




































 History of Meteorology 7 (2015) 39 

 
 

 

 

 

 

 

 

 

 

On climates and disciplines in Norway in the 1870s 
 

Gunnar Ellingsen 

Gunnar.Ellingsen@uib.no 

AHKR, University of Bergen 

 

In the 1870s there were two scientific experts on climate in Norway. Their climates shared 

space, but not time, and the knowledge about them was produced from different scientific 

objects: the atmosphere and the flora.
1
 This paper discusses how these bodies of knowledge 

about climate were formed in different emerging disciplines, and how they represent 

distinctive views of what constituted scientific knowledge about climate. Formed within the 

same small scientific institution in Christiania, and influenced by the political agendas of an 

emerging nation-state, they show both the political significance and the semantic diversity of 

the scientific concept ‘climate’ in Norwegian science in the 1870s.  

The first expert was Axel Blytt (1843-1898), botanist at the Botanical Garden in 

Christiania (now Oslo) from 1862, and professor of botany at the University from 1880.
2
 It 

was the history of the Norwegian flora that caught Blytt’s interest and turned his attention 

towards climate. Throughout history, varying climate had produced plant distribution patterns 

in Norway, manifested as separate layers in peat bogs. From the study of these patterns and 

layers, Blytt produced knowledge about Norway’s climate in the past.  

The other expert, working at the same institution, was Henrik Mohn (1835-1916), who 

was appointed first director of the Norwegian Meteorological Institute and professor of 

meteorology at the University in Christiania by the Norwegian Parliament in 1866.
3
 Unlike 

Blytt, Mohn was interested in the directly observable climate and not its history.   

This article will discuss differences and similarities in Blytt’s and Mohn’s climate 

studies, including their relationships to objectivity, to historization, and to ideological or 

political aspects of their work. In Blytt’s theory, the immigration of plants was an element 

with strong nationalistic connotations and relevance for contemporary historicizations of the 

Norwegian people. His theory is an illuminating example of Katherine Anderson’s argument 

that climate ideas originated outside meteorology.
4
 In Andersons view, meteorology was a 

“test case” where speculation challenged “disciplined, Baconian observation” in the claim for 

authority. While the botanist Blytt was a free speculator, the climatologist and meteorologist 

Mohn put considerable effort into balancing between the objective observer and the creative 

craftsman.  

                                                           
1
 The historicity and epistemological roles of scientific objects is discussed in Daston, Lorraine (ed.). 

Biographies of Scientific Objects. Chicago and London, 2000.  
2
 For a biography of Axel Blytt, see: Nordhagen, Rolf. “Axel Blytt. En norsk og internasjonal forskerprofil”. 

Blyttia 1/1943, vol. 1: 21-55. 
3
 For a biography of Henrik Mohn, see: Engelbrethsen, Per. “Professor Mohn og det norske meteorologiske 

institut”. Naturen 4, 1895: 97-104.  
4
 Anderson, Katherine. Predicting the Weather. Victorians and the Science of Meteorology. Chicago, 2005: 

Introduction.  

mailto:Gunnar.Ellingsen@uib.no


 History of Meteorology 7 (2015) 40 

 
 

I will start with presenting and discussing Blytt and his studies of the flora and the 

climates in the past that formed it. Moving over to Mohn, I will present his climatology and 

how his type of knowledge about the atmosphere shaped his ideas of climate. In the end I will 

discuss how these two sets of scientific knowledge about climate both were formed by 

emerging international scientific disciplines, by aspirations of a yet unsovereign nation, and 

by the little community at a small university. I will argue that both Blytt and Mohn negotiated 

between different disciplinary objectivities, or different consensuses regarding what 

constituted truth, in their research.
5
 

 

The botanical climate  

 

As the son of the University professor of botany and director of the Botanical Garden Mathias 

Numsen Blytt (1789-1862), Axel Blytt took over his father’s work on a three-volume 

Norwegian Flora in 1862.
6
 He received a scholarship from the University in Christiania in 

1873 and a professorship of botany in 1880. The second and third volumes of the Flora were 

published in 1874 and 1876. In the latter year, he also published Essay on the immigration of 

the Norwegian Flora during alternating rainy and dry periods, which presented his theory of 

the origin and history of the Norwegian Flora.
7
 While Norges Flora was a descriptive work 

with purely textual descriptions and no theories or hypotheses, the Essay was a discussion 

rather than a description.  

