German artillery fire
immediately deteriorated. On the other hand, the British artillery,
now having the benefit of aerial guidance, was able to repay the
German onslaughts with interest, and speedily compelled that elaborate
digging-in of the infantry lines which has now become so characteristic
of the opposing forces.

So far as the British lines are concerned the men in the trenches keep a
sharp look-out for hostile aeroplanes. The moment one is observed to
be advancing, all the men seclude themselves and maintain their
concealment. To do otherwise is to court a raking artillery outburst.
The German aeroplane, detecting the tendency of the trenches describes
in the air the location of the vulnerable spot and the precise
disposition by flying immediately above the line. Twice the manoeuvre
is repeated, the second movement evidently being in the character of a
check upon the first observation, and in accordance with instructions,
whereupon the Tommies, to quote their own words, "know they are in for
it!" Ere the aeroplane has completed the second manoeuvre the German
guns ring out.

The facility with which artillery fire can be concentrated through the
medium of the aeroplane is amazing. In one instance, according to the
story related to me by an officer, "a number of our men were resting in
an open field immediately behind the second line of trenches, being in
fact the reserves intended for the relief of the front lines during the
following night. An aeroplane hove in sight. The men dropped their kits
and got under cover in an adjacent wood. The aeroplane was flying at a
great height and evidently laboured under the impression that the kits
were men. Twice it flew over the field in the usual manner, and then
the storm of shrapnel, 'Jack Johnsons' and other tokens from the Kaiser
rained upon the confined space. A round four hundred shells were dropped
into that field in the short period of ten minutes, and the range was
so accurate that no single shell fell outside the space. Had the men not
hurried to cover not one would have been left alive to tell the tale,
because every square foot of the land was searched through and through.
We laughed at the short-sightedness of the airman who had contributed
to such a waste of valuable shot and shell, but at the same time
appreciated the narrowness of our own escape."

The above instance is by no means isolated. It has happened time after
time. The slightest sign of activity