8 Wilde, Moving Force of Terrestrial and Celestial Bodies. 



correlatively equal they are expressed by the same 

 numbers and their reciprocals, Mercury = rooo, and 



Neptune = ^ ^0'000i6,as in the similar calculus of the 

 6020 



moving and attractive forces of the moon during its 

 orbital revolution. 



17. The planetary distances in radii of that of Mercury 

 may be taken as astronomically correct, as they are 

 derived from the periodic times ; but the numerical 

 expression of them in miles is necessarily only a near 

 approximation, from the fact that the value of the unit of 

 distance has not }'ct been exactly determined. Accepting, 

 provisionally, the unit distance of Mercury to be 35,860,000 

 miles, we have for the mean distance of the Earth from 

 the Sun, 2-583x35,860,000 = 92,626,380 miles, and of 

 Neptune, 77-59x35,860,000=2,782,377,400 miles. In like 

 manner the intermediate planetary distances in miles may 

 also be determined. 



