Ibrahim Ibn Saîd al-Sahlì () (11th century) was an Andalusian globe-maker, active from 1050 to 1090. Ibrahim Ibn Saîd al-Sahlì worked in

Valencia Valencia ( va, València) is the capital of the Autonomous communities of Spain, autonomous community of Valencian Community, Valencia and the Municipalities of Spain, third-most populated municipality in Spain, with 791,413 inhabitants. It is ...

and Toledo in what is now Spain, and was mentioned in a list of mathematics students in

Andalusia Andalusia (, ; es, Andalucía ) is the southernmost Autonomous communities of Spain, autonomous community in Peninsular Spain. It is the most populous and the second-largest autonomous community in the country. It is officially recognised as a ...

in a book written in 1068. Ibrahim Ibn Saîd al-Sahlì created the "

astrolabe An astrolabe ( grc, ἀστρολάβος ; ar, ٱلأَسْطُرلاب ; persian, ستاره‌یاب ) is an ancient astronomical instrument that was a handheld model of the universe. Its various functions also make it an elaborate inclin ...

of Al-Sahli", an instrument to determine the positions of the stars on the sky, in the city of Tulaytulah (now Toledo, Spain) in the year 1066. He built four more astrolabes between 1067 and 1086. His first astrolabe was characterized by the peculiarity of its operation, as other astrolabes made in his time were not similar.

References

Museo Galileo Museo Galileo, the former ''Istituto e Museo di Storia della Scienza'' (Institute and Museum of the History of Science) is located in Florence, Italy, in Piazza dei Giudici, along the River Arno and close to the Uffizi Gallery. The museum, dedicate ...

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Ibrâhim 'Ibn Saîd as Sahlì
. Catalogue of the Museo Galileo's Instruments on Display. ''catalogue.museogalileo.it'' {{authority control Al-Andalus scientific instrument makers Inventors of the medieval Islamic world Mathematicians of Al-Andalus Astronomers of Al-Andalus