer appendix table 1: report on solar alignments west of obelisk zone: 1 software used: stellarium 3d plug-ins: 3d sceneries (a) meridian augusti revised (=29.6 m obelisk); (b) 30.7m obelisk (used in stress tests) settings: view-markings-projection: perspective. height of gnomon: 29.6 m (100 roman feet) year investigated: 9 bc (" -8 " on stellarium's clock) time: utc alignment: obelisk's finial centered on sun's disk year:9 bc190 observer: bernard frischer    date: 8/12/2015 note 1: sun is never high enough in sky for an alignment until the observer is at least 80 meters west of the obelisk. in practice, as the table shows, there is no solar alignment closer than ca. 98 meters to the obelisk. note 2: observations arbitrarily stopped at 196 meters west of obelisk. in the modern city, this corresponds to the intersection of the modern via di pallacorda and the via metastasio. there is no evidence of imperial building in the zone studied, which appears to have retained its nature as a public park by (cf. strabo 5.3.8) long after the reign of augustus. if one wanted, the study of solar alignments could be extended farther to the west until the tiber is reached more than 1 km away from the obelisk along the line running from the middle of the ara pacis and the middle of the obelisk.191 note 3: on the following table, the measurements in meters are approximate and are offered to give users a quick idea of where to move stellarium's camera. the grid coordinates are exact. note 4: on the table, date-1 and time-1 give the times when the centers of the finial and solar disk closely coincide. date-2 and time-2 give the equivalent dates later in the year. usually, the centers do not coincide as closely on these latter dates. the slight difference is detectable at the small fovs used for analytical purposes but not at the more realistic fov of 90° which approximates what the ancient observer will have seen. note 5: in the published version of the simulation, the user may go directly to the grid coordinates indicated on the table. to do so, open the configuration window (the wrench icon on the left side of the screen). select plugins and click "configure" in the bottom left. in the 3d scenery window, click on "load/save viewpoints." a list of stored viewpoints is displayed. click on the date as per date-1 on the tale below. stellarium moves the camera to the appropriate grid coordinates. stellarium does not, however, change the date or time. do this by click on the clock icon on the left side of the screen. set the date to 132 (ad); and key in the appropriate month, day, hour, minute, and second, as per the table below. 190 in using the year 9 bc, we are aware of the fact that in that year, the calendar had not yet been re-synched to the leap year. that would not happen until ad 4. but the romans were already aware of the problem and were addressing it. so the obelisk-ara pacis alignment will have been based on the corrected julian calendar. here and in the other tables, we have therefore “proleptically corrected” the solar data for 9 bc (see: https://en.wikipedia.org/wiki/proleptic_ julian_calendar). 191 in the area not studied, one interesting zone is the modern piazza s. apollinare where, according to palmer 1990: 15-17, the games celebrating augustus’ return in 13 and 7 bc were held. the games of 13 were votive games given by tiberius on the occasion of augustus’ return from spain, gaul, and germany. they are thus closely connected with the festivities that saw the senate’s vow of the ara pacis. the line running from the center of the ara pacis to the obelisk passes through this general area. the distance to the piazza from the obelisk is ca. 435 m. a solar alignment with the obelisk is seen in this area on august 13 (feriae jovi). presumably, tiberius’ games took place during the ludi romani (sacred to jupiter) in september, not during the festival on august 13. the tiber sets a limit of late april=late august to possible alignments that could be viewed in the campus martius. the relationship between the montecitorio obelisk and the ara pacis     1:84 note 6: on table b we present the observations for three randomly selected dates listed on table a. only one date in a date-pair was studied. note 7: since at present it is not possible to lock the camera onto a fixed path in stellarium, the data that follows below are only approximately correct. we estimate they are accurate to ± 10.00 m and ± 30 seconds. since the point of the table is to show that, without doubt, there are many solar alignments in the area of the ara pacis and obelisk, we consider this degree of accuracy to be acceptable. appendix table 1a: dates and times of alignment (29.6 m obelisk) meters from obelisk (estimate) date-1 time-1 date-2 time-2 grid coordinates 292 5/8 04:33:19 8/10 04:42:54 -277.18m, -67.24m, -1.50m 272 5/9 04:34:30 8/9 04:44:25 -258.06m, -61.27m, -1.50m 255 5/10 04:35:33 8/8 04:45:42 -242.75m, -56.56m, -1.50m 240 5/11 04:36:50 8/7 04:47:09 -228.12m, -52.01m, -1.50m 226 5/12 04:37:54 8/6 04:48:18 -216.08m, -48.39m, -1.50m 216 5/13 04:38:58 8/5 04:49:33 -205.11m, -45.04m, -1.50m 206 5/14 04:40:06 8/4 04:50:46 -195.28m, -42.04m, -1.50m 196 5/15 04:41:24 8/3 04:52:09 -186.93m, -39.36m, -1.50m 189 5/16 04:42:31 8/2 04:53:23 -179.31m, -37.05m, -1.50m 182 5/17 04:43:40 8/1 04:54:32 -171.45m, -34.56m, -1.50m 175 5/18 04:44:45 7/31 04:55:41 -164.85m, -32.57m, -1.50m 167.5 5/19 04:45:48 7/30 04:56:48 -158.34m, -30.56m, -1.50m 162 5/20 04:46:52 7/29 04:57:34 -152.88m, -28.89m, -1.50m 156 5/21 04:47:58 7/28 04:58:56 -147.78m, -27.31m, -1.50m 151 5/22 04:49:08 7/27 04:59:53 -142.89m, -25.78m, -1.50m 147.5 5/23 04:50:03 7/26 05:00:49 -139.11m, -24.67m, -1.50m 143.5 5/24 04:51:14 7/25 05:01:50 -135.12m, -23.38m, -1.50m 140 5/25 04:52:09 7/24 05:02:46 -131.75m, -22.37m, -1.50m 136 5/26 04:53:18 7/23 05:03:40 -127.64m, -21.06m, -1.50m 134 5/27 04:54:16 7/22 05:04:28 -125.14m, -20.33m, -1.50m 131 5/28 04:55:11 7/21 05:05:16 -122.23m, -19.44m, -1.50m 128 5/29 04:56:14 7/20 05:05:18 -119.58m, -18.60m, -1.50m 125 5/30 04:57:03 7/19 05:06:47 -117.09m, -17.90m, -1.50m 123 5/31 04:58:02 7/18 05:07:27 -113.84m, -17.18m, -1.50m 120.5 6/1 04:59:02 7/17 05:08:07 -112.39m, -16.41m, -1.50m the relationship between the montecitorio obelisk and the ara pacis     1:85 118 6/2 05:00:01 