THE ROYAL ARTILLERY INSTITUTION. 
373 
nearest to that of the sliot whose loss of velocity is required. So .that 
if some of the guns for which tables have been prepared should be 
abandoned, the' tables might still be of use. But to facilitate calcu¬ 
lations respecting tbe powers of any other guns, General Tables have 
been prepared for both spherical and elongated ogival-lieaded shot. 
Use of the Tables for calculating the remaining Velocity. —The elon¬ 
gated shot are in general supposed to start with a velocity of 1700 
f.s., and the spherical shot with a velocity of 2100 f.s., and the cal¬ 
culations are continued till the velocities are reduced to 1000 or 900 
f.s., because the coefficients of resistance have been accurately deter¬ 
mined within those limits. It is not, however, intended that the 
full extent of the table should be used on any one occasion, but only 
so much as corresponds to ranges which the shot may be supposed 
to describe approximately in a straight line. Any velocity within the 
limits of the table may be supposed to be the initial velocity. For 
instance, suppose the initial velocity of a 9-inch elongated shot be 
1310 f.s.; this is found in Table 9, opposite 5700 feet in the distance 
column. Let it be required to find the loss of velocity in 1000 yards 
= 3000 feet. Adding 3000 to 5700 the distance opposite the given 
initial velocity, we obtain 8700, and opposite this number in the 
distance column we find 1153 f.s., so that the loss of velocity in 
1000 yards = 1310 — 1153 = 157 f.s. If the given initial velocity be 
not exactly found in the table a little calculation is required. Thus 
suppose that in the above case the given initial velocity had been 
1300 f.s., by proportional parts it is found that the shot would have 
a velocity of 1300 f.s. at a distance 5867 feet, and adding 3000 to 
this, we get 8867, and the velocity at this distance = 1145, and the 
loss of velocity in 1000 yards would be 1300 — 1145 = 155 f.s. It 
may be remarked that in simple cases of this kind it will suffice to 
adopt the velocity nearest to the given velocity. In this case it 
would be 1298 opposite 5900 in the distance column, and adding 
3000 as before, we obtain 8900, and opposite this number in the 
distance column we get 1144. So that the loss of velocity in 1000 
yards = 1298—1144= 154 f.s. If the initial velocity be supposed 
1310 f.s., as before, opposite this we find 3 // *830 in the column t , 
and 2973 in the column E ; and adding 3000 to 5700 we get 8700, 
opposite which in the distance column we find 1153 in the column 
v, and 6 //# 277 in the column t, and 2305 in the column E. So that 
the time of flight=6"*2 77 ~^-3 //a 830 = 2 // *447, and the loss of energy 
= 2973—2305 = 668 foot-tons. 
Suppose it to be required to find with what velocity a 7001b. 
elongated shot, 11*52 inches in diameter, fired with an initial ve¬ 
locity of 1400 f.s. would strike an object at a distance of 500 yards 
= 1500 feet. Turning to Table 6, we find the velocity 1400 f.s. 
opposite 7100 feet in the distance column, to which, adding 
1500 feet, we obtain 8600 feet. Opposite 8600 feet in the distance 
column we find 1344 f.s. for the striking velocity. The energy of 
the shot on striking would =8768, and the time of flight = 5"*699 — 
4 // *606 = l"*093. The energy lost in 500 yards = 9518— 8768= 750 
