The astronomer, mathematician, and geographer, Abu al‐Abbas Ahmad ibn Muhammad ibn Kathir al-Farghani (798-865), known in Europe as Alfraganus, was probably born in the Farghana Valley in present day Uzbekistan. Under Abbasid Caliph Mamun’s patronage in Baghdad, he collaborated in the accurate measurement of the world’s diameter, and wrote ‘The Elements of Astronomy’ and his famous treatise on the mathematical principles of the astrolabe. The astrolabe became highly developed in the 9th century and was extremely valuable in Islam to define prayer times and the direction of Mecca.
Farghani moved to Cairo later in his life where he restored the Nilometer in 861. Nilometer existed since the Pharaonic Period, the Umayyads (the first Arab dynasty) constructed a Nilometer on Roda Island (then Fustat) around 715 AD. This structure was restored in 815, but was destroyed by a flood in 850. The Nilometer existent on Roda Island today was designed by al-Farqhani.His last years were spent in Egypt and he is buried in the Qarafa mausoleum in Cairo.
The statue of al-Farghani, standing at the Manasterly Palace entrance and the Nilometer on Roda Island, was given by Uzbekistan in 2007.
A moon crater, Alfraganus, was named after al-Farghaniī in recognition of his contribution to science.
(Published in Obelisque Magazine, 2011. All rights reserved by Lesley Lababidi)
Cairo’s Street Stories, click here.