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