i66 REMARKS on the 



•or geocentric place, 8cc. would difcover the leading ideas of the 

 Copernican fyftem, were no other defcription of it preferved. 



37. In the manner of applying thefe two inequalities, to cor- 

 re6l the mean place of a planet, the rules of this aftronomy 

 are altogether lingular. In the cafe of a fuperior planet, they 

 do not make ufe of the mean anomaly, as the argument for 

 finding out the equation manda, but of that anomaly, when 

 corredled firft by half the equation fchigram, and afterwards 

 by half the equation manda *. By the equation of the centre, 

 obtained with this argument, the mean longitude of the planet 

 is corredled, and its true heliocentric place confequently found, 

 to which there is again applied the parallax of the annual orbit, 

 that the geocentric place may be obtained. The only difficulty 

 here, is in the method of taking out from the tables the equa- 

 tion to the centre. It is evidently meant for avoiding fome 

 inaccuracy, which was apprehended from a more dired method 

 of calculation, but of which, even after the ingenious remarks 

 of M. Bailly, it feems impoffible to give any clear and fatis- 

 fadory account. 



38. The manner of calculating the places of the inferior 

 planets has a great refemblance to the former ; with this differ- 

 ence, however, that the equation manda, or of the centre, is 

 applied to corredl, not the mean place of the planet, but the 

 mean place of the fun ; and to this laft, when fo corre<Sed, is 

 applied the QqyxaXion fchigram, which involves the planet's elon- 

 gation from the fun, and gives its geocentric place f . This 

 neceffarily implies, that the centre, about which the inferior 

 planets revolve, has the fame apparent mean motion with the 

 fun : but whether it be a point really different from the fun, or 

 the fame ; and, if the fame, whether it be in motion or at refl, 

 are left entirely undetermined, and we know not, whether, 

 in the aftronomy of India, we have here difcovered a refem- 

 blance 



* Aft. Ind. p. 194. 

 \- Ibid. p. 199, &c. 