In the Essay, Blytt argued that two parameters in the natural condition of Norway were 

decisive for the distribution of plants: the humidity of the climate, and the hardness of the 

bedrock (substratum) on the spot. These two parameters decided which types of plants would 

be able to grow on a certain place, Blytt argued. “The hard substratum has a uniform flora 

poor in species (…), on looser substrata the covering of vegetation is more dispersed, the 

number of individuals is less, but that of the species is greater…”.
8
 Further, some plants 

thrived in a wet climate, others in a dry. Some plants were “general”, meaning that they 

thrived in either of the conditions. Blytt made the basic assumption that the plants in Norway 

had immigrated as the ice pulled back and that they had been distributed according to their 

preferences for wet or dry climate and hard or loose bedrock.
9
 Blytt did not see temperature as 

decisive in itself.
10

  

To explain how the climate affected the distribution of the Norwegian flora, Blytt used 

a simple climate model with three main agents: the ocean, the mountains and the wind.
11

 The 

ocean produced moist air, which was blown into Norway by the prevailing south-westerly 

winds. The mountains were an obstacle to these winds, and provided shelter from them on 

                                                           
5
 Porter, Theodore M. Trust in Numbers. The Pursuit of Objectivity in Science and Public Life. Princeton, 1995: 

Introduction.  
6
 Blytt, Mathias Numsen. Norges Flora eller Beskrivelse over de i Norge vildtvoxende Karplanter tilligemed 

Angivelser af de geographiske Forholde under hvilke de forekomme. Christiania, 1861.  
7
 This text was first published in Norwegian as an article under the title “Forsøg til en Theori om Indvandringen 

af Norges Flora under vexlende regnfulde og tørre Tider” in the Norwegian journal Nyt Magazin for 

Naturvidenskaberne in 1876. The English title refers to the book that was published in Christiania in the same 

year as a response to the great attention that the article and its theory had received. In the following, I will refer 

to the English version.  
8
 Blytt 1876: 26.  

9
 Blytt’s studies of plant distribution was inspired by Edward Forbes, who had described types of distribution of 

flora and fauna in 1846. Nordhagen 1943: 26.  
10

 Blytt 1876: 19-20.  
11

 Blytt 1876: 15ff.  



 History of Meteorology 7 (2015) 41 

 
 

their north-eastern side.
12

 Plants close to the ocean, or in a place inland where these winds 

blew, were called insular. Plants that were far inland or behind mountains, protected from the 

moist air, were called continental plants. In this way, Blytt made his own climatic-

geographical classification system based on a simple climate model and a theory of plant 

immigration.   

One observation that sat uneasy with the assumption of immigration was that the 

distribution of some alpine plants had large gaps that did not fit into the picture. For instance, 

some plants were found only in single spots in Norway and then on other continents.
13

 

Despite a long discussion of how Norwegian plants were transported, he could not explain the 

patchwork pattern in this distribution. He concluded that this was not a result of the agency of 

the plants themselves, but of the agency of long-term changes in their living conditions. Of his 

two parameters, hardness of the soil and humidity of the climate, the latter was clearly the 

most likely to have changed since the Ice Age. Blytt therefore had to superimpose time on his 

classification system, which is how he ended up in a discussion on the history of the 

Norwegian climate.  

To find out more about this history, Blytt followed the recommendation of the Scottish 

geologist James Geikie to excavate peat bogs.
14

 Containing different layers of plants and 

other material from different periods, peat bogs were seen as archives of natural history. 

Using his categorization of plants as a tool, Blytt established a chronology of climate types 

since the Ice Age. He found that the same type of plants dominated different layers, indicating 

repeated periods of similar climate.  

Not all peat bogs could be assumed to contain material from the whole postglacial 

period. Since the Norwegian land mass had risen continually after the withdrawal of the ice, 

only peat bogs at altitudes more than 600 feet above the present sea level would contain the 

oldest bottom layers. Blytt saw this as essential for their interpretation. It not only informed 

the chronology of the immigration of plants, it also removed incompatibilities between his 

own results and those from similar investigations of peat bogs in Denmark, where Blytt 

argued that no land rise had occurred.
15

  

Blytt’s conclusion was that the climate in Norway had gone through several wet and 

dry periods since the Ice age. He tried to connect this theory to natural phenomena that were 

subject to astronomical laws. The theories of James Croll, which Blytt had mentioned only 

briefly at the end of his Essay, turned out to be a useful way to structure the history of the 

Norwegian flora and climate.
16

  

Croll’s theories, presented in the book Climate and Time in 1875, highlighted the 

earth’s position in relation to the sun as the key to understanding many large-scale processes 

in nature.
17

 The sun was the source of heat on earth, and wind patterns in the atmosphere and 

                                                           
12

 In the 1960s, climatologists Theodor Hesselberg and Bernt Andreas Birkeland calculated the effect of the 

mountain ranges in southern Norway on precipitation and wind based on large data sets of meteorological 

observations. See Vollset’s paper in this issue.  
13

 Blytt 1876: 22-23.  
14

 Axel Blytt’s draft of testimonial of James Geikie, 19.12.1881. National Library of Norway, Collection of 

Letters 66. On Geikie see also: Hamlin, Christopher. “James Geikie, James Croll, and the Eventful Ice Age”. 

