stresses to which an aeroplane might be subjected and to take
steps to provide for them by increasing strength where
necessary.

When the year 1914 opened a speed of 126 miles per hour had been
attained and a height of 19,600 feet had been reached. The
Sopwith and Avro (the forerunner of the famous training machine
of the War period) were probably the two leading tractor
biplanes of the world, both two-seaters with a speed variation
from 40 miles per hour up to some 90 miles per hour with 80
horse-power engines. The French were still pinning their faith
mainly to monoplanes, while the Germans were beginning to come
into prominence with both monoplanes and biplanes of the 'Taube'
type. These had wings swept backward and also upturned at the
wing-tips which, though it gave a certain measure of automatic
stability, rendered the machine somewhat clumsy in the air, and
their performances were not on the whole as high as those of
either France or Great Britain.

Early in 1914 it became known that the experimental work of
Edward Busk--who was so lamentably killed during an experimental
flight later in the year--following upon the researches of
Bairstow and others had resulted in the production at the Royal
Aircraft Factory at Farnborough of a truly automatically stable
aeroplane. This was the 'R.E.' (Reconnaissance Experimental), a
development of the B.E. which has already been referred to. The
remarkable feature of this design was that there was no
particular device to which one could point out as the cause of
the stability. The stable result was attained simply by detailed
design of each part of the aeroplane, with due regard to its