500 
PENETRATION OP EARTH AND MASONRY. 
High explo¬ 
sive shell v. 
casemates, 
&c. 
Craters of 
high explo¬ 
sive shell. 
Effect of 
shell in 
earth. 
Smothered. 
Effect of 
breaking 
shell. 
Difficulty 
■with Fuzes, 
most desired wlien shells are fired into earth is a great transporting 
effect; it is sought to throw the largest quantity of earth to the greatest 
distance. High explosives act too locally, they expend too large a 
proportion of their power, in making the grains of earth still smaller; 
in reducing them to impalpable powder; instead of throwing them to a 
distance. In the craters of high explosive shell in shingle at Lydd 
this is very strikingly exhibited, the craters being lined with fine white 
flint powder showing an immense amount of work done, yet but little 
shingle is thrown to any distance, though a portion is thrown violently 
enough. 
High explosive shell, however, are most effective in earth when the 
earth is used as a protection to something underneath, such as masonry, 
and the object of the atttack is rather to destroy what the earth covers 
than to remove the earth itself. Here, if the high explosive shell can 
be fired so as to penetrate the earth and reach the masonry, the earth 
acts as efficient tamping, and the high explosive rends and destroys the 
masonry in a fashion with which powder filled shell cannot compete. 
Thus nothing is better for the attack of casemates, magazines, &c., 
protected by earth, than high explosives, nor is there the usual difficulty 
in getting them to burst in exactly the right place, all that is wanted 
is to get them as far through the earth covering as possible,-and they 
may be equally as effectively burst at rest as when in passage through 
the earth. 
Under very favourable circumstances shells filled with high explosives 
make very large craters; but more frequently their effect on earth de¬ 
fences, and especially the lighter forms of earth, is insignificant; while, 
so far, it has always been more difficult to burst them in the desired 
position than it is to burst powder filled shell. 
The effect of shell in earth, and especially in the looser and finer 
forms of earth, such as sand, shingle, &c., does not depend much on 
the velocity of impact. As long as the shell buries itself to a point 
where the mine which it contains has just sufficient power to completely 
blow away what is over it, it is most effective. If it exceeds that 
depth to any considerable extent its effect is what is called cc smothered.” 
There is a dull sound, the earth shakes, there is a slight upheaval and 
subsidence; if the shell is reasonably near the surface a little smoke 
oozes through; and with high explosives a flame is frequently seen ; 
if deeper, it is difficult to distinguish a bursting shell from a blind, no 
effect at all is visible. 
Now and then a shell breaks up before its contents are exploded, in 
’ which case there is always very little effect. A single large shell, 
burst at the proper place, may make an enormous crater and practically 
destroy the defences. 
Supposing a shell to strike just where required, and to take exactly 
the intended path, the difficulty of arranging a fuze so that it shall not 
burst too soon or too late, has been found extremely great at practice. 
Various delay action fuzes have been tried, some with long delay, with 
the intention of allowing the shell to reach the end of its path before 
being exploded. These have been mainly defeated by ricochet and 
the irregular path of projectiles in earth. 
