upon Gun-powder, &c. 25 j 
v — egsjf x ? *> is Dr., hutton’s theorem, which is 
t o 
fufficiently accurate, and far more dimple and expeditious than: 
either of the preceding. It is to be remembered, that g, h, 
and c, may be expreffed in any meafure ; but f mu ft be Engliftv 
feet, and v will he the velocity of the bullet in Engiilh feet in 
a fecond.. 
The velocities of the bullets in moft of the foregoing expe- 
riments were firft computed by euler’s method, as I had not 
then feen Dr. hutton’s paper ; but in going over the calcula- 
tions a fecond time, I made ufe of Dr. .hutton’s theorem. 
Both thefe methods gave the fame velocity very nearly, but the 
Doctor’s method is by much the eafieft in pradlice. 
In thefe computations care was taken to make a proper allow- 
ance for the bullets that were lodged in the pendulum, and alfo 
for the velocity loft, by the bullet in palling through the fcreen. 
The corredtionsmeceftary on account of the bullets lodged in, 
the pendulum were made in the following manner.. 
b was continually added to the value of P, 
x b to the value of g 9 and 
f— h 
d-y- x $ * v . to the value of f. 
Of the /paces occupied by the' different charges of powder. - 
The heights of the charges' of powder, or the lengths of 
the fpaces which they occupied in the bore, were determined 
by meafurement ; and: in order, that this might be done with 
greater accuracy, inches and : tenths of inches were marked' 
upon the ram-rod,, and the charge was gently forced down till it 
occupied the fame fpace in each experiments 
The following table fhews the heights of the charges as they 
were, determined by meafurement, and alfo their heights com- 
puted 