7/16 05:08:46 -110.70m, -15.89m, -1.50m 116.5 6/3 05:00:45 7/15 05:09:19 -108.80m, -15.31m, -1.50m 114 6/4 05:01:36 7/14 05:08:04 -107.03m, -14.76m, -1.50m 111 6/5 05:02:26 7/13 05:10:23 -105.35m, -14.25m, -1.50m 109 6/6 05:03:14 7/12 05:10:52 -103.89m, -13.79m, -1.50m 108 6/7 05:03:58 7/11 05:11:17 -102.40m, -13.34m, -1.50m 107 6/8 05:04:43 7/10 05:10:15 -101.09m, -12.94m, -1.50m 106 6/9 05:05:42 7/9 05:12:15 -99.76m, -12.45m, -1.50m 105 6/10 05:06:25 7/8 05:12:25 -98.63m, -12.07m, -1.50m 104 6/11 05:07:08 7/7 05:12:59 -97.66m, -11.78m, -1.50m 103.5 6/12 05:07:43 7/6 05:13:05 -96.80m, -11.54m, -1.50m 103 6/13 05:07:53 7/5 05:13:20 -95.98m, -11.29m, -1.50m 102.5 6/14 05:08:53 7/4 05:13:26 -95.29m, -11.08m, -1.50m 102 6/15 05:09:25 7/3 05:13:35 -94.57m, -10.87m, -1.50m 101 6/16 05:09:57 7/2 05:13:39 -94.11m, -10.73m, -1.50m 100 6/17 05:10:25 7/1 05:13:31 -93.54m, -10.61m, -1.50m 99 6/18 05:10:53 6/30 05:13:43 -92.97m, -10.38m, -1.50m 98.5 6/19 05:11:21 6/29 05:13:40 -92.54m, -10.25m, -1.50m 98 6/20 05:11:44 6/28 05:13:17 -92.62m, -10.37m, -1.50m 98 6/21 05:11:46 6/27 05:13:11 -92.35m, -10.28m, -1.50m 98 6/22 5:12:20 6/26 05:13:14 -91.84m, -10.08m, -1.50m 97 6/23 5:12:36 6/25 05:13:04 -91.81m, -10.07m, -1.50m 97 6/24192 5:12:51 -- -- -91.78m, -10.06m, -1.50m appendix table 1b: observations of years 1, 2, and 3 of the four-year leap-year cycle for a random sample of alignments listed on appendix table 1a. year in cycle date-1 time-1 date-2 time-2 grid coordinates 1 5/20 04:46:52 7/29 04:57:34 -152.88m, -28.89m, -1.50m 2 “ “ 04:46:27 “ “ 04:57:46 -153.92m, -29.29m, -1.50m 3 “ “ 04:46:12 “ “ 04:57:58 -155.45m, -29.75m, -1.50m 1 5/30 04:57:03 7/19 05:06:47 -117.09m, -17.90m, -1.50m 2 “ “ 04:56:46 “ “ 05:06:45 -117.97m, -18.17m, -1.50m 3 “ “ 04:56:29 “ “ 05:06:47 -118.37m, -18.30m, -1.50m 1 6/17 05:10:16 7/1 05:13:31 -93.54m, -10.61m, -1.50m 192 the summer solstice in 9 bc according to nasa’s calculator: http://data.giss.nasa.gov/ar5/srvernal.html the relationship between the montecitorio obelisk and the ara pacis     1:86 2 “ “ 5:10:11 “ “ 05:13:30 -93.69m, -10.66m, -1.50m 3 “ “ 5:10:10 “ “ 05:13:30 -93.69m, -10.66m, -1.50m appenxix table 1c: stress tests with 30.7 m obelisk meters from obelisk (estimate) date-1 time-1 date-2 time-2 grid coordinates 170 5/21 04:45:16 7/28 04:56:06 -160.72m, -33.66m, -1.50m 165 5/22 04:46:18 7/27 04:57:08 -155.69m, -32.07m, -1.50m 159 5/23 04:47:21 7/26 04:58:09 -150.65m, -30.48m, -1.50m 105 6/22 5:09:17 6/26 05:10:17 -98.90m, -14.08m, -1.50m 103 6/23 5:09:48 6/25 05:10:11 -98.90m, -14.08m, -1.50m 103 6/24 5:09:58 -- -98.24m, -13.89m, -1.50m appendix table 1d: stress tests of 29.6 m obelisk with 5cm of subsidence to the southwest year: 9 bc method: three randomly chosen dates from appendix table 1a were asked to see if the dates of alignment would be changed or invalidated after the 29.6 m obelisk had subsided 5 cm. meters from obelisk (estimate)193 date-1 time-1 date-2194 time-2 grid coordinates195 194 (182) 5/15 4:41:40 8/3 (8/1) 4:52:33 -184.61m, -38.62m, -1.50m 138 (140) 5/25 4:52:33 7/24 5:03:09 -131.00m, -22.21m, -1.50m (-131.75m, -22.37m, -1.50m) 166 (118) 6/2 5:00:33 7/16 5:09:25 -109.62m, -15.56m, -1.50m (-110.70m, -15.89m, -1.50m) 193 number in parentheses is estimated of meters from obelisk in the simulation without subsidence of the 29.6 m obelisk. 194 date in parentheses is best date of the second alignment in the year in the simulation without the subsidence of the 29.6 m obelisk. 195 coordinates in parentheses are those of the simulation without subsidence of the 29.6 m obelisk. the relationship between the montecitorio obelisk and the ara pacis     1:87 appendix table 2: report on solar alignments from the west entrance of the ara pacis to the obelisk zone: 2 software used: stellarium 3d plug-ins: 3d sceneries (a) meridian augusti revised (=29.6 m obelisk); (b) 30.7m obelisk (used in stress tests) settings: view-markings-projection: perspective. height of gnomon: 29.6 m (100 roman feet) year investigated: 9 bc (" -8 " on stellarium's clock) time: utc alignment: obelisk's finial centered on sun's disk year: 9 bc observer: bernard frischer    date: 8/12/2015 note 1: on the following table, the measurements in meters are approximate and are offered to give users a quick idea of where to move stellarium’s camera. the grid coordinates are exact. note 2: on the table, date-1 and time-1 give the times when the centers of the finial and solar disk closely coincide. date-2 and time-2 give the equivalent dates later in the year. usually, the centers do not coincide as closely on these latter dates. the slight difference is detectable at the small fovs used for analytical purposes but not at the more realistic fov of 90° which approximates what the ancient observer will have seen. note 3: in the published version of the simulation, the user may go directly to the grid coordinates indicated on the table. to do so, open the configuration window (the wrench icon on the left side of the screen). select plugins and click “configure” in the bottom left. in the 3d scenery window, click on “load/save viewpoints.” a list of stored viewpoints is displayed. click on the date as per date-1 on the tale below. stellarium moves the camera to the appropriate grid coordinates. stellarium does not, however, change the date or time. do this by click on the clock icon on the left side of the screen. set the date to 132 (ad); and key in the appropriate month, day, hour, minute, and second, as per the table below. note 4: since at present it is not possible to lock the camera onto a fixed path in stellarium, the data that follows below are only approximately correct. we estimate they are accurate to ± 10.00 m and ± 30 minutes. since the point of the table is to show that, without doubt, there are many solar alignments in the area of the ara pacis and obelisk, we consider this degree of accuracy to be acceptable. note 5: as noted in the text, the first two alignments (at ca. 90 meters and 89 meters) are intervisible. the rest are interpositional. appendix table 2a: dates and times of alignment (29.6 m obelisk) meters from obelisk (estimate) date-1 time-1 date-2 time-2 grid coordinates 91 3/19 15:45:21 9/27 15:28:21 90.84m, 45.60m, 1.01m 88 3/20 15:41:13 9/26 15:24:46 88.19m, 45.48m, 0.15m 88 3/21 15:41:28 9/25 15:25:37 