Aerophilia | Page 6

African campaign emphasised the value of the British
balloon section of the Army, and revealed services to which it was
specially adapted, but which had previously more or less been ignored.
The British Army possessed indifferent maps of the Orange Free State
and the Transvaal. This lamentable deficiency was remedied in great
measure by recourse to topographical photographs taken from the
captive balloons. The guides thus obtained were found to be of extreme
value.
During the early stages of the war the hydrogen was shipped in
cylinders from the homeland, but subsequently a manufacturing plant
of such capacity as to meet all requirements was established in South
Africa. The cylinders were charged at this point and dispatched to the
scene of action, so that it became unnecessary to transport the
commodity from Britain. The captive balloon revealed the
impregnability of Spion Kop, enabled Lord Roberts to ascertain the
position of the Boer guns at the Battle of Paardeburg, and proved of
invaluable assistance to the forces of General White during the siege of
Ladysmith.

CHAPTER II

THE MILITARY USES of THE CAPTIVE BALLOON
Although the captive balloon is recognised as indispensable in military
operations, its uses are somewhat limited. It can be employed only in
comparatively still weather. The reason is obvious. It is essential that
the balloon should assume a vertical line in relation to its winding plant
upon the ground beneath, so that it may attain the maximum elevation
possible: in other words, the balloon should be directly above the
station below, so that if 100 yards of cable are paid out the aerostat may
be 100 yards above the ground. If a wind is blowing, the helpless craft
is certain to be caught thereby and driven forwards or backwards, so
that it assumes an angle to its station. If this become acute the vessel
will be tilted, rendering the position of the observers somewhat
precarious, and at the same time observing efficiency will be impaired.
This point may be appreciated more easily by reference to the
accompanying diagram. A represents the ground station and B the
position of the captive balloon when sent aloft in calm weather, 300
feet of cable being paid out. A wind arises and blows the vessel
forward to the position C. At this point the height of the craft in relation
to the ground has been reduced, and the reduction must increase
proportionately as the strength of the wind increases and forces the
balloon still more towards the ground. At the same time, owing to the
tilt given to the car, observation is rendered more difficult and
eventually becomes extremely dangerous.
A wind, if of appreciable strength, develops another and graver danger.
Greater strain will be imposed upon the cable, while if the wind be
gusty, there is the risk that the vessel will be torn away from its
anchoring rope and possibly lost. Thus it will be seen that the effective
utilisation of a captive balloon is completely governed by
meteorological conditions, and often it is impossible to use it in
weather which exercises but little influence upon dirigibles or
aeroplanes.
The captive balloon equipment comprises the balloon, together with the
observer's basket, the wire-cable whereby it is anchored and controlled,
and the winding apparatus. Formerly a steam engine was necessary for

the paying in and out of the cable, but nowadays this is accomplished
by means of a petrol-driven motor, an oil-engine, or even by the engine
of an automobile. The length of cable varies according to the capacity
of the balloon and the maximum operating height.
The average British balloon is able to lift about 290 or 300 pounds,
which may be taken to represent the weight of two observers. On the
other hand, the French and German balloons are able to carry four
times this weight, with the exception of the French auxiliaries, which
are designed to lift one observer only. The balloons of the two latter
Powers have also a greater maximum altitude; it is possible to ascend to
a height of some 2,000 feet in one of these.
The observing station is connected with the winding crew below either
by a telephone, or some other signalling system, the method practised
varying according to circumstances. In turn the winding station is
connected with the officer in charge of the artillery, the fire of which
the captive balloon is directing. The balloon observer is generally
equipped with various instruments, such as telescope, photographic
cameras, and so forth, so as to be able, if necessary, to prepare a
topographical survey of the country below. By this means the absence
of reliable maps may be remedied, or if not regarded, as sufficiently
correct they may be checked and counter-checked by the data gained
aloft.
Seeing that the gas has to be