Each of these systems has had, and still does have, supporters determined to stand their ground on the point.
However, Robur, for many reasons, had rejected the last two.
That the ornithopter, the mechanical bird, presents certain advantages, no doubt. The work and experiments of Monsieur Piraud, in 1884, proved as much. But, as people said to him at the time, one must not slavishly imitate nature. Trains are not modeled after quadrupeds, nor steamships after fish. The former are fitted with wheels that are not legs, the latter with propellers that are nothing like fins. And they work none the worse for it; quite the contrary. Besides, do we know what actually happens mechanically in bird flight, a series of very complex movements? Didn’t Dr. Marey suspect that the quills separate during the lift of the wing to let the air pass through, a movement difficult to produce, to say the least, with an artificial machine?
On the other hand, airplanes had given a few good results; that could not be doubted. Propellers opposing an oblique plane to the air was the way to produce ascension, and experiments with model apparatuses proved that the available weight, that is to say the weight available in addition to that of the apparatus itself, increases with the square of the speed. These were great advantages—superior even to those of balloons in motion.
Nevertheless, Robur had believed that what was best was still what was simplest. Moreover, propellers—those “Saint Helixes” that had been thrown in his face at the Weldon Institute—would suffice for all the needs of his flying machine. Some would keep the apparatus suspended in midair; others would pull it through the sky in marvelous conditions of speed and security.
The fact is that, in theory, with a propeller of sufficiently short length but considerable surface area, as Mr. Victor Tatin said, one could “extend the idea to its extreme, and support an indefinite weight with the most minimal force.”7
If the orthopter—flapping bird wings—rises by resting on the air in the normal way, the helicopter rises by hitting the air obliquely with its propeller blades, as if it were ascending on an inclined plane. The blades, in fact, are helicoidal wings in place of paddle-shaped wings. The propeller runs necessarily in the direction of its axle. Is that axle vertical? Then it moves vertically. Is it horizontal? Then it moves horizontally.
The whole flying machine of the engineer Robur was in those two functions.
Here is its exact description, which can be divided into three basic sections: the platform, the suspension and propulsion engines, the machinery.
Platform.—This is a construction thirty meters long and four wide, a genuine ship’s deck, with a bow shaped like a spear. Below it swells a solidly reinforced hull, which contains the machines that produce mechanical power, the munitions hold, the tackle, the tools, and the general hold for supplies of all sorts, including the ship’s stock of freshwater. Around the deck, some lightweight supports linked by wire netting, to hold up a guardrail. On the surface rise three deckhouses, with some compartments designed for lodging the crew and others for the machinery. In the central deckhouse is the machine that drives all the suspension propellers; in the one near the bow, the machine for the front propeller; in the one near the stern, the machine for the back propeller—these three machines each running individually. On the bow side, in the first deckhouse, are the office, the galley, and the crew’s quarters. On the stern side, in the last deckhouse, various cabins are arranged, including the engineer’s own cabin and a dining room, and above them, a glass box for the helmsman who steers the apparatus by means of a powerful rudder. All these deckhouses are illuminated by portholes made of tempered glass, which offers ten times as much resistance as ordinary glass. Below the hull a system of flexible springs is set up to reduce bumps, although landing can be done with extreme grace when the engineer is master over the movements of the apparatus.
Engines for suspension and propulsion.—Above the platform, thirty-seven axes rise vertically: fifteen on each side, and seven higher ones in the center. It might be taken for a ship with thirty-seven masts. Only, each of these masts, instead of bearing sails, carry two horizontal propellers, relatively small in pitch and diameter, but rotatable at prodigious speed.8 Each of these axes moves independently from the others, and moreover, in pairs, the axes turn in opposite directions—an arrangement necessary to prevent the apparatus from gyrating. Thus, the propellers, while still rising on a vertical column of air, are balanced against horizontal resistance. Consequently, the apparatus is fitted with seventy-four suspension propellers, with the three blades of each one held on the outside by a metal circle, which, functioning as a flywheel, economizes the driving force. At the bow and the stern, mounted on horizontal axes, two propulsion propellers, with four blades each, of very high reverse pitch, turning in opposite directions and communicating the movement of propulsion. These propellers, of much larger diameter than the suspension propellers, can also turn with excessive speed.
The Albatross
In short, this apparatus combines the systems already recommended by Messrs. Cossus, de La Landelle, and de Ponton d’Amé-court, systems perfected by the engineer Robur. But above all it was in the choice and application of driving force that he has the right to be considered a true inventor.
Machinery.—It is neither steam from water or other liquids, nor compressed air or other elastic gases, nor explosive mixtures susceptible of producing mechanic action, that Robur calls upon for the power necessary to sustain and move his apparatus. It is electricity, that agent which will be, someday, the soul of the industrial world. Moreover, no electromotive machine to produce it. Nothing but batteries and accumulators. Only, what are the elements that enter into the composition of these batteries, what acids set them to work? That is Robur’s secret. The same goes for the accumulators. Of what nature are their positive and negative forces? That remains unknown. The engineer had refrained—for good reason—from taking out a patent on the invention. In short, indisputable result: batteries of extraordinary efficiency, acids with almost absolute resistance to evaporation or congelation, accumulators far ahead of the Faure-Sellon-Volckmar type, and, finally, currents whose amperes are measured out in numbers hitherto unknown. Hence, electricity of virtually infinite horsepower,9 working propellers that give the apparatus suspension and propulsion power surpassing all its needs, no matter what the circumstance.
But, as must be repeated, all this belonged only to the engineer Robur. He guarded it with the strictest secrecy. If the president and secretary of the Weldon Institute could not manage to discover it, very probably the secret would be lost to humanity.
It might be taken for a ship with thirty-seven masts.
It goes without saying that the apparatus was sufficiently stable, because of the position of its center of gravity. No danger that it would tilt to disquieting angles from the horizontal, no upturning to fear.
It still remains to be explained what material the engineer Robur had employed to construct his aircraft—a word that can very exactly be applied to the Albatross.10 What was this material, so durable that Phil Evans’s bowie knife could not cut it, and whose nature Uncle Prudent had been unable to explain? Simple paper.
For many years already, this process had undergone considerable development. Unsized paper, soaked in dextrin and starch, then pressed hydraulically, forms a material as hard as steel. People have used it to make pulleys, rails, and wagon wheels, more solid than metal and yet lighter at the same time. It was this solidity and lightness that Robur had wanted when constructing his aerial locomotive. Everything, hull, body, deckhouses, cabins, was made of straw paper, made metallic by the compression process, and even—which is nothing to be sneezed at for an apparatus running at such great heights—incombustible. As for the various mechanisms in the suspension and propulsion engines, axes, and propeller blades, the same gelatinous fiber had furnished a substance that was both resistant and flexible. That material, usable in all its forms, insoluble in most gases