Street and its neighborhood with their tumult. Several times had the inhabitants complained of the noisy way in which the proceedings ended, and more than once had the policemen had to interfere to clear the thoroughfare for the passersby, who for the most part were supremely indifferent on the question of aerial navigation. But never before had the tumult attained such proportions, never had the complaints been better founded, never had the intervention of the police been more necessary. But there was some excuse for the members of the Weldon Institute. They had been attacked in their own house. To these enthusiasts for "lighter than air" a no less enthusiast for "heavier than air" had said things absolutely abhorrent. And at the moment they were about to treat him as he deserved, he had disappeared. So they cried aloud for vengeance. To leave such insults unpunished was impossible to all with American blood in their veins. Had not the sons of Amerigo been called the sons of Cabot? Was not that an insult as unpardonable as it happened to be just--historically? The members of the club in several groups rushed down Walnut Street, then into the adjoining streets, and then all over the neighborhood. They woke up the householders; they compelled them to search their houses, prepared to indemnify them later on for the outrage on their privacy. Vain were all their trouble and searching. Robur was nowhere to be found; there was no trace of him. He might have gone off in the "Go-Ahead," the balloon of the Institute, for all they could tell. After an hour's hunt the members had to give in and separate, not before they had agreed to extend their search over the whole territory of the twin Americas that form the new continent. By eleven o'clock quiet had been restored in the neighborhood of Walnut Street. Philadelphia was able to sink again into that sound sleep which is the privilege of non-manufacturing towns. The different members of the club parted to seek their respective houses. To mention the most distinguished amongst them, William T. Forbes sought his large sugar establishment, where Miss Doll and Miss Mat had prepared for him his evening tea, sweetened with his own glucose. Truck Milnor took the road to his factory in the distant suburb, where the engines worked day and night. Treasurer Jim Chip, publicly accused of possessing an alimentary canal twelve inches longer than that of other men, returned to the vegetable soup that was waiting for him. Two of the most important balloonists--two only--did not seem to think of returning so soon to their domicile. They availed themselves of the opportunity to discuss the question with more than usual acrimony. These were the irreconcilables, Uncle Prudent and Phil Evans, the president and secretary of the Weldon Institute. At the door of the club the valet Frycollin waited for Uncle Prudent, his master, and at last he went after him, though he cared but little for the subject which had set the two colleagues at loggerheads. It is only an euphemism that the verb "discuss" can be used to express the way in which the duet between the president and secretary was being performed. As a matter of fact they were in full wrangle with an energy born of their old rivalry. "No, Sir, no," said Phil Evans. "If I had had the honor of being president of the Weldon Institute, there never, no, never, would have been such a scandal." "And what would you have done, if you had had the honor?" demanded Uncle Prudent. "I would have stopped the insulter before he had opened his mouth." "It seems to me it would have been impossible to stop him until he had opened his mouth," replied Uncle Prudent. "Not in America, Sir; not in America." And exchanging such observations, increasing in bitterness as they went, they walked on through the streets farther and farther from their homes, until they reached a part of the city whence they had to go a long way round to get back. Frycollin followed, by no means at ease to see his master plunging into such deserted spots. He did not like deserted spots, particularly after midnight. In fact the darkness was profound, and the moon was only a thin crescent just beginning its monthly life. Frycollin kept a lookout to the left and right of him to see if he was followed. And he fancied he could see five or six hulking follows dogging his footsteps. Instinctively he drew nearer to his master, but not for the world would he have dared to break in on the conversation of which the fragments reached him. In short it so chanced that the president and secretary of the Weldon Institute found themselves on the road to Fairmount Park. In the full heat of their dispute they crossed the Schuyllkill river by the famous iron bridge. They met only a few belated wayfarers, and pressed on across a wide open tract where the immense prairie was broken every now and then by the patches of thick woodland--which make the park different to any other in the world. There Frycollin's terror became acute, particularly as he saw the five or six shadows gliding after him across the Schuyllkill bridge. The pupils of his eyes broadened out to the circumference of his iris, and his limbs seemed to diminish as if endowed with the contractility peculiar to the mollusca and certain of the articulate; for Frycollin, the valet, was an egregious coward. He was a pure South Carolina Negro, with the head of a fool and the carcass of an imbecile. Being only one and twenty, he had never been a slave, not even by birth, but that made no difference to him. Grinning and greedy and idle, and