The Durham daily globe., 1893-05-12
JUST HOW MAN WILL FLY
NOT BY FLAPPlNG ARTIFICIAL WINGS,
BUT BY SOARING.

Come Near to Solving the Problem.
Man will yet learn how to fly. Pro
fessor Langley, secretary of the Smith
sonian institution, so declared in an ad-
dress delivered before the National
Academy of Sciences This ought to
! give much encouragement to thinkers
who hope that mankind will some day
secure domain in the element Of birds,
just as it has already done, thanks to the
evolution of submarine boats and diving
gear, in that of fishes. The distinguish
ed scientist referred to expressed conf
dence that the contrivance of the future
for aerial navigation would be on the
! kite principle.
! The air possesses elements of buoy
ancy which have not been recognized
hitherto There is no truth in the popu-
lar conception that body heavier than
the atmosphere cannot be suspended in
that medium without motion A kite
Of sticks and paper is much heavier than
the fluid which it displaces, but it is sus-
tanned aloft. You can find an example
much more striking, however, in the
eagle or the frigate bird, which, though
an animal of considerable weight, re-
mains poised in the sky upon extended
pinious motlonless for hours together, so
that telescope may be trained on it.
Thousands Of feet above the earth it is
sustained without movement of feath-
er, though in rarefed atmosphere.
This is possible because the suspended
fowl has an instructive knowledge of the
way in which to utilize the air currents
for its support. When man has learned
how this can be done he will be able to
| fly. The most advanced investigators in
this subject reject the balloon and all
other such lifting devices as impracti-
cable; gas lighter than air can never
be safely confined within a receptacle
that is not weighty, and the same objec-
tion applies to vacuum.
Ballooning today is about where it
was when it was first invented, and in
the nature Of things it never get much
further Aluminium is light for metal,
but it is several times too heavy to be
| successfully utilized for such purposes.
Pray, what has become Of those alumni
nun trains of cars that were to be run
| through the air from Chicago to New
York at sixty minutes the trip?
LESSONS FRoM BIRDS
There is a school of flying machine in
ventors who may be designated as the
''fappers," inasmuch as their idea is to
sustain their contrivances by the flap
ping Of birdlike wings. But they doubt
less forget that the best flyers among
! birds do not support themselves by flap
ping. On the contrary, they only resort
to that performance when it is necessary
for start.
The eagle, if launching himself from
level ground, is obliged to take quite a
run first; then, Tapping his wings with
a violent muscular effort which he could
not keep up for long, he gains suff
cient altitude to render it possible for
| him to strike along the plane of an air
! current which holds him up.
| Floating with ibrating pinions from
one air current to another, he is lifted,
with an occasional broad sweep of his
| powerful wings, to the upper aerial re-
gions, where he simply floats, opposing
to each movement Of the suspended
ether the gentle force necessary to main
tain him in his stationary position.
These principles which the eagle ap
! plies for purposes of flight are perfectly
understood in the theory of mechanics
1t is only necessary to adapt them with
suitable apparatus in order to give to
human beings like powers. True, the
bird is lighter in proportion to its size
than is man; its bones are hollow and
/ filled with warm air from the lungs.
But the difference in this respect is
not very material, and it may easily be
compensated for by bigger wings. Pow
er to flap them is not what is required,
inasmuch as the start can be made from
a height; what is wanted is the knowl-
edge which inherited experience-"in-
stinct"-has given the fowl as to how to
adapt the angles Of the wings to the air
currents.
PRACTICABLE MACHINE
This is precisely what Professor Lang
ley has been experimenting with. What
be is attempting is to produce machine
adapted to fiotatlon upon the air cur
rents like a kite. You can find very
simple illustration of the principle he is
working on in the trick done with play
ing cards by the prestidigitator Herr
mann, who throws them from the stage
into the highest gallery of the biggest
theater in the United States, distributing
them one after another among the
gods of that select circle. How does
he do it?
Simply by skllfully utilizing the air
currents. The scrap of pastboard is
heavier than the atmosphere, but, ju
diciously projected, it mounts to a
great height and distance with very lit
tie force. 1t would stay up, too, even if
thrown outdoors, supposing that it pos
sessed the intelligence necessary to &C
commodate its surface to the winds.
What can be done in this way may be
accomplished on a larger scale. Lest
this proposition be disputed it will be
sufficient to refer to flying machine
patented in Australia 1t weighs alto
gether nineteen pounds, and its back
bone is a long copper cylinder two inches