Having treated of the balloon in all its different aspects, it is both just and appropriate to conclude with an account of the theory and construction of that curious machine which is, according to some enthusiastic aeronauts, to supplant the balloon altogether, and enable us to accomplish that which has been one of the great aims and desires of mankind from the earliest ages, namely, the directing of our flight, or steering a course, not only through, but, if need were, in opposition to the winds.

Monsieur Nadar being, perhaps, the most zealous advocate of this machine, we draw our information chiefly from his writings. Of course the reader will understand that we do not support the views which we are about to set forth; neither, however, do we treat them lightly, because we have lived long enough to see proposals which, not many years ago, would have been deemed worthy of the most visionary of lunatics, carried out to a successful issue and reduced to sober facts.

When we hear of a flying machine which is to rise from the earth at the bidding of man, and, like the fabulous creations in the Arabian Nights’ Entertainment, dart through the air with passengers and luggage bound for definite localities, turning hither and thither, or alighting on the earth according to the will of a steersman—we confess to a feeling which is apt to wrinkle our visage with the smile of incredulity; but we sternly rebuke the smile, for we know that similar smiles wreathed the faces of exceedingly wise people when, in former days, it was proposed to drive ships and coaches by steam, and hold instantaneous converse with our friends across the Atlantic by means of electricity!

Let us therefore gravely consider the aerial locomotive.

Monsieur Nadar, as the reader already knows, scouts the idea of steering balloons.

In reference to this he states with truth that, “a balloon which presents to the action of the atmosphere a volume of from 22,000 to 42,000 (cubic) feet of a gas from ten to fifteen times lighter than air, is, by its very nature, smitten with incapacity to struggle against the slightest current, no matter what may be the resisting motive force which may be imparted to it. Both by its constitution, and by the medium which drives it hither and thither at the pleasure of the winds, it can never become a vessel. It is a buoy, and remains a buoy.”

Discarding, therefore, with contempt, the balloon as an aerial locomotive, he announces his belief that it is the screw which is destined to drive us, or clamber with us, into the blue vault above, and convey us from place to place. And here it is right to assure the reader that the theoretical power of the screw to accomplish the end in view is not a disputable question. It has been practically proved by models, and the only point that remains to be settled is the possibility of applying the power to machines large enough to carry human beings with a sufficient degree of safety to warrant risking the attempt.

Monsieur Nadar sets out with a statement which he deems self-evident, namely, that, “in order to contend against the air, we must be specifically heavier than the air”—a truth which was also, we are told, announced by the first Napoleon in the epigrammatic sentence, “There can be no progress without resistance.” From this the Frenchman proceeds to prove that, in order to command the air, it is necessary to support one’s-self upon it, instead of being at its mercy; that we can only rest upon that which resists, and that the air itself furnishes us amply with the needful resistance—it being “the same atmosphere which overturns walls, tears up by the root trees a century old, and enables ships to ascend impetuous currents.” Glowing with the ardour of a man whose faith is refreshingly great, he tells us that the time has at last come when the atmosphere must yield to man. “It is for man,” he says, “to restrain and subdue this insolent and abnormal rebellion, which has for so many years laughed at our vain efforts. We are in turn about to make it serve us as a slave, just as the water on which we launch the ship, as the solid earth on which we press the wheel!”

There is a toy called the spiralifer, which is common enough in towns, and which is, doubtless, known to almost every one. It consists of four flat fans attached to a spindle somewhat after the manner of the arms of a windmill. It is placed in a hollow tube and made to spin violently by pulling a string wound round the spindle. The result is that the spiralifer leaps out of the hollow tube and ascends powerfully as long as the violent spinning motion continues. If properly constructed, this toy acts with great force and certainty, and if the spinning motion could only be kept up, by any means, the ascent would be continued. The principal here involved is precisely the same as that which causes a windmill to turn, a screw-propeller to drive a ship, and a cork-screw to enter a cork. It is pressure against a resisting medium. Air is the resisting medium in the case of the mill; water and cork respectively in the other cases. The only difference between the windmill and the spiralifer is, that the first is moved by the air pressing against it, the other by itself, in its rotatory action, pressing against the air. If you turn a bottle upside down, and, while in that position, send a cork-screw up into the cork, you set in motion the same force which is applied in the spiralifer. As the screw screws itself up into the cork, so the spiralifer screws itself up into the air. Of course the screw remains sticking there when the motive power ceases, because of the density of the medium through which it moves, while the spiralifer, when at rest, sinks, because of the fluidity of the air; but the principle of motion in each is the same. The screw-propeller of a ship is just a spiralifer placed horizontally, acting on water instead of air, and having a vessel placed in front of it.

Now, Monsieur Nadar’s aerial locomotive is a huge spiralifer, made strong enough to carry up a steam-engine which shall keep it perpetually spinning, and, therefore, perpetually ascending. Perhaps we should have said that his locomotive is a huge machine to which several spiralifers are attached, so that while one set raises or (by reversing the engine) depresses it, other sets drive it sideways. The theory is perfect, and the practice has been successfully attempted in models. Messieurs Ponton d’Amécourt and de la Laudelle, we are told—“the one a man of the world, and the other a man of letters”—engaged the services of two skilled mechanics, Messieurs Joseph of Arras and J. Richard, who constructed models of machines which ascended the atmosphere, carrying their motive power (springs) along with them.

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