From "THE BOYS' BOOK OF INVENTIONS," Chapter IX, by Ray
Stannard Baker. Copyright, 1899, by Doubleday, Page & Co.
Probably no American inventor of flying machines is better known or
has been more successful in his experiments than Professor S. P.
Langley, the distinguished secretary of the Smithsonian Institution at
Washington. Professor Langley has built a machine with wings, driven
by a steam-engine, and wholly without gas or other lifting power
beyond its own internal energy. And this machine, to which has been
given the name Aerodrome (air-runner), actually flies for considerable
distances. So successful were Professor Langley's early tests, that
the United States Government recently made a considerable
appropriation to enable him to carry forward his experiments in the
hope of finally securing a practical flying machine. His work is,
therefore, the most significant and important of any now before the
public (1899).
The invention of the aerodrome was the result of long years of
persevering and exacting labor, with so many disappointments and
set-backs that one cannot help admiring the astonishing patience which
kept hope alive to the end. Early in his experiments, Professor
Langley had proved positively, by mathematical calculations, that a
machine could be made to fly, provided its structure were light enough
and the actuating power great enough. Therefore, he was not in pursuit
of a mere will-o'-the-wisp. It was a mechanical difficulty which he
had to surmount, and he surmounted it.
Professor Langley made his first experiments more than twelve years
ago at Allegheny, Pennsylvania.... Professor Langley formed the
general conclusion that by simply moving any given weight in plate
form fast enough in a horizontal path through the air it was possible
to sustain it with very little power. It was proved that, if
horizontal flight without friction could be insured, 200 pounds of
plates could be moved through the air and sustained upon it at the
speed of an express train, with the expenditure of only one
horse-power, and that, of course, without using any gas to lighten the
weight.
Every boy who has skated knows that when the ice is very thin he must
skate rapidly, else he may break through. In the same way, a stone may
be skipped over the water for considerable distances. If it stops in
any one place it sinks instantly. In exactly the same way, the plate
of brass, if left in any one place in the air, would instantly drop to
the earth; but if driven swiftly forward in a horizontal direction it
rests only an instant in any particular place, and the air under it at
any single moment does not have time to give way, so to speak, before
it has passed over a new area of air. In fact, Professor Langley came
to the conclusion that flight was theoretically possible with engines
he could then build, since he was satisfied that engines could be
constructed to weigh less than twenty pounds to the horse-power, and
that one horse-power would support two hundred pounds if the flight
was horizontal.
That was the beginning of the aerodrome. Professor Langley had worked
out its theory, and now came the much more difficult task of building
a machine in which theory should take form in fact. In the first
place, there was the vast problem of getting an engine light enough
to do the work. A few years ago an engine that developed one
horse-power weighed nearly as much as an actual horse. Professor
Langley wished to make one weighing only twenty pounds, a feat never
before accomplished. And then, having made his engine, how was he to
apply the power to obtain horizontal speed? Should it be by flapping
wings like a bird, or by a screw propeller like a ship? This question
led him into a close study of the bird compared with the man. He found
how wonderfully the two were alike in bony formation, how curiously
the skeleton of a bird's wing was like a man's arm, and yet he finally
decided that flapping wings would not make the best propeller for his
machine. Men have not adopted machinery legs for swift locomotion,
although legs are nature's models, but they have, rather, constructed
wheels--contrivances which practically do not exist in nature.
Therefore, while Professor Langley admits that successful flying
machines may one day be made with flapping wings, he began his
experiments with the screw propeller.
There were three great problems in building the flying machine. First,
an engine and boilers light enough and at the same time of sufficient
power. Second, a structure which should be rigid and very light.
Third, the enormously difficult problem of properly balancing the
machine, which, Professor Langley says, took years to solve....
Professor Langley established an experimental station in the Potomac
River, some miles below Washington. An old scow was obtained, and a
platform about twenty feet high was built on top of it. To this spot,
in 1893, the machine was taken, and here failure followed failure; the
machine would not fly properly, and yet every failure, costly as it
might be in time and money, brought some additional experience.
Professor Langley found out that the aerodrome must begin to fly
against the wind, just in the opposite way from a ship. He found that
he must get up full speed in his engine before the machine was allowed
to go, in the same way that a soaring bird must make an initial run on
the ground before it can mount into the air, and this was, for various
reasons, a difficult problem. And then there was the balancing.
"If the reader will look at the hawk or any soaring bird," says
Professor Langley, "he will see that as it sails through the air
without flapping the wing, there are hardly two consecutive seconds of
its flight in which it is not swaying a little from side to side,
lifting one wing or the other, or turning in a way that suggests an
acrobat on a tight-rope, only that the bird uses its widely
outstretched wings in place of the pole."
