m for
enterprise, for genius, and for skill; once and again there is room for
daring, as in the first Atlantic flight. Yet that again was a thing of
mathematical calculation and petrol storage, allied to a certain stark
courage which may be found even in landsmen. For the ventures into the
unknown, the limit of daring, the work for work's sake, with the almost
certainty that the final reward was death, we must look back to the age
of the giants, the age when flying was not a business, but romance.

VII. LILIENTHAL AND PILCHER

There was never a more enthusiastic and consistent student of the
problems of flight than Otto Lilienthal, who was born in 1848 at Anklam,
Pomerania, and even from his early school-days dreamed and planned the
conquest of the air. His practical experiments began when, at the age
of thirteen, he and his brother Gustav made wings consisting of wooden
framework covered with linen, which Otto attached to his arms, and then
ran downhill flapping them. In consequence of possible derision on the
part of other boys, Otto confined these experiments for the most part to
moonlit nights, and gained from them some idea of the resistance offered
by flat surfaces to the air. It was in 1867 that the two brothers
began really practical work, experimenting with wings which, from
their design, indicate some knowledge of Besnier and the history of his
gliding experiments; these wings the brothers fastened to their backs,
moving them with their legs after the fashion of one attempting to swim.
Before they had achieved any real success in gliding the Franco-German
war came as an interruption; both brothers served in this campaign,
resuming their experiments in 1871 at the conclusion of hostilities.

The experiments made by the brothers previous to the war had convinced
Otto that previous experimenters in gliding flight had failed through
reliance on empirical conclusions or else through incomplete observation
on their own part, mostly of bird flight. From 1871 onward Otto
Lilenthal (Gustav's interest in the problem was not maintained as was
his brother's) made what is probably the most detailed and accurate
series of observations that has ever been made with regard to the
properties of curved wing surfaces. So far as could be done, Lilienthal
tabulated the amount of air resistance offered to a bird's wing,
ascertaining that the curve is necessary to flight, as offering far more
resistance than a flat surface. C