THE ARABS. 593 



Indian influences. Atmospheric conditions merely favoured 

 that which had been called forth by mental qualifications, and 

 by the contact of highly-gifted races with more civilized neigh- 

 bouring nations. How many rainless portions of tropical 

 America, as Cumana, Coro, and Payta, enjoy a still more 

 transparent atmosphere than Egypt, Arabia, and Bockhara ! 

 A tropical sky, and the eternal clearness of the heavens, 

 radiant in stars and nebulous spots, undoubtedly every- 

 where exercise an influence on the mind, but they can 

 only lead to thought, and to the solution of mathematical pro- 

 positions, where other internal and external incitements, 

 independent of climatic relations, affect the national character, 

 and where the requirements of religious and agricultural 

 pursuits make the exact division of time a necessity prompted 

 by social conditions. Among calculating commercial nations 

 (as the Phoenicians) ; among constructive nations, partial to ar- 

 chitecture and the measurement of land (as the Chalda3ans and 

 Egyptians), empirical rules of arithmetic and geometry were 

 early discovered; but these are merely capable of preparing 

 the way for the establishment of mathematical and astrono- 

 mical science. It is only in the later phases of civilization 

 that the established regularity of the changes in the heavens 

 is known to be reflected, as it were, in terrestrial phenomena, 

 and that, in accordance with the words of our great poet, we 

 seek the " fixed pole." The conviction entertained in all 

 climates of the regularity of the planetary movements, has 

 contributed more than anything else to lead man to seek 

 similar laws of order in the moving atmosphere, in the oscil- 

 lations of the ocean, in the periodic course of the magnetic 

 needle, and in the distribution of organisms over the earth's 

 surface. 



The Arabs were in possession of planetary tables* as early 

 as the close of the eighth century. We have already ob- 

 served that the Susmta* the ancient incorporation of all the 



* On the Indian tables which Alphazari and Alkoresmi translated 

 into Arabic, see Chasles, Reclierclics sur I' Astronomic Indienne, in the 

 Comptes rendus des Seances de I' A cad. des Sciences, t. xxiii. 1846, pp. 

 846-850. The substitution of the sine for the arc, which is usually 

 ascribed to Albategnius, in the beginning of the tenth century, also 

 belongs originally to the Indians; tables of sines are to be found in the 

 Surya-Siddhanta. 



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