A history of Greek mathematics - Wilbourhall.org

ASTRONOMY, ETC. 109
word 'Ao-TpovofjLia (Suidas), which latter word is perhaps a mistake
for 'Ao-rpoOeo-la corresponding to the title 'AcrrpoOeo-icu
(coSloov found in the manuscripts. The work as we have it
contains the story, mythological and descriptive,
of the constellations,
&c., under forty-four heads ; there is little or
nothing belonging to astronomy proper.
Eratosthenes is also famous as the first to attempt a scientific
chronology beginning from the siege of Troy; this was the
subject
of his Xpovoypa(piai, with which must be connected
the separate 'OXv/imovLKai in several books. Clement of
Alexandria gives a short resumS of the main results of the
former work, and both works were largely used by Apollodorus.
Another lost work was on the Octaeteris (or eightyears'
period), which is twice mentioned, by Geminus and
Achilles ; from the latter we learn that Eratosthenes regarded
the work on the same subject attributed to Eudoxus
as not genuine. His Geographica in three books is mainly
known to us through Suidas's criticism of it. It began with
a history of geography down to his own time ;
Eratosthenes
then proceeded to mathematical geography, the spherical form
of the earth, the negligibility in comparison with this of the
unevennesses caused by mountains and valleys, the changes of
features due to floods, earthquakes and the like. It would
appear from Theon of Smyrna's allusions that Eratosthenes
estimated the height of the highest mountain to be 10 stades
or about 1/ 8000th part of the diameter of the earth.