a magnificent poltroon, he had been the servant of Uncle Prudent for about three years. Over and over again had his master threatened to kick him out, but had kept him on for fear of doing worse. With a master ever ready to venture on the most audacious enterprises, Frycollin's cowardice had brought him many arduous trials. But he had some compensation. Very little had been said about his gluttony, and still less about his laziness. Ah, Valet Frycollin, if you could only have read the future! Why, oh why, Frycollin, did you not remain at Boston with the Sneffels, and not have given them up when they talked of going to Switzerland? Was not that a much more suitable place for you than this of Uncle Prudent's, where danger was daily welcomed? But here he was, and his master had become used to his faults. He had one advantage, and that was a consideration. Although he was a Negro by birth he did not speak like a Negro, and nothing is so irritating as that hateful jargon in which all the pronouns are possessive and all the verbs infinitive. Let it be understood, then, that Frycollin was a thorough coward. And now it was midnight, and the pale crescent of the moon began to sink in the west behind the trees in the park. The rays streaming fitfully through the branches made the shadows darker than ever. Frycollin looked around him anxiously. "Brrr!" he said, "There are those fellows there all the time. Positively they are getting nearer! Master Uncle!" he shouted. It was thus he called the president of the Weldon Institute, and thus did the president desire to be called. At the moment the dispute of the rivals had reached its maximum, and as they hurled their epithets at each other they walked faster and faster, and drew farther and farther away from the Schuyllkill bridge. They had reached the center of a wide clump of trees, whose summits were just tipped by the parting rays of the moon. Beyond the trees was a very large clearing--an oval field, a complete amphitheater. Not a hillock was there to hinder the gallop of the horses, not a bush to stop the view of the spectators. And if Uncle Prudent and Phil Evans had not been so deep in their dispute, and had used their eyes as they were accustomed to, they would have found the clearing was not in its usual state. Was it a flour mill that had anchored on it during the night? It looked like it, with its wings and sails--motionless and mysterious in the gathering gloom. But neither the president nor the secretary of the Weldon Institute noticed the strange modification in the landscape of Fairmount Park; and neither did Frycollin. It seemed to him that the thieves were approaching, and preparing for their attack; and he was seized with convulsive fear, paralyzed in his limbs, with every hair he could boast of on the bristle. His terror was extreme. His knees bent under him, but he had just strength enough to exclaim for the last time, "Master Uncle! Master Uncle!" "What is the matter with you?" asked Uncle Prudent. Perhaps the disputants would not have been sorry to have relieved their fury at the expense of the unfortunate valet. But they had no time; and neither even had he time to answer. A whistle was heard. A flash of electric light shot across the clearing. A signal, doubtless? The moment had come for the deed of violence. In less time that it takes to tell, six men came leaping across from under the trees, two onto Uncle Prudent, two onto Phil Evans, two onto Frycollin--there was no need for the last two, for the Negro was incapable of defending himself. The president and secretary of the Weldon Institute, although taken by surprise, would have resisted. They had neither time nor strength to do so. In a second they were rendered speechless by a gag, blind by a bandage, thrown down, pinioned and carried bodily off across the clearing. What could they think except that they had fallen into the hands of people who intended to rob them? The people did nothing of the sort, however. They did not even touch Uncle Prudent's pockets, although, according to his custom, they were full of paper dollars. Within a minute of the attack, without a word being passed, Uncle Prudent, Phil Evans, and Frycollin felt themselves laid gently down, not on the grass, but on a sort of plank that creaked beneath them. They were laid down side by side. A door was shut; and the grating of a bolt in a staple told them that they were prisoners. Then there came a continuous buzzing, a quivering, a frrrr, with the rrr unending. And that was the only sound that broke the quiet of the night. Great was the excitement next morning in Philadelphia Very early was it known what had passed at the meeting of the Institute. Everyone knew of the appearance of the mysterious engineer named Robur--Robur the Conqueror--and the tumult among the balloonists, and his inexplicable disappearance. But it was quite another thing when all the town heard that the president and secretary of the club had also disappeared during the night. Long and keen was the search in the city and neighborhood! Useless! The newspapers of Philadelphia, the newspapers of Pennsylvania, the newspapers of the United States reported the facts and explained them in a hundred ways, not one of which was the right one. Heavy rewards were offered, and placards were pasted up, but all to no purpose. The earth seemed to have opened and bodily swallowed the president and secretary of the Weldon Institute. Chapter VI THE PRESIDENT AND SECRETARY SUSPEND HOSTILITIES A bandage over the eyes, a gag in the mouth, a cord round the