May 29, 1915. 
LAND AND .WATER. 
BOMBS USED BY AIRCRAFT. 
By L. BUN DESBLEDS. 
SINCE the outbreak of hostilities hombs have been 
dropped, almost daily, from aircraft on railway 
junctions and stations, trenches, batteries, food and 
ammunition depots, reinforcement convoys, engineer- 
ing works and workshops, shipyards, warships and 
submarines, military, naval, and aerial bases, defended and 
undefended towns and villages, and, in most cases, the bombs 
have had a considerable destructive effect. In view of the 
success which has attended the numerous offensive uses to 
which aircraft have already been put, it is very difficult, if 
not impossible, to understand why they are not, for offensive 
operations, used on a realiy comprehensive and sustained 
scale. 
To the demand for more shrapnel and explosive sheila 
for our field batteries should be added another plea, just as 
earnest and every bit as pressing, for bombs for our aircraft. 
In fact, it should fee ever kept in mind that we have already 
in the aeroplane and in the airship the equivalent to guns 
of 150 and 300 miles range respectively. 
For obvious reasons tlie writer cannot deal with all the 
aerial bombs that have been proposed or used. In the first 
place, the number of air bombs that has already been invented 
and patented is so large that they would require, for even 
their briefest description, a volume rather than an article. 
Also, the fact that some of those bombs which have been a 
subject for the inspiration of our inventors, and some of 
which inventions are of really great worth, precludes any 
description being given which may prove of value to the 
enemy. For these two reasons the writer will confine the 
greater part of his article to the German aerial bombs. 
Bombs employed by aircraft may be divided into two 
great classes: (i.) the explosive, and (n.\ the incendiary 
bomb. 
The Explosive Aerial Bomb. 
The explosive aerial bomb may belong to one of two 
categories : (i.) It may be designed with a view to being 
dropped from the aircraft with no initial velocity of its own; 
or (ii.) it may have provision for being propelled with a high 
initial velocity of the order of tliat «f a bullet leaving the 
muzzle of a gun. 
Explosive aerial bombs of the first kind are generally 
very simple in construction. They are nearly all of the 
type illustrated by the sketch shown in Fig. 1, which repre- 
•ents the cross section of an aerial bomb greatly in favour 
with the enemy. 
An examination of the sketch i^ ■^^ "^ 
shows that the aerial bomb consists '-^^^ 
of a hollow vessel V made of iron. "^ 
This vessel, which is somewhat . 
pear-shaped and is open at its top, Q 
constitutes the bomb propver. 
Through the oj>en top of th 
hollow pear-shaped iron bomb i.s ^ 
screwed a detonating device to the D 
upper part of which are fixed four r 
small metal wings which are A 
slightly inclined to the vertical 
axis of the bomb, and which, in 
effect, constitute a small aerial 
propeller. When the bomb is 
dropped the pressure of the air on 
these small wings, or blades, causes 
the bomb to rotate at a great 
speed, with the result that the 
bomb is not very greatly affected by the wind and keeps its 
downward course fairly well. Another important function 
of these blades is explained a little further on. Two of these 
blades, marked C G, are shown in the sectional sketch. 
The four blades which impart a rotation to the bomb are 
protected from injury by means of a number of stout steel 
wires, IF, curved round them. In some models of aerial 
bombs these steel wires are absent, and the bomb is carried 
by means of a handle, as shown in Fig. 2. 
The sketch shown in Fig. 1 can also be used to explain 
the working of an aerial bomb. The pointed portion, marked 
P, is the one which causes the percussion. It is kept, by 
means of a spring, S, at some distance above the capsule. A, 
which, when struck by the percussion point, P, sets fire to 
the detonator, D, the inflammation of which causes the 
principal charge, E, to explode, with the result that the 
=^ 
SECTIONAL SKETCH OF 
EXPLOSIVE AEKIAL BOMB 
body, F, of the bomb is burst into many pieces, which are 
scattered with great force. 
It will be easily understood that the handling of an 
aerial bomb, such as the one which has been described, would 
be a very dangerous operation, were it not possible to ensure 
that the pin, P, would not accidentally strike against the 
detonating cap, A. The object of the spring, S, is to keep 
the percussion pin, P, away from the detonating cap A. To 
make sure that no accidental shock will cause the spring S to 
move down, there is a hole, H, through the axis, M , to whidi 
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BECTIONAL SKETCH OF SHRAPNEL BOMB. 
the blades, C C, are attached. Through that hole, K, a pin, 
F, is passed, and so long as the pin, F , is through the hole, H, 
the axis, M, which is screwed, at B, on to the percussion 
pin, cannot move down. The presence of the pin, F , there- 
fore, ensures that it is impossible for the detonating cap. A, 
to be struck by the percussion pin, P. 
At the moment of dropping the bomb the safety pin, F^ 
is removed. 
As soon as the bomb begins to fall the action of the air 
causes the small four-bladed aerial screw, C C, to rotato. 
This rotation unscrews the axis, B, and sets free the per- 
cussion point, P, which, being rectangular, and placed in a 
rectangular hole, G, cannot rotate. 
When the bomb hits the ground or the aimed object, 
the shock causes the point, P, to strike against the detonating 
cap, A , thereby causing the explosive charge, E, to explode 
and the bomb to burst. 
The Shrapnel Aerial Bomb. 
The bomb shown in section in Fig. 2 works on the same 
principle as the one already described. It contains 340 steel 
balls and is, in truth, a sort of shrapnel. 
The employment of this type of explosive aerial bomb 
is especially effective against troops in close formation, as ia 
usually the case, for instance, of troops held in reserve a short 
distance behind the firing line. 
When' the explosive charge is fired the parts of the 
shrapnel aerial bomb, as well as the bullets it contains, fly 
radially in all directions v,ith considerable fcrce. 
The two kinds of bombs already described are made of 
various sizes and are used both on aeroplanes and on airshipi. 
They are either dropped by hand or by means of an apparatus 
called a " bomb-dropper." 
Some of the bombs whi *.i the Germans dropped during 
the aerial bombardment of Antwerp by the Zeppelin airships 
differed from the preceding . ones both in shape and in 
construction. 
They were not pear-shaped, but circular. They were 
made up of three distinct circjlar shells inside one another. 
These three shells were soldered at various places with brass 
soldering with a view, probably, to causing three pieces of 
shell to fly off from each bursting-point. 
A number of rivets went through the three shells. These 
rivets had circular heads, which pressed against the inner 
surface of the innermost shell. They were 0.58in. in 
diamet'Cr and were placed 0.78in. apart. These bombs were 
provided with a number of percussion needles, and at least 
one of them was ezpectcd to act and set fire to the explosive 
charge in the inmost shell whatever might be the manner in 
which the bomb dropped. 
Several of the shells which were dropped on Antwerp did 
not, however, explode, and this is how it has come to pass 
that the construction of the Zeppelin Antwerp bombs is no 
longer a secret of the German War Office. 
17* 