It must be remembered that air currents, unlike the Gulf Stream, do
not flow steadily in one direction. They are forever changing and
shifting, now fast, now slow, with something of the commotion and
restlessness of the rapids below Niagara.
All of these things Professor Langley had to meet as a part of the
difficult balancing problem, and it is hardly surprising that nearly
three years passed before the machine was actually made to fly--on
March 6, 1896.
"I had journeyed, perhaps for the twentieth time," says Professor
Langley, "to the distant river station, and recommenced the weary
routine of another launch, with very moderate expectation indeed; and
when, on that, to me, memorable afternoon the signal was given and the
aerodrome sprang into the air, I watched it from the shore with hardly
a hope that the long series of accidents had come to a close. And yet
it had, and for the first time the aerodrome swept continuously
through the air like a living thing, and as second after second passed
on the face of the stop-watch, until a minute had gone by, and it
still flew on, and as I heard the cheering of the few spectators, I
felt that something had been accomplished at last; for never in any
part of the world, or in any period, had any machine of man's
construction sustained itself in the air before for even half of this
brief time. Still the aerodrome went on in a rising course until, at
the end of a minute and a half (for which time only it was provided
with fuel and water), it had accomplished a little over half a mile,
and now it settled, rather than fell, into the river, with a gentle
descent. It was immediately taken out and flown again with equal
success, nor was there anything to indicate that it might not have
flown indefinitely, except for the limit put upon it."
MARCONI AND HIS GREAT ACHIEVEMENTS--NEW EXPERIMENTS IN WIRELESS
TELEGRAPHY
From "SECOND BOOK OF INVENTIONS," Chapter VII, by Ray
Stannard Baker. Copyright, 1903, by Doubleday, Page & Co.
At noon on Thursday (December 12, 1901), Marconi sat waiting, a
telephone receiver at his ear, in a room of the old barracks on Signal
Hill. To him it must have been a moment of painful stress and
expectation. Arranged on the table before him, all its parts within
easy reach of his hand, was the delicate receiving instrument, the
supreme product of years of the inventor's life, now to be submitted
to a decisive test. A wire ran out through the window, thence to a
pole, thence upward to the kite which could be seen swaying high
overhead. It was a bluff, raw day; at the base of the cliff 300 feet
below thundered a cold sea; oceanward through the mist rose dimly the
rude outlines of Cape Spear, the easternmost reach of the North
American Continent. Beyond that rolled the unbroken ocean, nearly
2,000 miles to the coast of the British Isles. Across the harbor the
city of St. John's lay on its hillside wrapped in fog; no one had
taken enough interest in the experiments to come up here through the
snow to Signal Hill. Even the ubiquitous reporter was absent. In Cabot
Tower, near at hand, the old signalman stood looking out to sea,
watching for ships, and little dreaming of the mysterious messages
coming that way from England. Standing on that bleak hill and gazing
out over the waste of water to the eastward, one finds it difficult
indeed to realize that this wonder could have become a reality. The
faith of the inventor in his creation, in the kite-wire, and in the
instruments which had grown under his hand, was unshaken.
"I believed from the first," he told me, "that I would be successful
in getting signals across the Atlantic."
Only two persons were present that Thursday afternoon in the room
where the instruments were set up--Mr. Marconi and Mr. Kemp.
Everything had been done that could be done. The receiving apparatus
was of unusual sensitiveness, so that it would catch even the faintest
evidence of the signals. A telephone receiver, which is no part of the
ordinary instrument, had been supplied, so that the slightest clicking
of the dots might be conveyed to the inventor's ear. For nearly half
an hour not a sound broke the silence of the room. Then quite suddenly
Mr. Kemp heard the sharp click of the tapper as it struck against the
coherer; this, of course, was not the signal, yet it was an indication
that something was coming. The inventor's face showed no evidence of
excitement. Presently he said:
"See if you can hear anything, Kemp."
Mr. Kemp took the receiver, and a moment later, faintly and yet
distinctly and unmistakably, came three little clicks--the dots of the
letter S, tapped out an instant before in England. At ten minutes past
one, more signals came, and both Mr. Marconi and Mr. Kemp assured
themselves again and again that there could be no mistake. During this
time the kite gyrated so wildly in the air that the receiving wire was
not maintained at the same height, as it should have been; but again,
at twenty minutes after two, other repetitions of the signal were
received. Thus the problem was solved. One of the great wonders of
science had been wrought.