ill the Solar Sjjstein. 

 '2d Supposition. 



29 



From the comparison of these results with those procured 

 from observation, I am induced to give the preference to the 

 latter supposition, or to suppose that the mass of Mercury is 

 very incondderable : the errors of the second hypothesis are ; 

 for Mercury's aphelion and node, +"-98 and —"-79; forMars's, 

 2"-53 and —"-71 ; lor Venus's, Jupiter's, and Saturn's nodes, 

 + r'-37, 2"-5, and —"-06 respectively, which are at least as 

 trifling as the nature of the subject will admit of. As the 

 mass of Mercury can only be determined from its effect on 

 the motion of Venus's perihelion, I am at present engaged in 

 determinino- the elements of her orbit from some observations 

 in my possession, which I think will enable me to determine 

 the motion with considerable accuracy. In the mean time 

 I may state that, from using jo onoD a"^ ToTTg^T f^r the 

 masses of Venus and Mars, most of the annual changes of the 

 orbits of the planets are deduced with as great accuracy as 

 from Laplace's, and some of them with greater. 



The change in the obliquity from each hypothesis is 

 Mercury -00861 -00000 



Venus -22581 -23796 



Mars -02149 -01794 



Jupiter -15764 -15764 



Saturn -01304 -01304 



Georgian ;00009 -00009 



^2667 -42667 



The inclinations of their orbits to the ecliptic are subject 

 to the following changes: Mercin-y "-158, Venus "-019, Mars 

 -"•050, Jupiter -"-190, Saturn -"-106 and the Georgian 



"-023. 



V. Answer 



