Ammon (geometer)
Encyclopedia
Ammon was a geometrician who made a measurement of the walls of Rome, around the time of the first invasion of the Goths, that is, the 3rd century
3rd century
The 3rd century was the period from 201 to 300 in the Christian/Common Era.In this century, the Roman Empire saw a crisis, marking the beginning of Late Antiquity. In Persia, the Parthian Empire was succeeded by the Sassanid Empire....

, and found them to be 21 miles in circumference.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK