244 THE GREEK ASTRONOMY. 



processes, received considerable improvements at 

 their hands. In the former, especially, they ren- 

 dered a service to the world which it is difficult 

 to estimate too highly, in abolishing the cumbrous 

 Sexagesimal Arithmetic of the Greeks, and intro- 

 ducing the notation by means of the digits 1, 2, 3, 

 4, 5, 6, 7, 8, 9, 0, which we now employ* 2 . These 

 numerals appear to be of Indian origin, as is 

 acknowledged by the Arabs themselves ; and thus 

 form no exception to the sterility of the Arabian 

 genius as to great scientific inventions. Another 

 improvement, of a subordinate kind, but of great 

 utility, was Arabian, being made by Albategnius. 

 He introduced into calculation the sine, or half- 

 chord of the double arc, instead of the chord of 

 the arc itself, which had been employed by the 

 Greek astronomers. There have been various con- 

 jectures concerning the origin of the word sine; 

 the most probable appears to be that sinus is the 

 Latin translation of the Arabic word gib, which 

 signifies a fold, the two halves of the chord being 

 conceived to be folded together. 



The great obligation which Science owes to the 

 Arabians, is to have preserved it during a period 

 of darkness and desolation, so that Europe might 

 receive it back again when the evil days were 

 past. We shall see hereafter how differently the 

 European intellect dealt with this hereditary trea- 

 sure when once recovered. 



4i Mont. i. 376. 



