Evening star., 1903-10-07

Siy oeAect WIN ALI these 18 that they Deln&
lighter than the airyhoa on It rather than
lie In 1t. and thus Become prey to every
changing current af
The behavior Of the soaring bird, such as
the buzzard. the alhatross and the condor.
has been copied In ehe construction OF Prof.
cnns not The wings OF the ma
no motive powef Their function is to sup
ply the sustaining surface. Extended and
fixed In flight they act like the wings OF a
buazard when tscen Ia Its familiar attitude
soaring above fhe tree tops.
Nature initiated.
But poorly do these sustaining surfaces
Of mans device and construction initiate
those Of nature. BY far more power is
needed in the, mechanical device than in
the bird, with equal expanse of wing. If
a model flying machine and bird of equal
weight be compared the machine will re-
qu1re many times greater power and a
much larger sustaining area
The inertia and elasticity of the air rank
high among the properties relied upon Tor
the fight of the langley machine. To
body falling vertically the inertia of the
air directly under it offers a certain amount
of resistance. The same body in the same
period of time being made to pass in a
horizontal course over thousand or more
times that space of air meets. a resistance
to it's downward tendency that Is definitely
multiplied.
Ills was oilc VI tIle tdIhcot SohSiuSioiiS
Of Prof. Langley in his Investigations in
aerodynamics. Putting it in practice it
has been verified. The elastic nature of
the atmosphere is also made use OF by the
inventor.
High Speed Necessary.
High velocity is essential to the most
satisfactory flight of the machine Prof
Langley has held this view from practically
the first of his experiments. In this con-
nection some interesting tests he made
with a brass bar which was caused to travel
through the air at a high speed are re-
called He attached the piece, weighing
one pound. to the end Of a beam which was
made to pass through a circumference of
POO feet at a velocity up to seventy miles
an hour.
As the speed increased gradually the
weight was recorded. Instead of increas-
ing, according to the then existing IDEAS
it registered less and less as the speed de-
veloped When the highest velocity was
reached, with the beam going like a swift
winged bird, the bar seemed to float on the
air, registering scarcely anything at ALL
Prof. Langley, having thus got the idea
of the essential character of speed in air
navigation, has constructed his machine
with that constantly in view. He has con-
stantly borne in mind the physical law,
which he himself elaborated, by which the
power required to support a body in hori-
zontal flight decreases steadily as the speed
increases.
Having followed these principles, Prof
Langleys machine is at present without
facilities for starting off on voyage with
out the initial momentum being furnished
from the outside AM it is also lacking in
ability to remain suspended stationary in
the air
Starting Device Requisite.
Some device for starting it of is, there
fore. necessary. Future developments of
the flying machine may obviate this. There
may come a time when airships start
from most any position by simply getting
up steam and applying the motive power.
and it may be that subsequent inventions
will enable the machine to remain station
ary in the air. but the accomplishment of
these feats viii mean the employment Of
principles as yet undetermined and GER
tainly as yet unused in the Langley airship.
From the very nature of the physical
laws on which the aerOdrome is operated
this must be 50. AS speed is a requisite to
successful flight. inathe present develop
ment of the science. when speed is reduced
flight begins to- fail And speed is as nee
essary at the real beginning of the aerial
journey as it is at the point where it be-
gins to end. e
The launching carriage, propelled at a
velocity that reaches seventy feet per sec
ond, is the means employed by Prof Lang
ley for furnishing his airship with the
initial momentum. The start of the airship
therefore, resembles that of the buzzard
the eagle and other big birds Before they
begin to fly theyz.dig their talons in the
earth. run forward several PAGES with wings
extended, eventually leaving the ground at
gradual inclination.
The aerodrOme is built to balance itself
in the air much as the bird does. This
balancing is one of the most difficult ac-
complishments in aerial flight. 1t means
that the airship must be so adjusted in all
its parts that it tends to maintain it's poise
1t must adjust itself almost instinctively
almost as of it's own volition, to the vary
ing conditions of each moment
When the equilibrium is disturbed by the
multitudinOuS currents of the air the ship
must regain 1t at once or successful flight
is impossible This Is what the bird does
in soaring Its body is constantly rocking
it's transverse plane is repeatedly shifting
The bird it's instinct in the wonder
fully delicate art of balancing
Their Hope on Wings.
Beyond the possibility of carrying the
imitat ton of nature here the flying machine
experts have placed their hope In the mech
anism of the wings. Long has Prof Lang
ley labored over this problem, and in the
construction of the wings of the present
machine is seen his best thought and care.
The irregular currents Of the wind are of
prime importance In the mana agement Of the
aerodrome, particularly with regard to it's
/ balancing. There never is an absolute
calm of more than mOmentary duration
Currents are always moving however
slight and apparently imperceptible they
may be. With the thermometer Prof Lang
ley has made careful study of air streams.
He has found counter currents to be in
Vulnerable and to exist simultaneously In
every breeze. -.-.
They going in every direction, here,
there and everywhere. While the whole is
travelling in one general course the counter
currents are going toward every point of
the compass. This is what makes balanc-
ing for an airship 50 difficult