ARMOUR AND ITS ATTACK BY ORDNANCE. 
160 
1813 f.s. The shot was again broken up, but the plate was cracked. 
The third projectile struck with 1960 f.s. velocity, that is, it was fired 
with the full charge. The shot passed through the plate, lodging in 
the form of fragments in the backing. A fourth round was fired with 
1815 f.s. striking velocity, when the shot again broke up without per¬ 
forating and without making further cracks. No part of the plate fell 
from the backing. 
This is a most remarkable trial, for it must be borne in mind that 
the resisting power of a plate is more nearly as the square of its thick¬ 
ness than as the first power, so that for a 6-inch plate to break up a 
projectile which until recently was a match for lOJ-inch is a great 
triumph, and it may be seen from the account that any structure 
behind the backing would have been protected. Attention must be 
called to the fact that while the shot was broken up at 1815 f.s. velo¬ 
city in such a way that a great part of its striking energy must 
have fallen harmlessly on the plate, it cannot be argued, that a 
shot is only capable of delivering a fixed quantity of energy before 
fracture, and that all energy over and above that is lost, for it appears 
that at 1960 f.s. velocity much more injury was done, apparently 
because more energy was delivered before the work of fracture was 
complete. Probably the fracture of the projectile occupies such a 
period of time that more work is done on the plate during the process 
by increasing the velocity, because, although the shot is the weakest 
element, there is not time to find the line of least resistance before the 
additional injury is done to the plate. It is perhaps the same action 
as causes fulminate not to follow the lines of least resistance taken by 
slower powder in bursting a shell. 
Attack of Ships. 
The attack of armour-clad ships entails among other questions the Shell attack, 
choice of projectiles, in order to produce the best effect on the particular 
structure attacked. The highest authorities seem agreed that failing any 
letter achievement distinctly presented as within the power of attack , the 
best course is to fire common shells at the weaker portions of ships, which in 
nearly all cases constitute a larger target than the thickly armoured 
parts. The fire should be directed on the central part of the ship 
where the crew and guns are placed, and some Q.F. guns should be 
specially directed just in front of the funnels , where the conning tower is 
generally placed . A ship may be crippled in its powers even by the 
lightest gun fire directed on the locality of the conning tower. 1 It is 
well to insist on this before discussing any other matter in even the 
most general way. Steel common shells now contain larger charges 
of powder than the older common shells of cast-iron. High explosives 
can be safely employed, and, lastly, the rate of fire has been in¬ 
creased so much by the introduction of Q.F. guns that a ship 
may suffer destruction from fire directed on her weaker parts to an 
extent that was formerly out of the question. On this account the 
term “ shell attack ” is substituted for “ secondary attack f which 
1 By confining the staff inside the conning tower, as pointed out by Lieutenant Homier, R.N., 
Assistant Secretary Ordnance Committee, and late of H.M.S. Excellent. 