87.76m, 44.68m, 0.06m 86 3/22 15:39:31 9/24 15:24:16 86.46m, 44.30m, -0.49m 85 3/23 15:37:29 9/23 15:22:49 85.00m, 43.88m, -0.89m 84 3/24 15:35:30 9/22 15:21:29 84.00m, 43.58m, -1.50m 81 3/25 15:33:32 9/21 15:20:13 81.49m, 42.81m, -1.50m 79 3/26 15:31:35 9/20 15:18:53 79.15m, 42.12m, -1.50m the relationship between the montecitorio obelisk and the ara pacis     1:88 77 3/27 15:29:33 9/19 15:17:28 76.85m, 41.43m, -1.50m 75 3/28 15:27:32 9/18 15:16:06 74.66m, 40.78m, -1.50m 72 3/29 15:25:36 9/17 15:14:44 72.75m, 40.21m, -1.50m 70 3/30 15:23:35 9/16 15:13:24 70.69m, 39.59m, -1.50m 69 3/31 15:21:39 9/15 15:11:59 68.93m, 39.07m, -1.50m 67 4/1 15:19:42 9/14 15:10:39 67.19m, 38.55m, -1.50m 65 4/2 15:17:27 9/13 15:09:23 65.35m, 38.05m, -1.50m 64 4/3 15:14:21 9/12 15:07:51 63.13m, 37.64m, -1.50m 62 4/4 15:12:17 9/11 15:05:04 61.57m, 37.19m, -1.50m 60 4/5 15:10:18 9/10 15:03:44 60.11m, 36.76m, -1.50m 59 4/6 15:08:15 9/9 15:02:31 58.71m, 36.36m, -1.50m 57 4/7 15:06:31 9/8 15:01:21 57.35m, 35.86m, -1.50m 56 4/8 15:04:44 9/8196 15:01:19 56.29m, 35.52m, -1.50m 55 4/9 15:02:44 9/7 15:00:02 54.88m, 35.09m, -1.50m 54 4/10 15:00:57 9/6 14:58:40 53.93m, 34.80m, -1.50m 53 4/11 14:59:10 9/5 14:57:22 52.89m, 34.48m, -1.50m 52 4/12 14:56:58 9/4 14:55:28 51.70m, 34.18m, -1.50m 50 4/13 14:54:53 9/3 14:54:07 50.54m, 33.86m, -1.50m 49 4/14 14:52:45 9/2 14:52:45 49.43m, 33.57m, -1.50m 48 4/15 14:50:40 9/1 14:51:01 48.39m, 33.29m, -1.50m 47 4/16 14:48:36 8/31 14:49:28 47.41m, 33.02m, -1.50m 46 4/17 14:46:31 8/30 14:47:50 46.39m, 32.75m, -1.50m 45 4/18 14:44:31 8/29 14:46:40 45.52m, 32.51m, -1.50m 44 4/19 14:42:29 8/28 14:46:09 44.55m, 32.25m, -1.50m 44 4/20 14:42:18 8/27 14:45:18 44.24m, 31.88m, -1.50m 43 4/21 14:40:37 8/26 14:43:37 43.42m, 31.62m, -1.50m 43 4/22 14:39:01 8/25 14:42:50 42.88m, 31.45m, -1.50m 42 4/23 14:34:29 8/25 14:40:08 42.08m, 31.16m, -1.50m 41 4/24 14:35:21 8/24 14:41:38 41.24m, 30.92m, -1.50m 40 4/25 14:33:32 8/23 14:40:20 40.64m, 30.74m, -1.50m 40 4/26 14:31:54 8/22 14:38:54 39.79m, 30.48m, -1.50m 39 4/27 14:30:17 8/21 14:37:38 39.27m, 30.31m, -1.50m 38 4/28 14:28:38 8/20 14:36:25 38.67m, 30.13m, -1.50m 38 4/29 14:26:55 8/19 14:25:16 38.07m, 29.94m, -1.50m 37 4/30 14:25:22 8/18 14:33:53 37.46m, 29.76m, -1.50m 37 5/1 14:23:48 8/17 14:32:29 36.88m, 29.58m, -1.50m 196 9/8 is a better fit than 9/7. the relationship between the montecitorio obelisk and the ara pacis     1:89 36 5/2 14:22:14 8/16 14:31:14 36.32m, 29.41m, -1.50m 35 5/3 14:20:34 8/15 14:29:43 35.53m, 29.18m, -1.50m 35 5/4 14:19:04 8/14 14:28:29 35.17m, 29.07m, -1.50m 34 5/5 14:17:24 8/13 14:27:07 34.62m, 28.91m, -1.50m 34 5/6 14:15:57 8/12 14:25:46 34.15m, 28.77m, -1.50m 33 5/7 14:14:20 8/11 14:24:27 33.66m, 28.63m, -1.50m 33 5/8 14:12:47 8/10 14:23:07 33.14m, 28.48m, -1.50m 33 5/9 14:11:23 8/9 14:21:41 32.72m, 28.35m, -1.50m 32 5/10 14:09:40 8/8 14:19:56 32.22m, 28.15m, -1.50m 32 5/11 14:08:34 8/7 14:19:04 31.82m, 28.09m, -1.50m 31 5/12 14:06:54 8/6 14:17:23 31.40m, 27.97m, -1.50m 31 5/13 14:05:41 8/5 14:16:12 30.97m, 27.84m, -1.50m 30 5/14 14:04:19 8/4 14:15:19 30.58m, 27.73m, -1.50m 30 5/15 14:03:02 8/3 14:13:40 30.19m, 27.62m, -1.50m 30 5/16 14:01:39 8/2 14:12:39 29.81m, 27.51m, -1.50m 29 5/17 14:00:24 8/1 14:11:24 29.47m, 27.41m, -1.50m 29 5/18 13:59:11 7/31 14:10:11 29.12m, 27.31m, -1.50m 29 5/19 13:57:52 7/30 14:08:28 28.74m, 27.20m, -1.50m 28 5/20 13:56:37 7/29 14:07:37 28.42m, 27.11m, -1.50m 28 5/21 13:55:26 7/28 14:06:26 28.09m, 27.02m, -1.50m 28 5/22 13:54:26 7/27 14:05:21 27.82m, 26.95m, -1.50m 27 5/23 13:53:21 7/26 14:03:37 27.47m, 26.85m, -1.50m 27 5/24 13:52:14 7/25 14:02:31 27.19m, 26.77m, -1.50m 27 5/25 13:51:18 7/24 14:01:29 26.94m, 26.70m, -1.50m 26 5/26 13:50:19 7/23 14:00:29 26.69m, 26.63m, -1.50m 26 5/27 13:48:57 7/22 13:58:47 26.31m, 26.53m, -1.50m 26 5/28 13:48:13 7/21 13:58:08 26.13m, 26.47m, -1.50m 26 5/29 13:47:30 7/20 13:56:49 25.89m, 26.40m, -1.50m 26 5/30 13:46:38 7/19 13:55:51 25.70m, 26.35m, -1.50m 25 5/31 13:45:36 7/18 13:54:32 25.41m, 26.26m, -1.50m 25 6/1 13:44:57 7/17 13:53:47 25.22m, 26.21m, -1.50m 25 6/2 13:44:07 7/16 13:52:38 24.98m, 26.14m, -1.50m 25 6/3 13:43:38 7/15 13:51:54 24.79m, 26.08m, -1.50m 24 6/4 13:42:54 7/14 13:50:54 24.63m, 26.04m, -1.50m 24 6/5 13:42:21 7/13 13:50:15 24.52m, 26.00m, -1.50m 24 6/6 13:41:48 7/12 13:49:05 24.30m, 25.94m, -1.50m 24 6/7 13:41:10 7/11 13:48:28 24.14m, 25.89m, -1.50m 24 6/8 13:40:33 7/10 13:47:28 24.00m, 25.85m, -1.50m the relationship between the montecitorio obelisk and the ara pacis     1:90 24 6/9 13:40:28 7/9 13:46:30 23.86m, 25.81m, -1.50m 24 6/10 13:40:08 7/8 13:46:00 23.74m, 25.77m, -1.50m 24 6/11 13:40:00 7/7 13:45:16 23.74m, 25.77m, -1.50m 24 6/12 13:39:29 7/6 13:44:29 23.51m, 25.71m, -1.50m 23 6/13 13:38:47 7/5 13:43:41 23.36m, 25.66m, -1.50m 23 6/14 13:38:28 7/4 13:42:51 23.22m, 25.62m, -1.50m 23 6/15 13:38:32 7/3 13:42:31 23.18m, 25.61m, -1.50m 23 6/16 13:38:29 7/2 13:41:58 23.15m, 25.59m, -1.50m 23 6/17 13:38:18 7/1 13:41:32 23.07m, 25.56m, -1.50m 23 6/18 13:38:32 6/30 13:41:13 23.05m, 25.56m, -1.50m 23 6/19 13:38:24 6/29 13:40:33 22.97m, 25.54m, -1.50m 23 6/20 13:38:33 6/28 13:40:11 22.94m, 25.53m, -1.50m 23 6/21 13:38:36 6/27 13:39:50 22.91m, 25.52m, -1.50m 23 6/22 13:38:50 6/26 13:39:47 22.91m, 25.52m, -1.50m 23 6/23 13:39:20 6/25 13:39:20 22.91m, 25.52m, -1.50m 23 6/24 13:38:58 -- 22.90m, 25.51m, -1.50m appendix table 2b: observations of years 1, 2, and 3 of the four-year leap-year cycle for a random sample of alignments listed on table a. year in cycle date-1 time-1 date-2 time-2 grid coordinates 1 3/21197 15:39:44 9/25 15:23:55 90.52m, 46.05m, -1.50m 2 “ “ 15:40:09 9/25 15:23:31 91.15m, 46.26m, -1.50m 3 “ “ 15:40:38 9/26198 15:24:28 91.96m, 46.51m, -1.50m 1 3/28 15:25:45 9/18 15:14:26 73.32m, 40.81m, -1.50m 2 “ “ 15:26:16 9/19 15:15:20 73.77m, 40.97m, -1.50m 3 “ “ 15:26:44 “ “ 15:14:59 74.28m, 41.13m, -1.50m 1 4/3 15:14:10 9/12 15:06:25 62.80m, 37.55m, -1.50m 2 “ “ 15:15:14 9/13 15:07:57 63.59m, 37.71m, -1.50m 3 " " " " 15:07:33 63.03m, 37.54m, -1.50m 198 vernal equinox in 9 bc according to nasa; see: http://data.giss.nasa.gov/ar5/srvernal.html the relationship between the montecitorio obelisk and the ara pacis     1:91 appendix table 2c: stress tests with 30.7 m obelisk meters from obelisk (estimate) date-1 time-1 date-2 time-2 grid coordinates 90 3/21199 15:36:25 9/25 