Before revision: Eratosthenes of Cyrene, head librarian under Ptolemy III Euergetes and a polymath, who worked on literary criticism, philosophy, geography, and mathematics (e.g., his sieve for prime numbers and his measure of the earth ’s circumference).
After revision: Eratosthenes of Cyrene, head librarian under Ptolemy III Euergetes and a polymath, who worked on literary criticism, philosophy, geography, and mathematics (e.g., his sieve for prime numbers and his measure of the Earth ’s circumference).