Annals of Science 39/6 (1982): 565-583. 
15

 Blytt 1876.  
16

 Blytt 1876: 87-88. James Geikie was perhaps the one who introduced Croll’s ideas to Blytt. On Geikie and his 

influence from Croll, see: Hamlin 1982.  
17

 Croll, James. Climate and Time in their Geological Relations. A Theory of Secular Changes of the Earth’s 

Climate. 1875. On Croll see also: Fleming, James R. “James Croll in Context: The Encounter Between Climate 

Dynamics and Geology in the Second Half of the Nineteenth Century”. History of Meteorology 3 (2006): 43-54. 

Fleming describes Croll’s ideas between cosmic and terrestrial physics and geology, placing him in a position 

between emerging disciplines.  



 History of Meteorology 7 (2015) 42 

 
 

current patterns in the ocean were among the most important factors deciding how this heat 

was distributed on its surface. Croll’s argument was that the earth’s elliptic path around the 

sun, as well as the inclination of its rotational axis, went through regular variations with vast 

consequences for the quantity and distribution of heat – that is, for climate on earth. Through 

a long chain of causes and effects these variations explained the phenomenon of ice ages. 

Hence, according to Croll, ice ages could be astronomically calculated – both those of the past 

and those of the future. Croll’s theories provided Blytt with a connection between the history 

of the Norwegian flora, climate and astronomical laws. In a number of publications in the 

following decades, Blytt expanded his grand theory on the history of the Norwegian flora and 

climate and worked Croll’s ideas into it.
18

 

 

Seeking communities from other disciplines 

The style of writing in the Essay and in later papers from Blytt’s hand embraced ideals from 

geology rather than from botany. In 1882 the geologist Amund Helland described Norway as 

“the country of geological discussion”, referring to the legacy of the grand old man of 

Norwegian geology, Theodor Kierulf.
19

 Kierulf was a friend of the Blytt family and had had a 

significant influence on the young Axel Blytt.
20

 At the end of his career, Blytt threw himself 

into the core of geological debate and advocated revisions in the established periodization.
21

 

In his correspondence with Blytt, James Geikie especially valued the “suggestive” character 

in the publications.
22

 Charles Darwin also wrote to Geikie about Axel Blytt, and praised the 

deed of being “a good theoriser”.
23

 To geologists, being suggestive and theorising were 

important epistemic virtues.  

This was not necessarily the case among botanists. The problem was not Blytt’s theory 

in itself, but the method by which it had been produced. In several letters to Blytt, the botanist 

Johan Emanuel Zetterstedt called for caution when making hypotheses. Geology was young, 

he wrote, and consisted more or less of “guesses”. However, proving was better than 

guessing: “Hypotheses give life to questions, they turn out not to be true, and science 

                                                           
18

 On the upheaval of the Norwegian land mass, see: Blytt, Axel. “Om vexellagring og dens mulige betydning 

for tidsregningen i geologien og læren om arternes forandringer”. Christiania Videnskabsselskabs Forhandlinger 

No. 9 1883. Published in German as “Ueber Wechsellagrung und deren mutmaasliche Bedeutung für die 

Zeitrechnung der Geologie und Für die Lehre von der Veränderung der Arten” in Biologisches Centralblatt III 

No. 14-15: 418-434 et 449-461. Erlangen, 1883. On the history of ocean currents and on the distribution of land 

and ocean in the northern hemisphere through times, see: Blytt, Axel. “Om den sandsynlige årsag til den 

periodiske ændring af havstrømmenes styrke”. Archiv for Mathematik og Naturvidenskab Vol. 9, 1884. 

