Archaeologists discovered a rare structure called a nilometer in the ruins of the ancient city of Thmuis in Egypt’s Delta region. The nilometer was used to predict harvest and set taxes linked to the rise and fall of the Nile River. The device was constructed during the 3rd century B.C. and was used for roughly a thousand years to calculate the water level of the river during the annual flooding of the Nile. Fewer than two dozen of the devices are known to exist.
The archaeologists from University of Hawaii suspect it was originally located within a temple complex. Made from large limestone blocks, the nilometer was a circular well roughly 2.4 meters in diameter with a staircase leading down into its interior. It was connected with the Nile via a channel or it could have measured the water table as a proxy for the strength of the river. The site of the nilometer was likely part of a sacred temple complex where priests used the structure to predict the seasonal floods and farmers left offerings in hopes of winning the river god’s favour.
(after National Geographic)