by Jules Verne
His eyes lowered towards the ground, Marcel Camaret gave this explanation with the calmness of a professor delivering a lecture. He never faltered, never groped for words, which came to him of themselves. Without a pause he continued in the same tones:
"Let us proceed to the second point. At the moment of take-off, the wings of the heliplane are lowered and furled against the pylon. At the same time the axis of the screw, free to move in a verticle plane perpendicular to the wings, rises, bringing the screw to the horizontal. The apparatus thus becomes a helicopter, and the sole function of its screw is suspensory. But, when it has reached a sufficient height, the wings open, and at the same time the axis of the screw inclines forward until it is horizontal Gradually the screw thus becomes propulsive, and the helicopter is transformed into an airplane.
"As for the motive force, it is provided by liquid air. From a fuel-tank constructed of the antidiatlicrmic substance I mentioned, the liquid air, its flow regulated by a series of valves, reaches a tube which is always kept warm. The air at once returns to its gaseous state, exerts a great pressure, and actuates the motor."
"What speed do you get with these heliplanes?" asked Amedee Florence.
"Two hundred and fifty miles an hour for three thousand miles, with no need for refuelling," replied Camaret.
Nil mirari, so said Horace, don't be surprised at anything. But Camaret's hearers could not conceal their admiration. As they returned to the tower they could not find terms enthusiastic enough to praise his genius. But that strange man, who none the less sometimes showed so overwhelming a pride, seemed to care little for their applause, as though he valued only the praise he bestowed on himself.
"Now we are coming to the very heart of the Factory," he said when they reached the tower. "This tower includes six floors similar to this and equipped with similar apparatus. You have undoubtedly noticed that its summit is surmounted by a very tall metal pylon. This pylon is a 'wave projector'. The tower bristles, moreover, with a number of points; these are smaller projectors."
"Wave projectors, you say?" asked Dr. Chatonnay.
"I'm not going to give you a course in physics," said Marcel Camaret smilingly. "But a few explanations of its principles are however necessary. I will remind you, then, if you know it already, or tell you, if you don't, that a celebrated German physicist called Hertz noticed some time ago that when an electric spark from an induction coil flashes across a short gap between the two terminals of a condenser, or a resonator or oscillator, whichever word pleases you best, that spark sets up between the two poles of the instrument an oscillating discharge.
"The gap is crossed by an alternating current, or, in other words, the two poles are alternatively positive and negative throughout the one discharge, until this returns to a state of equilibrium. The speed of these oscillations, also known as their frequency, can be very great, as much as a hundred thousand million a second.
"Now these oscillations are not limited to the points which produce them. On the other hand they set up a disturbance in their surroundings, the air, or, more precisely, in the imponderable fluid which at once fills interstellar space and the intermolecular interstices of material bodies, and which is called the ether.
"To each oscillation there thus corresponds an etheric vibration which by degrees is transmitted ever further away. These vibrations are rightly called the Hertzian Waves. Have I made myself clear?"
"Admirably," replied Barsac, who, as a politician, was perhaps of all Camaret's hearers the least prepared for scientific questions.
"Except for myself," the scientist continued, "these waves were only a laboratory curiosity. They were used to electrify, without any material contact, metallic bodies at varying distances from their point of emission. They had the overwhelming defect of spreading in all directions round that point, exactly like the concentric circles formed in a pool when a stone is dropped into it. The result is that their initial energy is diluted, weakened, dissipated, so to speak, in spreading over an ever-increasing space. So that, at only a few yards from their source, nothing more than insignificant reactions can be obtained. Do you still understand? I am quite clear?"
"Luminously," declared Amedee Florence.
"Again except for myself, though it had been noticed that these waves can be reflected like light, nobody had ever drawn any conclusion from this. But, thanks to a metal of superconductivity which I have discovered, the very same with which I have garnished the crest of our wall. I have been able to construct reflectors which enable the whole strength of the waves to be concentrated in any direction I wish.
