al-Khwarizmi's astronomical tables (Zij al-Sindhind)

The zij of al-Khwarizmi is a set of astronomical tables mentioned by Ibn al-Nadim in the Fihrist, in a passage the editors of the Cairo edition of the Book of al-Jabr and al-Muqabala quote from the Cairo printing of the Fihrist. ¹

Ibn al-Nadim says that al-Khwarizmi was one of the experts in astronomy, that before and after the observations people relied on his first and second tables, known as the Sindhind, and that he wrote "the Book of the Zij" in two versions, a first and a second, besides a book on the sundial, two books on using and making the astrolabe, and a book of history. ¹

The editors note that al-Biruni refers to al-Khwarizmi's tables and astronomical works and wrote at least three works, all commentaries on al-Khwarizmi's books. ^{2 3} They report Suter's opinion that Muhammad ibn Musa was one of those whom al-Ma'mun charged with measuring a degree of the earth's circumference. ³

The text of the tables was not read here; everything on this page comes from the introduction to the Cairo edition of the Algebra.