THE ROYAL ARTILLERY INSTITUTION. 
221 
Ordnance. 
Charge. 
Projectile. 
Initial 
velocity. 
Weight. 
Diameter. 
Britten’s (32-pr. rifled) . 
lbs. 
5 
"9 
10 
lbs. 
50-36 
41-25 
68-40 
68-56 
74-60 
68-56 
in. 
6-24 
4.75 
6-4 
{r 3 } 
6-4 
1209 
1197 
1283 
1132 
1271 
1199 
Armstrong's 40-pr. 
a 3-grooved shunt ...... 
Whitworth’s 70-pr. 
Armstrong’s 70-pr... 
Whitworth’s 70-pr... 
Mr Whitworth and his admirers have constantly asserted that his small¬ 
bore gives a flatter trajectory than the larger bores chosen by Armstrong, 
Britten, and others. This is, however, not the case under all circumstances, 
and arose partly from the fact of the Whitworth guns first tried, being fired 
with charges of ^ of the weight of the projectile, whereas the greater number 
of other rifled guns used charges of only i or -fo, Mr Whitworth is quite 
right to use as large a charge as he can, but this must be taken into account 
in drawing comparisons. In practice from two rifled guns of different 
calibres, but firing projectiles of the same weight with equal charges, the 
large bore will give a lower trajectory for a short range than the small bore, 
but at long ranges the small bore will give the lower trajectory. Tor the 
larger bore will give the higher I.Y., and therefore up to a certain range the 
lower trajectory; but 'as the projectile with the smaller diameter is less 
retarded, its trajectory will gradually become lower, as compared with the 
other, until beyond a certain range the smaller bore will give the lower 
trajectory. Small bores have found little favour on the continent, and it is 
for the authorities to demand either a large or a small bore, as circumstances 
may require. 
The following conditions are requisite in any rifled gun to ensure accuracy 
of fire:—a rotatory motion must be given to the projectile round an axis 
parallel to, or coincident with, that of the bore; the axis of the shot must be 
stable on leaving the bore; and the velocity of rotation imparted to the 
projectile must be sufficient to counteract the pressure of the air tending to 
turn the shot over or render it unsteady in flight. 
Great numbers of rifled guns with projectiles to correspond have been 
proposed, but most of the systems of rifling that have been adopted by any 
service, or tried on the practice-ground, may be divided into the following 
classes:— 
(1) Muzzle or breech-loading guns having projectiles of iron fitting the 
peculiar form of the bore mechanically. 
(2) Muzzle-loading guns, with projectiles having soft metal studs, or 
ribs to fit the grooves. 
(B) Muzzle-loading guns, with projectiles having a soft metal envelope, 
coating, or cup, which is expanded by the gas in the bore, 
