ASTRONOMERS
'(<a href="http://www.j-archive.com/media/2008-11-24_DJ_14.jpg" target="_blank">Jon of the Clue Crew points to an astronomical diagram on the monitor.</a>)  In the 200s B.C. Eratosthenes calculated Earth's girth using the difference in the angle of the Sun's rays between Aswan & this Egyptian city'
Alexandria