1^2 Mr. \ ijsCE, on the Motion ef' 



ExF. 4, A body weighing 8 oz. by a moving force of 4 oZo 

 defcribed 33I inches in 2'^; and by loading the body with 8 

 oz. and the moving force with 4 oz. the fpace defcribed in the 

 fame time was 47 inches. 



Exp. 5. A body whofe weight was 9 oz. by a moving force of-" 

 4I oz. defcribed 48 inches in 2^^; and by loading the body with. 

 9 oz. and the moving force with 4i oz. the fpace defcribed in 

 the fame time was 60 inches. 



Exp. 6. A body weighing 10 oz. by amoving force of 3 oz. 

 defcribed 20 inches in 2/'', by loading the body with 10 oz.. 

 and the moving force with 3 oz. the fpace defcribed in the fame- 

 time was 31 inches ; and by loading the body again with 30- 

 Qz. and the moving force with 9, oz. the fpace defcribed was. 

 34 inches in z^/. 



From thefe experiments, and many others which it Is not 

 neceflary here to relate, it appears, that the fpace defcribed is 

 always increafed by increafing the weight of the body and the 

 acceleratlve force in the fame ratio; and as the accelerationr 

 ariiing from the moving force continued the fame, it is manifeft, 

 that the retardation arifing from the fridion muft have beenr 

 diminifhed, for the whole acceleratlve force muft have been in- 

 creafed on account of the increafe of the fpace defcribed in the 

 fame time ; and hence (as the retardation from friction varies as 



Quantity of friftion \ ,-, .. r r 'ct' • r • r r u' 



~ — T^ — ^ the quantity of fnciton increales m a lejs ratio 



Quantity ot matter J i ^ ^ -^ -^ -^ 



than the quantity of matter or weight of the body. 



6. We come now to the laft thing which it was propofed ta 

 determine, that is, whether the fri£lion varies by varying the fur- 

 face on which the body moves. Let us call two of the furfaces 

 A and ^, the former being the greater, and the latter the lels. 

 Now the weight on every given part of a is as much greater 

 2 than 



