n of a cheap,
high-powered and reliable engine, but the existence at the end of the
war of machines weighing 15 tons indicates the progress achieved, while
British engines of 600 horse-power are now in use, and one of 1,000
horse-power will shortly be available.

TACTICS AND THE STRATEGIC AIR OFFENSIVE.

During the war there were three concurrent movements in process: the
ratios of the various forms of air tactics were constantly changing, and
the components of our air forces varied in accordance with the
development of reconnaissance, artillery co-operation, bombing and
fighting. Secondly, their total strength was increasing rapidly; and,
thirdly, it was increasing relatively faster than the Army or Navy.

It was an evident and logical development and in accord with the
shortage of national man power and the consequent tendency to a
reduction in the strength of the Army, that, the necessary uses of
aircraft with the Army and Navy being ensured, any available margin of
air power should be employed on an independent basis for definite
strategic purposes. The difficulty was to arrive at an agreement as to
the minimum tactical and grand tactical requirements of the Army and
Navy. The British Army was not alone in asserting that there was no
minimum and that it wanted every available airman, and agreed with the
French that anything which it could temporarily spare should be lent to
the French Army. It was argued that the Armies could as easily and
better arrange for strategic bombing. Fortunately in 1918, when I was
Chief of the Air Staff, we managed to secure a margin and formed the
Independent Air Force in June of that year. It was, of course,
understood that, in the event of either the British or French Armies
being hard put to it, the Independent Air Force could temporarily come
to their direct assistance and act in close co-operation with them.

In 1915 in accordance with the old doctrine that offence is the best
defence, the surest method of protecting specialized machines on the
battle front was found to be in the attack of enemy aircraft by fighting
machines. In 1918 it was decided that raids on the centres of German war
industry would not only cripple the enemy's output of material
essential to victory, but also relieve the pressure on the Western
Front, the vital point of the war. The Germans had had the same
intention in the many raids which started over Dover on December 21st,
1914.

Long-range bombing h