152 REMJRKS on the 



through vanity or fuperftition, they have referred the places of 

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

 tend that their anceftors obferved. 



21. In doing this, hovpever, the Brahmins muft have fur- 

 niflied us with means, almofl infallible, of detedling their im- 

 pofture. It is only for aftronomy, in its mofl: perfedl (late, to 

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

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

 The modern aftronomy of Europe, with all the accuracy tliat it 

 derives from the telefcope and the pendulum, could not venture 

 on fo diiHcult a tafk, were it not aflifled by the theory of gra- 

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

 years of almofl continual improvement, been able, at lafl, to 

 determine the diflurbances in our fyftem, which arife from the 

 adlion of the planets on one another. 



Unless the corredlions for thefe diflurbances be taken into 

 account, any fyflem of aflronomical tables, however accurate 

 at the time of its formation, and however diligently copied 

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

 ther before or after that time, and will continually diverge 

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

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

 corredlions, but alfo from the fmall errors unavoidably com- 

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

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

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

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

 may be eflabliflicd as a maxim, that, if there be given a fyflem 

 of aflronomical tables, founded on obfervations of an unknown 

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

 tables reprefent the celeflial motions mofl exa<5lly. 



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

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

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



modern 



