İhsan Fazlıoğlu

Ibn Abī al‐Fatḥ al‐Ṣūfī: Shams al‐Dīn Abū ʿAbd Allāh Muḥammad ibn Abī al‐Fatḥ al‐Ṣūfī

Alternate name

Abī al‐Fatḥ al‐Ṣufi

Flourished  Cairo, (Egypt), late 15th century/early 16th century

Ibn Abī al‐Fatḥ al‐Ṣūfī was an important Egyptian astronomer who wrote some 26 works on astronomy. These works include astronomical instruments, tables for timekeeping and other purposes, and important studies on Ulugh Beg'sZīj. His name and death date have been variously reported by both historical and modern sources. He has sometimes been confused with his father who pursued similar studies and had a similar name.

Although little is known about his life, we can surmise that Ibn Abī al‐Fatḥ al‐Ṣūfī was probably first educated by his father. He informs us in his Nihāyat al‐rutba fī al‐ʿamal bi‐jadwal al‐nisba that his education was guided by the famous Egyptian astronomer Sibṭ al‐Māridīnī. Indeed, his approach to astronomy, relying on mathematics and arithmetic and avoiding philosophical content, does place him within the tradition of the “Egyptian school” that began with Ibn al‐Hāʾim in 13th‐century Egypt, was further developed in the 14th‐century Maghrib with Ibn al‐Bannāʾ, continued with Ibn al‐Majdī, and matured with Sibṭ al‐Māridīnī.

There are 26 works attributed to Ibn Abī al‐Fatḥ al‐Ṣūfī that are currently extant; some of these may, though, be actually by his father. These works include astronomical and timekeeping tables, treatises dealing with astronomical instruments, and reworkings of Ulugh Beg'sZīj. In his Tashīl zīj Ulugh Beg (or Mukhtaṣar zīj Ulugh Beg), Ibn Abī al‐Fatḥ al‐Ṣūfī recalculated Ulugh Beg's tables, originally prepared for Samarqand, for Egypt. Similarly, Abū al‐Fatḥ al‐Ṣūfī wrote another work consisting only of tables called Bahjat al‐fikr fīḥall al‐shams wa‐ʾl‐qamar. Undoubtedly, his most important astronomical study is Zīj Muḥammad ibn Abī al‐Fatḥ al‐Ṣūfī, which purports to be an emendation of Zīj‐i Ulugh Beg. His student, Taqī al‐Dīn, mentions in his Sidrat muntahā al‐afkār that Abū al‐Fatḥ al‐Ṣūfī improved the arithmetic of the zīj, as well as made new observations (although he provides little detailed information about their details).

Ibn Abī al‐Fatḥ al‐Ṣūfī wrote several books on astronomical instruments based on the work of Ibn al‐Shāṭir and Ibn al‐Sarrāj. He wrote on a quadrant called al‐rubʿ al‐mujannaḥ and on a timekeeping device called ṣandūq al‐yawāqīt that was invented by Ibn al‐Shāṭir. In other works he describes two little‐known instruments called the “Goose Chest” and the “Crow Wing” and how to use sand clocks.

Ibn Abī al‐Fatḥ al‐Ṣūfī's influence was widespread and enduring as indicated by a commentary on his Nubdhat al‐isʿāf fī maʿrifat qaws al‐khilāf by the Egyptian astronomer Ramaḍān ibn Ṣāliḥ al‐Khwānakī (died: 1745). He also trained a number of students. He encouraged his student Yaḥyā ibn ʿAlī al‐Rifāʿī to translate Ulugh Beg's Zīj from Persian into Arabic. This translation made this Zīj more widely accessible in Ottoman lands; there are currently more than 20 extant copies. Ibn Abī al‐Fatḥ al‐Ṣūfī's most important student, though, was the great astronomer Taqī al‐Dīn, who corrected and completed Ulugh Beg's Zij and would become the founder of the Istanbul Observatory.  

Selected References

Bağdadlı İsmail, Paşa (1955). Hadiyyat al‐ʿārifīn. Vol. 2, pp. 198, 238, 621. Istanbul.

——— Īḍāḥal‐maknūn. Vol. 1: (1945): 197; Vol. 2: (1947): 530. Istanbul.

Brockelmann, Carl (1949). Geschichte der arabischen Litteratur. 2nd ed. Vol. 2: 159; Suppl. 2 (1938): 159. Leiden: E. J. Brill.

İhsanoğlu, Ekmeleddin et al. (1997). Osmanlı Astronomi Literatürü Tarihi (OALT) (History of astronomy literature during the Ottoman period). Vol. 1, pp. 116–126 (no. 58). Istanbul: IRCICA.

Janin, Louis and David A. King (1977). “Ibn al‐Shāṭir's Ṣandūq al‐yawāqīt: An Astronomical ‘Compendium.’” Journal for the History of Arabic Science 1: 187–256. (Reprinted in King, Islamic Astronomical Instruments, XII. London: Variorum Reprints, 1987.)

Kātib Čelebī (1941). Kashf al‐ẓunūn ʿan asāmī al‐kutub wa‐ʾl‐funūn. Vol. 1, cols. 127, 966–967, 970. Istanbul.

King, David A. (1981 and 1986). A Catalogue of the Scientific Manuscripts in the Egyptian National Library (in Arabic). 2 Vols. Cairo: General Egyptian Book Organization.

Rosenfeld, B. A. and Ekmeleddin Ihsanoğlu (2003). Mathematicians, Astronomers, and Other Scholars of Islamic Civilization and Their Works (7th–19th c.). Istanbul: IRCICA, pp. 300–303.