ब्राह्मस्फुटसिद्धान्त (ब्रह्मगुप्त - शून्य, कुट्टक, बीजगणित एवं सम्पूर्ण २१ अध्याय सान्वय सटीक)

ARABS AND GREEKS 11 the calculus of the stars known as the Sindhind (i. e. Siddhānta), and possessed methods for solving equations founded on the kardagas (i. e. kramajyā, sines) calculated for every half degree, also methods for computing eclipses and other things. Al Mansur ordered the book in which all this was contained to be translated into Arabic, and that a work should be prepared from it which might serve as a foundation for computing the motions of the planets. This was accordingly done by Muham- med ben Ibrahim Al Fazari, whose works the Arabs call the great Sindhind, and from it an abstract was afterwards made for Al Mamun by Abu Giafar Muhammed ibn Musa al Kwarizmi, who made use of it to prepare his tables, which obtained great renown in the lands of Islam. But when Al Mamun became Caliph, he promoted these noble studies and called in the most learned men in order to examine the Almagest and make instru- ments for new observations. Arabs and Greeks The account of which the above is an abstract shows us clearly the origin of the study of astronomy and mathematics under the Abbasid Caliphs. But though the first impulse came from India the further development of Arabian science was to a considerable extent founded on that of Greece and Alexandria. It was through the court physicians from the flourishing medical school kept up by Nestorian Christians of Khusistan that a knowledge of Greek Philosophy and science was first spread among the subjects of the Caliphs; and by degrees the works of Aristotle, Archimedes, Euclid, Apollonius, Ptolemy, and other mathematicians were translated into Arabic. Fresh translations of Ptolemy were made from time to time in the various king- doms into which the vast empire of the Caliph was soon split up,¹ and a thorough knowledge of Ptolemaic astronomy was thus spread from the Indus to the Ebro. There were several special inducements for Muhamedans to pay attention to astronomy, such as the necessity of determining the direction in which the

1. The earliest is probably that of Al Haggag ben Jusuf ben Matar early in the ninth century. See Suter, Die Mathematiker und Astronomen der Araber und ihre Werke, Leipzig, 1900 (p. 9), which valuable bibliographical summary has been follwed by J. L. E. Dreyer as regards names and dates (J. L. E. Dreyer’s A History of Astronomy, 1953; we have reproduced this account from his chapter XI.)