wrists, a cord round the ankles, unable to see, to speak, or to move, Uncle Prudent, Phil Evans, and Frycollin were anything but pleased with their position. Knowing not who had seized them, nor in what they had been thrown like parcels in a goods wagon, nor where they were, nor what was reserved for them--it was enough to exasperate even the most patient of the ovine race, and we know that the members of the Weldon Institute were not precisely sheep as far as patience went. With his violence of character we can easily imagine how Uncle Prudent felt. One thing was evident, that Phil Evans and he would find it difficult to attend the club next evening. As to Frycollin, with his eyes shut and his mouth closed, it was impossible for him to think of anything. He was more dead than alive. For an hour the position of the prisoners remained unchanged. No one came to visit them, or to give them that liberty of movement and speech of which they lay in such need. They were reduced to stifled sighs, to grunts emitted over and under their gags, to everything that betrayed anger kept dumb and fury imprisoned, or rather bound down. Then after many fruitless efforts they remained for some time as though lifeless. Then as the sense of sight was denied them they tried by their sense of hearing to obtain some indication of the nature of this disquieting state of things. But in vain did they seek for any other sound than an interminable and inexplicable f-r-r-r which seemed to envelop them in a quivering atmosphere. At last something happened. Phil Evans, regaining his coolness, managed to slacken the cord which bound his wrists. Little by little the knot slipped, his fingers slipped over each other, and his hands regained their usual freedom. A vigorous rubbing restored the circulation. A moment after he had slipped off the bandage which bound his eyes, taken the gag out of his mouth, and cut the cords round his ankles with his knife. An American who has not a bowie-knife in his pocket is no longer an American. But if Phil Evans had regained the power of moving and speaking, that was all. His eyes were useless to him--at present at any rate. The prison was quite dark, though about six feet above him a feeble gleam of light came in through a kind of loophole. As may be imagined, Phil Evans did not hesitate to at once set free his rival. A few cuts with the bowie settled the knots which bound him foot and hand. Immediately Uncle Prudent rose to his knees and snatched away his bandage and gag. "Thanks," said he, in stifled voice. "Phil Evans?" "Uncle Prudent?" "Here we are no longer the president and secretary of the Weldon Institute. We are adversaries no more." "You are right," answered Evans. "We are now only two men agreed to avenge ourselves on a third whose attempt deserves severe reprisals. And this third is--" "Robur!" "It is Robur!" On this point both were absolutely in accord. On this subject there was no fear of dispute. "And your servant?" said Phil Evans, pointing to Frycollin, who was puffing like a grampus. "We must set him free." "Not yet," said Uncle Prudent. "He would overwhelm us with his jeremiads, and we have something else to do than abuse each other." "What is that, Uncle Prudent?" "To save ourselves if possible." "You are right, even if it is impossible." "And even if it is impossible." There could be no doubt that this kidnapping was due to Robur, for an ordinary thief would have relieved them of their watches, jewelry, and purses, and thrown their bodies into the Schuyllkill with a good gash in their throats instead of throwing them to the bottom of--Of what? That was a serious question, which would have to be answered before attempting an escape with any chance of success. "Phil Evans," began Uncle Prudent, "if, when we came away from our meeting, instead of indulging in amenities to which we need not recur, we had kept our eyes more open, this would not have happened. Had we remained in the streets of Philadelphia there would have been none of this. Evidently Robur foresaw what would happen at the club, and had placed some of his bandits on guard at the door. When we left Walnut Street these fellows must have watched us and followed us, and when we imprudently ventured into Fairmount Park they went in for their little game." "Agreed," said Evans. "We were wrong not to go straight home." "It is always wrong not to be right," said Prudent. Here a long-drawn sigh escaped from the darkest corner of the prison. "What is that?" asked Evans. "Nothing! Frycollin is dreaming." "Between the moment we were seized a few steps out into the clearing and the moment we were thrown in here only two minutes elapsed. It is thus evident that those people did not take us out of Fairmount Park." "And if they had done so we should have felt we were being moved." "Undoubtedly; and consequently we must be in some vehicle, perhaps some of those long prairie wagons, or some show-caravan--" "Evidently! For if we were in a boat moored on the Schuyllkill we should have noticed the movement due to the current--" "That is so; and as we are still in the clearing, I think that now is the time to get away, and we can return later to settle with this Robur--" "And make him pay for this attempt on the liberty of two citizens of the United States." "And he shall pay pretty dearly!" "But who is this man? Where does he come from? Is he English, or German, or French--" "He is a scoundrel, that is enough!" said Uncle Prudent. "Now to work." And then the two men, with their hands stretched out and their fingers wide apart, began