497 
PENETRATION AND EFFECT OF PROJECTILES 
ON EARTH AND MASONRY. 
BY 
COLONEL J. B. RICHARDSON, R.A. 
Dealing only with land warfare, since the time when the term artillery 
first began to be used in connection with guns proper, continuous en¬ 
deavours have been made to obtain protection from their projectiles. 
The ultimate result of these attempts has been, in all ages, the same, 
namely to prove that there is nothing so cheap and effective as a proper 
arrangement of earth. 
This, though patent to artillerymen, has not always been realised in 
its entirety by military engineers, especially in times of peace ; and 
they have been led away into the erection of: complicated and intricate 
structures, entailing the use of masonry and other more expensive 
materials, occupying less space, but involving a vastly increased ex¬ 
penditure, though nothing at any time has caused so great a waste of 
ammunition, or has so successfully resisted artillery attack for so long 
a period, as the universal, simple, easily handled, but space occupying 
material, earth. 
Masonry defences, however, exist in profusion, and it is necessary to 
study their attack and the effect which projectiles produce on them. 
It is not intended to imply that earth heaped up at random is the 
best possible defence. High mounds of earth presenting a steep slope 
to the attacking batteries are breached with the greatest ease, by guns 
throwing a long heavily charged shell, at a tolerably high velocity. 
In 1887 the parapet of a 6-inch hydro-pneumatic gun emplacement 
was fired at by an 8-inch B.L. gun at 2000 yards range with a view to 
get hits near the crest. The emplacement was protected by 7 feet of 
concrete covered with 37 feet of earth, the exterior slope being about 
45°. Two ranging shell struck the exterior slope and practically 
breached the earth right up to the masonry, making craters 17' x 20' 
x 6' 6" and 21' x 20' x 8' respectively. Had the exterior slope been 
considerably less these shell would have burrowed upwards and pro¬ 
bably have made quite insignificant craters. It is difficult to obtain 
any effect from guns when a gentle slope is fired at. 
Thrown up earth is not only favourable to the penetration of pro¬ 
jectiles (and, sometimes, if they contain a sufficiently powerful bursting 
charge, to their effect) but to the ease with which they may be made 
to strike, while newly thrown up works are easily seen, especially if very 
regular. Excavations in earth present by far the most difficult de- 
9. YOL. XX. 
Earlh as a 
defence. 
Nothing has 
ever proved 
so effective 
as earth. 
Masonry 
defences 
exist. 
Earth must 
be properly 
arranged. 
8-inch B.L. 
gun at 2000 
yards range. 
Thrown up 
earth. 
Excavation^ 
