Eratosthenes, who lived in Alexandria around 200 B. C., learned that at noon on the summer solstice the sun shined vertically into a well in Syene (modern Aswan, due south of Alexandria). He found that on the same day in Alexandria the sun was about 7 degrees short of being directly overhead. Since 7 degrees is about 1 50 of a full circle of 360 degrees, he concluded that the distance from Syene to Alexandria was about 1 50 of the Earth's circumference. He knew from travels that it was a 50-day trip and that camels could travel 100 stades per day. What was Eratosthenes' measure, in stades, of the circumference of the Earth? stades One estimate is that the stade is 0.104 mile. Using this estimate, what was Eratosthenes' measurement of the circumference of Earth in miles? mi