15:20:35 90.34m, 46.04m, -1.50m 87.5 3/22 15:34:26 9/24 15:19:14 87.53m, 45.15m, -1.50m 85 3/23 15:32:30 9/23 15:18:20 84.94m, 44.33m, -1.50m 63.5 4/3 15:10:51 9/12 15:03:17 63.46m, 37.50m, -1.50m 62 4/4 15:09:05 9/11 15:01:50 62.08m, 37.07m, -1.50m 60 4/5 15:07:04 9/10 15:00:24 60.58m, 36.61m, -1.50m appendix table 2d: stress tests of 29.6 m obelisk with 5 cm of subsidence to the southwest year: 9 bc method: three randomly chosen dates from appendix table 2a were tested to see if the dates of alignment would be changed or invalidated after the 29.6 m obelisk had subsided 5 cm. meters from obelisk (estimate)200 date-1 time-1 date-2201 time-2 grid coordinates202 89.5 (90) 3/21203 15:39:09 9/25 15:23:21 89.65m, 45.74m, -1.50m (90.52m, 46.05m, -1.50m) 74(75) 3/27 15:26:57 9/19 15:14:48 74.58m, 41.21m, -1.50m (75.36m, 41.42m, -1.50m) 60.5 (61.5) 4/4 15:11:16 9/11 15:04:13 60.69m, 36.87m, -1.50m (61.46m, 37.13m, -1.50m) 199 vernal equinox in 9 bc according to nasa; see: http://data.giss.nasa.gov/ar5/srvernal.html 200 number in parentheses is estimate of meters from obelisk in the simulation without subsidence of the 29.6 m obelisk. 201 date in parentheses is best date of the second alignment in the year in the simulation without the subsidence of the 29.6 m obelisk. 202 coordinates in parentheses are those of the simulation without subsidence of the 29.6 m obelisk. 203 vernal equinox in 9 bc according to nasa; see: http://data.giss.nasa.gov/ar5/srvernal.html the relationship between the montecitorio obelisk and the ara pacis     1:92 appendix table 3: report on solar alignments over the ara pacis zone: 3 software used: stellarium 3d plug-ins: 3d sceneries (a) meridian augusti revised (=29.6 m obelisk); (b) 30.7m obelisk (used in stress tests) settings: view-markings-projection: perspective. height of gnomon: 29.6 m (100 roman feet) year investigated: 9 bc (“ -8 ” on stellarium’s clock) time: utc alignment: center of the solar disk rising on axis over the ara pacis as seen by an observer looking toward the east. year: 9 bc observer: bernard frischer    date: 8/23/2015 note 1: on the following table, the measurements in meters are approximate and are offered to give users a quick idea of where to move stellarium’s camera. the grid coordinates are exact. note 2: on the table, date-1 and time-1 give the times when the centers of the solar disk and west elevation of the ara pacis closely coincide. date-2 and time-2 give the equivalent dates later in the year. usually, the centers do not coincide as closely on these latter dates. the slight difference is detectable at the small fovs used for analytical purposes but not at the more realistic fov of 90o which approximates what the ancient observer will have seen. note 3: in the published version of the simulation, the user may go directly to the grid coordinates indicated on the table. to do so, open the configuration window (the wrench icon on the left side of the screen). select plugins and click “configure” in the bottom left. in the 3d scenery window, click on “load/save viewpoints.” a list of stored viewpoints is displayed. click on the date as per date-1 on the tale below. stellarium moves the camera to the appropriate grid coordinates. stellarium does not, however, change the date or time. do this by click on the clock icon on the left side of the screen. set the date to -8 (=9 bc204); and key in the appropriate month, day, hour, minute, and second, as per the table below. note 4: since at present it is not possible to lock the camera onto a fixed path in stellarium, the data that follows below are only approximately correct; moreover, in the case of the alignments reported here, there was nothing like the obelisk’s finial to determine the centering. we estimate they are accurate to ± 10.00 m and ±30 minutes. since the point of the table is to show that, without doubt, there are many solar alignments in the area of the ara pacis and obelisk, we consider this degree of accuracy to be acceptable. appendix table 3a meters from west entrance of ara pacis (estimate) date-1 time-1 date-2 time-2 grid coordinates 90 4/30 04:23:24 8/18 04:29:37 1.43m, 18.52m, 0.08m 85 5/1 04:24:37 8/17 04:32:07 7.74m, 20.58m, -0.58m 77 5/2 04:25:15 8/16 04:33:15 8.56m, 20.85m, -1.02m 75 5/3 04:25:15 8/15 04:34:25 9.48m, 21.17m, -1.50m 66 5/4 04:27:09 8/14 04:35:28 18.33m, 23.68m, -1.50m 60 5/5 04:28:12 8/13 04:37:30 24.81m, 25.82m, -1.50m 204 stellarium has 0 bc/ad, a non-existent year. hence, to get dates bc, one must add a year. so, as in the present case, 9 bc in stellarium is year -8. the relationship between the montecitorio obelisk and the ara pacis     1:93 55 5/6 04:29:25 8/12 04:38:25 30.83m, 27.58m, -1.50m 50 5/7 04:30:25 8/11 04:39:39 35.55m, 29.13m, -1.50m 46 5/8 04:31:39 8/10 04:40:55 39.26m, 30.13m, -1.50m 42 5/9 04:32:55 8/9 04:42:49 43.14m, 31.38m, -1.50m 40 5/10 04:34:49 8/8 04:44:37 46.63m, 32.39m, -1.50m 38 5/11 04:36:00 8/7 04:45:48 49.21m, 33.26m, -1.50m 36 5/12 04:37:48 8/6 04:47:37 52.03m, 34.22m, -1.50m 34 5/13 04:39:37 8/5 04:49:32 54.53m, 35.09m, -1.50m 33 5/14 04:40:32 8/4 04:50:18 55.85m, 35.35m, -1.50m 31 5/15 04:43:18 8/3 04:53:09 58.03m, 36.08m, -1.50m 30 5/16 04:43:25 8/2 04:54:08 58.79m, 36.19m, -1.50m 29 5/17 04:43:45 8/1 04:55:19 59.58m, 36.47m, -1.50m 28 5/18 04:44:47 7/31 04:56:14 60.60m, 36.84m, -1.50m 27 5/19 04:45:54 7/30 04:57:18 61.49m, 37.15m, -1.50m 27 5/20 04:46:18 7/29 04:57:22 62.18m, 37.28m, -1.50m 26 5/21 04:47:07 7/28 04:57:49 62.97m, 37.53m, -1.50m 25 5/22 04:48:30 7/27 04:58:40 63.75m, 37.78m, -1.50m 25 5/23 04:49:49 7/26 04:59:03 64.34m, 37.97m, -1.50m 25 5/24 04:50:21 7/25 05:00:11 65.07m, 38.20m, -1.50m 24 5/25 04:51:11 7/24 05:00:58 65.60m, 38.37m, -1.50m 24 5/26 04:53:11 7/23 05:02:25 66.43m, 38.63m, -1.50m 23 5/27 04:54:59 7/22 05:03:12 66.59m, 38.70m, -1.50m 23 5/28 04:53:58 7/21 05:03:47 67.18m, 38.87m, -1.50m 23 5/29 04:54:36 7/20 05:04:22 67.49m, 38.96m, -1.50m 23 5/30 04:55:07 7/19 05:04:46 67.66m, 39.01m, -1.50m 22 5/31 04:55:20 7/18 05:05:05 67.72m, 39.02m, -1.50m 22 6/1 04:55:32 7/17 05:05:20 67.91m, 39.08m, -1.50m 22 6/2 04:56:14 7/16 05:05:52 68.23m, 39.16m, -1.50m 21 6/3 04:57:44 7/15 05:06:07 68.63m, 39.28m, -1.50m 21 6/4 04:58:21 7/14 05:06:11 68.93m, 39.37m, -1.50m 21 6/5 04:59:11 7/13 05:06:22 69.25m, 39.48m, -1.50m 20 6/6 05:00:04 7/12 