"Their original strength can thus be completely transmitted in any direction through space, because it has not been expended in any sort of work. Methods of varying the frequency of these oscillations being well known. I was able to think up receivers for the waves which would respond solely to an assigned frequency. This is what physicists call 'syntonization'l
"A receiver can thus be constructed only to react to all the waves having the frequencies for which it was designed. The number of possible frequencies being infinite, I can construct an infinite number of motors among which there will not be two sensitive to identical waves. Do you still understand me?"
It's harder," Barsac conceded, "but we can follow you all the same."
"I've finished, anyhow," said Camaret. "It is by their aid that we actuate numerous agricultural machines which draw their energy, some distance away, from one or other of the projections bristling from that tower. Similarly, that's the way we control the wasps. Each has four screws and contains four small-sized motors differing in syntonization, and we can actuate one or more of them as we wish. Finally, that is how I could destroy the whole town, if ever I should want to."
"You could destroy the town from here!" cried Barsac.
"Quite easily. Harry Killer asked me to make it impregnable and I made it impregnable. Below every street, below all the houses, below the Palace and below the Factory itself, are powerful explosives, each with a detonator syntonized with waves known only to myself. To blow up the town, I need only send towards each of the mines waves with a frequency corresponding to its detonator."
Amedee Florence, who was feverishly taking notes, had a fleeting impulse to suggest that it would be as well to make use of this process to put an end to Harry Killer. But he remembered in time the scanty success obtained by his suggestion to use the aerial torpedoes for the same purpose, and prudentiy kept silent.
"And the large pylon on top of the tower?" asked Dr. Chatonnay.
"I'm coming to it, and will end with it," Camaret replied. "It's very strange that the so-called Hertzian waves act as though they were subject to the attraction of gravity: radiating from the point of emission, they incline slowly towards the earth, where they are finally lost.
"So if they are to be sent any distance they have to be generated at an appropriate height For my purposes, that would be even more necessary, for my aim is to send them not to a great distance but to a great height, and that's more difficult still. But I have succeeded, thanks partly to a pylon a hundred yards high connected to the oscillator, partly to a reflector I invented, placed at the top of the pylon."
"Why do you want to send the waves upwards?" asked Amedee, who was rather out of his depth.
"To make rain. It is the basic principle of the invention I had in mind when I knew Harry Killer, and he helped me to accomplish it By means of the pylon and the reflector I direct waves against the clouds, and I electrify to saturation point the raindrops they contain. When the difference or potential between a cloud and the earth or one of the adjacent clouds is great enough, and this does not take very long, a storm breaks, and the rain descends. The transformation of the desert into fertile country is quite enough to prove the efficiency of the process."
"But you've got to have the clouds," Dr. Chatonnay put in.
"Naturally, or at least a damp enough atmosphere. But clouds are bound to come some day or other. The problem is
to break them here and not somewhere else. Now that the land is cultivated and the tree are beginning to grow, a series of regular rainfalls is tending to begin, and the clouds are getting more plentiful. As soon as one arrives this is all I have to do," explained Camaret, throwing over a switch, "and at once waves, emitted with a force of a thousand horse-power, bombard them with countless vibrations."
"Marvellous!" his hearers were enthusiastic.
"At this very moment, though you cannot in any way perceive it," he continued, more and more excited as he described his inventions, "waves are flowing from the summit of the pylon and losing themselves in the infinite. But I can imagine another future for them. I feel, I know, I'm certain, that they can be employed for a hundred different purposes. For example, it would be possible to communicate with the whole surface of the earth, by telegraph or telephone, without needing a wire to link the respective stations."
"Without a wire!" exclaimed his hearers,
"Without a wire. What would we need for that? Very little. I've only got to think out a suitable receiver. I'm working on it, I've almost got it, but I haven't quite got it yet."
"We're beginning to get out of our depth," Barsac protested.
