A nilometer is a structure for measuring the Nile River's clarity and water level during the annual flood season in Egypt.[1] There were three main types of nilometers, calibrated in Egyptian cubits: (1) a vertical column, (2) a corridor stairway of steps leading down to the Nile, and (3) a deep well with a culvert.[1] If the water level was low, the fertility of the floodplain would suffer. If it was too high, the flooding would be destructive. There was a specific mark that indicated how high the flood should be if the fields were to get good soil.[1][2]
Nilometers originated in pharaonic times, were also built in Roman times, and were highly prevalent in Islamic Egypt in Rashidun, Ummayad, Abbasid, Tulunid, Mamluk, Alawiyya and Republican periods, until the Aswan Dam rendered them obsolete in the 1960s.
- ^ a b c Helaine Elsin (2008). "Nilometer". Encyclopaedia of the History of Science, Technology, and Medicine in ... p. 1753.
- ^ Brian Fagan (1 August 2010). The Great Warming: Climate Change and the Rise and Fall of Civilizations. Bloomsbury Publishing. p. 167. ISBN 978-1-59691-780-4.