05:06:30 69.45m, 39.54m, -1.50m 20 6/7 05:00:29 7/11 05:07:15 69.81m, 39.67m, -1.50m 20 6/8 05:01:00 7/10 05:07:25 70.02m, 39.74m, -1.50m 20 6/9 05:01:25 7/9 05:07:37 70.11m, 39.77m, -1.50m 20 6/10 05:01:55 7/8 05:07:47 70.31m, 39.84m, -1.50m 20 6/11 05:02:30 7/7 05:08:15 70.46m, 39.89m, -1.50m 19 6/12 05:02:58 7/6 05:08:35 70.59m, 39.93m, -1.50m the relationship between the montecitorio obelisk and the ara pacis     1:94 19 6/13 05:03:35 7/5 05:08:42 70.75m, 39.98m, -1.50m 19 6/14 05:04:00 7/4 05:08:53 70.87m, 40.02m, -1.50m 19 6/15 05:04:33 7/3 05:09:05 70.93m, 40.04m, -1.50m 18 6/16 05:05:02 7/2 05:08:31 71.11m, 40.10m, -1.50m 18 6/17 05:05:30 7/1 05:08:41 71.26m, 40.02m, -1.50m 18 6/18 05:05:43 6/30 05:08:49 71.32m, 40.04m, -1.50m 18 6/19 05:06:34 6/29 05:08:54 71.40m, 40.07m, -1.50m 18 6/20 05:07:07 6/28 05:09:00 71.47m, 40.21m, -1.50m 18 6/21 05:07:34 6/27 05:08:46 71.52m, 40.23m, -1.50m 6/22 05:08:26 6/26 05:09:08 71.63m, 40.26m, -1.50m 6/23 05:08:43 6/25 05:08:43 71.69m, 40.28m, -1.50m 6/24 05:09:13 -- -- 71.74m, 40.29m, -1.50m appendix table 3b. observations in years 1, 2, and 3 of the four-year leap-year cycle for a random sample of alignments listed on table a. year in cycle date-1 time-1 date-2 time-2 grid coordinates205 1 5/4 04:27:09 8/14 04:35:28 18.33m, 23.68m, -1.50m 2 5/4 “ “ “ 8/14 “ “ “ “ “ “ 3 5/4 “ “ “ 8/14 “ “ “ “ “ “ 1 5/7 4:30:25 8/11 04:39:39 35.55m, 29.13m, -1.50m 2 5/7 “ “ “ 8/11 “ “ “ “ “ “ 3 5/7 “ “ “ 8/11 “ “ “ “ “ “ 1 5/13 04:39:30 8/5 04:49:32 54.53m, 35.09m, -1.50m 2 5/13 “ “ “ 8/5 “ “ “ “ “ “ 3 5/13 “ “ “ 8/5 “ “ “ “ “ “ 205 the grid coordinates are always those best for the date-1 alignment. the relationship between the montecitorio obelisk and the ara pacis     1:95 appendix table 4: report on solar alignments east of ara pacis zone: 4 software used: stellarium 3d plug-ins: 3d sceneries (a) meridian augusti revised (=29.6 m obelisk); (b) 30.7m obelisk (used in stress tests) settings: view-markings-projection: perspective. height of gnomon: 29.6 m (100 roman feet) year investigated: 9 bc (“ -8 ” on stellarium’s clock) time: utc alignment: obelisk’s finial centered on sun’s disk year: 9 bc observer: bernard frischer date:    8/12/2015 note 1: observations arbitrarily stopped at 196 meters east of ara pacis. as far as is known, no other building occupied this area in augustan rome. note 2: on the following table, the measurements in meters are approximate and are offered to give users a quick idea of where to move stellarium’s camera. the grid coordinates are exact. note 3: on the table, date-1 and time-1 give the times when the centers of the finial and solar disk closely coincide. date-2 and time-2 give the equivalent dates later in the year. usually, the centers do not coincide as closely on these latter dates. the slight difference is detectable at the small fovs used for analytical purposes but not at the more realistic fov of 90° which approximates what the ancient observer will have seen. note 4: in the published version of the simulation, the user may go directly to the grid coordinates indicated on the table. to do so, open the configuration window (the wrench icon on the left side of the screen). select plugins and click “configure” in the bottom left. in the 3d scenery window, click on “load/save viewpoints.” a list of stored viewpoints is displayed. click on the date as per date-1 on the tale below. stellarium moves the camera to the appropriate grid coordinates. stellarium does not, however, change the date or time. do this by click on the clock icon on the left side of the screen. set the date to -8 (=9 bc206); and key in the appropriate month, day, hour, minute, and second, as per the table below. note 5: since at present it is not possible to lock the camera onto a fixed path in stellarium, the data that follows below are only approximately correct. we estimate they are accurate to ± 10.00 m and ± 30 minutes. since the point of the table is to show that, without doubt, there are many solar alignments in the area of the ara pacis and obelisk, we consider this degree of accuracy to be acceptable. note 6: table b presents the results using the stellarium model with an obelisk that is 30.7 m and moved 1 m south along the extension of the meridian line. it presents the first three and last three pairs of dates on table a appendix table 4a meters from east entrance of ara pacis (estimate) date-1 time-1 date-2 time-2 grid coordinates 16 10/3 15:35:02 3/13 15:55:40 117.08m, 54.11m, -0.22m 24 10/4 15:36:09 3/12 15:57:24 121.93m, 55.63m, -0.22m 29 10/5 15:37:11 3/11 15:59:08 127.01m, 57.31m, -0.22m 206 stellarium has 0 bc/ad, a non-existent year. hence, to get dates bc, one must add a year. so, as in the present case, 9 bc in stellarium is year -8. the relationship between the montecitorio obelisk and the ara pacis     1:96 35 10/6 15:38:51 3/10 16:01:04 133.33m, 59.26m, -0.22m 43 10/7 15:40:22 3/9 16:03:02 141.02m, 61.56m, -0.22m 50 10/8 15:41:44 3/8 16:04:53 148.84m, 63.99m, -0.22m 59 10/9 15:43:04 3/7 16:06:43 157.17m, 66.59m, -0.22m 68 10/10 15:44:31 3/6 16:08:40 166.26m, 69.34m, -0.22m 79 10/11 15:45:52 3/5 16:10:30 176.91m, 72.66m, -0.22m 91 10/12 15:47:19 3/4 16:12:19 188.75m, 76.32m, -0.22m 104 10/13 15:48:44 3/3 16:14:11 202.28m, 80.52m, -0.22m 118 10/14 15:50:09 3/2 16:16:03 218.02m, 85.29m, -0.22m 138 10/15 15:51:35 3/1 16:17:51 236.24m, 90.93m, -0.22m 165 10/16 15:52:58 2/29208 16:19:38 256.40m, 97.15m, -0.22m 190 10/17 15:54:21 2/28 16:21:28 280.72m, 104.61m, -0.22m appendix table 4b. observations in years 1, 2, and 3 of the four-year leap-year cycle for a random sample of alignments listed on table a. year in cycle date-1 time-1 date-2 time-2 grid coordinates208 1 10/5 15:37:11 3/11 15:59:08 127.01m, 57.31m, -0.22m 2 “ “ 15:37:06 “ “ 15:59:24 126.20m, 57.07m, -0.22m 3 “ “ 15:36:42 3/12209 15:58:01 124.47m, 56.56m, -0.22m 1 10/9 15:43:04 3/7 16:06:43 157.17m, 66.59m, -0.22m 2 “ “ 15:42:41 “ “ 16:07:04 154.85m, 65.91m, -0.22m 3 “ “ 15:42:15 3/8 16:05:39 152.30m, 65.15m, -0.22m 1 10/14 15:50:09 3/2 16:16:03 218.02m, 85.29m, -0.22m 2 “ “ 15:49:46 “ “ 16:16:28 212.60m, 83.67m, -0.22m 3 “ “ 15:49:23 “ “ 16:16:48 209.54m, 82.75m, -0.22m 207 this is a hypothetical date since in this year the leap year was suppressed. 208 the grid coordinates are always those best for the date-1 alignment. 