From: Thomas Hockey et al. (eds.). The Biographical Encyclopedia of Astronomers, Springer Reference. New York: Springer, 2007, p. 1119

Courtesy of

abarī: Abū Jaʿfar Muammad ibn Ayyūb al‐āsib al‐abarī

Živa Vesel

Flourished(Iran), 1092–1108

abari lived in Iran under the Saljūqs, probably in Āmul, and is the author of two independent treatises in Persian on the astrolabe as well as several other books, including two on arithmetic. Although several modern studies place him in the 13th century, he must have lived earlier based upon manuscript sources and since he is mentioned by al‐Bayhaqī in his Tatimmat iwān al‐ikma (1164).

The first astrolabe treatise is known under the title Shish fal (Six chapters [on the knowledge of the astrolabe]), the oldest manuscript copy dating to 1176–1177. It was probably composed at the request of some students and is arranged in a question–answer (q/a) format:


On the parts of the astrolabe and their names (60 q/a);


On lines, figures, inscriptions, and circles on the astrolabe (77 q/a);


On knowing the functioning of the back part of the astrolabe (49 q/a);


On knowing the functioning of the face side of the astrolabe (136 q/a);


On knowing how to check the exactness of the astrolabe (28 q/a);


On the use of the astrolabe for land‐surveying/measuring (misāa) (17 q/a).

The second treatise is a shorter and simplified version of the “six chapters” and is arranged simply into 104 entries. Entitled ʿAmal wa‐alqāb ([On the] functions and names [of the astrolabe]), the oldest extant manuscript copy is dated 1162. It was written for a certain nobleman of his time, who is named in two copies as Abū al‐Fat Dawlatshāh ibn Sulaymān. In the beginning of the treatise, abari states that there are three types of astrolabes: (1) spherical (kurī) used in earlier times; (2) circular (dawrī), used in the time of the author, who describes it as circular and flat; and (3) boat‐shaped/navicula (King, 1999, p. 352) (zawraqī), which is nevertheless described by abari as a “hemisphere, like a cup,” who indicates that it was used in pre‐Islamic Iran and that the astrolabe was called in Pahlavi “the cup that mirrors the world” ( jām‐i jahān‐namā). This passage is not found in Abū Rayān al‐Bīrūnī's Tafhīm and is quoted here as a curiosity.

abarī's two treatises on the astrolabe are among the oldest extant Persian texts on the subject. For a detailed study of their content, they should be compared to the earlier chapter on the astrolabe in Bīrūnī's Tafhīm and to the later Bist bāb dar maʿrifat‐i usurlāb (20 chapters on knowledge on the astrolabe) by Naīr al‐Dīn al‐ūsī.

Selected References

King, David A. (1999). World‐Maps for Finding the Direction and Distance to Mecca. Leiden: E. J. Brill.

Lazard, G. (1969). “A quelle époque a vécu l'astronome Moḥammad b. Ayyūb Ṭabarī?” In Yādnāmah‐i Īrānī‐i Mīnūrskī, edited by Mujtabá Mīnuvī and Īraj Afshār, pp. 1–8. Tehran: 1347 H. Sh.

Maddison, F. (1997). “Observatoires portatifs.” In Histoire des sciences arabes, edited by Roshdi Rashed. Vol. 1, pp. 139–172. Paris: Seuil.

Pingree, D. (1987). “Asṭorlāb.” In Encyclopaedia Iranica, edited by Ehsan Yarshater. Vol. 2, pp. 853–857. Winona Lake, Indiana: Eisenbrauns.

Ṭabarī, Muḥammad ibn Ayyūb. (1993). “Maʿrifat‐i usṭurlāb” maʿrūf bih “Shish faṣl” bih ḍamīmah‐i “ ʿAmal wa al‐alqāb,” edited by M. Amīn Riyāhī. Tehran: 1371 H. Sh.