The Librarian's Thirst for KnowledgeEratosthenes was the chief librarian in the great library of Alexandria in Egypt. At his disposal was the latest scientific knowledge of his day. He was always interested in learning new things.
One of the things that he thought about was the size the earth. He was convinced that the earth was a sphere. But he wasn't sure how big around it was. Finding this out was particularly important to him since he wanted to write a geography book. So how did he do it?