209 note the shift of one day. the relationship between the montecitorio obelisk and the ara pacis     1:97 appendix table 4c: stress tests with 30.7 m obelisk meters from east entrance of ara pacis (estimate) date-1 time-1 date-2 time-2 grid coordinates 15 10/3 15:31:54 3/13 15:52:30 116.08m, 54.01m, -0.22m 20 10/4 15:34:03 3/12 15:54:25 121.26m, 55.69m, -0.22m 25 10/5 15:34:27 3/11 15:56:13 126.60m, 57.42m, -0.22m 94 10/13 15:45:36 3/3 16:11:08 195.31m, 79.31m, -0.22m 114 10/14 15:47:09 3/2 16:13:04 209.66m, 83.93m, -0.22m 130 10/15 15:48:34 3/1 16:14:52 225.82m, 88.97m, -0.22m appendix table 4d. stress tests of 29.6 m obelisk with 5 cm of subsidence to the southwest year: 9 bc method: three randomly chosen dates from appendix table 3a were tested to see if the dates of alignment would be changed or invalidated after the 29.6 m obelisk had subsided 5 cm. meters from obelisk (estimate)210 date-1 time-1 date-2211 time-2 grid coordinates212 21 (21) 10/4 15:35:52 3/12 15:56:58 121.21m, 55.37m, -0.22m (121.93m, 55.63m, -0.22m) 46 (47) 10/8 15:41:17 3/8 16:04:31 147.10m, 63.42m, -0.22m (148.84m, 63.99m, -0.22m) 99 (101) 10/13 15:48:22 3/3 16:13:45 200.44m, 79.91m, -0.22m (202.28m, 80.52m, -0.22m) 210 number in parentheses is estimated of meters from obelisk in the simulation without subsidence of the 29.6 m obelisk. 211. date in parentheses is best date of the second alignment in the year in the simulation without the subsidence of the 29.6 m obelisk. 212 coordinates in parentheses are those of the simulation without subsidence of the 29.6 m obelisk. the relationship between the montecitorio obelisk and the ara pacis     1:98 appendix table 5: report on observations of shadow striking axis of façade of ara pacis date: 9 bc time: utc software: unity observer: bernard frischer    date: august 10, 2015 note 1: these alignments are all interpositional: the best observations of the shadow projected onto the west façade of the ara pacis are seen by someone standing with his back to the obelisk positioned somewhere between the obelisk and the western staircase of the ara pacis. no positional data are reported (in contrast to appendix tables 1-3) because it does not matter where you stand between the obelisk and the front steps of the ara pacis. note 2: there are dates (such as march 22) when the obelisk’s shadow falls onto the western staircase of the ara pacis. these dates are not included on the table. appendix table 5a: dates and times of shadow alignments date and time-1 date and time-2 description of shadow feb. 25, 16:28 october 21, 16:01 shadow of the trunk of the obelisk reaches the altar inside the ara pacis feb. 26, 16:26 october 20, 16:00 “ “ feb. 27, 16:25 october 19, 15:58 “ “ feb. 28, 16:23 october 18, 15:56 “ “ march 1, 16:19 october 17, 15:54 “ “ march 2, 517 october 16, 15:53 “ “ march 3, 16:15 october 15, 15:52 “ “ march 4, 16:13 october 14, 15:50 “ “ march 5, 16:12 october 13, 15:49 “ “ march 6, 16:10 october 12, 15:48 “ “ march 7, 16:08 october 11, 15:46 “ “ march 8, 16:06 october 10, 15:45 “ “ march 9, 16:04 october 9, 15:43 “ “ march 10, 16:02 october 8, 15:42 “ “ march 11, 16:00 october 7, 15:40 “ “ march 12, 15:58 october 6, 15:39 shadow of the pyramidion reaches the altar inside the ara pacis march 13, 15:56 october 5, 15:38 “ “ march 14, 15:54 october 4, 15:36 “ “ march 15, 15:52 october 3, 15:35 shadow of the pyramidion over the western doorway, the trunk of the obelisk over the altar inside the ara pacis the relationship between the montecitorio obelisk and the ara pacis     1:99 march 16, 15:50 october 2, 15:34 shadow of the pyramidion over the lintel of the western doorway, the trunk of the obelisk reaches the steps to the altar inside the ara pacis march 17, 15:48 october 1, 15:33 shadow of the pyramidion over the steps and lower part of the altar inside the ara pacis march 18, 15:46 september 30, 15:31 “ “ march 19, 15:45 september 29, 15:30 shadow of the pyramidion over the steps of the altar inside the ara pacis march 20, 15:45 september 28, 15:28 “ “ march 21, 15:45 september 27, 15:27 shadow over the threshold to the interior of the ara pacis appendix table 5b: observations in years 2 and 3 of the four-year leap-year cycle for a random sample of alignments listed on table a. year in cycle date and time-1 date and time-2 description of shadow 1 feb. 25, 16:26 october 21, 16:01 shadow of the trunk of the obelisk reaches the altar inside the ara pacis 2 “ “ “ “ “ “ “ “ “ 3 “ “ “ “ “ “ “ “ “ 1 march 1, 16:18 october 17, 15:54 “ “ “ 2 “ “ “ “ “ “ “ “ “ 3 “ “ “ “ “ “ “ “ “ 1 march 6, 16:09 october 12, 15:47 “ “ “ 2 “ “ “ “ “ “ “ “ “ 3 “ “ “ “ “ “ “ “ “ table 5c.1: stress test of the shadow alignments (30.7 m obelisk) date and time-1 date and time-2 description of shadow feb. 25, 16:23;42 october 21, 15:57:06 shadow of the trunk of the obelisk reaches the altar inside the ara pacis feb. 26, 16:22:06 october 20, 15:55:45 “ “ feb. 27, 16:20:15 october 19, 15:54:08 “ “ march 19, 15:40:08 shadow of the pyramidion on west threshold of the ara pacis september 29, 15:26:18 shadow of pyramidion on steps of interior altar the relationship between the montecitorio obelisk and the ara pacis     1:100 march 20, 15:45 test failed: pyramidion on west staircase (not in ara pacis) september 28, 15:28 shadow of pyramdion on west threshold of ara pacis march 21, 15:45 test failed: pyramidion on west staircast (not in ara pacis) september 27, 15:27 shadow over the threshold to the interior of the ara pacis appendix table 5c.2. dates and times of shadow alignments with the 30.7 m obelisk that are not observed with the 29.6 m obelisk date and time-1 date and time-2 description of shadow february 17, 16:37:21 - shadow of trunk of obelisk covers interior altar february 18, 16:35:25 october 28, 16:08:02 “ “ february 19, 16:33:47 october 27, 16:06:00 “ “ february 20, 16:32:35 october 26, 16:04:45 “ “ february 21, 16:30:35 october 25, 16:03:14 “ “ february 22, 16:28:56 october 24, 16:01:45 “ “ february 23, 16:27:15 october 23, 16:00:10 “ “ february 24, 16:25:21 october, 22, 15:58:38 “ “ appendix table 5d: stress tests of 29.6 m obelisk with 5 cm of subsidence to the southwest. dates and times of shadow alignments. year: 9 bc method: three randomly chosen dates from appendix table 4a were tested to see if the dates of alignment