upon Gun-powder* &c. - 257 
* v == 5,672 egs/f x — ^ is Dr. hutton’s theorem, which is 
fufficiently accurate, and far more fimple. 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 muft be Engliftt 
feet, and v will be the velocity of the bullet in Englifh 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 
t,hen 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 practice. 
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 corrections neceffary 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* and 
x b . . . 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 experiment. 
The following table fhews the heights of the charges as they 
were determined by meafurement, and alfo their heights com- 
puted 
