104 
ERATOSTHENES 
Long as the present chapter is, it is nevertheless the most 
appropriate place for Eratosthenes of Gyrene. It was to him 
that Archimedes dedicated The Method, and the Cattle-Problem 
purports, by its heading, to have been sent through him to 
the mathematicians of Alexandria. It is evident from the 
preface to The Method that Archimedes thought highly of his 
mathematical ability. He was, indeed, recognized by his con 
temporaries as a man of great distinction in all branches of 
knowledge, though in each subject he just fell short of the 
highest place. On the latter ground he was called Beta, and 
another nickname applied to him, Pentathlos, has the same 
implication, representing as it does an all-round athlete who 
was not the first runner or wrestler but took the second prize 
in these contests as well as in others. He was very little 
younger than Archimedes; the date of his birth was probably 
284 b.c. or thereabouts. He was a pupil of the philosopher 
Ariston of Chios, the grammarian Lysanias of Gyrene, and 
the poet Callimachus ; he is said also to have been a pupil of 
Zeno the Stoic, and he may have come under the influence of 
Arcesilaus at Athens, where he spent a considerable time. 
Invited, when about 40 years of age, by Ptolemy Euergetes 
to be tutor to his son (Philopator), he became librarian at 
Alexandria; his obligation to Ptolemy he recognized by the 
column which he erected with a graceful epigram inscribed on 
it. This is the epigram, with which we are already acquainted 
(vol. i, p. 260), relating to the solutions, discovered up to date, 
of the problem of the duplication of the cube, and commend 
ing his own method by means of an appliance called fieaoXa^ov, 
itself represented in bronze on the column. 
Eratosthenes wrote a book with the title TIXoltcwlkos, and, 
whether it was a sort of commentary on the Timaeus of 
Plato, or a dialogue in which the principal part was played by 
Plato, it evidently dealt with the fundamental notions of 
mathematics in connexion with Plato’s philosophy. It was 
naturally one of the important sources of Theon of Smyrna’s 
work on the mathematical matters which it was necessary for 
the student of Plato to know ; and Theon cites the work 
twice by name. It seems to have begun with the famous 
problem of Delos, telling the story quoted by Theon how the 
god required, as a means of stopping a plague, that the altar 
there, 
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320, 32