For a space of several seconds no one moved or spoke. In the flickering light of the candle they looked at one another, and then at the fantastic pillars of salt all about them. Then Mr. Damon started forward.
"Bless my trolley car!" he exclaimed. "It isn't possible! There must be some mistake. If we'll keep on we'll come out all right. You know your way about, don't you, Mr. Petrofsky?"
"I thought I did, from what the guard told us, but it seems I must have taken a wrong turning."
"Then it's easily remedied," suggested Tom "All we'll have to do will be to go to the place where we started, and begin over again."
"Of course," agreed Ned, and they all seemed more cheerful.
"And if we start out once more, and get lost again, then what?" asked Mr. Damon.
"Well, if worst comes to worst, we can go, back in the tunnel, go to our cells and ask the guard to come with us and show us the way went on Tom.
"Never!" cried the exile. "It would be the most dangerous thing in the world to go back to the prison. Our escape has probably been discovered by this time, and to return would only be to put our heads in the noose. We must keep on at any cost!"
"But if we can't get out," suggested Tom, "and if we haven't anything to eat or drink, we—"
He did not finish, but they all knew what he meant.
"Oh, we'll get out!" declared Ned, who was something of an optimist. "You've been in salt mines before, haven't you, Mr. Petrofsky?"
"Yes, I was condemned to one once, but it was not in this part of the country, and it was not an abandoned one. I imagine this was only an isolated mine, and that there are no others near it, so when they abandoned it, after all the salt was taken out, most people forgot about it. I remember once a party of prisoners were lost in a large salt mine, and were missed for several days."
"What happened to them?" asked Tom.
"I don't like to talk about it," replied the Russian with a shudder.
"Bless my soul! Was it as bad as that?" asked Mr. Damon.
"It was," replied the exile. "But now let's see if we can find our way back, and start afresh. I'll be more careful next time, and watch the turns more closely."
But he did not get the chance. They could not find the tunnel whence they had started. Turn after turn they took, down passage after passage sometimes in such small ones that they almost had to crawl.
But it was of no use. They could not find their way back to the starting place, and they could not find the opening of the mine. They had used two of the slow burning candles and they had only half a dozen or so left. When these were gone—
But they did not like to think of that, and stumbled on and on. They did not talk much, for they were too worried. Finally Ned gasped:
"I'd give a good deal for a drink of water."
"So would I," added his chum. "But what's the use of wishing? If there was a spring down here it would be salt water. But I know what I would do—if I could."
"What?" asked Mr. Damon.
"Go back to the prison. At least we wouldn't starve there, and we'd have something to drink. If they kept us we know we could get free—sometime."
"Perhaps never!" exclaimed Ivan Petrofsky. "It is better to keep on here, and, as for me, I would rather die here than go back to a Russian prison. We must—we shall get out!"
But it was idle talk. Gradually they lost track of time as they staggered on, and they hardly knew whether a day had passed or whether it was but a few hours since they had been lost.
Of their sufferings in that salt mine I shall not go into details. There are enough unpleasant things in this world without telling about that. They must have wandered around for at least a day and a half, and in all that while they had not a drop of water, and not a thing to eat. Wait, though, at last in their desperation they did gnaw the tallow candles, and that served to keep them alive, and, in a measure, alleviate their awful sufferings from thirst.
Back and forth they wandered, up and down in the galleries of the old salt mine. They were merely hoping against hope.
"It's worse than the underground city of gold," said Ned in hollow tones, as he staggered on. "Worse—much worse." His head was feeling light. No one answered him.
It was, as they learned later, just about two days after the time when they entered the mine that they managed to get out. Forty-eight hours, most of them of intense suffering. They were burning their last candle, and when that was out they knew they would have the horrors of darkness to fight against, as well as those of hunger and thirst.
But fate was kind to them. How they managed to hit on the right gallery they did not know, but, as they made a turn around an immense pillar of salt Tom, who was walking weakly in advance, suddenly stopped.
"Look! Look!" he whispered. "Another candle! Someone—someone is searching for us! We are saved!"
