dy for firing. In those cases where
the enemy's artillery is concealed perhaps behind a hill, the airman is
of incalculable value, inasmuch as he is able to reveal a position which
otherwise would have to be found by considerable haphazard firing, and
which, even if followed by a captive balloon anchored above the firing
point, might resist correction.

The accuracy of the airman's work in communicating the range has been
responsible for the high efficiency of the British and French artillery.
The latter, with the 75 millimetre quick-firing gun, is particularly
adapted to following up the results of the aeroplane's reconnaissance,
especially with the system of rafale fire, because the whole position
can be searched through and through within a minute or two. According
to information which has been given to me by our artillery officers, the
British system also has proved disastrous to the enemy. The practice
is to get the range as communicated by the aeroplane, to bring the
artillery into position speedily, to discharge salvo after salvo with
all speed for a few minutes, and then to wheel the artillery away before
any hostile fire can be returned. The celerity with which the British
artillery comes into, and goes out of, action has astonished even
our own authorities. This mobility is of unique value: it is taking
advantage of a somewhat slow-witted enemy with interest. By the time
the Germans have opened fire upon the point whence the British guns were
discharged, the latter have disappeared and are ready to let fly from
another point, some distance away, so that the hostile fire is abortive.
Mobility of such a character is decidedly unnerving and baffling even to
a quick-witted opponent.

In his search for hostile artillery the airman runs grave risks and
displays remarkable resource. It is invariably decided, before he sets
out, that he shall always return to a certain altitude to communicate
signals. Time after time the guns of the enemy have been concealed
so cunningly from aerial observation as to pass unnoticed. This trait
became more pronounced as the campaigns of the Aisne progressed.
Accordingly the airman adopts a daring procedure. He swoops down over
suspicious places, where he thinks guns may be lurking, hoping that the
enemy will betray its presence. The ruse is invariably successful. The
airman makes a sudden dive towards the earth. The soldiers in hiding
below, who have become somewhat demoralised by the