vey immediately to its
friends.

The aeroplane has established its value in another manner. Coal-burning
vessels when moving at any pronounced speed invariably throw off large
quantities of smoke, which may be detected easily from above, even when
the vessels themselves are completely hidden in the mist. It was this
circumstance which revealed the presence of the British squadron in the
affair of the Bight of Heligoland.

The German airman on patrol duty from the adjacent base on the island of
Heligoland detected the presence of this smoke, above the low-lying bank
of fog, although there were no other visible signs of any vessels. Fully
cognisant of the fact that the German Fleet was at anchor in a safe
place he naturally divined that the smoke proceeded from a hostile
squadron, evidently bent upon a raid. He returned to his headquarters,
conveyed the intelligence he had collected to his superior officers,
upon receipt of which a German cruiser squadron was sent out and engaged
the British vessels to its own discomfiture. But for the airman's
vigilance and smartness there is no doubt that the British squadron
would have accomplished a great coup.

This incident, however, served to reveal that the aerial scout is prone
to suffer from over-keenness and to collect only a partial amount
of information. Upon this occasion the German watchman detected the
presence of the British torpedo-boat and light cruiser force. Had
he continued his investigations and made a wider sweep he would have
discovered the proximity of the British battle-cruiser squadron
which routed the German force, the latter having acted on incomplete
information.

While the low-lying sea-fog is the navigator's worst enemy, it is the
airman's greatest friend and protection. It not only preserves him
against visual discovery from below, but is an excellent insulator
of sound, so that his whereabouts is not betrayed by the noise of his
motor. It is of in calculable value in another way. When a fog prevails
the sea is generally as smooth as the pro verbial mirror, enabling the
waterplanes to be brought up under cover to a suitable point from which
they may be dispatched. Upon their release by climbing to a height of a
few hundred feet the airmen are able to reach a clear atmosphere, where
by means of the compass it is possible to advance in approximately the
desired direction, safe from discovery from below owing to the fog.
If they are "spotted" they can d