ublicity; papers read
to learned societies were more concerned with theory than with practice;
but there was hope in the air, and hundreds of minds were independently
at work on the problem of flight. Some idea of the variety of
suggestions and devices may be gathered from Mr. Octave Chanute's
_Progress in Flying Machines_, a reprint of a series of articles by him,
which appeared, from 1891 onwards, in _The Railroad and Engineering
Journal_ of New York City. It was said in the ancient world that there
is nothing so absurd but some philosopher has believed it; there is no
imaginable way of flight that has not engaged the time and effort of
some inventor. Yet among the multitude of attempts it is not difficult
to trace the ancestry of the modern flying machine. Wing-flapping
machines left no issue. Machines supported in the air by helicopters,
that is, by horizontal revolving blades, can be made to rise from the
ground, but cannot easily be made to travel. The way to success was by
imitation of soaring birds; and it is worthy of note that some of the
best minds were, from the first, fascinated by this method of flight,
and were never tired of observing it. Cayley remarks that the swift,
though it is a powerful flyer, is not able to elevate itself from level
ground. Wenham records how an eagle, sitting in solitary state in the
midst of the Egyptian plain, was fired at with a shotgun, and had to run
full twenty yards, digging its talons into the soil, before it could
raise itself into the air. M. Mouillard, of Cairo, spent more than
thirty years in watching the flight of soaring birds, and devoted the
whole of his book, _L'Empire de l'Air_ (1881), to the investigation of
soaring flight. The pelican, the turkey-buzzard, the vulture, the
condor, have all had their students and disciples. M. Mouillard, indeed,
maintains that if there be a moderate wind, a bird can remain a whole
day soaring in the air, with no expenditure of power whatever. To those
who have watched seagulls this may perhaps seem credible; but air is
invisible, and soaring birds are skilful to choose a place, in the wake
of a ship or in the neighbourhood of a cliff, where there is an
up-current of air, so that when they glide by their own weight, though
they are losing height in relation to the air, they are losing none in
relation to the surface of the earth.

The parents of the modern flying machine were the gliders, that is, the
men who launched themselves