e design of some
early flying machines. He also invented the soaring kite. His hope that
man would fly was more than hope; he refused to argue the question with
objectors, for 'I know', he said, 'that success is dead sure to come'.
Moreover he put all his researches at the disposal of others. He refused
to take out any patents. He did all he could to induce workers to follow
his example and communicate their ideas freely, so that progress might
be quickened. His own ideas, his own inventions, and his own carefully
recorded experiments were a solid step in that staircase of knowledge
from which at last man launched himself into the air, and flew.

In America the pioneer who did most to further the science of human
flight was Professor Samuel Pierpont Langley, of the Smithsonian
Institute, in Washington. He was well known as an astronomer before ever
he took up with aeronautics. From 1866 to 1887 he was professor of
astronomy at the Western University of Pennsylvania, at Pittsburg.
During his later years there he built a laboratory for aerial
investigations, and carried out his famous experiments. His whirling
table, with an arm about thirty feet long, which could be moved at all
speeds up to seventy miles an hour, was devised to measure the lifting
power of air resistance on brass plates suspended to the arm. In 1891 he
published his _Experiments in Aerodynamics_, which embodied the definite
mathematical results obtained by years of careful research. It would be
difficult to exaggerate the importance of this work. The law which
governs the reaction of the air on planes travelling at various speeds
and various angles of incidence had been guessed at, or seen in
glimpses, by earlier investigators; but here were ascertained numerical
values offered to students and inventors. The main result is best stated
in Professor Langley's own words: 'When the arm was put in motion I
found that the faster it went the less weight the plates registered on
the scales, until at great speed they almost floated in the air.... I
found that only one-twentieth of the force before supposed to be
required to support bodies under such conditions was needed, and what
before had seemed impossible began to look possible.... Some
mathematicians, reasoning from false data, had concluded that if it took
a certain amount of power to keep a thing from falling, it would take
much additional power to make it advance. My experiment showed just the
reverse ..