7^2 , ^ Mr.Yi^cE, on the Motio7iof ' 



Exp. 4. A body weighing 8 oz. by a moving force of 4 oz»l 

 rIcTcribed 33! inches in 2'^; and by loading the body with 8 

 ozc and the moving force with 4 oz. the fpace deferibed in. the- 

 fame time was 47 inches, 



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

 4^ oz. deferibed 48 inches In i'^ ; and by loading the body with- 

 9 oz. and tiie moving force with 4I oz. the fpace deferibed iu: 

 the fame time was 60 inches. 



Exp. 6, A body weighing 10 oz, by a moving force of 3 oz. 

 deferibed 20 inches in z'' \ by loading the body with 10 oz; 

 and the moving force with 3 oz. the fpace deferibed in the fame 

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

 oz. and the moving force with 9 oz.the fpace deferibed was 

 34 inches in z'\ 



From thefe experiments, and" many others which it is notr 

 neceiTary here to relate, it appears, that the fpace deferibed is 

 aHvays increafed by increafmg the weight of the body and the 

 j^ccelerative force in the fame ratio ; and" as the acceleratloa 

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

 that the retardation arifing from the fridion muft have beea 

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

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

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



Qiwntity of friftion \ 7 . ^,.^. . f. • in ^' 



~ : — —. A the Quantity of friction increa es m a lefs ratio 



Quantity ot matter J t^ y ^ <^ -J ./ 



t^m the quantity of matter or iveight of the body. 



6. We came now to the laH: thing which it was propofed to 

 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 lefs. 

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

 2 than 



