The Democratic press. [volume] (Ravenna, O. [Ohio]) 1868-1901, 1881-06-30
The Sneed of tbe Wing.

+ A writer in Frazes's Magazine says:
The speed at which some wings are
| driven is enormous. 1t is occasionally
! SO great as to cause the pinions to emit
! a drumming sound. To this source the
| buzz of the fly, the drone of the bee,
and the boom of the beetle are to be re-
ferred. When a grouse, partridge, or
pheasant suddenly springs into the air,
the sound produced by the whirring of
its wings greatly resembles that pro-
| duced 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 33C times
per second, i. e., 19, 800 time per min
ute, and that the butterfly moves its
wings nine times per second, or $40
times per minute. The movements rep
resent an incredibly high speed even at
the roots of the wings; but the speed is
enormously increased at the tips of the
wings, from the fact that the tips rotate
upon the roots as centers. In reality,
and as it has been already indicated,
the speed at the tips of the wings in
creases in proportion as the tips are re-
moved 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 a very much
greater space in given time than the
part nearer the root of the wing. The
progressive increase in tho spread of
the wings, in proportion as tho 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 large
bats and birds are driven more Ieisurely
than the small and short wings of small
bats and birds. That the wing is driv-
en- 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
grllls flap their wings much more slow
1y than small guils; the contiguration
and relative size of the wings to the
body being the same in both. This is a
hopeful feature in the construction of
flying machines, as there can be no
doubt that comparatively very slow
will suffice for driving the
long, powerful wings required TO elevate
and propel fyingmachines. The speed
of the wing is, in part regulated by the
of the wing. Thus, if the
Wing DO DTO'ttl ~ wen dS louS, tHc DedLS
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 slow
est flying birds we have. have timed
the heron on several occasions, and find
that in ordinary flight its wings make
exactly sixty up and sixty down strokes
i. g., 120 beats per minute. In the
the great extinct Saurian,
the wing was enormously elongated,
and in this particular instance probably |
from fifty to sixty beats of the wing !
per minute sulficod for flight Fifty or
sixty pulsations of the wing per minute
do not involve much wear and tear of |
the working parts. and l am strongly |
Of opinion that artificial flight. if once
achieved, will become a comparatively |
safe means of locomotion, as far as the |
machinery required is concerned.