William J. Claxton - The Mastery of the Air
of which had as many as half a dozen planes arranged one above another. His best results, however, were
obtained by the two-plane machine, resembling to a remarkable extent the modern biplane.
CHAPTER XVII. The Aeroplane and the Bird
We have seen that the inventors of flying machines in the early days of aviation modelled their various
craft somewhat in the form of a bird, and that many of them believed that if the conquest of the air was to
be achieved man must copy nature and provide himself with wings.
Let us closely examine a modern monoplane and discover in what way it resembles the body of a bird in
build.
First, there is the long and comparatively narrow body, or FUSELAGE, at the end of which is the rudder,
corresponding to the bird's tail. The chassis, or under carriage, consisting of wheels, skids, may well be
compared with the legs of a bird, and the planes are very similar in construction to the bird's wings. But
here the resemblance ends: the aeroplane does not fly, nor will it ever fly, as a bird flies.
If we carefully inspect the wing of a bird - say a large bird, such as the crow - we shall find it curved or
arched from front to back. This curve, however, is somewhat irregular. At the front edge of the wing it is
sharpest, and there is a gradual dip or slope backwards and downwards. There is a special reason for this
peculiar structure, as we shall see in a later chapter.
Now it is quite evident that the inventors of aeroplanes have modelled the planes of their craft on the
bird's wing. Strictly speaking, the word "plane" is a misnomer when applied to the supporting structure of
an aeroplane. Euclid defines a plane, or a plane surface, as one in which, any two points being taken, the
straight line between them lies wholly in that surface. But the plane of a flying machine is curved, or
CAMBERED, and if one point were taken on the front of the so-called plane, and another on the back, a
straight line joining these two points could not possibly lie wholly on the surface.
All planes are not cambered to the same extent: some have a very small curvature; in others the curve is
greatly pronounced. Planes of the former type are generally fitted to racing aeroplanes, because they
offer less resistance to the air than do deeply-cambered planes. Indeed, it is in the degree of camber that
the various types of flying machine show their chief diversity, just as the work of certain shipmasters is
known by the particular lines of the bow and stern of the vessels which are built in their yards.
Birds fly by a flapping movement of their wings, or by soaring. We are quite familiar with both these
actions: at one time the bird propels itself by means of powerful muscles attached to its wings by means
of which the wings are flapped up and down; at another time the bird, with wings nicely adjusted so as to
take advantage of all the peculiarities of the air currents, keeps them almost stationary, and soars or
glides through the air.
The method of soaring alone has long since been proved to be impracticable as a means of carrying a
machine through the air, unless, of course, one describes the natural glide of an aeroplane from a great
height down to earth as soaring. But the flapping motion was not proved a failure until numerous
experiments by early aviators had been tried.
Probably the most successful attempt at propulsion by this method was that of a French locksmith named
Besnier. Over two hundred years ago he made for himself a pair of light wooden paddles, with blades at
either end, somewhat similar in shape to the double paddle of a canoe. These he placed over his
shoulders, his feet being attached by ropes to the hindmost paddles. Jumping off from some high place in
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