On the Precession of the Equinoxes, 325 



As the Moon has more effect upon the Earth th;?n the 

 Sun has, and especially upon the Equatorial ring, it is prob- 

 able, that the variation of the Ecliptick angle, and the con- 

 sequent nutation of the Earth's poles are occasioned by it. 

 But it will readilj' be seen, that this effect must be very ir- 

 regular, and could result in nothing like the annual preces- 

 sion of the Equinoxes. 



How far these objections affect the prevailing theory, 1 

 leave for others to judge. They certainly render it ob- 

 scure, and until some of them are removed, 1 shall be dis- 

 posed to give credence to the following simple, consistent, 

 and interesting theory. 



The precession of the Equinoxes is caused by the revo- 

 lution of the Solar System round a distant centre. 



In fig. 3, pi. 3, letC be the grand centre, around which the 

 Solar System revolves ; A P L the orbis mundorum, or a 

 portion of the circle of this revolution ; S a fixed star, and 

 E L V the Ecliptick. 



When the earth is at the first of aries E, let a spectator 

 view the Star S carefully noting its position ; and if the 

 system did not move, while the earth was performing one 

 annual revolution, the star would appear in the same posi- 

 tion again when he arrived at the first of aries. But while 

 the Earth is performing one annual revolution in the direc- 

 tion ELY the system moves from O to P ; so that in 

 relation to the Sun the revolution is completed at R, and 

 R N T may now represent the Ecliptick. But the po- 

 sition of the Star S is different when seen from R, from 

 what it was, when seen from E : of course the earth must 

 move from R to E to complete the siderial year, and the 

 distance R E or O P is the precession of the Equinoxes, 

 or the difference between the Solar and Siderial year. 

 Since, therefore, no other satisfactory reason can be given 

 for this phenomenon, and such a revolution appears very 

 probable from analogy, the precession of the Equinoxes is 

 a strong proof of the revolution. 



Corollary 1. The Solar System revolves from west to 

 east, like the Earth in its orbit : for if it revolved the oth- 

 er way it would produce an effect contrary to that of the 

 precession. 



Corollary 2. This revolution affects all the bodies in the 

 solar system ; and the discovery of its effect upon any one 

 of them, would be an additional confirmation of this theory. 



