jxS: Mr. Thompson^ Experiments 
The agreement between the actual and computed velocities 
is here very remarkable, and particularly in the five firft expe- 
riments, which are certainly thofe upon which the greateft 
dependence may be placed. 
And hence we are enabled to determine the natures- of the 
- 
inn, and gf (fig. for fince B (which exprefles the weight 
of the bullet), is as the length taken from A towards B in the* 
figure in the feveral experiments and as the velocities are as 
the lines drawn perpendicular to the line AB from the places 
where thofe lengths terminate, as w, u, &c. ending at the 
curve tn,n; if we put a=l P, a: = B, and yxz wu ; then 
will the relation of x and y be defined by this equation, 
—l==r =:y. And if z be put to denote the line w r, and 
%/ a + x z 
the recoil when the given charge is fired without any bullet, it 
will be — b in the curve gf r x being the abfciffa, and. 
{ j £ iff). ‘iTf-f ■- f’-i - ^ ... ,V\ 
% 11 
z the correfponding ordinate to the curve. 
■ ! ;'1 .fiArf rj ; f. ... ' ;-Y P 
Ip the 9 id experiment half the weight of the powder ( = ^) 
iyas grains ; the weight of the bullet was 2352 grains 
( =x) ; the recoil ( = z) was 32,25 inches, and with the given 
charge Without any bullet the recoil (~^) was 4,4 inches ; if 
now from thefe data y and the known weight of the bullet in 
each of other experiments in this let, the recoil. be computed 
by means of the theorem 
b — z, we fhall fee how the 
o £ 
; ; ■ i 
\/ a + x* 
experiments agrees with this theory : thus, 
- -. 'y-/ 3 * W:: 5 /§ (, 
■ - Kt ■■ • 
9 2d. 