Published in German as “Ueber die wahrscheinliche Ursache der periodischen Veränderungen in der Stärke der 

Meeresströmungen” in Biologisches Centralblatt IV No. 2: 33-48. Erlangen 1884. On the history of the Earth 

and its crust and previous changes in its spherical form, see: Blytt, Axel. “Om den sandsynlige årsag til 

strandliniernes forskyvning. Et forsøg på en geologisk tidsregning”. Nyt Magazin for Naturvidenskaberne XXXI, 

Vol. 11, 1886. Published in English as “The probable cause of the displacement of beach-lines. An attempt to 

compute geological epochs”. Christiania Videnskabs-Selskabs Forhandlinger No. 1, 1889. On geological 

periodization see: Blytt, Axel. “Til forsvar for mit Forsøg på en geologisk Tidsregning”. Arkiv for Mathematik 

og Naturvidenskab 14 B (1890): 197-219.  
19

 “…den geologiske Diskussions Land”. “By thoroughly discussing problems, misunderstandings are often 

removed, and new light is thrown over the matter”. Kierulf quoted by Helland, Amund. Forsøg paa en geologisk 

Diskussion. 1882: 1-2. (My translation).  
20

 Axel attended Kjerulf’s lectures as a student. Nordhagen argues that Kierulf’s theories about the Ice Age had a 

profound influence on the natural sciences in Norway in the 1860s. Nordhagen 1943: 10.  
21

 Blytt 1890.  
22

 Letters from James Geikie to Axel Blytt 18.07.1881, 18.12.1881, and 27.12.1888. National Library of 

Norway, Special collections, Letter collection no. 66.  
23

 Letter from Charles Darwin to James Geikie 16.11.1876. Darwin, Francis (ed.). The Life and Letters of 

Charles Darwin Vol III, 1889: 244.   



 History of Meteorology 7 (2015) 43 

 
 

advances threefold”.
24

 Even though hypotheses were necessary, in Zetterstedt’s opinion, they 

were something scientists turned to only when they were desperate.
25

 Since geology was a 

science without disciplinary borders, and without a fully developed method, Zetterstedt 

recommended sticking to undisputable facts, rather than producing grand theories based on 

speculation.  

 

Immigration theories and the nation  

 

As Deborah Coen has shown, climatology could serve to unify an empire.
26

 In the 1880s, 

climatologists participated in consolidating the Austrian-Hungarian Empire in by describing 

natural regions that matched with political boundaries. Blytt’s historicism could be interpreted 

as having similar political overtones when seen in the light of contemporary theories about the 

history of the Norwegian land and people.  

In 1873, three years before Blytt’s Essay, the Norwegian historian Johan Ernst Sars 

(1835-1917) published the first volume of his history of Norway, in which he presented 

Norwegian history as a dialectic process from golden age to crisis and then to the “synthesis” 

of Sars’ own time. This dialectic history was governed by natural laws, dictated by natural 

surroundings and taking place through “organic” change. Norwegian farmers represented the 

continuity of this history, as bearers of the Norwegian identity.
27

  

The similarities between Blytt’s theory of the origin of the Norwegian Flora and Sars’ 

history of the Norwegian people are striking. First, as Sars, Blytt had a holistic view in which 

the scientific object was reduced to a singular long history. Second, the dialectic process in 

Sars’ history was reflected in Blytt’s alternations between rainy and dry periods. Finally, the 

development from origin to the present was embedded in natural conditions governed by 

laws.
28

  

Also other elements in Norwegian historical theory had similarities with Blytts’s 

theory. Theories of immigration were well-established in Scandinavian historical writing at 

the time, most famously the theories of historians Peder A. Munch (1810-1863) and Rudolf 

Keyser (1803-1864) in the 1840s and 1850s.
29

 Keyser and Munch, like Blytt and Mohn 

professors at the University in Christiania, argued that Norwegians had immigrated from the 

North. This gave the Norwegian people an origin distinguishable from those of the Swedes 

and the Danes, and a position among the oldest peoples in Europe. This was significant in a 

nation where there was a strong and growing wish for ending the union with Sweden which 

had begun in 1814, on the back of a a 400 year period under Danish rule. By bringing an 

                                                           
24

 Letter from Johan E. Zetterstedt to Axel Blytt 21.10.1877. National Library of Norway, Special collections, 

Letter collection no. 66.  
25

 Letter from Johan E. Zetterstedt to Axel Blytt 02.01.1877. Ibid.  
26

 Coen, Deborah. “Climate and Circulation in Imperial Austria”. The Journal of Modern History 82, 2010; 

Coen, Deborah. “Imperial Climatographies from Tyrol to Turkestan”. Osiris 26/1, 2011. 
27

 Sars, Johan Ernst. Udsikt over den norske historie. 4 volumes. 1874-1894. See also: Melve, Leidulf. Historie. 

Historieskriving frå antikken til i dag. Oslo 2010: 151-154; Andresen, Astri, Sissel Rosland et al. Å gripe fortida. 