"It may be the police!" said Ned.
"That is not a candle," spoke the Russian in hollow tones as he looked to where Tom pointed, to a little glimmer of light. "It is a star. Friends, we are saved, and by Providence! That is a star, shining through the opening of the mine. We are saved!"
Eagerly they pressed forward, and they had not gone far before they knew that the exile was right. They felt the cool night wind on their hot cheeks.
"Thank heaven!" gasped Tom, as he pushed on.
A moment later, climbing over the rusted rails on which the mine cars had run with their loads of salt, they staggered into the open. They were free—under the silent stars!
"And now, if we can only find the airship," said Tom faintly, "we can—"
"Look there!" whispered Ned, pointing to a patch of deeper blackness that the surrounding night. "What's that."
"The Falcon!" gasped Tom. He started toward her, for she was but a short distance from a little clump of trees into which they had emerged from the opening of the salt mine. There, on the same little plane where they had landed in her was the airship. She had not been moved.
"Wait!" cautioned Ivan Petrofsky. "She may be guarded."
Hardly had he spoken than there walked into the faint starlight on the side of the ship nearest them, a Cossack soldier with his rifle over his shoulder.
"We can't get her!" gasped Ned.
"We've got to get her!" declared Tom. "We'll die if we don't!"
"But the guards! They'll arrest us!" said the exile.
An instant later a second soldier joined the first, and they could be seen conversing. They then resumed their pacing around the anchored craft. Evidently they were waiting for the escaped prisoners to come up when they would give the alarm and apprehend them.
"What can we do?" asked Mr. Damon.
"I have a plan," said Tom weakly. "It's the only chance, for we're not strong enough to tackle them. Every time they go around on the far side of the airship we must creep forward. When they come on this side we'll lie down. I doubt if they can see us. Once we are on hoard we can cut the ropes, and start off. Everything is all ready for a start if they haven't monkeyed with her, and I don't think they have. We've got room enough to run along as an aeroplane and mount upward. It's our only hope."
The others agreed, and they put the plan into operation. When the Cossack guards were out of sight the escaped prisoners crawled forward, and when the soldiers came into view our friends waited in silence.
It took several minutes of alternate creeping and waiting to do this, but it was accomplished at last and unseen they managed to slip aboard. Then it was the work of but a moment to cut the restraining ropes.
Silently Tom crept to the motor room. He had to work in absolute darkness, for the gleam of a light would have drawn the fire of the guards. But the youth knew every inch of his invention. The only worriment was whether or not the motor would start up after the breakdown, not having been run since it was so hastily repaired. Still he could only try.
He looked out, and saw the guards pacing back and forth. They did not know that the much-sought prisoners were within a few feet of them.
Ned was in the pilot house. He could see a clear field in front of him.
Suddenly Tom pulled the starting lever. There was a little clicking, followed by silence. Was the motor going to revolve? It answered the next moment with a whizz and a roar.
"Here we go!" cried the young inventor, as the big machine shot forward on her flight. "Now let them stop us!"
Forward she went until Ned, knowing by the speed that she had momentum enough, tilted the elevation rudder, and up she shot, while behind, on the ground, wildly running to and fro, and firing their rifles, were the two amazed guards.
"Have we—have we time to get a drink?" gasped Ned, when the aeroplane, now on a level keel, had been shooting forward about three minutes. Already it was beyond the reach of the rifles.
"Yes, but take only a little," cautioned Tom. "Oh! it doesn't seem possible that we are free!"
He switched on a few interior lights, and by their glow the faint and starving platinum-seekers found water and food. Their craft had, apparently, not been touched in their absence, and the machinery ran well.
Cautiously they ate and drank, feeling their strength come back to them, and then they removed the traces of their terrible imprisonment, and set about in ease and comfort, talking of what they had suffered.
Onward sped the aeroplane, onward through the night, and then Tom, having set the automatic steering gear, all fell into heavy slumbers that lasted until far into the next day.
When the young inventor awoke he looked below and could see nothing—nothing but a sea of mist.
