32 On the Mot wn of Bodies affected lij Friction. 



pcriments were therefore made in order to ascerta'm this 

 matter. 



Exp. 1. A body weighing 10 oz. Ir/ a movinc; force of 

 4 oz. described in 2" a space ot 51 inches; l)y loading the 

 body with 10 oz. and the moving force with 4 oz. it (le- 

 scribcd 56 inches in \l" ; and by loading the body again with 

 10 oz. and the niovinsr force with 4 oz. it described 63 

 luetics in 2 . 



Exp. 2. A bodv, whose weight was 15 oz. bv a moving 



force of 5 oz, described a space oH 4 9 inclies in 3" ; and by 



loading the body v/ith 64 oz. and the moving force witl-^ 



20 oz. ibtj space described in the same time was (H^hrce of 



Exp. 3. A bodv weighing 6 oz. by a iKftmrg the body 



2i oz. described 2S inches m 2"; an'\6 oz. the space de- 



with 24 oz. and the moving fo* inches^ 



scribed in the same tiuViUig S oz. by a moving force of 4 



Exp. 4. A bo^*- inches in 2"; and bv loading the body 



oz. descrihmd the moving force with 4 oz. the space dc- 



withJ"in the same time was 47 inches. 



"Exp. 5. A body whose weioht was 9 oz. bv a moving 



force of 42 oz. described AH inches in 2^'; and by loading 



the bodv with 9 oz. and the moving force with 4^ oz. the 



space described in the same time was 60 inches. 



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

 oz. described 20 inches in 2"; bv loading the body with 10 

 oz. and the moving force with 3 oz. tlie space described in 

 the same time was 31 inches; and bv loading the body again 

 with 30 oz. and the moving force with 9 oz. the space de- 

 scribed was 34 inches in 2". 



From these experiments, and many others which it is not 

 necessary here to relate, it appears that the space described 

 is always increased bv increasing the weiiiht of tlie body 

 ind the accelerativc force in the same ratio : and as the ac- 

 celeration arising from the moving force continued the 

 same, it is manifest that the retardation arising I'rom the 

 friction must have been diminished ; for the whole aceele- 

 rative force must have been increased on accoimt of the in- 

 crease of the space described in the same time ; and hence, 



, , , • ,. ,. • • • OiKintitv of friction \ 



(as the retardation irom iriction varies as -. '- , J 



Ouaiitity of matter/ 



the q7tantitij of frlctivn increases in a less ratio than the 

 quantity of matter or iceitjht of the body. 



6. Wt: coiiie now to the last thing which it was proposed 

 tn determine, tlut is, whether the friction varies by varying 

 tiw surface on which the body moves. Let us call t\\o of 



the 