Innføring i historisk forståing og metode. Oslo 2012: 183-186. With the first volume of his Udsigt, Sars 

positioned himself as the leading Norwegian historian. It also led to considerable debate at the University and in 

Parliament around the proposal of an extraordinary professorship for him at the University in 1874. Kyllingstad, 

Jon and Tor Arne Rørvik. “Vitenskapenes universitet” in Collett, John P. (ed.). Universitetet i Oslos historie, 

Vol. 2, 2011: 97-100, 362-366.   
28

 Naomi Oreskes compares how today’s geologists and historians understand the past. Oreskes, Naomi. “Why I 

Am a Presentist”. Science in Context 26/4 2013: 595-609.  
29

 Keyser, Rudolf. “Om Nordmændernes Herkomst og Folkeslægtskab”. Samlinger til det Norske Folks Sprog og 

Historie, Vol. 6, 1839: 259-462; Munch, Peder Andreas. Det norske folks historie. 8 volumes. 1853-1863. For 

more about the works of Keyser and Munch in historiographical context, see: Dahl, Ottar. Norsk 

historieforskning i det 19. og 20. århundre. 1970 (1990).  



 History of Meteorology 7 (2015) 44 

 
 

immigration theory into botany, Blytt had given the Norwegian flora a set of political 

connotations.  

 

Henrik Mohn, climate, and how the atmosphere worked  

 

Meteorologist Henrik Mohn also saw the Norwegian climate as a distinguishable entity. 

Climatology was what had earned his Meteorological Institute a place within the University in 

Christiania. “Climatology is the statistics of the meteorological elements”, Mohn wrote in his 

1872 textbook Om Vind og Vejr.
30

 Mohn’s strategy for producing knowledge about the 

atmosphere was two-fold. First, it was about quantification, in line with other studies of nature 

and society at the time.
31

 Second, it was about analysing the observations and formulating 

what he called “laws” (lover), a process in which personal judgement, experience and skill 

had a significant part. The “laws” were more like rules of thumb, characterized by exceptions 

as they had been for centuries.
32

 To Mohn, producing weather forecasts was a craft based on 

scientific observations.  

Mohn saw climate as the property of place. To describe the climatic conditions of the 

whole globe or even a single country was a matter of making maps based on an immense 

amount of observations. However, “to fully understand the climatic conditions would require 

knowledge about the movements in the atmosphere and their attributed phenomena in 

detail”.
33

 Mohn’s study of the mechanisms of the atmosphere reflected his dual ambitions of 

both being able to predict storms and eventually weather, and to understand climate.  

One of the results of these studies was a model of atmospheric movement that he 

called “hvirvel” – whirl.
34

 The whirl described large air masses rotating counter-clockwise 

around barometric minima, and there would be a number of whirls in the atmosphere at any 

time, Mohn explained. They would move not only by rotation, but also linearly, following 

certain paths. In a whirl there would be winds of all directions, but those in its southern half 

would usually be the strongest. The storms that Mohn and his staff tried to warn the 

Norwegian population about in the late 1860s and early 1870s were most often the southern 

half of a whirl passing over some part of Norway. The paths they followed were essential for 

estimating the damage or potential danger that the winds would represent for Norwegian 

fishermen and seafarers. Whirls were the mechanism of the weather, and the machinery of the 

climate. The whirl model was a mathematical and physical construction developed as a tool 

for thinking theoretically about motion in gases, and thus objects that physicists could discuss. 

Processes in whirls could be described by equations and calculated, most often by people who 

took no interest in weather forecasting specifically. By identifying whirls on daily weather 

maps, Mohn introduced a theoretical scientific object into the craft of weather forecasting.   

In the foreword to his textbook Om vind og vejr, Mohn explained that he had been 

constantly concerned with maintaining “a sharp distinction between the field of secure 

                                                           
30

 Mohn, Henrik. Om Vind og Vejr. Christiania 1872. The book was translated into seven languages: German, 

French, Italian, Spanish, Polish, Russian, and Finnish. 
31

 Porter, Theodore. The Rise of Statistical Thinking 1820-1900. 1986; Lie, E. and H. Roll-Hansen. Faktisk talt. 

Statistikkens historie i Norge. Oslo 2001. 
32

 Daston, Lorraine. “Unruly Weather: Natural Law Confronts Natural Variability” in Daston, Lorraine and 

Stolleis, Michael (eds). Natural Law and the Laws of Nature in Early Modern Europe: Jurisprudence, Theology, 

Moral and Natural Philosophy. 2008: 233-248.   
33

 Mohn 1872: 280-281. (My italics).  
34

 His whirl model was most thoroughly presented in two publications on storms: Mohn, Henrik. Stormenes 

Love, Christiania 1868 and Mohn, Henrik. Det Norske Meteorologiske Instituts Storm-Atlas. Christiania 1870. 

