OUTLINES OF NATURAL PHILOSOPHY. 



b. The quantity and direction of these motions, as 

 determined by the theory of gravity, agree entire- 

 ly with the results of observation. 



268. Mercury is so near the Sun, that his 

 place in his orbit is not sensibly affected by the 

 action of the other planets ; but his orbit is ne- 

 vertheless disturbed, both in its form and posi- 

 tion. 



a. The disturbances of the four elements of the orbit 

 are as in the following Table, where, instead of the 

 secular change of the eccentricity, that of the great- 

 est equation of the centre is set down. The first 

 column gives the planet, to which the disturbances 

 opposite to it in the succeeding columns are to be 

 ascribed ; the second is the annual motion of the 

 nodes ; the third of the apsides, both in respect 

 of the fixed stars ; the fourth contains the secular 

 variations of the inclination ; the fifth those of 

 the greatest equation of the centre. 



The 



