Circa 285-194 B.C.E.
Librarian, Astronomer, Geographer

Encyclopedic Knowledge. Eratosthenes was born in Cyrene (present-day Libya) and became the librarian at Alexandria during the second half of the third century B.C.E. after studying with the philosopher Ariston of Chios, who himself was a student of Zeno, the founder of the Stoic school of philosophy. The period during which Eratosthenes lived, the Hellenistic period, was one that encouraged eclectic scholars, as many of the personalities connected with the Library at Alexandria demonstrate. In his post as librarian Eratosthenes followed such Hellenistic scholars as Apollonius of Rhodes, who is most noted for his adaptation of classical poetry. (Apollonius wrote the Argonautica, a famous poem on the myth of Jason and the Argonauts that brilliantly incorporates allusions to earlier Greek poetry.) Like Apollonius, Eratosthenes demonstrated the encyclopedic knowledge that characterized his time; he wrote on every subject...