PHYSICAL andLITERARY. 6$ 



makes it evident that the power of gra- 

 vity is continually inereafing from the 

 beginning to the end of the motion. 



In atccounting for this phsenomenon* I 

 have liegle<3:ed the njis infta^ though it 

 may probably a6l in conjundlion v^ith 

 gr^-vity in the defcent of bodies towards 

 the centre of the earth, as well as in the 

 curvilinear motion of the planets. For^ 

 if the force of gravity be fuppofed inva- 

 riable, the addition of the 'uis infttay which 

 is alfo an invariable force, wi]l only bring 

 out a greater invariable force, which c*ii 

 never produce an acceleration of motion. 

 The acceleration therefore muft be attfi^- 

 buted to gravity alone, the force of which, 

 in the beginning of the motion, is fup- 

 pofed to be lefs than any alTignable quan*- 

 tity, whereby a body, fet in motion by 

 the force of gravity, pafTes through every 

 degree of velocity, from reft till it acquires 

 that velocity which it has when it touches 

 the ground. 



I have dwelt the longer upon this pro- 

 perty of gravity, becaufe there is connec- 

 ted with it another property ; which is, 



that 