"But nothing could be simpler," Camaret declared, his excitement growing. "Look, here's a Morse instrument, the type used in ordinary telegraphy, which I have placed experimentally in a special circuit. I've only to work these switches," winch he was handling even as he spoke, "for the wave producing current to be connected with the circuit. When the Morse key is raised, the Hertzian waves are not transmitted. When it is depressed, and only while it is depressed, the waves are emitted from the pylon.
"But now it is not towards the sky that the waves are to be projected but towards the hypothetical receiver. This Is done by lurniiig in the appropriate direction the reflector which concentrates them. If the direction is unknown, it will be enough simply to cut out the reflector, which I can do by means of this other switch. Now the waves emitted will spread into space in all directions around us, and I can telegraph and be certain that I shall reach the receiver, if there is one, wherever it may be. Unfortunately there isn't one."
"You said telegraph?" asked Jane Blazon. "What did you mean by that?"
"Just what one usually means. I have only to use the switch in the ordinary way, making use of the Morse alphabet, which all telegraphists understood. But it will help you if I give an example. If that hypothetical receiver existed, you would take the first opportunity of using it to get out of your present position, I imagine?"
"There's no question about that!" said Jane.
"Well, act as if it were there," Camaret suggested, sitting before the Morse apparatus. "Whom would you telegraph to in that case?"
"In a country where we don't know anyone," Jane said smilingly. "I might well ask who. ... I only know Captain Marcenay," she added with a slight blush.
"Let's make it Captain Marcenay," agreed Camaret; as he spoke the Morse key was tapping out the longs and shorts of its alphabet. "Whereabouts is he?"
"I think he's at Timbuctoo just now," said Jane hesitatingly.
"Timbuctoo," Camaret repeated, still working the key. "Now what do you want to say to Captain Marcenay? Something of this sort, I suppose 'Jane Blazon.
"Excuse me," Jane interrupted him, "Captain Marcenay only knows me under the name of Jane Mornas."
"That doesn't matter, as the message will never arrive, still let's make it Mornas. So I'm sending: 'Come to the rescue of Jane Mornas held prisoner at Blackland.
Here Marcel Cnmaret interrupted himself:
"And, as Blackland seems to be unknown to the outer
world, I shall explain its situation, so I'll add: 'latitude
15°.50 north, longitude____"'
He jumped up from his seat.
"There!" he exclaimed, "Hany Killer has cut off the current."
Failing to realize the position, his guests crowded round him.
"As I told you," he explained, "the power reaches us from a hydroelectric station installed about six miles upstream. Harry Killer has cut us off from that station, that's all."
"But then the machines will stop!" said Dr. Chatonnay. "They've stopped already," Camaret replied. "And the wasps?"
"They've fallen to earth, there's no doubt about that."
"Then Harry Killer can use them," cried Jane Blazon.
"That's not so certain," the engineer replied. "Come up to the top, and you'll see he has not gained anything."
Quickly climbing to the higher floors, they entered the cycloscope. As before, they at once saw the outer face of the wall, together with the dyke around it; in its depths lay the motionless wasps.
On the Esplanade the Merry Fellows were shouting in triumph. Already they were returning to the attack. Some of them jumped into the dyke and laid their hands on the dead wasps, which had scared them so much while they were alive.
But they had scarcely touched them when they showed signs of disquiet. Recoiling in fright, they hastened to climb out of the dyke. A few of them were too weak to succeed, and one after another they fell unconscious.
"I would not give two sous for their lives," Marcel Camaret said coldly. "You may well believe that I foresaw what would happen and took my precautions accordingly. In cutting off the current from the station, Harry Killer has ipso facto opened a sluice through which containers of liquid carbon dioxide have emptied into the dyke, where it at once resumed the gaseous state. Being heavier than air, the gas remains in the dyke, and anyone in it must inevitably die of asphyxiation."
"Poor fellows!" exclaimed Jane Blazon.
