In the early part of the last century an Englishman, Sir George Cayley,
made many experiments with gliders and tabulated with great care the
results of his investigations. He concluded, like Swedenborg, that man
has not the power to fly by his own strength through any wing-flapping
device, or orthopter, but he intimated that with a lighter and more
powerful engine than had then been invented a plane like those used in
his gliders, if slightly inclined upward, might be made gradually to
ascend through the air. The results of his experiments he published in
1810. They clearly foreshadowed the triumph that came almost a century
later.
In 1844 two British inventors, Henson and String-fellow, working out the
suggestions of Cayley, made an aeroplane model equipped with a steam
engine which is said to have made a flight of forty yards--the first
real upward flight of a heavier than air machine on record. This model
was a monoplane, that is, the lifting surface was a single plane like
the outstretched wings of a bird. Twenty-two years later experiments
were made with a biplane, that is, an aeroplane with two lifting planes
or surfaces, one above the other.