Risala-yi asturlab-i Kushyar Gilani

Kushyar (Pers. Kushyar) b. Labban Gilani was a Persian astronomer and mathematician who flourished around 390/1000. All we know about his personal life is that he originated from the region of Gilan in northern Iran, bordering on the Caspian Sea. Given that he is cited in Abu Rayhan al-Biruni's (d. after 442/1050) Kitab fi ifrad al-maqal fi amr al-azlal, Kushyar must have become an authority by the time al-Biruni came to write this work. From his works in mathematics, Kushyar's Kitab fi usul hisab al-Hind on Indian arithmatic is the most important, and in astronomy his Zij-i jami?. His Arabic work on the astrolabe is published here for the very first time, accompanied by a Japanese translation, both by Taro Mimura of Japan. In addition, this volume also contains a facsimile edition of the anonymous medieval Persian translation of this work, followed by a critical edition, both by Mohammad Bagheri of Iran.