respects the helicopter has advantages not found in the
aeroplane.

What the Helicopter Is.

The helicopter gets its name from being fitted with
vertical propellers or helices (see illustration) by the
action of which the machine is raised directly from the
ground into the air. This does away with the necessity
for getting the machine under a gliding headway before
it floats, as is the case with the aeroplane, and consequently
the helicopter can be handled in a much smaller
space than is required for an aeroplane. This, in many
instances, is an important advantage, but it is the only
one the helicopter possesses, and is more than overcome
by its drawbacks. The most serious of these is that the
helicopter is deficient in sustaining capacity, and requires
too much motive power.

Form of the Ornithopter.

The ornithopter has hinged planes which work like
the wings of a bird. At first thought this would seem
to be the correct principle, and most of the early experimenters
conducted their operations on this line. It
is now generally understood, however, that the bird in
soaring is in reality an aeroplane, its extended wings
serving to sustain, as well as propel, the body. At any
rate the ornithoper has not been successful in aviation,
and has been interesting mainly as an ingenious toy.