170 REMJRKS on the 



aftronomers muft have fuppofed invariable, and of which, had 

 they fuppofed them to change, they had no rules to go by for 

 afcertaining the variations ; (ince, to the difcovery of thefe 

 rules is required, not only all the perfection to which aftro- 

 nomy is, at this day, brought in Europe, but all that which 

 the fciences of motion and of extenfion have likewife attained. 

 It is no lefs clear, that thefe coincidences are not the work 

 of accident ; for it will fcarcely be fuppofed that chance has 

 adjufted the errors of the Indian aftronomy with fuch Angu- 

 lar felicity, that obfervers, who could not difcover the true 

 flate of the heavens, at the age in which they lived, have fuc- 

 ceeded in defcribing one which took place feveral thoufand 

 years before they were born. 



44. The argument, however, which regards the originality 

 of thefe tables, is, in fome meafure, incomplete, till we have 

 confidered the geometrical principles which have been employed 

 in their conftruction. For it is not impomble, that when feen 

 connected by thofe principles, and united into general theo- 

 rems, they may be found to have relations to the Greek aftro- 

 nomy, which did not appear, when the parts were examined 

 fingly. On this fubject, therefore, I am now to offer a few ob- 

 fervations. 



45. The rules by which the phenomena of eclipfes' are de- 

 duced from the places of the fun and moon, have the moft 

 immediate reference to geometry ; and of thefe rules, as found 

 among the Brahmins of Tirvalore, M. le Gen til has given 

 a full account, in the Memoir that has been fo often quoted. 

 We have alfo an account of the method of calculation ufed at 

 Chrifnabouram by Father du Champ*. 



It is a neceffary preparation, in both of thefe, to find the time 

 of the fun's continuance above the horizon, at the place and the 

 day for which the calculation of an eclipfe is made, and the rule by 

 which the Brahmins refolve this problem, is extremely fimple 



and 



* Aft. Ind. p. 355, &c. 