"The worse for them," Camaret declared, "I can't do anything to help them. Regarding my machines, I've also taken precautions. Since this morning liquid air, I have an inexhaustible supply of it, has replaced the current from the generating station, and now that's the motive power of my electrical machines. That's already been done, and look, the machines are working. The wasps are again in flight."
The screws of the wasps had again begun their bewildering spin, and the machines had resumed their protective circling. Meanwhile the crowd of Merry Fellows, forsaking their comrades who lay in the dyke, had retired to the Palace.
Marcel Camaret turned towards his guests. He seemed nervous, even abnormally agitated, and the disquieting light which they had already noticed was once again marring the clearness of his gaze.
"We can sleep in peace, I fancy," he said, a little puffed up with naive vanity.
CHAPTER VIII
A CALL INTO SPACE
Very sadly Captain Marcenay left the Barsac Mission, and especially the lady whom he knew as Jane Mornas. He went off, however, without the slightest hesitation, and as far as Segou-Sikoro he travelled, as commanded, by forced march. He was first and foremost a soldier, and it may be the greatness of the military profession to demand complete selfsacrifice and absolute obedience towards ends which may not be self-evident but which are always dominated by the ideal of patriotism.
Hasten as he might, however, it took nine days to cross the three hundred miles which separated him from Segou-Sikoro, and it was not until the 22nd February, at a late hour of the evening, that he arrived. So it was only on the following morning that he could report to Colonel Sergines, the commandant, and show him Colonel Saint-Cuban's order.
Colonel Sergines read the order three times with increasing surprise. He did not seem to understand it.
"What an unusual procedurel" he said at last. "To call for men at Sikasso to send them to Timbuctool. It's unimaginable!"
"Then you weren't told we were coming, mon Colonel?" the Captain asked. "Decidedly not."
"The lieutenant who brought me the order," Marcenay explained, "said that unrest had broken out at Timbuctoo, and that the Touareg Aouelimmeden were dangerously astir."
"It's the first I've heard of it," the colonel declared. "Yesterday, in fact, Captain Peyrolles . . . perhaps you know him?"
"Yes, mon Colonel. Two years
ago we served in the same regiment."
"Well, he went through here, Peyrolles did, en route from Timbuctoo to Dakar. He left only yesterday, and he never said a word about it."
All that Captain Marcenay could do was to make a gesture disavowing all responsibihty.
"You're right, Captain," said Colonel Sergines. "It's not our place to argue. There is the order, and it will have to be obeyed. But the devil knows when you can set out, I must say."
It took some trouble, indeed, to get ready for that unforeseen expedition. More than eight days were taken up in finding stabling for the horses, who had been ordered to be left at Segou-Sikoro and to collect enough food and transport for the journey. It was only on the 2nd of March that Captain Marcenay was able to embark and begin the descent of the Niger.
The journey, often held up by the low level of the river in the last months of the dry season, then took two full weeks. So it was not until the 17th March that the former escort of the Barsac Mission disembarked at Kabara, the port of Timbuctoo, about ten miles distant.
When Captain Marcenay reported to Colonel Allegre, the local commandant, that officer showed the same surprise as his colleague at Segou-Sikoro. He declared that no trouble had been located in the region, that he had never asked for reinforcements, and that he could not explain why Colonel Saint-Auban had sent him without notice a hundred men for whom he had no need.
This seemed very strange, and Captain Marcenay was beginning to wonder if he had been taken in by a skilled forger. But why? What for? The answer was obvious. Inexplicable as the scheme might appear, the forgery could have no other purpose than to destroy the unprotected Barsac Mission. Logically forced to that conclusion, Captain Marcenay felt acute anguish when he thought of the grave responsibility which he would have incurred, and the dangers which threatened Mlle Mornas, whose memory dominated his spirit and heart.
These fears became even more acute when he could no more leam at Timbuctoo than at Segou-Sikoro anything whatever about Lieutenant Lacour; nobody knew of him. What was more, nobody had ever heard of a corps of Soudanese Volunteers, although these terms had been used by Colonel Saint-Auban himself.