48 
MINUTES OF PROCEEDINGS OF 
generally available; and in comparing one system with another it is 
absolutely necessary that certain conditions should be made common to 
both. Tor instance* in considering the smooth-bore and rifle systems* due 
advantage must be taken* in both cases* of the most approved method of 
manufacturing the guns ; also* the weights and recoil of the guns* as well 
as the strain or rather tendency to rupture the material of the guns at the 
discharge must be made equal. 
Now*—will anything be gained under the above conditions by applying, 
in the case in question* the principle followed in all rifle guns (a principle 
upon which their success has been hitherto chiefly owing) of using elon¬ 
gated shot with a reduction in the charge of powder equivalent to the 
increased strain and recoil due to the additional weight of projectile ? 
This question, and it is a very important one* must be viewed entirely with 
reference to the “ work ” required to be done to penetrate or destroy the 
protecting shield. 
The term “work done” denotes a certain pressure exerted through a 
certain distance. It is measured simply by the product of the pressure and 
the distance through which this pressure acts. The element time does not 
necessarily enter into the expression. 
In the case under consideration, the “ work done ” upon the shot at the 
discharge of the gun is measured* 
(1) By the intensity of the pressure of the exploded powder; 
(2) By the amount of sectional area of shot upon which the pressure acts* 
and 
(3) By the distance through which the pressure acts* namely* the length 
of bore* or nearly so. 
So that in order that the same amount of “ work 33 may be done on the 
elongated projectile as on the spherical shot* they must both be fired with 
equal charges. And* speaking generally* provided equal charges are used and 
the conditions as regards diameter of bore* windage* &c. are the same* no 
increase or diminution of “ work done ” on the shot will result from any 
variation in the weight of projectile. 
But* by a fundamental principle of mechanics* the work done upon the 
opposing shield and shot on impact, will be equal to the work done on the 
projectile by the charge of powder in the gun* (leaving out of account the 
resistance of the air* which may be done when the range is short); therefore, 
in order to produce the same effect as regards “ work ” upon the opposing 
shield* apart from other considerations which will be noticed hereafter* the 
elongated rifle shot must be fired with the same charge as the spherical 
projectile. 
If the same charge* however* be used with the elongated shot as with the 
spherical* namely, 50 lbs.* the recoil of the gun* as well as the strain 
tending to rupture the gun will exceed the limits allowed in the particular 
case before us. For both recoil and strain depend directly on the momentum 
of the shot and not upon the “ work done 33 to produce that momentum. In 
fact* time which affects both recoil and strain does not necessarily enter into 
