During the first half of the 19th Century there were many experiments
with wing surfaces, none of which gave any promise. In fact it was not
until 1865 that any advance was made, when Francis Wenham showed that
the lifting power of a plane of great superficial area could be obtained
by dividing the large plane into several parts arranged on tiers. This
may be regarded as the germ of the modern aeroplane, the first glimmer
of hope to filter through the darkness of experimentation until then.
When Wenham's apparatus went against a strong wind it was only lifted
up and thrown back. However, the idea gave thought to many others years
afterwards.

In 1885 the brothers Lilienthal in Germany discovered the possibility
of driving curved aeroplanes against the wind. Otto Lilienthal held
that it was necessary to begin with "sailing" flight and first of all
that the art of balancing in the air must be learned by practical
experiments. He made several flights of the kind now known as _gliding_.
From a height of 100 feet he glided a distance of 700 feet and found he
could deflect his flight from left to right by moving his legs which
were hanging freely from the seat. He attached a light motor weighing
only 96 lbs. and generating 2-1/2 horse power. To sustain the weight he
had to increase the size of his planes.

Unfortunately this pioneer in modern aviation was killed in an
experiment, but he left much data behind which has helped others. His
was the first actual flyer which demonstrated the elementary laws
governing real flight and blazed the way for the successful experiments
of the present time. His example made the gliding machine a continuous
performance until real practical aerial flight was achieved.