accuracy of the
British aerial bomb-throwers, have an attack of nerves. They open a
spirited fusillade in the hope of bringing the airman to earth. But
their very excitement contributes to his safety. The shots are fired
without careful aim and expend themselves harmlessly. Sweeping once more
upwards, the airman regains the pre-determined level, performs a certain
evolution in the air which warns the observer at his base that he has
made a discovery, and promptly drops his guiding signal directly over
the point from which he has drawn fire.

Operations at night are conducted by means of coloured lights or an
electrical searchlight system. In the former instance three lights
are generally carried--white, red, and green--each of which has a
distinctive meaning. If reliance is placed upon the electric light
signalling lamp, then communications are in code. But night operations
are somewhat difficult and extremely dangerous, except when the elements
are propitious. There is the ground mist which blots everything from
sight, rendering reconnaissance purely speculative. But on a clear night
the airman is more likely to prove successful. He keeps a vigilant eye
upon all ground-lights and by close observation is able to determine
their significance. It is for this reason that no lights of any
description are permitted in the advance trenches. The striking of a
match may easily betray a position to the alert eye above.

So far as the British Army is concerned a complete code is in operation
for communicating between aeroplanes and the ground at night. Very's
lights are used for this purpose, it being possible to distinguish the
respective colours at a distance of six miles and from an altitude of
2,000 feet. The lights are used both by the aeroplane and the battery of
artillery.

The code is varied frequently, but the following conveys a rough idea of
how communication is carried out by this means under cover of darkness.
The aeroplane has located its objective and has returned to the
pre-arranged altitude. A red light is thrown by the airman. It indicates
that he is directly over the enemy's position. A similarly coloured
light is shown by the artillery officer, which intimates to the airman
that his signal has been observed and that the range has been taken.

In observing the effects of artillery fire a code of signals is employed
between the airman and the artillery officer to indicate whether the
shot is "long" or "shor