Vital Physics. 53 



11 On the Degree of Uncertainty which Local Attrac- 

 tion, if not allowed for, occasions in the Operations of 

 Geodesy." By the Venerable J. H. Pratt, M.A., Archdeacon 

 of Calcutta, 1858 ; and again, 1863, to the Royal Society. 



In the repellent force, accumulation of force in relation to 

 mass is admitted, or that repulsion is in proportion to the mass ; 

 and that, in relation to distance, it diminishes less rapidly 

 than inversely to the square of the distance. To discuss 

 this rigidly is not attempted in the slightest in this short 

 chapter, but only the simplest illustration. If, then, heat 

 represents the repellent force in one form, few would be 

 disposed to doubt that its intensity increased in relation to 

 the mass that is burning, cceteris paribus ; but as applied 

 to the planetary system in relation to the orbital and the 

 diurnal motions, the following examples appear to bear 

 upon the present subjects. From Brand's " Dictionary of 

 Science," &c., 1852, Article " Planets" : 



The orbits of Mercury and Venus are less than that of the 

 earth, each respectively, and therefore to be nearly 24 hours 

 in rotation on the axis, or over that time, in so short an 

 orbit, shows retardation in the axoidal motion in relation to 

 the orbit. But in Mercury, in proportion to the orbit, the 

 axoidal motion is much slower than in Venus, but the mass 

 or volume is so much less ; and therefore it suffers much 



