Al-Nayrīzī

Born in Persia, al-Nayrīzī spent most of his life in Baghdad. He was a court astronomer/astrologer of caliph al-Mu^˓taḍid (r. 892–902), to whom he dedicated several treatises, among them Al-Risāla fī aḥdāth al-jaww (Treatise on Meteorological Phenomena) or Al-Risāla fī ma^˓rifat ālāt yu^˓lamu bihā ab^˓ād al-ashyā^˒al-shākhiṣ a fī l-hawā^˒wal-latī^˓alā basīṭ al-arḍ wa-aghwār al-audīya wa’l-abār wa-^˓urūḍ al-anhār (Treatise on the Knowledge of Instruments through which Distances between Distinct Things in the Air or Set up on the Ground and the Depth of Valleys and Wells, and the Widths of Rivers Can be Known). He wrote commentaries on Ptolemy’s (fl. ca. 127–167) Almagest and his astrological work Tetrabiblos and an astronomical handbook (Zīj), a longer and a shorter version. And he commented on Euclid’s (fl. ca. 300 BCE) Elements and his astronomical work Phainomena and wrote independent works on the determination of the qibla, the direction of Mecca, the spherical astrolabe, methods for...