into the air on wings or planes of their own
devising. The scientific investigators, who experimented with machines
embodying the same principle, did much to assist the gliders, but in
justice they must take a second place. The men who staked their lives
were the men who, after many losses, were rewarded with the conquest of
the air. There are stories of a certain Captain Lebris, how in 1854,
near Douarnenez in Brittany, he constructed an artificial albatross, and
tying it by a slip rope to a cart which was driven against the wind,
mounted in it to a height of three hundred feet. But the first glider of
whom we have any full knowledge is Otto Lilienthal of Berlin. He devoted
his whole life to the study of aviation at a time when in Germany people
looked upon such a pursuit as little better than lunacy. The principal
professor of mathematics at the Berlin Gewerbe Academie, on hearing that
Lilienthal was experimenting with aeronautics, advised him to spend no
money on such things--a piece of advice which, Lilienthal remarks, was
unhappily quite superfluous. In 1889 he completed, with the help of his
brother, a series of experiments on the carrying capacity of arched, or
cambered, wings, and published the results in a book entitled _Bird
Flight as the Basis of Aviation_. In his youth every crow that flew by
presented him with a problem to solve in its slowly moving wings.
Prolonged study led him to the conclusion that the slight fore-and-aft
curvature of the wing was the secret of flying. But he knew too much to
suppose that this conclusion solved the problem. A dozen other
difficulties, including the difficulty of balance, remained to be
mastered. When German societies for the advancement of aerial navigation
began to be formed, he at first held aloof from them, for the balloon,
which he regarded as the chief obstacle to the development of flight,
monopolized their entire attention. His insistence on the cambered wing
did not convince others, who went on experimenting with flat planes.
German and Austrian aviators, it is true, were induced by his book to
put aside flat surfaces and introduce arched wings. 'However,' he
remarks, 'as this was done mainly on paper, in projects, and in
aeronautical papers and discussions, I felt impelled myself to carry out
my theory in practice.' So, in the summer of 1891, on a pair of
bird-like wings, with eighty-six square feet of supporting surface,
stabilized by a horizontal tail and a ver