The Storm-Atlas was published with Norwegian and French parallel texts. On Mohn’s whirl model, see also: 

Kutzbach, Gisela. The Thermal Theory of Cyclones. A History of Meteorological Thought in the Nineteenth 

Century. American Meteorological Society, Historical Monograph Series. 1979: 76-84.  



 History of Meteorology 7 (2015) 45 

 
 

conclusions and the field of guesses”. Even though this had given the book a somewhat 

fragmented character, he continued, “...both the reader and science would benefit from a clear 

distinction between what is known and what is not known”.
35

 Numbers representing measured 

observations were known. What they could tell about future weather, however, was not 

known. As a meteorologist and weather forecaster, Henrik Mohn operated in the zone 

between “secure” knowledge and educated guesses. The events around the British 

meteorologist Robert Fitzroy, including the questioning of his scientific authority and the 

resulting discontinuation of weather forecasting after his death, clearly demonstrated the 

tension that could be displayed in this zone.
36

  

Hence, the thick volumes of climatological records in the annual Meteorologisk Årbog 

series from 1866 onwards, were what Mohn considered secure knowledge.
37

 Originally, this 

activity was the part of meteorology that was regarded as scientific, and what made 

meteorology deserve its place at the University. From the climatological records, one could 

calculate whatever average was needed: averages of a period (monthly, annual), of a 

geographical entity (cities, counties, regions, or the whole country) or of both. Like the Flora 

to Blytt, climatological records were collections of facts which could serve the theorizer.  

In 1868 Mohn presented the following law: the center of a whirl, that is, the 

barometric minimum, has an oval shape oriented in the direction that the whole whirl is 

moving.
38

 While some laws of whils and storms were universal, some depended on place. For 

instance, whirls were not a priori the same in Europe as in America. In his textbook from 

1872, Mohn pointed out that the laws governing the weather in America had been found to be 

“quite the same” as those in Europe.
39

 Mohn clearly saw his laws as something non-absolute, 

dependent of place, and not fully “secure knowledge”. 

 

Choosing between “knowing” and “guessing” 

 

With time, the whirl model became a factor in the larger equation defining whether and how 

the institute’s resources should be spent on storm warnings. After a few optimistic years, in 

1872 Mohn argued that the storm warnings were not sufficiently useful. The problem was not 

that the warnings were wrong, but that many storms came without any warning. Fishermen 

and sailors could trust the storm warnings, but they could not trust their absence.
40

  

In Mohn’s opinion, there were two ways to improve this. One was to follow the 

quantification strategy through increasing the number of observations and improving the 

means of dissemination: establishing more stations along the coast, and a storm warning 

center positioned among the stations on the western coast of Norway. The other way, which 

was the one he recommended, was to devote more time and resources to the scientific study of 

                                                           
35

 Mohn 1872: iv. (My translation).  
36

 Anderson 2005: ch 3. Mohn received the report from the Committee headed by Francis Galton that stated that 

Fitzroy’s forecasts were unscientific. The report was sent to the institute, and is now in the DNMI library store, 

Forskningsparken, Oslo.  
37

 Mohn, Henrik (ed.). Norsk Meteorologisk Aarbog, Det Norske Meteorologiske Institut. 1868. Published in 

Norwegian, German and French.   
38

 Mohn 1868: 18. According to Gisela Kutzbach, meteorologists were not eager to communicate theories in the 

1860s and 1870, due to a lack of estimation for theories about the atmosphere among physicists. Buchan did not 

allow himself to call his ideas theories, because theories should be firmly anchored in facts. Referring to F. 

Rosenberger. Die Geschichte der Physik, Vol 2. 1884: 327, Kutzbach describes this as an attitude which was 

spreading among meteorologists in this period. Kutzbach 1979: 75.  
39

 Mohn 1872: 233-234. 
40

 For more on the history of weather reports and its significance to the Norwegian fisheries and population 

along the coast, see: Fulsås, Narve. Havet, døden og véret. Kulturell modernisering i Kyst-Noreg 1850-1950. 

2003.  



 History of Meteorology 7 (2015) 46 

 
 

whirls, and less to observation.
41

 This strategy of analysis relied considerably on his personal 

accumulated experience.   

Mohn’s Danish colleague, the director of the Danish meteorological institute Niels 

Hoffmeyer, strongly advocated for forecasting based on personal skill. In Hoffmeyer’s 

opinion, weather forecasting relied on individual experience from drawing isobars on maps. 

