s been
necessary for the supply department to do a brisk trade in new ideas and
designs, experiment, improvement, and scrapping.

Although free-lance attacks by airmen on whatever takes their fancy down
below are now common enough, they were unknown little over a year ago.
Their early history is bound up with the introduction of contact
patrols, or co-operation with advancing infantry. Previous to the Somme
Push of 1916, communication during an attack between infantry on the one
hand and the guns and various headquarters on the other was a difficult
problem. A battalion would go over the top and disappear into the enemy
lines. It might have urgent need of reinforcements or of a concentrated
fire on some dangerous spot. Yet to make known its wants quickly was by
no means easy, for the telephone wires were usually cut, carrier-pigeons
went astray, and runners were liable to be shot. When the British
introduced the "creeping barrage" of artillery pounding, which moved a
little ahead of the infantry and curtained them from machine-gun and
rifle fire, the need for rapid communication was greater than ever.
Exultant attackers would rush forward in advance of the programmed speed
and be mown by their own barrage.

Credit for the trial use of the aeroplane to link artillery with
infantry belongs to the British, though the French at Verdun first
brought the method to practical success. We then developed the idea on
the Somme with notable results. Stable machines, equipped with wireless
transmitters and Klaxon horns, flew at a low height over detailed
sectors, observed all developments, signalled back guidance for the
barrage, and by means of message bags supplied headquarters with
valuable information. Besides its main purpose of mothering the
infantry, the new system of contact patrols was found to be useful in
dealing with enemy movements directly behind the front line. If the bud
of a counter-attack appeared, aeroplanes would call upon the guns to nip
it before it had time to blossom.

Last September we of the fighting and reconnaissance squadrons began to
hear interesting yarns from the corps squadrons that specialised in
contact patrols. An observer saved two battalions from extinction by
calling up reinforcements in the nick of time. When two tanks slithered
around the ruins of Courcelette two hours before the razed village was
stormed, the men in the trenches would have known nothing of this
unexpected advance-guard bu