the whole time it is required for operation.

There are various methods of consummating this end. One method is to
haul in the balloon and to peg it down on all sides, completing the
anchorage by the attachment of bags filled with earth to the network.
While this process is satisfactory in calm weather, it is impracticable
in heavy winds, which are likely to spring up suddenly. Consequently
a second method is practised. This is to dig a pit into the ground of
sufficient size to receive the balloon. When the latter is hauled in it
is lowered into this pit and there pegged down and anchored. Thus it
is perfectly safe during the roughest weather, as none of its bulk is
exposed above the ground level. Furthermore it is not a conspicuous
object for the concentration of hostile fire.

In some instances, and where the military department is possessed of
an elaborate equipment such as characterises the German army, when
reconnaissance is completed and the balloon is to be removed to another
point, the gas is pumped back into the cylinders for further use. Such
an economical proceeding is pretty and well adapted to manoeuvres, but
it is scarcely feasible in actual warfare, for the simple reason that
the pumping takes time. Consequently the general procedure, when the
balloon has completed its work, is to permit the gas to escape into the
air in the usual manner, and to draw a fresh supply of gas from further
cylinders when the occasion arises for re-inflation.

Although the familiar spherical balloon has proved perfectly adequate
for reconnoitring in the British and French armies, the German
authorities maintained that it was not satisfactory in anything but calm
weather. Accordingly scientific initiative was stimulated with a view to
the evolution of a superior vessel. These endeavours culminated in the
Parseval-Siegsfeld captive balloon, which has a quaint appearance. It
has the form of a bulky cylinder with hemispherical extremities. At one
end of the balloon there is a surrounding outer bag, reminiscent of a
cancerous growth. The lower end of this is open. This attachment serves
the purpose of a ballonet. The wind blowing against the opening, which
faces it, charges the ballonet with air. This action, it is claimed,
serves to steady the main vessel, somewhat in the manner of the tail of
a kite, thereby enabling observations to be made as easily and correctly
in rough as in calm weather. The appearance of the balloon while a