would be changed or invalidated after the 29.6 m obelisk had subsided 5 cm. date and time-1213 date and time-2214 description of shadow feb. 25, 16:27:04 (16:28 ) october 21, 16:01 (16:01 ) shadow of the trunk of the obelisk reaches the altar inside the ara pacis march 11, 15:59:19 (16:00) october 7, 15:40:19 (15:40) “ “ march 19, 15:43:35 (15:45) september 29, (15:30) shadow of the pyramidion over the steps of the altar inside the ara pacis 213 the number in parentheses is the corresponding value from appendix table 4a. 214 the number in parentheses is the corresponding value from appendix table 4a. the relationship between the montecitorio obelisk and the ara pacis     1:101 appendix table 6: overview of alignments by date, type, and zone note: this table aggregates the data on appendix tables 1a-5a and shows the days on which there is either a solar or shadow alignment in the area studied. month day solar alignment shadow alignment table 5 zone 1 table 1 zone 2 table 2 zone 3 table 3 zone 4 table 4 february 25 x 26 x 27 x x 28 x x (29) x x march 1 x x 2 x x 3 x x 4 x x 5 x x 6 x x 7 x x 8 x x 9 x x 10 x x 11 x x 12 x x 13 x x 14 x 15 x 16 x 17 x 18 x 19 x x 20 x x 21 x x 22 x 23 x 24 x 25 x 26 x 27 x 28 x 29 x 30 x the relationship between the montecitorio obelisk and the ara pacis     1:102 31 x april 1 x 2 x 3 x 4 x 5 x 6 x 7 x 8 x 9 x 10 x 11 x 12 x 13 x 14 x 15 x 16 x 17 x 18 x 19 x 20 x 21 x 22 x 23 x 24 x 25 x 26 x 27 x 28 x 29 x 30 x x may 1 x x 2 x x 3 x x 4 x x x x 6 x x 7 x x 8 x x x 9 x x x the relationship between the montecitorio obelisk and the ara pacis     1:103 10 x x x 11 x x x 12 x x x 13 x x x 14 x x x 15 x x x 16 x x x 17 x x x 18 x x x 19 x x x 20 x x x 21 x x x 22 x x x 23 x x x 24 x x x 25 x x x 26 x x x 27 x x x 28 x x x 29 x x x 30 x x x 31 x x x june 1 x x x 2 x x x 3 x x x 4 x x x 5 x x x 6 x x x 7 x x x 8 x x x 9 x x x 10 x x x 11 x x x 12 x x x 13 x x x 14 x x x 15 x x x 16 x x x 17 x x x 18 x x x the relationship between the montecitorio obelisk and the ara pacis     1:104 19 x x x 20 x x x 21 x x x 22 x x x 23 x x x 24 x x x 25 x x x 26 x x x 27 x x x 28 x x x 29 x x x 30 x x x july 1 x x x 2 x x x 3 x x x 4 x x x 5 x x x 6 x x x 7 x x x 8 x x x 9 x x x 10 x x x 11 x x x 12 x x x 13 x x x 14 x x x 15 x x x 16 x x x 17 x x x 18 x x x 19 x x x 20 x x x 21 x x x 22 x x x 23 x x x 24 x x x 25 x x x 26 x x x 27 x x x 28 x x x the relationship between the montecitorio obelisk and the ara pacis     1:105 29 x x x 30 x x x 31 x x x august 1 x x x 2 x x x 3 x x x 4 x x x 5 x x x 6 x x x 7 x x x 8 x x x 9 x x x 10 x x x 11 x x x 12 x x x 13 x x x 14 x x x 15 x x x 16 x x x 17 x x x 18 x x x 19 x x 20 x x 21 x x 22 x x 23 x x 24 x x 25 x x 26 x x 27 x x 28 x x 29 x x 30 x x 31 x x september 1 x x 2 x x 3 x x 4 x x 5 x x 6 x x the relationship between the montecitorio obelisk and the ara pacis     1:106 7 x x 8 x x 9 x x 10 x x 11 x 12 x 13 x 14 x 15 x 16 x 17 x 18 x 19 x 20 x 21 x 22 x 23 x 24 x 25 x 26 x 27 x x 28 x 29 x 30 x october 1 x 2 x 3 x x 4 x x 5 x x 6 x x 7 x x 8 x x 9 x x 10 x x 11 x x 12 x x 13 x x 14 x x 15 x x 16 x x the relationship between the montecitorio obelisk and the ara pacis     1:107 17 x x 18 x 19 x 20 x 21 x the relationship between the montecitorio obelisk and the ara pacis     1:108 15. appendix ii overview of the virtual meridian of augustus and the celestialengine john fillwalk cultures throughout history have endeavored to understand the passage of time, discovering numerous approaches to mark and impart celestial significance into their environments. archaeo-astronomers over the last several centuries have been engaged in the process of establishing a record of these techniques—decoding approaches and meaning in the potential celestial alignments of the structures of ancient peoples. until recently, a scholar studying such alignments would need to travel to a remote physical site and apply the field tools of archaeology, surveying, and engineering to understand such phenomena. carefully observed drawings, photographs, algorithms and measurements recorded on the dates and times of the study would have to be directly noted. with the aid of 3d modeling, virtual environments and celestial databases this process can be simulated, providing a dynamic and accurate framework of inquiry to rapidly establish potential candidates for further scholarly study. the data derived from the identified targets can then be further analyzed by specialists who can quickly begin the process of establishing significance as a celestial alignment. idia lab’s celestialengine was designed to an evolving set of specifications mainly provided by bernard frischer resulting from his use of the simulation in the period 2011 to 2017 as a tool for research to assess the validity of edmund buchner’s theory about the nature of the gnomonic instrument and the relationship of the montecitorio obelisk to the ara pacis. the simulator creates a digital representation of solar, lunar, and planetary objects as they are referenced in relation to terrestrial positioning over a span of time. the celestialengine was thus a key component of the virtual meridian of augustus, a simulation authored in the game engine unity specifically for this study. after importing an accurately measured, scaled, and constructed 3d model into the simulator, the positional coordinates of the site must be calibrated. this includes obtaining precise longitude, latitude, altitude, scale and orientation of the structure(s) in relation to geographic north. once this referencing process has taken place, ephemerides from the horizons database (jet propulsion laboratory, nasa. (http://ssd.jpl.nasa.gov/?horizons) are integrated within the simulator. these data inform the positioning of the virtual celestial objects (proxy sun, moon or planets). in the case of the present study, the 3d model utilized was jointly developed by the idia lab and by matthew r. brennan of the virtual world heritage laboratory in collaboration with project director bernard frischer. key elements in autocad were furnished by archaeologist-surveyors ismini miliaresis and adalberto ottati as well as by gnomonist paolo albèri auber. the position of the ara pacis reflects moretti 1948; the position of the section of the meridian at via di campo marzio 48 corresponds to where