"What's this?" he cried. "Are we above the clouds, or in a fog over some inland sea?"
He was quite worried, until Ivan Petrofsky informed him that they were in the midst of a dense fog, which was common over that part of Siberia.
"But where are we?" asked Ned.
"About over the province of Irtutsk," was the answer. "We are heading north," he went on, as he looked at the compass, "and I think about right to land somewhere near where my brother is confined in the sulphur mine."
"That's so; we've got to drop," said Tom. "I must get the gas pipe repaired. I wish we could see over what soft of a place we were so as to know whether it would be safe to land. I wish the mist would clear away."
It did, about noon, and they noted that they were over a desolate stretch of country, in which it would be safe to make a landing.
Bringing the aeroplane down on as smooth a spot as he could pick out, Tom and Ned were soon at work clearing out the clogged pipe of the gas generator. They had to take it out in the open air, as the fumes were unpleasant, and it was while working over it that they saw a shadow thrown on the ground in front of them. Startled they looked up, to see a burly Russian staring at them.
The sudden appearance of a man in that lonely spot, his calm regard of the lads, his stealthy approach, which had made it possible for him to be almost upon them before they were aware of his presence, all this made them suspicious of danger. Tom gave a quick glance about, however, and saw no others—no Cossack soldiers, and as he looked a second time at the man he noted that he was poorly dressed, that his shoes were ragged, his whole appearance denoting that he had traveled far, and was weary and ill.
"What do you make of this, Ned?" asked Tom, in a low voice.
"I don't know what to make of it. He can't be an officer, in that rig, and he has no one with him. I guess we haven't anything to be afraid of. I'm going to ask him what he wants."
Which Tom did in his plainest English. At once the man broke into a stream of confused Russian, and he kept it up until Tom held up his hand for silence.
"I'm sorry, but I can't understand you," said the young inventor. "I'll call some one who can, though," and, raising his voice, he summoned Ivan Petrofsky who, with Mr. Damon, was inside the airship doing some small repairs.
"There's a Russian out here, Mr. Petrofsky," said Tom, "and what he wants I can't make out."
The exile was quickly on the scene and, after a first glance at the man, hurried up to him, grasped him by the hand and at once the two were talking such a torrent of hard-sounding words that Tom and Ned looked at each other helplessly, while Mr. Damon, who had come out, exclaimed:
"Bless my dictionary! they must know each other."
For several minutes the two Russians kept up their rapid-fire talk and then Mr. Petrofsky, evidently realizing that his friends must wonder at it, turned to them and said:
"This is a very strange thing. This man is an escaped convict, as I once was. I recognized him by certain signs as soon as I saw him, though I had never met him before. There are certain marks by which a Siberian exile can never be forgotten," he added significantly. "He made his escape from the mines some time ago, and has suffered great hardships since. The revolutionists help him when they can, but he has to keep in concealment and travels from town to town as best he may. He has heard of our airship, I suppose from inquiries the revolutionists have been making in our behalf, and when he unexpectedly came upon us just now he was not frightened, as an ordinary peasant would have been. But he did not know I was aboard."
"And does he know you?" asked Tom. "Does he know you are trying to rescue your brother?"
"No, but I will tell him."
There was another exchange of the Russian language, and it seemed to have a surprising result. For, no sooner had Ivan Petrofsky mentioned his brother, than the other, whose name was Alexis Borious seemed greatly excited. Mr. Petrofsky was equally so at the reply his new acquaintance made, and fairly shouted to Tom, Ned and Mr. Damon.
"Friends, I have unexpected good news! It is well that we met this man or we would have gone many miles out of our way. My brother has been moved to another mine since the revolutionists located him for me. He is in a lonely district many miles from here. This man was in the same mine with him, until my brother was transferred, and then Mr. Borious escaped. We will have to change our plans."
"And where are we to head for now?" asked Tom.
"Near to the town of Haskaski, where my poor brother is working in a sulphur mine!"
"Then let's get a move on!" cried Tom with enthusiasm. "Do you think this man will come with us, Mr. Petrofsky, to help in the rescue, and show us the place?"
