HINDU, ARABIAN AND MOORISH SCIENCE 161 



the straits of Gibraltar. Egypt, Alexandria, and Carthage fell 

 before the Mohammedans, and the Arabian or Moslem empire 

 soon rivalled in extent its great predecessor, the Roman. In 711 

 Moslems crossed the straits of Gibraltar and entered Spain, 

 soon pushing northward into western France as far as Poitiers, 

 where their great western and northern movement was finally 

 checked by Charles Martel, in 732. This extraordinary onrush, 

 occurring almost within a single century, naturally left the Moslems 

 little time for the development of learning or for the arts and 

 sciences. But after it was over, the Mohammedan invaders 

 settled down in their various conquered countries and in some of 

 them cultivated the arts of peace. The successive Arabian rulers 

 (beginning with Al-Mansur, in 754) patronized learning, and to 

 this end collected Greek manuscripts, which, after the closing of the 

 Greek schools by Justinian in 529, had become scattered abroad. 

 In particular, certain Nestorian Jews were brought to Bagdad and 

 by them translations into Arabic were made of some of the works 

 of Aristotle, Euclid, Ptolemy, and other Greek authors. The 

 learning of India was also drawn upon, especially for the so-called 

 Arabic numerals. Thus began a kind of Arabian science, chiefly 

 imported at the outset, but destined within the next three centuries 

 to take on characteristics of its own. It was, however, under the 

 Caliph Al-Mamun (813-833), who has been called, as regards 

 schools and learning, the Charlemagne of his people, that Aristotle 

 was first translated into Arabic. Al-Mamun caused works on 

 mathematics, astronomy, medicine, and philosophy to be translated 

 from the Greek, and founded in Bagdad a kind of academy called 

 the "House of Science," with a library and an observatory. 



ARABIAN MATHEMATICAL SCIENCE. While the Arabs them- 

 selves were not in general much addicted to scientific pursuits, 

 their relations to the Greeks and Hindus, and subsequently to the 

 nations of western Europe are of very great importance in the 

 history of science. Even if we accept as typical the traditional 

 dictum attributed to the Caliph Omar, that whatever in the library 

 of Alexandria agreed with the Koran was superfluous, whatever 

 disagreed was worse, and all should therefore be destroyed, it was 