to feel round the walls to find a joint or crack. Nothing. Nothing; not even at the door. It was closely shut and it was impossible to shoot back the lock. All that could be done was to make a hole, and escape through the hole. It remained to be seen if the knives could cut into the walls. "But whence comes this never-ending rustling?" asked Evans, who was much impressed at the continuous f-r-r-r. "The wind, doubtless," said Uncle Prudent. "The wind! But I thought the night was quite calm." "So it was. But if it isn't the wind, what can it be?" Phil Evans got out the best blade of his knife and set to work on the wall near the door. Perhaps he might make a hole which would enable him to open it from the outside should it be only bolted or should the key have been left in the lock. He worked away for some minutes. The only result was to nip up his knife, to snip off its point, and transform what was left of the blade into a saw. "Doesn't it cut?" asked Uncle Prudent. "No." "Is the wall made of sheet iron?" "No; it gives no metallic sound when you hit it." "Is it of ironwood?" "No; it isn't iron and it isn't wood." "What is it then?" "Impossible to say. But, anyhow, steel doesn't touch it." Uncle Prudent, in a sudden outburst of fury, began to rave and stamp on the sonorous planks, while his hands sought to strangle an imaginary Robur. "Be calm, Prudent, be calm! You have a try." Uncle Prudent had a try, but the bowie-knife could do nothing against a wall which its best blades could not even scratch. The wall seemed to be made of crystal. So it became evident that all flight was impracticable except through the door, and for a time they must resign themselves to their fate--not a very pleasant thing for the Yankee temperament, and very much to the disgust of these eminently practical men. But this conclusion was not arrived at without many objurgations and loud-sounding phrases hurled at this Robur--who, from what had been seen of him at the Weldon Institute, was not the sort of man to trouble himself much about them. Suddenly Frycollin began to give unequivocal signs of being unwell. He began to writhe in a most lamentable fashion, either with cramp in his stomach or in his limbs; and Uncle Prudent, thinking it his duty to put an end to these gymnastics, cut the cords that bound him. He had cause to be sorry for it. Immediately there was poured forth an interminable litany, in which the terrors of fear were mingled with the tortures of hunger. Frycollin was no worse in his brain than in his stomach, and it would have been difficult to decide to which organ the chief cause of the trouble should be assigned. "Frycollin!" said Uncle Prudent. "Master Uncle! Master Uncle!" answered the Negro between two of his lugubrious howls. "It is possible that we are doomed to die of hunger in this prison, but we have made up our minds not to succumb until we have availed ourselves of every means of alimentation to prolong our lives." "To eat me?" exclaimed Frycollin. "As is always done with a Negro under such circumstances! So you had better not make yourself too obvious--" "Or you'll have your bones picked!" said Evans. And as Frycollin saw he might be used to prolong two existences more precious than his own, he contented himself thenceforth with groaning in quiet. The time went on and all attempts to force the door or get through the wall proved fruitless. What the wall was made of was impossible to say. It was not metal; it was not wood; it was not stone, And all the cell seemed to be made of the same stuff. When they stamped on the floor it gave a peculiar sound that Uncle Prudent found it difficult to describe; the floor seemed to sound hollow, as if it was not resting directly on the ground of the clearing. And the inexplicable f-r-r-r-r seemed to sweep along below it. All of which was rather alarming. "Uncle Prudent," said Phil Evans. "Well?" "Do you think our prison has been moved at all?" "Not that I know of." "Because when we were first caught I distinctly remember the fresh fragrance of the grass and the resinous odor of the park trees. While now, when I take in a good sniff of the air, it seems as though all that had gone." "So it has." "Why?" "We cannot say why unless we admit that the prison has moved; and I say again that if the prison had moved, either as a vehicle on the road or a boat on the stream, we should have felt it." Here Frycollin gave vent to a long groan, which might have been taken for his last had he not followed it up with several more. "I expect Robur will soon have us brought before him," said Phil Evans. "I hope so," said Uncle Prudent. "And I shall tell him--" "What?" "That he began by being rude and ended in being unbearable." Here Phil Evans noticed that day was beginning to break. A gleam, still faint, filtered through the narrow window opposite the door. It ought thus to be about four o'clock in the morning for it is at that hour in the month of June in this latitude that the horizon of Philadelphia is tinged by the first rays of the dawn. But when Uncle Prudent sounded his repeater--which was a masterpiece from his colleague's factory--the tiny gong only gave a quarter to three, and the watch had not stopped. "That is strange!" said Phil Evans. "At a quarter to three it ought still to be night." "Perhaps my watch has got slow," answered Uncle Prudent. "A watch of the Wheelton Watch Company!" exclaimed Phil Evans. Whatever might be the reason, there was no doubt that the day was breaking. Gradually the window became white in the deep darkness of the cell. However, if