5 72 Mr. Vince on the Motion of 
Exp. 4. A body weighing 8 oz. by a moving force of 4 oz« .. 
defcribed 33I inches in z" ; 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 inn. 
the fame time was do inches. 
Exp. 6. A body weighing 10 oz. by a moving force of 3 oz* 
defcribed 20 inches in z " ; by loading the body with 10 ozv 
and the moving force with 3 oz. the fpace defcribed in thfe fame 
time was 3 1 inches ; and by loading the body again with 30 
oz. 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 increafng the weight of the body and the 
accelerative force in the fame ratio; and as the acceleration 
arifmg from the moving force continued the fame, it is manifefh, 
that the retardation arifng from the fridtion mull have been 
diminifhed, for the whole accelerative 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, fridtion varies as 
Quantity of fnftion \ ^ quantity of trillion increafes in a lefs ratio 
Quantity ot matter J 7 y 
than the quantity of matter or weight of the body. 
6. We come now to the laid thing which it was propofed to 
determine, that is, whether the friction vanes by varying the fur- 
face on which the body moves. Let us call two of the surfaces 
A and d, the former being the greater, and the latter the lefs. 
Now the weight on every given part of d is as much greater 
o than 
i 
