The coming of the motor engine made events move rapidly in the world of
aviation. About the year 1906 people's attention was drawn to France,
where Santos Dumont was carrying out the wonderful experiments which we
have already described. Then came Henri Farman, who piloted the famous
biplane built by the Voisin brothers in 1907; an aeroplane destined
to bring world-wide renown to its clever constructors and its equally
clever and daring pilot.
There were notable points of distinction between the Voisin biplane
and that built by the Wrights. The latter, as we have seen, had two
propellers; the former only one. The launching skids of the Wright
biplane gave place to wheels on Farman's machine. One great advantage,
however, possessed by the early Wright biplane over its French rivals,
was in its greater general efficiency. The power of the engine was only
about one-half of the power required in certain of the French designs.
This was chiefly due to the use of the launching rail, for it needed
much greater motor power to make a machine rise from the ground by its
own motor engine than when it received a starting lift from a falling
weight. Even in our modern aeroplanes less engine power is required to
drive the craft through the air than to start from the ground.
Farman achieved great fame through his early flights, and, on 13th
January, 1908, at the flying ground at Issy, in France, he won the prize
of L2000, offered by MM. Deutsch and Archdeacon to the first aviator
who flew a circular kilometre. In July of the same year he won another
substantial prize given by a French engineer, M. Armengaud, to the first
pilot who remained aloft for a quarter of an hour.
Probably an even greater performance was the cross-country flight made
by Farman about three months later. In the flight he passed over hills,
valleys, rivers, villages, and woods on his journey from Chalons to
Rheims, which he accomplished in twenty minutes.
In the early models of the Voisin machine there were fitted between the
two main planes a number of vertical planes, as shown clearly in the
illustration facing p. 160. It was thought that these planes would
increase the stability of the machine, independent of the skill of the
operator, and in calm weather they were highly effective. Their great
drawback, however, was that when a strong side wind caught them the
machine was blown out of its course.
Subsequently Farman considerably modified the early-type Voisin biplane,
as shown by the illustration facing p. 160. The vertical planes were
dispensed with, and thus the idea of automatic stability was abandoned.
But an even greater distinction between the Farman biplane and that
designed by the Wrights was in the adoption of a system of small movable
planes, called AILERONS, fixed at extremities of the main planes,
instead of the warping controls which we have already described. The
ailerons, which are adapted to many of our modern aeroplanes, are really
balancing flaps, actuated by a control lever at the right side of the
pilot's seat, and the principle on which they are worked is very similar
to that employed in the warp system of lateral stability.