From: Thomas Hockey et al. (eds.). The Biographical Encyclopedia of Astronomers, Springer Reference. New York: Springer, 2007, p. 34

Courtesy of

ʿAlī ibn ʿĪsā al-Asurlābī

Marvin Bolt

Flourished Damascus, (Syria), 832

ʿAlī ibn ʿĪsā al-Asurlābī, author of an early Arabic treatise on the astrolabe and an opponent of astrology, enjoyed renown as an astronomical instrument maker and contributed to observations initiated by the ʿAbbāsid caliph Maʾmūn. He took part with Khālid ibn ʿAbd al-Malik al-Marwarrūdhī and others in an expedition to the Plain of Sinjār to measure 1° of latitude and, thus, the size of the Earth. ʿAlī ibn ʿĪsā made astronomical observations at Baghdad in 829/830 and at Damascus in 832–833. He divided the mural quadrant used for the Damascus observations to confirm results of the earlier missions.

Selected References

Barani, Syed Hasan (1951). “Muslim Researches in Geodesy.” In Al‐Bīrūnī Commemoration Volume, A.H. 362–A.H. 1362, pp. 1–52. Calcutta: Iran Society. (Includes transcriptions and an analysis of Arabic primary sources, as well as translations.)

King, D. A. (2000). “Too Many Cooks … A New Account of the Earliest Geodetic Measurements.” Suhayl 1: 207–241. (Provides translated texts related to ʿAlī ibn ʿĪsā's involvement with measuring the Earth.)

Rosenfeld, B. A. and Ekmeleddin Ihsanoğlu (2003). Mathematicians, Astronomers, and Other Scholars of Islamic Civilization and Their Works (7th– 19thc.). Istanbul: IRCICA, p. 28.

Sarton, George (1927). Introduction to the History of Science. Vol. 1, p. 566. Baltimore: Published for the Carnegie Institution of Washington by Williams and Wilkins.

Sayılı, Aydın (1960). The Observatory in Islam. Ankara: Turkish Historical Society. (See Chap. 2, “Al Maműn's Observatory Building Activity,” pp. 50–87, for a valuable discussion, beginning with a thorough analysis of early Islamic astronomical observations.)