Introduction to the Science of Cosmography


Al-tabṣira fī ʻilm al-hayʻa (Introduction to the science of cosmography) is a treatise attributed to Shams al-Din al-Khiraqi (also seen as al-Kharaqi), a mathematician, geographer, and leading Seljuk-era astronomer who died in 1138 or 1139. He was born in Khiraq (or Kharaq) near Merv, in present-day Turkmenistan. He probably was a court astronomer for Sultan Sanjar, who ruled the Seljuk Empire in 1118–57, and his vizier Abu al-Husayn Ali ibn Nasir al-Din, to whom al-Khiraqi dedicates this treatise. The work is an abridgment of al-Khiraqi’s own, longer treatise Muntahá al-idrāk fī taqāsīm al-aflāk (The ultimate in comprehending the divisions of the celestial spheres). In both works, al-Khiraqi builds on alternative theories developed by earlier Muslim astronomers—especially al-Hassan ibn al-Haytham (called Alhazen in the Latin West)—in which the planets are seen as supported by solid spheres rather than the imaginary circles suggested by Ptolemy in the Almagest. The treatise presented here is divided into two sections. The first, containing 22 chapters, discusses the physical structure of the universe and the locations of the various celestial bodies. It includes chapters on the sphericity of those bodies and explanations of such natural phenomena as the solar and lunar eclipses. The second section, comprised of 12 chapters, examines Earth, especially the seasons as they relate to the zodiacal signs and constellations. This copy of Al-tabṣira is incomplete, containing only the first 18 chapters of the first section. The second section, on Earth, is missing. Both this abridgment and the longer version of the work are sometimes incorrectly attributed to Abd al-Jabbar ibn Abd al-Jabbar al-Kharaqi, a near contemporary (died 1158), who also was from Kharaq.

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Title in Original Language

التبصرة فى علم الهيئة

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Physical Description

60 folios ; 23 x 13.5 centimeters sheets bound in 23.9 x 14.6 centimeters



  1. Sally P. Ragep, Jaghmīnī’s Mulakhkhaṣ: An Islamic Introduction to Ptolemaic Astronomy (New York: Springer-Verlag, 2016).

Last updated: January 10, 2018