LITERATURE OP THE ARABS. 107 



His idea was adopted by Copernicus ; and subse- 

 quently applied to the moon by Horoccius, Newton, 

 Flamstead, and Halley. 



Modern astronomy is indebted to the Saracens 

 for the introduction of observatories. Appended to 

 the celebrated mosque at Seville was the lofty tower 

 of the Giraldo, built under the superintendence 

 of the famous mathematician Geber (A. D. 1196), 

 which long served this purpose, and which still 

 remains one of the most noble and ancient monu- 

 ments, perhaps in Christendom, in honour of this 

 science. The learned Bailly attributes the revival 

 of astronomy to the Spanish Arabs, and the transla- 

 tions of the works of Alfragani. He affirms that 

 Kepler drew the ideas that led to his discovery of 

 the elliptical orbits of planets from Nureddin Pe- 

 trucci, whose Treatise on the Sphere is preserved in 

 the Escurial. From Lalande and Andres we learn 

 that Alfonso X., king of Castille, who has immor- 

 talized himself by his astronomical pursuits, and 

 whose Tables have contributed so much to promote 

 the knowledge of the heavenly bodies, received his 

 information chiefly from the Moors, whom his libe- 

 rality induced to settle at Toledo. 



The schools of Bagdad and Cordova did not neglect 

 the study of optics. Alfarabi, Ibn Haitim, and Al- 

 hazen, devoted their attention to this subject; but the 

 works of the two former are lost. The treatise of the 

 latter, who wrote in the twelfth century, has been 

 frequently noticed. It is cited by our distinguished 

 countryman Roger Bacon ; and was illustrated by 

 Vitellio, anati ve of Poland, who lived in the thirteenth 

 century. In mathematics, though the Saracens did 

 not ascend to the higher branches, yet in the other 



