CHAPTER V

DIFFERENT MACHINE TYPES AND THEIR CHARACTERISTICS


THERE are three distinct types of heavier-than-
air machines, which are widely separated in all
their characteristics, so that there is scarcely a
single feature in common.

Two of them, the aeroplane, and the orthopter,
have prototypes in nature, and are distinguished
by their respective similarities to the soaring
birds, and those with flapping wings.

The Helicopter, on the other hand, has no antecedent
type, but is dependent for its raising
powers on the pull of a propeller, or a plurality
of them, constructed, as will be pointed out hereinafter.

AEROPLANES.--The only form which has met
with any success is the aeroplane, which, in
practice, is made in two distinct forms, one with
a single set of supporting planes, in imitation of
birds, and called a monoplane; and the other having
two wings, one above the other, and called
the bi-plane, or two-planes.

All machines now on the market which do not
depend on wing oscillations come under those