ABSTRACT
The great Egyptian city of Alexandria was the technological center of the ancient world from its founding in 331 B.C.E. The oldest lighthouse in the world was constructed there between 290 and 270 B.C.E. Alexandria’s library was the largest in the world and a center for the study of mathematics and astronomy. The third librarian of Alexandria, Eratosthenes, calculated the circumference of the earth to within one percent of its actual value.