the dawn appeared sooner than the fortieth parallel permitted, it did not advance with the rapidity peculiar to lower latitudes. This was another observation--of Uncle Prudent's--a new inexplicable phenomenon. "Couldn't we get up to the window and see where we are?" "We might," said Uncle Prudent. "Frycollin, get up!" The Negro arose. "Put your back against the wall," continued Prudent, "and you, Evans, get on his shoulders while I buttress him up." "Right!" said Evans. An instant afterwards his knees were on Frycollin's shoulders, and his eyes were level with the window. The window was not of lenticular glass like those on shipboard, but was a simple flat pane. It was small, and Phil Evans found his range of view was much limited. "Break the glass," said Prudent, "and perhaps you will be able to see better." Phil Evans gave it a sharp knock with the handle of his bowie-knife. It gave back a silvery sound, but it did not break. Another and more violent blow. The same result. "It is unbreakable glass!" said Evans. It appeared as though the pane was made of glass toughened on the Siemens system--as after several blows it remained intact. The light had now increased, and Phil Evans could see for some distance within the radius allowed by the frame. "What do you see?" asked Uncle Prudent. "Nothing." "What? Not any trees?" "No." "Not even the top branches?" "No." "Then we are not in the clearing?" "Neither in the clearing nor in the park." "Don't you see any roofs of houses or monuments?" said Prudent, whose disappointment and anger were increasing rapidly. "No." "What! Not a flagstaff, nor a church tower, nor a chimney?" "Nothing but space." As he uttered the words the door opened. A man appeared on the threshold. It was Robur. "Honorable balloonists" he said, in a serious voice, "you are now free to go and come as you like." "Free!" exclaimed Uncle Prudent. "Yes--within the limits of the "Albatross!" Uncle Prudent and Phil Evans rushed out of their prison. And what did they see? Four thousand feet below them the face of a country they sought in vain to recognize. Chapter VII ON BOARD THE ALBATROSS "When will man cease to crawl in the depths to live in the azure and quiet of the sky?" To this question of Camille Flammarion's the answer is easy. It will be when the progress of mechanics has enabled us to solve the problem of aviation. And in a few years--as we can foresee--a more practical utilization of electricity will do much towards that solution. In 1783, before the Montgolfier brothers had built their fire-balloon, and Charles, the physician, had devised his first aerostat, a few adventurous spirits had dreamt of the conquest of space by mechanical means. The first inventors did not think of apparatus lighter than air, for that the science of their time did not allow them to imagine. It was to contrivances heavier than air, to flying machines in imitation of the birds, that they trusted to realize aerial locomotion. This was exactly what had been done by that madman Icarus, the son of Daedalus, whose wings, fixed together with wax, had melted as they approached the sun. But without going back to mythological times, without dwelling on Archytas of Tarentum, we find, in the works of Dante of Perugia, of Leonardo da Vinci and Guidotti, the idea of machines made to move through the air. Two centuries and a half afterwards inventors began to multiply. In 1742 the Marquis de Bacqueville designed a system of wings, tried it over the Seine, and fell and broke his arm. In 1768 Paucton conceived the idea of an apparatus with two screws, suspensive and propulsive. In 1781 Meerwein, the architect of the Prince of Baden, built an orthopteric machine, and protested against the tendency of the aerostats which had just been invented. In 1784 Launoy and Bienvenu had maneuvered a helicopter worked by springs. In 1808 there were the attempts at flight by the Austrian Jacques Degen. In 1810 came the pamphlet by Denian of Nantes, in which the principles of "heavier than air" are laid down. From 1811 to 1840 came the inventions and researches of Derblinger, Vigual, Sarti, Dubochet, and Cagniard de Latour. In 1842 we have the Englishman Henson, with his system of inclined planes and screws worked by steam. In 1845 came Cossus and his ascensional screws. In 1847 came Camille Vert and his helicopter made of birds' wings. In 1852 came Letur with his system of guidable parachutes, whose trial cost him his life; and in the same year came Michel Loup with his plan of gliding through the air on four revolving wings. In 1853 came Béléguic and his aeroplane with the traction screws, Vaussin-Chardannes with his guidable kite, and George Cauley with his flying machines driven by gas. From 1854 to 1863 appeared Joseph Pline with several patents for aerial systems. Bréant, Carlingford, Le Bris, Du Temple, Bright, whose ascensional screws were left-handed; Smythies, Panafieu, Crosnier, &c. At length, in 1863, thanks to the efforts of Nadar, a society of "heavier than air" was founded in Paris. There the inventors could experiment with the machines, of which many were patented. Ponton d'Amécourt and his steam helicopter, La Landelle and his system of combining screws with inclined planes and parachutes, Louvrié and his aeroscape, Esterno and his mechanical bird, Groof and his apparatus with wings worked by levers. The impetus was given, inventors invented, calculators calculated all that could render aerial locomotion practicable. Bourcart, Le Bris, Kaufmann, Smyth, Stringfellow, Prigent, Danjard, Pomés and De la