JS^ REMARKS on the 



could be made in an Indian calculation, is a degree of accuracy 

 that nothing but adtual obfervation could have produced. 



25. To confirm this conclufion, M.Bailly computes the place 

 of the moon for the fame epoch, by all the tables to which the 

 Indian aflronomers can be fuppofed to have ever had accefs *. 

 He begins with the tables of Ptolemy ; and if, by help 

 of them, we go back from the era of Nabonassar, to the 

 epoch of the Calyougham, taking into account the compa- 

 rative length of the Egyptian and Indian years, together with 

 the difference of meridians between Alexandria and Tirvalore, 

 we fliall find the longitude of the fun 10°, 21', 15" greater, 

 and that of the moon 11°, 52', 7" greater than has jufl been 

 found from the Indian tables f . At the fame time that this, 

 fliews, how difficult it is to go back, even for a lefs period than 

 that of 3000 years, in an aftronomical computation, it affords a 

 proof, altogether demonftrative, that the Indian aftronomy is 

 not derived from that of Ptolemy. 



The tables of Ulugh Beig are more accurate than thofe 

 of the Egyptian aftronomer. They were conflrudled in a coun- 

 try not far from India, and but a few years eailier than 1491, 

 the epoch of the tables of Chrifnabouram, Their date is 

 July 4. at noon, 1437, at Samarcand ; and yet they do not 

 agree with the Indian tables, even at the above mentioned epoch 

 of 1491 X- ^^^> f°'" ^^^^ year 31C2 before Christ, their dif- 

 ference from them, in the place of the fun, is 1°, 30', and in 

 that of the moon 6° ; which, though much lefs than the for^ 

 mer differences, are fvifScient to fliow, that the tables of India 

 are not borrowed from thofe of Tartary. 



The Arabians employed in their tables the mean rnotions of 

 Ptolemy ; the Perfians did the fame, both in the more ancient 

 tables of Chrysococca, and the later ones of Nassjueddjn ||. Jc 



is.. 



* Aft. Ind. p. 11.4. 

 + Ibid. p. iij. 

 X Ibid. p. 117. 

 II Ibid. p. 118, 



