Evening star. [volume] (Washington, D.C.) 1854-1972, 1881-03-19
Flight. Natural and Artificial.

All, under ordinary conditions is an eX-
tremely light, tenuous, and harmless hutd
Still air Is impalpabie to the touch, ard eXerts
10 pressure save that known az atmospheric
pressure. Rouse IL, however, as 1t rouses in
the tornado, and it becomes tremendous
power, equal to the upf0oting Of trees, the 10
roofing OF houses, and the destruction OF navies.
The mat er OF the air thus violently agttated
becomes In some senses Irresistible. It lifts
and whiTls along solid masses Incredible In their
dimensions and weight. We have only to
transfer the fury Of the hurricane to the wings
OF Tying creatures to understand how they llfr
their bodies and hurl them through space. In
light one or two things Is necessary; either
the wings must be driven at a very high speed
In stu cir; or the air, violently agtated must
strike the under surfaces OF the wings saoVing
gently, or held In one position at an upward
angle. after the manner OF boys kite. This
Is St'te qua non. The speed at which wings
are driven 01mintshes In proportion as the
wings become large. but In every case they
must be made to move more Or less briskly II
tne ar Is not moving; and they must be made
controlled, and the flying creature Is to fly In
any given direction. The great differences be-
tween the water ans she air as highways for
the water. being heavy, tncompress,ble
fiuid, hoats or buoys up the animal Immersed
IN IL; and affords comparatively substantial
recoil to its travelling surfaces. swim.
pIopel Itself; the air. on the contrary being
light and highly compressible fluid. does not
HOaC or DuOy up the anisCal Immersed In it,
neither does 1t afford q very substantial recoii
to its travelling surfaces A Tying animal
has, consequently, not only to propeI
Itself, but also to float or buoy itself. The
analogy which obtains between the water ana
the air as supporting medes has strangely and
gravely complicated the problem of fight; the
idea upperR0st in most minds being, that
lying creature must float upon the air as ship
noats upon the water. This idea led to the dis.
coyery OF balloon by the Montgolfier BROTH
ers In 1882, nearly 100 years ago. AS, however,
everything which flies is vestly heavier than
the air, 1t follows that the balloon has no ana
logue In nature. The balloon cannot In any
sense be regarded as lying machine. In
calm 1t can only rise and fall n vertical line,
and II air currents are present it is waited
about, and is completely at the mercy of the
wind. AS Its horizontal movements cannot be
controlled 1t is useless as means of transport
from one point to another. The balloon at best
| Is mere lifting apparatus. It resembles the
flying creature only In this. that It is immersed
In the ocean OF air IN which It SuStains itself.
The mode OF suspension Is wholly different.
The balloon floats because 1t Is lighter than
the atr-the lying creature Goats because 1t
extracts from the air. by the vigorous down
ward action OF its wings, certain amount Of
upward recotl. The balloon is passive; the fly
Ing creature is active. The balloon is controlled
by the wind; the flying creature controls the
wind. The balloon IN the absence OF wind can
only rise and fall in vertical line; the flying
creature can fly In q horizontal plane In any
given direction. The balloon Is inefficient be.
cause OF its levity: the lying creature is eff
Gent because OF its weight.-FrdzieT''S MGJd-
zine.