Pauze, Moy, Pénaud, Jobert, Haureau de Villeneuve, Achenbach, Garapon, Duchesne, Danduran, Pariesel, Dieuaide, Melkiseff, Forlanini, Bearey, Tatin, Dandrieux, Edison, some with wings or screws, others with inclined planes, imagined, created, constructed, perfected, their flying machines, ready to do their work, once there came to be applied to thereby some inventor a motor of adequate power and excessive lightness. This list may be a little long, but that will be forgiven, for it is necessary to give the various steps in the ladder of aerial locomotion, on the top of which appeared Robur the Conqueror. Without these attempts, these experiments of his predecessors, how could the inquirer have conceived so perfect an apparatus? And though he had but contempt for those who obstinately worked away in the direction of balloons, he held in high esteem all those partisans of "heavier than air," English, American, Italian, Austrian, French--and particularly French--whose work had been perfected by him, and led him to design and then to build this flying engine known as the "Albatross," which he was guiding through the currents of the atmosphere. "The pigeon flies!" had exclaimed one of the most persistent adepts at aviation. "They will crowd the air as they crowd the earth!" said one of his most excited partisans. "From the locomotive to the aeromotive!" shouted the noisiest of all, who had turned on the trumpet of publicity to awaken the Old and New Worlds. Nothing, in fact, is better established, by experiment and calculation, than that the air is highly resistant. A circumference of only a yard in diameter in the shape of a parachute can not only impede descent in air, but can render it isochronous. That is a fact. It is equally well known that when the speed is great the work of the weight varies in almost inverse ratio to the square of the speed, and therefore becomes almost insignificant. It is also known that as the weight of a flying animal increases, the less is the proportional increase in the surface beaten by the wings in order to sustain it, although the motion of the wings becomes slower. A flying machine must therefore be constructed to take advantage of these natural laws, to imitate the bird, "that admirable type of aerial locomotion," according to Dr. Marcy, of the Institute of France. In short the contrivances likely to solve the problem are of three kinds:-- 1. Helicopters or spiralifers, which are simply screws with vertical axes. 2. Ornithopters, machines which endeavour to reproduce the natural flight of birds. 3. Aeroplanes, which are merely inclined planes like kites, but towed or driven by screws. Each of these systems has had and still has it partisans obstinately resolved to give way in not the slightest particular. However, Robur, for many reasons, had rejected the two first. The ornithopter, or mechanical bird, offers certain advantages, no doubt. That the work and experiments of M. Renard in 1884 have sufficiently proved. But, as has been said, it is not necessary to copy Nature servilely. Locomotives are not copied from the hare, nor are ships copied from the fish. To the first we have put wheels which are not legs; to the second we have put screws which are not fins. And they do not do so badly. Besides, what is this mechanical movement in the flight of birds, whose action is so complex? Has not Doctor Marcy suspected that the feathers open during the return of the wings so as to let the air through them? And is not that rather a difficult operation for an artificial machine? On the other hand, aeroplanes have given many good results. Screws opposing a slanting plane to the bed of air will produce an ascensional movement, and the models experimented on have shown that the disposable weight, that is to say the weight it is possible to deal with as distinct from that of the apparatus, increases with the square of the speed. Herein the aeroplane has the advantage over the aerostat even when the aerostat is furnished with the means of locomotion. Nevertheless Robur had thought that the simpler his contrivance the better. And the screws--the Saint Helices that had been thrown in his teeth at the Weldon Institute--had sufficed for all the needs of his flying machine. One series could hold it suspended in the air, the other could drive it along under conditions that were marvelously adapted for speed and safety. If the ornithopter--striking like the wings of a bird--raised itself by beating the air, the helicopter raised itself by striking the air obliquely, with the fins of the screw as it mounted on an inclined plane. These fins, or arms, are in reality wings, but wings disposed as a helix instead of as a paddle wheel. The helix advances in the direction of its axis. Is the axis vertical? Then it moves vertically. Is the axis horizontal? Then it moves horizontally. The whole of Robur's flying apparatus depended on these two movements, as will be seen from the following detailed description, which can be divided under three heads--the platform, the engines of suspension and propulsion, and the machinery. Platform.