From: Thomas Hockey et al. (eds.). The Biographical Encyclopedia of Astronomers, Springer Reference. New York: Springer, 2007, pp. 970-971

Courtesy of

Riwān al‐Falakī: Riwān Efendi ibn ʿAbdallāh al‐Razzāz al‐Falakī

Salim Aydüz

BornCairo, (Egypt)

DiedCairo, (Egypt), 7 August 1711

Riwān Efendi al‐Falakī was an Egyptian–Ottoman astronomer known for his production of astronomical tables as well as various instruments and globes. He was also noted for the many students that he trained. There is little information on his birth, youth, and education. However, we know that Riwān al‐Falakī studied in Cairo and received his astronomical education from distinguished scholars. Indeed, he never left Cairo except in 1680, when he visited Mecca for the ajj (pilgrimage). Besides writing on astronomy, Riwān al‐Falakī wrote a number of books on mathematics and geometry. According to the sources on Ottoman astronomy, his works were so abundant that the drafts of his books were considered a camel's load. At the request of the timekeeper asan Efendi, in 1700 and 1701 he prepared spheres and astronomical devices upon which he marked the Arabic names of stars that he located through observation. Among Riwān al‐Falakī's many students in astronomy, only Yūsuf al‐Jamāli (the servant of asan Efendi) is known.

The titles of 17 of Riwān al‐Falakī's astronomical works are known, most of which are extant. All were written in Arabic. Several works are adaptations of the work done at the Samarqand Observatory under Ulugh Beg. His Zīj al‐mufīd ʿalā uūl al‐raad al‐jadīd al‐Samarqāndī, or al‐Zīj al‐Riwānī, is an astronomical handbook with tables based on Zīj‐i Ulugh Beg but adapted for Cairo's latitude. It consists of four parts in addition to an introduction and various tables. Riwān al‐Falakī's al‐Durr al‐farīd ʿalā al‐raad al‐jadīd is possibly a commentary written on Ulugh Beg's Zīj; it contains an introduction, 12 sections, and a conclusion. Asnā al‐mawāhib fī taqwīm al‐kawākib is another work he adapted from Zīj‐i Ulugh Beg for Cairo's latitude.

Riwān al‐Falakī is also known for his works on timekeeping. Of these, probably the most extensive is Dustūr uūl ʿilm al‐mīqāt wa‐naījat al‐nar fī tarīr al‐awqāt. Other treatises treat eclipses, lunar‐crescent visibility, sundials, and Jupiter–Saturn conjunctions. For a listing of his works, see Ihsanoğlu et al. (1997), and Rosenfeld and Ihsanoğlu (2003).

Selected References

Al‐Ziriklī, Khayr al‐Dīn (1980). Al‐Aʿlām. Vol. 3, p. 27. Beirut.

Bağdadlı, İsmail Paşa. Īā al‐Maknūn. Vol. 1 (1945): 82, 447, 621; Vol. 2 (1947): 81. Istanbul.

——— (1951). Hadiyyat al‐ʿĀrifīn. Vol. 1, p. 369. Istanbul.

Brockelmann Carl. Geschichte der arabischen Litteratur. 2nd ed. Vol. 2 (1949): 471; Suppl. 2 (1938): 487. Leiden: E. J. Brill.

Çakıroğlu, Ekrem (ed.) (1999). Yaşamları ve Yapıtlarıyla Osmanlılar Ansiklopedisi. Vol. 2, pp. 459–460. Istanbul: Yapi Kredi Yayinlari.

İhsanoğlu, Ekmeleddin et al. (1997). Osmanlı Astronomi Literatürü Tarihi (OALT) (History of astronomy literature during the Ottoman period). Vol. 1, pp. 377–384. Istanbul: IRCICA.

Jabartī, ʿAbd al‐Ramān (1978). ʿAjāʾib al‐āthār fī al‐tarājim wa‐ʾl‐akhbār. Vol. 1, pp. 130–131. Beirut.

Kaḥḥālah, ʿUmar Riā (1985). Muʿjam al‐muʾallifīn. Vol. 4, p. 165. Beirut.

King, David A. (1986). A Survey of the Scientific Manuscripts in the Egyptian National Library. Winona Lake, Indiana: Eisenbrauns, pp. 107–108.

——— (2004). In Synchrony with the Heavens: Studies in Astronomical Timekeeping and Instrumentation in Medieval Islamic Civilization. Vol. 1, The Call of the Muezzin (Studies I–IX). Leiden: E. J. Brill.

Rosenfeld, B. A. and Ekmeleddin Ihsanoğlu (2003). Mathematicians, Astronomers, and Other Scholars of Islamic Civilization and Their Works (7th–19th c.). Istanbul: IRCICA, pp. 386–387.