372 
MINUTES OF PROCEEDINGS OF 
Tables of values of t made for a given value of d 2 -+-w apply equally 
well to all other shot of similar form which, have the same value of 
d 2 -i-w. 
Calculation of Energy. —The numbers in the columns headed E 
denote the energy of the shot moving with the velocity placed oppo¬ 
site. E equals one-half of the vis viva of the shot due to translation 
= iyt? 2 H-448(k/. The numerical values of E denote that if a shot 
struck an object which opposed a uniform resistance of E tons to the 
shot, it would penetrate one foot before it was brought to rest. If 
the uniform resistance opposed to the shot’s motion was J E tons, 
then it would penetrate just two feet. If the uniform resistance was 
E-i -n tons then the shot would penetrate n feet. And generally if 
the shot penetrated a medium which opposed a uniform resistance of 
P tons, it would penetrate m feet, so that E =mxP. The energy of 
the shot due to rotation is usually neglected, as being small com¬ 
pared with the energy due to translation. It also probably con¬ 
tinues nearly constant during the flight of the shot. As the energy 
of a shot depends upon its weight and velocity, it is plain that the 
numbers in column E will be the energy of a shot of equal weight of 
any form when moving with the velocity placed opposite. Thus, 
referring to Table 7, 5503 will be the energy of a 6001b. shot of any 
form when moving with a velocity of 1150 f.s. Also 2652 is the 
energy of a 2501b. shot of any form when moving with a velocity 
1237 f.s. Strictly speaking, these tables of values of v and t are 
calculated on the supposition that the shot, having been projected, 
is acted upon by the resistance of the air alone, and is therefore not 
drawn out of the straight line by the action of gravity. When, 
therefore, the initial velocity of the shot is high, and the angle of 
elevation of the gun is not great, as in attempts to pierce iron 
plates, the following tables will be applicable for ranges of 1000, 
2000, or 3000 yards, according to the weight of shot. But if the 
elevation of the gun be considerable, and the path of the shot much 
curved, the following tables will only serve to give a general idea of 
the comparative powers of different guns and projectiles. In the 
case of vertical fire and long ranges recourse must be bad to other 
and more extensive tables, which are in preparation, and to calcula¬ 
tions which require considerable mathematical knowledge. But the 
following tables may be used with great facility and profit by all 
artillery officers and by many non-commissioned officers. 
These extended tables have been adapted, as far as possible, to 
guns permanently in the service or likely to be adopted. It is, how¬ 
ever, already contemplated to bore out the ll*6-inch gun to make it 
a 12-inch gun. Also it is urged that a bore of 3*6 inches is too large 
for a shot of 161bs., and that a bore of 3*3 or 3*4 inches would be 
more in accordance with the rules which govern the service bores 
and shot. It has been already pointed out that in the following 
tables the columns v and t apply exactly to all other shot of similar 
forms which have the same value of d?-+-w. Often, for a limited range, 
in such cases it will suffice to take the table having the value d 2 -v-w 
