reached, owing to the very multiplicity of experimenters, to
continue dealing in anything approaching detail with all the
different types of machines; and it is proposed, therefore, from
this point to deal only with tendencies, and to mention
individuals merely as examples of a class of thought rather than
as personalities, as it is often difficult fairly to allocate
the responsibility for any particular innovation.

During 1907 and 1908 a new type of machine, in the monoplane,
began to appear from the workshops of Louis Bleriot, Robert
Esnault-Pelterie, and others, which was destined to give rise to
long and bitter controversies on the relative advantages of the
two types, into which it is not proposed to enter here; though
the rumblings of the conflict are still to be heard by
discerning ears. Bleriot's early monoplanes had certain new
features, such as the location of the pilot, and in some cases
the engine, below the wing; but in general his monoplanes,
particularly the famous No. XI on which the first Channel
crossing was made on July 25th, 1909, embodied the main
principles of the Wright and Voisin types, except that the
propeller was in front of instead of behind the supporting
surfaces, and was, therefore, what is called a 'tractor' in
place of the then more conventional 'pusher.' Bleriot aimed at
lateral balance by having the tip of each wing pivoted, though he
soon fell into line with the Wrights and adopted the warping
system. The main features of the design of Esnault-Pelterie's
monoplane was the inverted dihedral (or kathedral as this was
called in Mr S. F. Cody's British Army Biplane of 1907) on the
wings, whereby the tips were considerably lower than the roots at
the body. This was designed to give automatic lateral stability,