THE ROYAL ARTILLERY INSTITUTION. 
375 
find from the General Table in what space the given velocity is lost, 
and then dividing this space by the value of d 2 w for the given shot, 
the space is found in which the given shot would lose the specified 
velocity. In this way the tables adapted for particular shot have been 
tested. In the General Table 21 for elongated shot ^ = 1400 f.s. 
corresponds to s = 1348*5 feet, and v x = 1300 f.s. corresponds to s x — 
1865 feet, and v a = 1200 f.s. corresponds to s 2 —2455 feet. Hence the 
space in which the velocity of an elongated projectile, where d?-~ 
w~ 1, would be reduced from 1400 to 1300 f.s. = 1865 —1348*5 
= 516*5 feet. Again the space in which the same shot would have 
its velocity reduced from 1300 to 1200 f.s. = 2455 —1865 = 590 feet. 
Suppose now we wished to know in what ranges the velocity of a 
6001b. ll*52-inch elongated shot would have its velocity reduced by 
the resistance of the air from 1400 to 1300 f.s. This will = 516*5 
-=-*2212 = 2335 feet. Also the velocity of the same shot would be 
reduced from 1300 to 1200 f.s. in a range of 590 -h* 2212 = 2667. 
If now we refer to Table 7, we find a velocity of 1400 f.s. opposite 
6100 feet, and 1300 f.s., about 8425 feet—showing that the velocity 
is reduced from 1400 to 1300 f.s. in a space 8425 — 6100 = 2325 feet. 
Opposite a velocity of 1200 f.s. we find in the distance column 11100, 
showing that the velocity of the shot is reduced from 1300 to 1200 f.s. 
in a distance = 11100 —8425 feet = 2675 feet. In the same manner 
all the other tables may be tested, by simply dividing 515 feet by the 
proper value of d 2 ~-w , which would give the distance in which the 
velocity of the shot would be reduced from 1400 to 1300 f.s. 
Suppose it was desired to compare the powers of a 161b. elongated 
shot of 3*52, 3*32, and 3*22 inches in diameter. The corresponding 
values of d 2 —w are *7744, *6889, and *6480. Hence the shot fired from 
the 3*6, 3*4, and 3*3-inch bores would have their velocities reduced 
from 1400 to 1300 f.s. in the ranges 516*5-^*7744 = 667 feet; 516*5 
— •6889 = 750 feet, and 516*5-=-*6480 = 797 feet respectively; and 
from 1300 to 1200 f.s. in ranges of 590-?-*7744 = 762 feet; 590 -h* 6889 
= 856 feet, and 590-f-*6480 = 911 feet respectively. Thus there is a 
fall in velocity from 1400 to 1200 f.s. for the 3*6-inch gun in a range 
of 667 + 762 = 1429 feet; for the 3*4-inch gun in a range of 750 + 
856 = 1606 feet; and for the 3*3-inch, in a range of 797 + 911 = 
1708 feet. The General Table for spherical shot is used in precisely 
the same manner. 
Suppose it be now required to find, by the use of the General 
Tables, what velocity a shot starting with a given velocity would 
lose in a certain range. First multiply the given range by the value of 
d 2 -~w to obtain a reduced range. Find, then, in the usual manner by 
the help of the proper General Table 20 or 21, what would be the 
loss of velocity in this reduced range with the given initial velocity. 
This would be the same as that which the given projectile would lose 
in the given range. For example, let an elongated projectile of 
400 lbs. be fired from a 10-inch gun with an initial velocity of 
1270 f.s., and let it be required to find what would be the velocity at 
a distance of 1000 yards = 3000 feet. Here cZ 2 h-w = *246 and the 
reduced range = 3000 x *246 = 738 feet. Referring to General Table 21, 
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