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

38 ASTRONOMY IN ANCIENT NATIONS after all not be very surprising if some learned Jews had been influenced by the opinion of Herakleides, since it is an established fact that the doctrines of the Kabbalists were intimately connec- ted with the later Greek philosophy. But any how nothing came of this isolated case, and the daily rotation of the heavens conti- nued to be universally accepted as a self-evident fact. Arabian astronomers and Ptolemaic system— Arabian astronomers who really wished to follow in detail the celestial motion were therefore obliged to adopt the Ptolemaic system altogether. New planetary tables had long been found to be a necessity, and this important work was at last undertaken by King Alfonso X. of Castille and several Jewish and Christian astronomers working under him at Toledo, who prepared the celebrated Alfonsine Tables, Apparently the King must have had his doubts about the physical truth of the system, judging from his well-known saying that if God had consulted him when creating the world, he would have given Him good advice. The tables were prepared under the direction of the Jew Ishak ben Said, called Hasan, and a physician, Jehuda ben Mose Cohen, and were finished in 1252, the year in which Alfonso ascended the throne of Castille. They continued in great repute for three hun- dred years as the best planetary tables; they were first printed in 1483, but had been spread all over Europe long before that time in numerous MS copies, many of which are still in existence, Twenty-six codices are counted up in the Libros del Saber de Astronomia del Rey D. Alfonso X.de Castella, Madrid, 1863-67 (5 vols. fol.). This compilation, a series of chapters on spherical and theoretical astronomy followed by tables, must have been made up from several codices, as there are numerous repetitions even of very elementary matters. In the third volume the theo- ries of the planets are dealt with, but one looks in vain for any improvement on Ptolemy; on the contrary, the low state of astro- nomy in the Middle Ages is nowhere better illustrated. In gene- ral the elements of the orbits are those of Ptolemy, though some- times only approximations are given, while different values are given in different chapters, though Ptolemy places the centre of the deferent midway between the centre of the equant and the Earth, the Libros del Saber places the centre of the equant (cerco del alaux.¹) midway between the Earth and the centre of the deferent

1. al is the Arbic article, aux (apside) is a corruption of the Arabic Oudj (Abu 'l Faraj, II. p. 25). The equant is called the cerco del Y guador.