penetration of earth and masonry. 
501 
The course of shells fired at moderate angles of elevation, so as to Course of 
obtain accuracy of practice into earth is very variable and seemingly shellmearth 
very difficult to reduce to any law. When travelling with great velocity 
they sometimes seem as if they disregarded the path which in theory 
is that of least resistance ; as if time was not afforded to them to take 
it, and that as they slow down they endeavoured to revert to the line 
of least resistance in an exaggerated degree. Small objects which the 
head of the shell meets with, as it is coming to rest in its passage 
through earth, and which would offer no appreciable obstacle to the 
even path of the projectile in flight, tend to greatly influence its course, 
and that, apparently, directly in proportion to the exhaustion of its 
energy. Bullets from the high velocity magazine rifle, fired into sand Magazine 
here, have been found to alter their course on arriving at a sheet of paper, u e s * 
and sometimes to be deflected without penetrating this slight obstacle, 
though the paper would not have appreciably affected either the course 
or the velocity of the bullet in air. So, too, plugged shell of the far Heavy shell 
heavier 16-inch and 12‘5-inch R.M.L. guns have been known to be thkTwo e od. by 
largely deflected on meeting with a mere thin wooden partition, placed 
in the butt for convenience in holding the earth together when re¬ 
covering the shell at proof, a partition which would be as nothing had 
the shell met with it in its flig*ht through the air. 
A little change in the nature or density of the material, therefore, is change of 
apt to make a great change in the course of a projectile in earth. fleets! 7 de " 
Ricochet is fatal to effect; a shell striking earth seldom gets its Rico*het. 
contents exploded in time to make any thing of a crater if it com¬ 
mences to rise out of the ground on striking. If it does not explode 
in time it merely makes a narrow scoop, removing but little earth. If 
the charge does explode before the shell has completely risen, a pear- 
shaped crater, almost always of moderate dimensions, is formed. 
The shape of the head of a shell has great influence on ricochet, shape of 
Since the early days of the Whitworth rifled guns it has been known hea ofshell ‘ 
that flat-headed projectiles have a minimum tendency to ricochet, 
while the shape of head generally adopted as most favourable to the 
flight of a shell through air probably most favours the ricochet of a 
shell on striking a dense medium. Instances have lately occurred shell 
where shell, with very pointed heads, fired at an earth butt at a very ba°£ hetinff 
high velocity, have actually come back over the gun from which they 
were fired ; a ricochet backwards. 
Shells fired from the Zalinski gun, which have a sort of screw on 
the outside, long shell too, have wormed themselves through 40 feet of 
earth butt apparently in quite a straight line. 
The length .of the shell itself does not seem to have a very great Long shell, 
bearing one way or another on its capability of holding a straight 
course through earth, but they are more likely to break up on striking. 
The practical result of the employment of long delay action fuzes. Long delay 
such as five seconds delay, in shell fired at moderate angles of elevation fuzes * 
is that a considerable proportion ricochet from, and burst in the air 
behind, the target works, while very few are in the desired position at 
the moment of explosion. 