"He says he will," translated the exile, "though he is much afraid of our strange craft. Still he knows that to trust himself to it is better than being captured, and sent back to the mines to starve to death!"
"Good!" cried Tom. "And if he wants to, and all goes well, we'll take him out of Russia with us. Now get busy, Ned, and we'll have this machine in shape again soon."
While Ivan Petrofsky took his new friend inside, and explained to him about the workings of the Falcon, Tom and Ned labored over the gas machine with such good effect that by night it was capable of being used. Then they went aloft, and making a change in their route, as suggested by Mr. Borious, they headed for the desolate sulphur region.
For several days they sailed on, and gradually a plan of rescue was worked out. According to the information of the newcomer, the best way to save Mr. Petrofsky's brother was to make the attempt when the prisoners were marched back from the mines to the barracks where they were confined.
"It will be dark then," said Mr. Borious, "and if you can hover in your airship near at hand, and if Mr. Petrofsky can call out to his brother to run to him, we can take him up with us and get away before the guards know what we are doing."
"But aren't the prisoners chained?" asked Tom.
"No, they depend on guards to prevent escapes."
"Then we'll try that way," decided the young inventor.
On and on they sailed, the Falcon working admirably. Verst after verst was covered, and finally, one morning, Mr. Borious, who knew the country well, from having once been a prisoner there, said:
"We are now near the place. If we go any closer we may be observed. We had better remain hidden in some grove of trees so that at nightfall we can go forth to the rescue."
"But how can we find it after dark?" asked Ned.
"You can easily tell by the lights in the barracks," was the answer. "I can stand in the pilot house to direct you, for nearly all these exile prisons are alike. The prisoners will march in a long line from the mine. Then for the rescue."
It was tedious waiting that day, but it had to be done, and to Tom, who was anxious to effect the rescue, and proceed to the place of the winds to try his air glider, it seemed as if dusk would never come as they remained in concealment.
But night finally approached and then the great airship went silently aloft, ready to hover over the prison ground. Fortunately there was little wind; and she could be used as a balloon, thus avoiding the noise of the motor.
"The next thing I do, when I get home," remarked Tom, as they drifted along. "Will be to make a silent airship. I think they would be very useful."
With Mr. Borious in the pilot house, to point out the way, Tom steered through the fast-gathering darkness. The Russian had soon become used to the airship, and was not at all afraid.
"Can you go just where you want to, as a balloon?" asked the new guide.
"No, but almost," replied Tom. "At the last moment I've got to take a chance and start the motor to send us just where we want to go. That's why I think a silent airship would be a great thing. You could get up on the enemy before he knew it."
"There are the prison barracks," said the guide a little later, his talk being translated by Mr. Petrofsky. Below and a little ahead of them could been seen a cluster of lights.
"Yes, that looks like a line of prisoners," remarked Ned, who was peering through a pair of night glasses.
"Where?" asked Tom eagerly, and they were pointed out to him. He took an observation, and exclaimed:
"There they are, sure enough. Now if your brother is only among them, Mr. Petrofsky, we'll soon have him on board."
"Heaven grant that he may be there!" said the exile in a low voice.
A moment later, the Falcon, meanwhile having been allowed to drift as close as possible to the dimly-seen line of prisoners, Tom set in motion the great motor, the propeller blades heating the air fiercely.
At the sound there was a shout on the ground below, but before the excitement had time to spread, or before any of the guards could form a notion of what was about to take place, Tom had sent his craft to earth on a sharp slant, closer to the line of prisoners than he had dared to hope.
Mr. Petrofsky sprang out on deck, and in a loud voice called in Russian:
"Peter! Peter! If you are there, come here! Come quickly! It is I, your brother Ivan who speaks. I have come to save you—save you in the wonderful airship of Tom Swift! Come quickly and we will take you away! Peter Petrofsky!"
For a moment there was silence, and then the sound of some one running rapidly was borne to the ears of the waiting ones. It was followed, a moment later, by angry shouts from the guards.
