over England, and, although the new and
powerful Zeppelin L.Z.38, which attacked London on May 31st, was
destroyed by an aeroplane counter-attack in its shed near Brussels, no
real counter measures were evolved until 1916, when Home Defence was
taken over by the War Office. During that year a Home Defence Squadron
of B.E.2c's, rapidly expanded to a Wing, was formed; and the systematic
training of night pilots, the standardization of night-flying equipment
and armament, and the lighting of aerodromes, was taken in hand. A
continuous aeroplane and searchlight barrage with night landing grounds
was gradually formed between Dover and the Forth; the wireless signals
employed to assist Zeppelins in finding their way were intercepted, thus
enabling our rapidly improving fighting machines to pick up and attack
raiding airships; and the constant attacks to which airship sheds were
exposed in Belgium, caused their withdrawal to positions further inland
and increased their distance from England. During 1916 there were
twenty-two raids by airships, six of which were destroyed, the first
being brought down in September at Cuffley by Leefe Robinson.
Thenceforward airship raids declined, the destruction of the majority of
the largest and latest which raided England on October 19th, 1917,
sealing their fate.

On the other hand, aeroplane daylight and night raids on London, the
first of which occurred in November, 1916, increased in number and
strength with the object, in addition to the destruction of material and
civilian _morale_, of forcing upon us the unsound retention at home of a
considerable air defence force. The largest of these attacks was made by
seventeen aeroplanes at midday on June 13th, 1917, but, the Zeppelin
danger nullified, counter measures to meet the new menace were gradually
evolved. New squadrons were raised and the number of home defence
squadrons was raised to fourteen service and eight night training
squadrons; a Northern Home Defence Wing was formed at York; and the Home
Defence Group became the 6th Brigade. The first night aeroplane raid
occurred in September, and the systematic training of night-fighting
pilots on scout machines was hurried on. Separate zones for aeroplanes,
guns and searchlights--the latter provided with sound locators--forming
an outer barrage, were instituted, and aprons, supported by
kite-balloons, formed a protective barrage up to 8,000 feet. A system of
wireless and ground telephonic