Al-Nayrizi
Abu-l-Abbas al-Fadl ibn Hatim al-Nairizi, Latin name: Anaritius, was a 9–10th century Persian mathematician and astronomer from Nayriz, a town near Shiraz, Fars, Iran.
He flourished under al-Mu'tadid, Caliph from 892 to 902, and compiled astronomical tables, writing a book for al-Mu'tadid on atmospheric phenomena.
Nayrizi wrote commentaries on Ptolemy and Euclid. The latter were translated by Gherardo da Cermona. Nairizi used the so-called umbra (versa), the equivalent to the tangent, as a genuine trigonometric line (but he was anticipated in this by al-Marwazi).
He wrote a treatise on he spherical astrolabe, which is very elaborate and seems to be the best Arabic work on the subject. It is divided into four books:
- Historical and critical introduction.
- Description of the spherical astrolabe; its superiority over plane astrolabes and all other astronomical instruments.
- Applications.
- Applications.
Ibn al-Nadim mentions Nayrizi as a distinguished astronomer with Eight works by him listed in his book al-Fihrist.
Sources
- H. Suter: Die Mathematiker und Astronomen der Araber (45, 1900)
- Nachtrage (164, 1902).