"Quick! Quick, Peter!" cried the brother, "over this way!"
For an instant only the exile showed a single electric flash light, that his brother might see in which direction to run. The echo of the approaching footsteps came nearer, the shouts of the guards redoubled, and then came the sound of many men running in pursuit.
"Hurry, Peter, hurry!" cried Mr. Petrofsky, and, as he spoke in Russian the guards, of course, understood.
Suddenly a rifle shot rang out, but the weapon seemed to have been fired in the air. A moment later a dark figure clambered aboard the airship.
"Peter, is it you?" cried Ivan Petrofsky, hoarsely.
"Yes, brother! But get away quickly or the whole guard will be swarming about here!"
"Praise the dear Lord you are saved!"
"Is it all right?" cried Tom, who wanted to make sure they were saving the right man.
"Yes! Yes, Tom! Go quickly!" called Ivan Petrofsky, as he folded his brother in his arms. A moment later, with a roar, the Falcon shot away from the earth, while below sounded angry cries, confused shouts and many orders, for the guards and their officers had never known of such a daring rescue as this.
There was a volley of shots from the prison guards, and the flashes of the rifles cut bright slivers of flame in the darkness, but, so rapidly did the airship go up, veering off on a wide slant, under the skillful guidance of Tom that the shots did no harm.
"Bless my bullet pouch!" cried Mr. Damon. "They must be quite excited."
"Shouldn't wonder," calmly observed Ned, as he went to help his chum in managing the airship. "But it won't do them any good. We've got our man."
"And right from under their noses, too," added Ivan Petrofsky exultingly. "This rescue of an exile will go down in the history of Russia."
The two exile brothers were gazing fondly at each other, for now that the Falcon was so high, Tom ventured to turn on the lights.
A moment later the three Russians were excitedly conversing, while Tom and Ned managed the craft, and Mr. Damon, after listening a moment to the rapid flow of the strange language, which quite fascinated him, hurried to the galley to prepare a meal for the rescued one, who had been taken away before he had had a chance to get his supper.
His wonder at his startling and unexpected rescue may well be imagined, but the joy at being reunited to his brother overshadowed everything for the time being. But when he had a chance to look about, and see what a strange craft he was in, his amazement knew no bounds, and he was like a child. He asked countless questions, and Ivan Petrofsky and Mr. Borious took turns in answering them. And from now on, I shall give the conversation of the two new Russians just as if they spoke English, though of course it had to be translated by Ivan Petrofsky, Peter's brother.
If Peter was amazed at being rescued in an airship, his wonder grew when he was served with a well-cooked meal, while high in the air, and while flying along at the rate of fifty miles an hour. He could not talk enough about it.
By degrees the story of how Tom and his friends had started for Russia was told, and there was added the detail of how Mr. Borious came to be picked up.
"But brother Ivan, you did not come all that distance to rescue me; did you?" asked Peter.
"Yes, partly, and partly to find the platinum mine."
"What? The lost mine that you and I stumbled upon in that terrible storm?"
"That is the one, Peter."
"Then, Tom Swift may as well return. I doubt if we can even locate the district where it was, and if we did find it, the winds blow so that even this magnificent ship could not weather the gales."
"I guess he doesn't understand about my air glider," said Tom with a smile, when this was translated to him. "I wish I had a chance to put it together, and show him how it works."
"Oh, it will work all right," replied Ned, who was very proud of his friend's inventive ability.
"Now, what is the next thing to be done?" asked Tom, a little later that evening, when, supper having been served, they were sitting in the main cabin, talking over the events of the past few days. "I'd like to get on the track of that platinum treasure."
"And we will do all in our power to aid you," said Ivan Petrofsky. "My brother and I owe much to you—in fact Peter owes you his life; do you not?" and he turned to him.
"I do," was the firm answer.
"Oh, nonsense!" exclaimed Tom, who did not like to be praised. "I didn't do much."
