Autolycus of Pitane, "De Ortibus" 1.6 Huxley, George Greek, Roman and Byzantine Studies; Spring 1968; 9, 1; ProQuest pg. 58

Autolycus of Pitane, De Ortibus 1.6 

George Huxley 

p{TOLYCUS discusses in this chapter the interval between two 
true morning risings of a star in conjunction with the sun. He 
points out that true conjunctions at yearly intervals after an 

integral number of revolutions of the sun do not occur exactly. On the 
fractional difference he remarks, according to the text of Mogenet's 
fine edition: 0 8~ €VUXVTO~ ytYV€TCt.t Tep ~Atlf:J €t OAWV TT€ptcf>Opwv 1(Ct.~ 
T€TapTOV (p.225, lines 5-6).1 Here €t is superfluous: the genitives alone 
would suffice; and a number has fallen out before OAWV. We must 
therefore replace €t by Tt€', an easy palaeographical change. Thus 
Autolycus declared the year to be 365! days long. 

The length is that worked out by Callippus and his 'school', accord­
ing to Geminus in his Isagoge.2 The first Callippic cycle began in 
330/29 B.C.,3 and Autolycus flourished about 300 B.C. or a little earlier.' 
So the estimate of the year's length was a quite recent one when 
Autolycus gave it. For a meeting between Callippus and Autolycus 
there is no evidence, but both men were much concerned with the 
Eudoxian system of spheres and with "saving the phenomena";5 
Autolycus may well therefore be one of the members of the Callippic 
'school', oi TT€P~ Ka)J.LTTTTov, to which Geminus refers. 

THE QUEEN'S UNIVERSITY OF BELFAST 

February, 1968 

1 Joseph Mogenet, Autolycus de Pitane (Louvain 1950). 
2 8.57-60 (p.122 Manitius). 
3 Sir Thomas Heath, Aristarchus of Sames (Oxford 1913) 296. 
4 See Mogenet, op.cit. 9. 
5 Heath, op.cit. 221-223, quoting Simplicius on Aristotle, de Caelo pp.504-506 Heiberg. 

58