Hoffmeyer pointed to himself as the best example: “It would be quite unnatural of me to say 

that I believe someone else could draw better curves than myself, because there is hardly any 

meteorologist who has as long experience within this sport as I”.
42

 Weather forecasting was 

simply “unscientific”: “…We must not hide our ignorance, but simply confess it”, he 

argued.
43

 The Danish Meteorological Institute had been established separately from the 

University of Copenhagen precisely because its tasks were regarded to be more “practical” 

than “scientific”.
44

  

 

Concluding remarks – shorelines  

 

Representing separate disciplines whose contours were only emerging, Blytt and Mohn  

applied different “objectivities”.
45

 To use Theodore M. Porters concept, Blytt acquired 

disciplinary objectivity – a consensus within a discipline of what was or made truth – from 

geology.
46

 He applied an analytic approach to the origin of what constituted a new scientific 

object: the Norwegian flora as a whole. His interest in origins made time just as essential as 

order. The Essay represented a shift not only of scientific object, but also of method and of 

epistemic virtue, from the traditional botanical truth-to-nature that focused on categories, to a 

holistic approach to the history of the flora of a nation.
47

 It was a historicizing turn which 

produced the first history of the Norwegian climate. This deep-time perspective was 

unfamiliar in traditional botany, but was about to become a standard perspective in geology.  

Mohn, on the other hand, swore to the authority that fact-producing instruments could 

give him, and that lay in expressing facts in numbers. Climate could be studied as sets of 

measurements of weather in certain places.
48

 The disciplinary objectivity of climatology lay in 

the numbers and the methods for producing them. Contrary to contemporary climate studies 

based on archival records,
 
Mohn showed little interest in the climate of the past. However, in 

his laws of whirls we see negotiations of the disciplinary objectivity of meteorology. For 

instance, while Heinrich Dove’s classical Winddrehungsgesetz was considered old-fashioned 

by most meteorologists of the 1870s, Mohn did his best to implement it in his model. The 

Winddrehungsgesetz was a rule of meteorology through which one could use single-point 

observations to predict changes in wind direction at that point.
49

 The rule was considered to 

be imprecise and to be applicable only in certain conditions and only in certain parts of the 

world, limitations that also characterized Mohns own rules. Mohn presented his new whirl 

                                                           
41

 The Norwegian Meteorological Institute. Annual Report. 1872.  
42

 Letter from Niels Hoffmeyer to Henrik Mohn, 17.02.1876. National Archive of Norway, Archive of the 

Meteorological Institute. Correspondence 1876. RA/S-1570/D/Dc/L0003/0002.  
43

 Letter from Niels Hoffmeyer to Henrik Mohn, 17.12.1875. RA/S-1570/D/Dc/L0003/0001.  
44

 Meteorologisk institut gennem hundrede aar. 1872-1972. Det Danske Meteorologiske Institut. Copenhagen, 

1972: 20-24.  
45

 The emergence of climatology between disciplines is also discussed in Philipp N. Lehmann’s paper in this 

issue.  
46

 Porter 1995: Introduction.   
47

 Lorraine Daston and Peter Galison points to botany as a discipline in which the epistemological virtue “truth-

to-nature” existed as an ideal up to the late 19
th

 century. Daston, Lorraine and Peter Galison. Objectivity. 2007: 

197.  
48

 Mohn, Henrik. Oversikt over Norges Klimatologi. 1870; Mohn, Henrik. Norges Vind- og Stormstatistik. 1870.  
49

 Dove, Heinrich Wilhelm. Meteorologische Untersuchungen. Berlin 1837.  



 History of Meteorology 7 (2015) 47 

 
 

and the rules that governed it as the surroundings of the single point of observation from 

which Dove described a wind shift.
50

 In this way, Mohn’s ideas of atmospheric movement, 

fundamentally different from Dove’s, were presented as a continuation, not a rejection, of 

older ideas.  

What were the similarities between Blytt’s and Mohn’s climate studies? Prediction, 

whether of the future or of the past, was an important part of their scientific work.
51

 This 

brought both of them to the borders of “secure knowledge”. Both worked within the frames of 

a national scientific enterprise where the flora, the weather, the climate, and history had 

distinct Norwegian identities.
52

 Although they were internationally oriented scientists, Blytt 

studied the Norwegian Flora and Mohn the Norwegian weather. They were also colleagues at 

an institution which had only a handful of scientific staff in this period, whose humanistic 

“culture of unity” had long been threatened by a growing gap between natural and human 

sciences.
53

 Defenders of this culture considered Darwinism, positivism, and the growing 

belief in the significance of measuring as threats to the University as a scientific institution. In 

their eyes, producing knowledge was inseparable from producing meaning.
54

 Both Blytt’s 

Darwinism-inspired focus on the past and Mohn’s insistence on numerical facts can be 

interpreted as parts of this new threat to the University.  

