ed. The position-finding system consists
of two or more ground stations fitted with apparatus capable of taking
bearings with respect to true north and connected by direct telephone
line. The aircraft calls up by wireless one of these stations, requests
her position and then makes a series of signals for about half a minute.
The stations take the aircraft's bearings, plot its position, and
transmit the information to the aircraft. Wireless direction and
position-finding, as well as wireless telephony, have on several
occasions proved their value to navigation, but in spite of instances of
successful night flying, developments have not been such as to render
night services practicable.

Marine experience has been a valuable guide, but aerial illumination
has entailed many new problems of its own--the distribution of light
through very wide angles, the installation of light and powerful lamps
in aircraft, the elimination of shadows and the prevention of dazzle,
the provision of apparatus to indicate the strength and direction of the
wind, and the like.

Very shortly the first organized and equipped night-flying route will be
available; that between London and Lympne on the Continental air
highway. The Boulogne-Paris section will probably be ready a little
later. There will be four lighthouses on the English section, of which
two will be automatic, requiring no attention for twelve months at a
time. These, and many other, facilities will much assist the progressive
establishment of services during the hours of darkness, and will provide
valuable data for the establishment of other night-flying routes. There
is no real difficulty given a reasonably clear atmosphere.

ORGANIZATION.

I have mentioned the broad lines on which the organization of the air
services was built up before and during the war. We have seen that the
initial foundations and framework remained and bore the great systematic
structural development which was gradually required. In August, 1914,
there were some 240 officers, 1800 men and 200 machines; in November,
1918, 30,000 officers, 170,000 men, and 22,000 machines, all of them
better and of a higher performance than those of 1914. Our casualties
during the war were about 18,000; air formations had been active in
some fifteen theatres of operations; 8,000 enemy machines and 300
observation balloons had been destroyed; some three-quarters of a
million photographs taken over hostile country, and 12,00