--This was a framework a hundred feet long and twelve wide, a ship's deck in fact, with a projecting prow. Beneath was a hull solidly built, enclosing the engines, stores, and provisions of all sorts, including the watertanks. Round the deck a few light uprights supported a wire trellis that did duty for bulwarks. On the deck were three houses, whose compartments were used as cabins for the crew, or as machine rooms. In the center house was the machine which drove the suspensory helices, in that forward was the machine that drove the bow screw, in that aft was the machine that drove the stern screw. In the bow were the cook's galley and the crew's quarters; in the stern were several cabins, including that of the engineer, the saloon, and above them all a glass house in which stood the helmsman, who steered the vessel by means of a powerful rudder. All these cabins were lighted by port-holes filled with toughened glass, which has ten times the resistance of ordinary glass. Beneath the hull was a system of flexible springs to ease off the concussion when it became advisable to land. Engines of suspension and propulsion.--Above the deck rose thirty-seven vertical axes, fifteen along each side, and seven, more elevated, in the centre. The "Albatross" might be called a clipper with thirty-seven masts. But these masts instead of sails bore each two horizontal screws, not very large in spread or diameter, but driven at prodigious speed. Each of these axes had its own movement independent of the rest, and each alternate one spun round in a different direction from the others, so as to avoid any tendency to gyration. Hence the screws as they rose on the vertical column of air retained their equilibrium by their horizontal resistance. Consequently the apparatus was furnished with seventy-four suspensory screws, whose three branches were connected by a metallic circle which economized their motive force. In front and behind, mounted on horizontal axes, were two propelling screws, each with four arms. These screws were of much larger diameter than the suspensory ones, but could be worked at quite their speed. In fact, the vessel combined the systems of Cossus, La Landelle, and Ponton d'Amécourt, as perfected by Robur. But it was in the choice and application of his motive force that he could claim to be an inventor. Machinery.--Robur had not availed himself of the vapor of water or other liquids, nor compressed air and other mechanical motion. He employed electricity, that agent which one day will be the soul of the industrial world. But he required no electro-motor to produce it. All he trusted to was piles and accumulators. What were the elements of these piles, and what were the acids he used, Robur only knew. And the construction of the accumulators was kept equally secret. Of what were their positive and negative plates? None can say. The engineer took good care--and not unreasonably--to keep his secret unpatented. One thing was unmistakable, and that was that the piles were of extraordinary strength; and the accumulators left those of Faure-Sellon-Volckmar very far behind in yielding currents whose ampères ran into figures up to then unknown. Thus there was obtained a power to drive the screws and communicate a suspending and propelling force in excess of all his requirements under any circumstances. But--it is as well to repeat it--this belonged entirely to Robur. He kept it a close secret. And, if the president and secretary of the Weldon Institute did not happen to discover it, it would probably be lost to humanity. It need not be shown that the apparatus possessed sufficient stability. Its center of gravity proved that at once. There was no danger of its making alarming angles with the horizontal, still less of its capsizing. And now for the metal used by Robur in the construction of his aeronef--a name which can be exactly applied to the "Albatross." What was this material, so hard that the bowie-knife of Phil Evans could not scratch it, and Uncle Prudent could not explain its nature? Simply paper! For some years this fabrication had been making considerable progress. Unsized paper, with the sheets impregnated with dextrin and starch and squeezed in hydraulic presses, will form a material as hard as steel. There are made of it pulleys, rails, and wagon-wheels, much more solid than metal wheels, and far lighter. And it was this lightness and solidity which Robur availed himself of in building his aerial locomotive. Everything--framework, hull, houses, cabins--were made of straw-paper turned hard as metal by compression, and--what was not to be despised in an apparatus flying at great heights--incombustible. The different parts of the engines and the screws were made of gelatinized fiber, which combined in sufficient degree flexibility with resistance. This material could be used in every form. It was insoluble in most gases and liquids, acids or essences, to say nothing of its insulating properties, and it proved most valuable in the electric machinery of the "Albatross." Robur, his mate Tom Turner, an engineer and two assistants, two steersman and a cook--eight men all told--formed the crew of the aeronef, and proved ample for all the maneuvers required in aerial navigation. There were arms of the chase and of war; fishing appliances; electric lights; instruments of observation, compasses, and sextants for checking the course, thermometers for studying the temperature, different barometers, some for estimating the heights attained, others for indicating the variations of atmospheric pressure; a storm-glass for forecasting tempests; a small library; a portable printing press; a field-piece mounted on a pivot; breech loading and throwing a three-inch shell; a supply of powder, bullets, dynamite cartridges; a cooking-stove, warmed by currents from the accumulators; a stock of preserves, meats and vegetables sufficient to last for months. Such were the outfit and stores of the aeronef--in addition to the famous trumpet. There was besides a light india-rubber