least one squadron to each
corps, one squadron to each army headquarters, and one for General
Headquarters.' The corps squadrons were needed for artillery work and
photography; the others to carry out reconnaissances for the three
armies and for General Headquarters. On this basis he asks for three
more squadrons as soon as possible. 'In addition I would ask that a
squadron per army be sent out when formed, for special work such as bomb
raids.' His plea for a good supply of anti-aircraft guns illustrates a
difference which persisted throughout the war between British and German
usages. The British corps machines were incessantly at work over the
enemy. The German corps machines were more prudent. Their constant
practice was to carry out their observation of artillery fire and their
photographic work obliquely, from a position in the air low down over
their own lines, so that they were protected by their own guns, and
could be attacked from the air only at very great risk. But the German
anti-aircraft guns had already succeeded in hitting some of our
aeroplanes when they were flying more than three miles inside our own
lines, at a height of six thousand feet. If we had guns as good as this,
says Colonel Trenchard, and in sufficient number, we could attack the
German machines and could protect our own machines when they are at
work above the enemy lines. Hostile aeroplanes are easier to see from
the ground than from the air, and the bursts of our anti-aircraft shell
would serve to show our aircraft the whereabouts of enemy machines.

At this time there were three British armies on the western front. When
news came in September that a Fourth Army was about to be formed,
General Trenchard at once asked for a fourth wing, to consist of
headquarters and three squadrons.

These demands were all fulfilled as soon as the uncertainty of
deliveries permitted. In March 1916, some three and a half months before
the beginning of the battles of the Somme, General Trenchard took
another step forward. The work to be done by the Royal Flying Corps had
outgrown its strength. Each of the British armies on the front had
allotted to it at this time one brigade of the Royal Flying Corps,
consisting of two aeroplane wings, namely, a corps wing and an army
wing, and two kite balloon sections. But in practice it had been found
necessary to use the squadrons of the corps wing to help the army wing
in patrol work, army reconnaissance, and bombin