(This is an expanded version of a previous post about nilometers. It will appear in the August 2017 edition of Egypt Today)
Nilometers were used in Egypt, particularly during the pharaonic, Roman and medieval periods, to measure the Nile’s water level during the annual summer flood.
Essentially, apart from such ritual functions they may have served in ancient Egypt, nilometers worked on the Goldilocks principle as far as the rulers of Egypt were concerned. If the water level in August–September was too high, the effects on the narrow band of fields either side of the river, and the surrounding infrastructure, would be devastating and there was no point sending out the tax collectors. If the water level was too low, the population would starve, and there was also no point sending out the tax collectors. If the water level was just right, a rich layer of alluvial silt would be deposited as the flood subsided, crops would grow, and off would go the tax collectors, no doubt singing merrily to themselves. (more…)