The Owosso times. (Owosso, Mich.) 18??-1882, 1882-03-24
The Speed OF the Wing.

A writer in Frazier's Magazine ays
The speed at which some wings are
driven is enormous. 1t is occasionally
50 great as to emit drumming sound
To this source the buzz of the fly, the
drOne of the bee, and the boom of the
beetle are to be referred. When a
grouse, partridge, or. pheasant suddenly
springs into the air, the sound produced
by the whirring of its wings
greatly resembles that produced
by the contact of steel with the rapidly
revolving stone of the knife grinder
1t has been estimated that the common
fly moves its wings $50 times per sec
OnI, j. e., l9,S00 times per minute. and
that the butterfly moves its wings nine
times per second, or $40 times per min
ute. These movements represent an
incredibly high speed even at the roots
of the wings. but the speed is encr-
mOusly increased at the tips of the
wings, from the fact that the tips ro-
tate upon the roots as centers. In re-
ality, and as it has been already indi-
Gated, the speed at the tips of the wings
increases in proportion as the tips are
removed from the axis of rotation, and
in proportion as the wings are long.
This is explained on the principle well
understood in mechanics. If rod or
wing hinged at one point be made to
vibrate, the free end of the rod or wing
always passes through very much
greater space in u given time than the
part nearer to the root of the wing.
The progressive increase in the spread
of the wings, in proportion as the wings
become larger, explains why the wings
of bats and birds are not driven at the
extravagant speed of insect wings, and
how the large and long wings of bats
and birds are driven more leisurely
than the small and short wings of
small bats and birds. That the wing
is driven more slowly in proportion to
its length is proved by experiment, and
by observing the flight of large and
small birds of the same genus. Thus,
large gullshap their wings much more
slowly than small gulls; the confgura-
tiOn and relative size of the wings to
the body being the same in both. This
is hopeful feature in the construction
of flying machines, as there can be no
doubt that comparatively very slow
movements will suffice for driving the
long, powerful wings required to ele-
vate and prOpel flying machines. The
speed of the wings is partly regulated
by its amplitude. Thus, if the wing be
broad as well as long, the beats are
necessarily reduced in frequency. This
is especially true of the heron, which is
one of the most picturesque, and at the
same time one of the slowest flying
birds we have. have timed the heron
on several occasions, and find that in
ordinary flights it's wings make exactly
sixty up strokes and SIXTY down strokes
that is, 12O beats Yer minute. In
the pterodactyl, the great extinct Sau-
rian, the wing was enormously elOng-
ated, and in this particular instance
probably from fifty to sixty beats of
the wing per minute sufficed for flight.
Fifty or sixty pulsations of the wing
per minute do not involve much wear
and tear of the working parts, and 1
am strongly of opinion that artificial
fight, if once achieved, will become a
comparatively safe means of locomO-
ton, as far as the machinery required
is concerned.