i 5 2 REMJRKS on the 



through vanity or fu perdition, they have referred the places of 

 the heavenly bodies, and have only calculated what they pre- 

 tend that their ancedors obferved. 



21. In doing this, however, the Brahmins mud have fur- 

 nifhed us with means, almoft infallible, of detecting their im- 

 podure. It is only for aftronomy, in its mod perfect date, to 

 go back to the didance of forty-fix centuries, and to afcertain 

 the fituation of the heavenly bodies at fo remote a period. 

 The modern adronomy of Europe, with all the accuracy that it 

 derives from the telefcope and the pendulum, could not venture 

 on fo difficult a talk, were it not aflided by the theory of gra- 

 vitation, and had not the integral calculus, after an hundred 

 years of almod continual improvement, been able, at lad, to 

 determine the didurbances in our fydem, which arife from the 

 action of the planets on one another. 



Unless the corrections for thefe didurbances be taken into 

 account, any fydem of adronomical tables, however accurate 

 at the time of its formation, and however diligently copied 

 from the heavens, will be found lefs exact for every indant, ei- 

 ther before or after that time, and will continually diverge 

 more and more from the truth, both for future and pad ages. 

 Indeed, this will happen, not only from the neglect of thefe 

 corrections, but alfo from the fmall errors unavoidably com- 

 mitted, in determining the mean motions, which mud ac- 

 cumulate with the time, and produce an effect that be- 

 comes every day more fenfible, as we retire, on either fide, 

 from the indant of obfervation. For both thefe reafons, it 

 may be edablifhed as a maxim, that, if there be given a fydem 

 of adronomical tables, founded on obfervations of an unknown 

 date, that date may be found, by taking the time when the 

 tables reprefent the celedial motions mod exactly. 



Here, therefore, we have a criterion, by which we are to 

 judge of the pretenfions of the Indian adronomy to fo great an- 

 tiquity. It is true, that, in applying it, we mud fuppofe our 



modern 