ottati and miliaresis surveyed it (see frischer forthcoming); and the position of the obelisk was determined using the data and methodology outlined by frischer in this paper. the horizons system itself can generate positional data on 660,515 celestial features, including 3,298 comets, 178 planetary satellites, 8 planets, and the sun. the celestialengine is designed to accept any jpl provided ephemeris, driving and dynamically updating the real time-positioning of a 3d proxy celestial object within the virtual simulator. two modes of celestialengine have been developed and are employed depending on the requirements of a scope of study. in the case of an archaeo-astronomical project that requires a limited range of years and dates, such as in the virtual meridian of augustus, we scrape that specific dataset and build it into the simulation, baking it into the published project. this provides an immediate response in entering various dates and times in the study the relationship between the montecitorio obelisk and the ara pacis     1:109 of an alignment. in some simulations, however, such as in our virtual stonehenge project, the years of interest span millennia and involve multiple celestial objects, requiring real-time and dynamic access at the request of the investigator. depending on network speed, this may cause a slight delay as the ephemerides are returned and the simulation’s virtual celestial objects are updated. the advantage of the scraped data approach is that the simulation is self-contained and does not require a live network connection. the disadvantage of the scraping method is in factors limiting performance, since the load times and file size of the build increase with greater amounts of data. the february 2017 version of the virtual meridian augusti simulation includes several updates and features. the project was ported away from unity’s web browser plugin-based webplayer system to the new standard that is based in webgl and executable versions. a stand-alone executable was also created which (alongside the webgl version) employed a new unity 5.5 lighting scheme and a unity-based (instead of image-based) dynamic skybox. also significant is the development of a stellarium plugin, which allows us to toggle between unity and stellarium skyboxes. this gives an investigator the ability to bring in the visible planets, stars, sun, moon and comets to potentially discover other celestial alignments using the power of stellarium merged with the 3d capabilities of unity. the methods that we designed for celestialengine to access horizons could potentially be connected to any live 3d simulation environment to visually represent the spatial relationships of interest to archaeo-astronomers. in almost all of our celestial heritage simulations, however, we have integrated unity 3d as the simulation environment. unity is a platform-agnostic game engine and integrated development environment that allows developers to create dynamic virtual simulations for the web, various desktop platforms, game consoles and ios and android-based devices. in the instance of a project that requires a dynamic request of celestial ephemerides, we employ a method in unity that calls out to a url and returns new data into the simulator. the celestialengine code then inspects the request to see if it has completed before refreshing and advancing the simulation. the advantage of this modality is that a scholar or student can make a request for any date or time within any frame of interest. the horizons dataset spans the years from 9999 bc to ad 9999. within the simulation, the virtualized celestial objects must be referenced to the 3d geometries representing the virtual site. the celestial proxy objects are positioned in the virtual sky dome, which is scripted to be driven by the jpl data. the spheres or planes of the proxies are set so as always to face the perspective of the virtual observer. this creates a phenomenological problem, since, in physical reality, celestial objects are effectively at an infinite distance relative to a terrestrial observer. any distance traveled within the scope of even a vast terrestrial site results in an insignificant change in observational angle. this is not the case in a 3d virtual simulation. if a virtual observer translates his position by even a small amount of distance, the angle of observation relative to the viewer and virtual object changes significantly. to overcome this phenomenon, a method had to be developed to effectively represent the viewer/object relationship continuously at infinity. this effect is accomplished within the simulation by parenting the virtual object to the viewer’s camera or avatar. as the virtual observer changes his position, the proxy objects within the celestial sphere update with the new translation coordinates, thus maintaining the appropriate relationship of effective infinity. celestialengine has been employed in numerous idia lab archaeo-astronomical studies that have included sites from various periods and cultures, including several unesco world heritage sites. one of our projects, virtual stonehenge, a simulation created for the history channel’s the universe series, investigates both lunar and solar alignments of the monument over the span of centuries of its phased development. in another the relationship between the montecitorio obelisk and the ara pacis     1:110 study, idia lab worked with bernard frischer and the virtual world heritage laboratory at indiana university on a complex virtual world and celestial study of hadrian’s villa, in which investigators could examine suspected alignments of the expansive virtual restored site from any vantage point. visitors to our virtual chichen itza can study potential solar alignments along and across the axis of the ball court site. other projects have included a lunar alignment simulation of the temple of artemis at ephesus and virtual izapa, a mayan site where its group f ball court complex has a well-known solstice alignment and is considered to be the origin of the development of the mayan long count calendar. it is the goal of virtual simulation technologies like celestialengine to enhance processes that might not be feasible or even possible with conventional tools of 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