boat, insubmersible, which could carry eight men on the surface of a river, a lake, or a calm sea. But were there any parachutes in case of accident? No. Robur did not believe in accidents of that kind. The axes of the screws were independent. The stoppage of a few would not affect the motion of the others; and if only half were working, the "Albatross" could still keep afloat in her natural element. "And with her," said Robur to his guests--guests in spite of themselves--"I am master of the seventh part of the world, larger than Africa, Oceania, Asia, America, and Europe, this aerial Icarian sea, which millions of Icarians will one day people." Chapter VIII THE BALLOONISTS REFUSE TO BE CONVINCED The President of the Weldon Institute was stupefied; his companion was astonished. But neither of them would allow any of their very natural amazement to be visible. The valet Frycollin did not conceal his terror at finding himself borne through space on such a machine, and he took no pains whatever to hide it. The suspensory screws were rapidly spinning overhead. Fast as they were going, they would have to triple their speed if the "Albatross" was to ascend to higher zones. The two propellers were running very easily and driving the ship at about eleven knots an hour. As they leaned over the rail the passengers of the "Albatross" could perceive a long sinuous liquid ribbon which meandered like a mere brook through a varied country amid the gleaming of many lagoons obliquely struck by the rays of the sun. The brook was a river, one of the most important in that district. Along its left bank was a chain of mountains extending out of sight. "And will you tell us where we are?" asked Uncle Prudent, in a voice tremulous with anger. "I have nothing to teach you," answered Robur. "And will you tell us where we are going?" asked Phil Evans. "Through space." "And how long will that last?" "Until it ends." "Are we going round the world?" asked Phil Evans ironically. "Further than that," said Robur. "And if this voyage does not suit us?" asked Uncle Prudent. "It will have to suit you." That is a foretaste of the nature of the relations that were to obtain between the master of the "Albatross" and his guests, not to say his prisoners. Manifestly he wished to give them time to cool down, to admire the marvelous apparatus which was bearing them through the air, and doubtless to compliment the inventor. And so he went off to the other end of the deck, leaving them to examine the arrangement of the machinery and the management of the ship or to give their whole attention to the landscape which was unrolling beneath them. "Uncle Prudent," said Evans, "unless I am mistaken we are flying over Central Canada. That river in the northwest is the St. Lawrence. That town we are leaving behind is Quebec." It was indeed the old city of Champlain, whose zinc roofs were shining like reflectors in the sun. The "Albatross" must thus have reached the forty-sixth degree of north latitude, and thus was explained the premature advance of the day with the abnormal prolongation of the dawn. "Yes," said Phil Evans, "There is the town in its amphitheater, the hill with its citadel, the Gibraltar of North America. There are the cathedrals. There is the Custom House with its dome surmounted by the British flag!" Phil Evans had not finished before the Canadian city began to slip into the distance. The clipper entered a zone of light clouds, which gradually shut off a view of the ground. Robur, seeing that the president and secretary of the Weldon Institute had directed their attention to the external arrangements of the "Albatross," walked up to them and said: "Well, gentlemen, do you believe in the possibility of aerial locomotion by machines heavier than air?" It would have been difficult not to succumb to the evidence. But Uncle Prudent and Phil Evans did not reply. "You are silent," continued the engineer. "Doubtless hunger makes you dumb! But if I undertook to carry you through the air, I did not think of feeding you on such a poorly nutritive fluid. Your first breakfast is waiting for you." As Uncle Prudent and Phil Evans were feeling the pangs of hunger somewhat keenly they did not care to stand upon ceremony. A meal would commit them to nothing; and when Robur put them back on the ground they could resume full liberty of action. And so they followed into a small dining-room in the aftermost house. There they found a well-laid table at which they could take their meals during the voyage. There were different preserves; and, among other things, was a sort of bread made of equal parts of flour and meat reduced to powder and worked together with a little lard, which boiled in water made excellent soup; and there were rashers of fried ham, and for drink there was tea. Neither had Frycollin been forgotten. He was taken forward and there found some strong soup made of this bread. In truth he had to be very hungry to eat at all, for his jaws shook with fear, and almost refused to work. "If it was to break! If it was to break!" said the unfortunate Negro. Hence continual faintings. Only think! A fall of over four thousand feet, which would smash him to a jelly! An hour afterwards Uncle Prudent and Phil Evans appeared on the deck. Robur was no longer there. At the stem the man at the wheel in his glass cage, his eyes fixed on the compass, followed imperturbably without hesitation the route given by the engineer. As for the rest of the crew, breakfast probably kept them from their 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000