OF THE UNIVERSE. THE ARABIANS. 225 



the foundation of theoretical astronomy, and to a correct 

 view of the motions of the heavenly bodies in space. The 

 light kindled in the part of Asia inhabited by Tatar nations 

 extended in the fifteenth century to the westward as far as 

 Samarcand, where Ulugh Beig a descendant of Timour 

 established an astronomical observatory, and a gymnasium 

 of the class of the Alexandrian Museum, and caused a 

 star catalogue to be prepared founded entirely on new and 

 independent observations. ( 354 ) 



Besides the tribute of praise which we have here paid to 

 the advances made by the Arabians in the knowledge of 

 nature, both in the terrestrial and celestial spheres, we have 

 still to allude to the additions which, in the solitary paths 

 of the development of ideas, they made to the treasury of 

 pure mathematical knowledge. According to the most 

 recent works written in England, Prance, and Germany ( 355 ) 

 on the history of mathematics, the algebra of the Arabians 

 is to be regarded as " having originated from the confluence 

 of two streams whicli had long flowed independently of 

 each other, one Indian and one Greek/' The compendium 

 of algebra written by the command of the Caliph Al-Mamun 

 by the Arabian mathematician Mahommed Ben-Musa (the 

 Chowarezmian) is based, as my deceased learned friend 

 Friedrich Rosen has shewn, ( 356 ) not on the works of Diophan- 

 tus, but on Indian knowledge ; and even as early as under 

 Almansor at the end of the eighth century Indian astrono- 

 mers were called to the brilliant court of the Abas- 

 sides. According to Castri and to Colebrooke, Diophantus 

 was not translated into Arabic until the end of the tenth 

 century by Abul-Wefa Buzjani. The Arabians were in- 

 debted to the Alexandrian school for that which we miss in 