The only object of study that Mohn and Blytt shared was shorelines.
55

 Shorelines are 

linear marks in the bedrock along the Norwegian coast in different heights above the present 

sea level. They were believed to be traces of previous sea levels, thus demonstrating the 

different stages in the rise of the Norwegian land mass. Both Blytt and Mohn wrote an article 

on this phenomenon, with radically different approaches. Blytt’s article Om den sandsynlige 

aarsag til strandliniernes forskyvning (“Probable causes of the displacement of beach lines”) 

was a long discussion where his own hypothesis was connected to a wide range of existing 

theories, starting with Immanuel Kant from 1754. His own hypothesis was focused on the 

origin of mountain ranges in the Northern hemisphere. Blytt was aware of his very 

hypothetical approach, and asked for “patience for the many deficiencies and imperfections 

connected to such an attempt”. He hoped “that the hypothesis at least will be found worthy of 

a closer examination”.
56

  

Mohn’s article on shorelines was the result of a documentary project in which he 

presented his observations, measurements, drawings and statistical analysis of shorelines 

between Bergen and Vardø. Of 53 pages in his article Bidrag til Kundskaben om gamle 

Strandlinier i Norge (“Contributions to the Knowledge about Old Beach-Lines in Norway”), 

only the last four were devoted to a discussion of the possible origin of the shorelines. “To 

theorise on the creation of shorelines,” Mohn concluded, “the present material and knowledge 

                                                           
50

 Mohn. Storm-Atlas. 1870: 23. On Mohn’s alignment with Dove’s theory, see Kutzbach 1979: 78-79. On the 

status of Dove’s theory among meteorologists, see Kutzbach 1979: 88-93. 
51

 On the concept of prediction of the past, see Anderson 2005 and Stanley, Mathew. “Predicting the Past: 

Ancient Eclipses and Airy, Newcombe and Huxley on the Authority of Science”. Isis 103/2 2012: 254-277.  
52

 Deborah Coen discusses climate studies as a part of political and cultural projects in Austria-Hungary in the 

1880s in Coen 2010 and Coen 2011.  
53

 While Blytt occasionally refers to Mohn’s work in his publications, I have not seen any references to Blytt by 

Mohn. I have not found any correspondence between them in the personal collection of letters after Blytt 

(National Library in Oslo) or in Mohn’s correspondence in the archive of the Norwegian meteorological institute 

(National Archives in Oslo). On the threat against the “culture of unity”, see: Kyllingstad and Rørvik 2011 and 

Phillips, Denise. Acolytes of Nature. Defining Natural Science in Germany 1770-1850. Chicago 2012.  
54

 Among the fiercest defenders of this culture of unity were the philosophy professor Marcus Monrad (1816-

1897) and professor of medicine Ferdinand Lochmann (1820-1891). Kyllingstad and Rørvik 2011: 27-41.  
55

 Blytt 1886. In the English version of his article, Axel Blytt used the term “beach lines”. Mohn, Henrik. 

“Bidrag til Kundskaben om gamle Strandlinier i Norge”. Særtryk af Nyt Magazin for Naturvidenskaberne. 

Christiania 1876.  
56

 Blytt 1888: 240.  



 History of Meteorology 7 (2015) 48 

 
 

about their nature and topographical conditions is still far too poor”.
57

 Axel Blytt disagreed, 

and this contrast between him and Mohn illustrates the difference between their approaches to 

climate as well. The botanist practicing geology was free to speculate, while the meteorologist 

could rely only on direct observations.  

 

 

 

 

 

 

 

 

 

 

Acknowledgements  

 

The topic of this paper was presented and discussed twice in Bergen in November 2014, both 

in the research group “Health, welfare and history of science” at the Department of 

Archaeology, History, Culture and Religious Studies at the University of Bergen and at the 

international workshop “Climate in Meteorology, Meteorology in Climate Studies”. It was 

also presented at the 6
th

 Norwegian Conference on the History of Science in Oslo in February 

2015. I have received useful comments from three reviewers, and from Magnus Vollset, Svein 

Atle Skålevåg, Yngve Nilsen and James R. Fleming. I wish to thank the contributors for 

valuable input.  

                                                           
57

 Mohn. Strandlinier. 1876: 53.  


