t.

It was not until 1896 that the mechanical genius which characterised
the two brothers was turned to the consideration of aeronautics. In that
year they took up the problem thoroughly, studying all the aeronautical
information then in print. Lilienthal's writings formed one basis for
their studies, and the work of Langley assisted in establishing in
them a confidence in the possibility of a solution to the problems of
mechanical flight. In 1909, at the banquet given by the Royal Aero Club
to the Wright Brothers on their return to America, after the series of
demonstration flights carried out by Wilbur Wright on the Continent,
Wilbur paid tribute to the great pioneer work of Stringfellow, whose
studies and achievements influenced his own and Orville's early work. He
pointed out how Stringfellow devised an aeroplane having two propellers
and vertical and horizontal steering, and gave due place to this early
pioneer of mechanical flight.

Neither of the brothers was content with mere study of the work of
others. They collected all the theory available in the books published
up to that time, and then built man-carrying gliders with which to test
the data of Lilienthal and such other authorities as they had consulted.
For two years they conducted outdoor experiments in order to test the
truth or otherwise of what were enunciated as the principles of flight;
after this they turned to laboratory experiments, constructing a wind
tunnel in which they made thousands of tests with models of various
forms of curved planes. From their experiments they tabulated thousands
of readings, which Griffith Brewer remarks as giving results equally
efficient with those of the elaborate tables prepared by learned
institutions.

Wilbur Wright has set down the beginnings of the practical experiments
made by the two brothers very clearly. 'The difficulties,' he says,
'which obstruct the pathway to success in flying machine construction
are of three general classes: (1) Those which relate to the construction
of the sustaining wings; (2) those which relate to the generation and
application of the power required to drive the machine through the air;
(3) those relating to the balancing and steering of the machine after
it is actually in flight. Of these difficulties two are already to
a certain extent solved. Men already know how to construct wings, or
aeroplanes, which, when driven through the air at sufficient speed, will
not only sustain the