ne.

In September, 1917, they covered 83,000 miles, and sighted 8 submarines,
of which 5 were attacked.

In the four weeks ending December 8, 1917, they covered 50,000 miles,
sighted 6 submarines, and attacked 5 of them.

The airships were more affected by short days, and particularly by bad
weather, than the heavier than air craft, and the fact that they covered
practically the same mileage in the winter days of December as in the
summer days of June shows clearly the development that took place in the
interval.

During the whole of 1917 it was estimated that our heavier than air
craft sighted 135 submarines and attacked 85 of them, and our lighter
than air craft sighted 26 and attacked 15. The figures given in Chapter
IX of the number of submarines sunk during the war by aircraft (viz. 7
as a minimum), when compared with the number of attacks during 1917
alone suggest the difficulties of successful attack.

In September, 1917, as extensive a programme as was consistent with
manufacturing capabilities, in view of the enormous demands of the Army,
was drawn up by the Naval Staff for the development of aircraft for
anti-submarine operations during 1918.

The main developments were in machines of the large "America" type and
heavy bombing machines for attacking enemy bases, as well as other
anti-submarine machines and aircraft for use with the Grand Fleet.

Included in the anti-submarine operations of aircraft during 1917 were
the bombing attacks on Bruges, since the German submarines and the
shelters in which they took refuge were part of the objective.

These attacks were carried out from the aerodrome established by the
Royal Naval Air Service at Dunkirk. During 1917 the Naval Air Forces of
the Dover Command, which included the squadrons at Dunkirk, were under
the command of Captain C.L. Lambe, R.N., and the operations of this
force were of a very strenuous character and of the utmost value.

Bombing operations prior to the year of 1917 had been carried out by
various types of machines, but the introduction of the Handley-Page
aeroplanes in the spring of 1917 enabled a much greater weight of
bombs--viz. some 1,500 lbs.--to be carried than had hitherto been
possible. These machines were generally used for night bombing, and the
weight of bombs dropped on the enemy bases in Belgium rose with great
rapidity as machines of the Handley-Page type were delivered, as did the
number of nights on which attacks were mad