[ m J 
parts bear the greater, or Jefs preflu re * and yet this 
obdru&ion is but little attended to. The theorid 
makes no allowance on account of friction ; and the 
practical mechanician, who feels the effeds, yet, as 
if unavoidable, feldom takes the trouble of fcarching 
for a remedy. 
Amongd the few who have endeavoured to afcer- 
tain the quantity of fridtion proceeding from weight, 
fome have deemed it equal to q, others to 4, and 
others more, or lefs, according to their different me- 
thods, or accuracy in making experiments. Dodtor 
Defaguillers gives an account of fome experiments, 
which (hew the quantity of fridfion in a cylinder, to - 
be equal to 1 . of the power required to move it, 
when the furface of the cylinder moves as fad as 
the power. 
In order to examine the quantities of fridfion pro- 
ceeding from different weights, I had an exadt bal- 
ance made, which weighed 27 ounces; the pevets 
of the axis were 4. inch diameter, and turned in brafs 
fock'ets, fixed in a frame for the purpofe. 
Seven pound fufpended on each arm, at 18 inches 
diftance from the center, required 1 I ounce, 2 penny 
weight, to be applied to either end, to overcome the 
refiffance from fri&ron in the flighted degree; and 3 
ounces to carry it down 2 inches. 
Fourteen pound, applied in the fame manner, re- 
quired 3 1 ounces to move the balance; and 6 ± ounces 
to fink either end 2 inches. 
Twenty one pound required 41 ounces to give it the 
lead motion, and 7*. ounces to fink it about 2 inches. 
Seven pound, fufpended on each arm at 9 inches 
diftance from the center, required 3 ounces and _L to 
move cither end in the lead degree. 
Fourteen 