"Much! You do not call taking me away from that place—that sulphur mine—that horrible prison barrack with the cruel guards—you do not call that much? My friend," spoke the Russian solemnly, "no one on earth has done so much for me as you have, and if it is the power of man to show you where that lost mine is, my brother and I will do so!"
"Agreed," spoke Ivan quietly.
"Then what plans shall we make?" asked Tom, after a little more talk. "Are we to go about indiscriminately, or is there any possible way of getting on the trail?"
"My brother and I will try and decide on a definite route," spoke Ivan Petrofsky. "It is some time since I have seen him, and longer since we accidently found the mine together, but we will consult each other, and, if possible make some sort of a map."
This was done the next day, the present maps aboard the Falcon being consulted, and the brothers comparing notes. They began to lay out a stretch of country in which it was most likely the lost mine lay. It took several days to do this, for sometimes one brother would forget some point, and again the other would. But at last they agreed on certain facts.
"This is the nearest we can come to it," said Ivan Petrofsky to Tom. "The lost platinum mine lies somewhere between the city of Iakutsk and the first range of the Iablonnoi mountains. Those are the northern and southern boundaries. As for the western one, it is most likely the Lena river, and the eastern one the Amaga river. So you see you have quite a large stretch of country to search, Tom Swift."
"Yes, I should say I had," agreed the young inventor. "But I have had harder tasks. Now that I know where to head for I'll get there as soon as possible."
"And what will you do when you arrive?" asked Ned.
"Fly about in the Falcon, in ever-widening circles, starting as near the centre of that area as possible," replied Tom. "And as soon as I run into a steady hurricane I'll know that I'm at the place of the big winds, and I'll get out my glider, for I'll be pretty sure to be near the place."
"Bless my gas meter!" cried Mr. Damon. "That's the talk!"
Tom put his plan into operation at once, by heading the nose of his craft for the desolate region mapped out by the Russian brothers.
The days that followed were filled with weary searching. It was like the time when they had sought for the plain of the great ruined Temple in Mexico, that they might locate the underground city of gold. Only in this case they had no such landmark as a great Aztec ruin to guide them.
What they were seeking for was something unseen, but which could be felt—a mysterious wind—a wind that might be encountered any time, and which might send the Falcon to the earth a wreck.
The Russian brothers, staggering about in the storm, had seen the mine under different conditions from what it would be viewed now. Then it was winter in Siberia. Now it was summer, though it was not very warm.
On and on sailed the Falcon. The weather could not have been better, but for once Tom wanted bad weather. He wanted a blow—the harder the better—and all eyes anxiously watched the anemometer, or wind gage. But ever it revolved lazily about in the gentle breeze.
"Oh, for a hurricane!" cried Tom.
He got his wish sooner than he anticipated. It was about two days after this, when they were going about in a great circle, about two hundred miles from the imaginary centre of the district in which the mine lay, that, as Mr. Damon was getting dinner a dish he was carrying to the table was suddenly whisked out of his hand.
"I say, what's the matter?" he cried. "Bless my—"
But he had no time to say more. The airship fairly stood on end, and then, turning completely about, was rapidly driven in the opposite direction, though her propellers were working rapidly.
"What's up?" yelled Ned.
"We are capsizing!" shouted Ivan Petrofsky, and indeed it seemed so, for the airship was being forced over.
"I guess we've struck what we want!" cried Tom. "We're in a hurricane all right! This is the place of the big wind! Now for my air glider, if I can get the airship to earth without being wrecked! Ned, lend a hand! We've got our work cut out for us now!"
For several moments it seemed as if disaster would overtake the little band of platinum-hunters. In spite of all that Tom and Ned could do, the Falcon was whipped about like a feather in the wind. Sometimes she was pointing her nose to the clouds, and again earthward. Again she would be whirling about in the grip of the hurricane, like some fantastic dancer, and again she would roll dangerously. Had she turned turtle it probably would have been the last of her and of all on board.
"Yank that deflecting lever as far down as it will go!" yelled Tom to his chum.
"I am. She won't go any farther."
"All right, hold her so. Mr. Damon, let all the gas out of the bag. I want to be as heavy as possible, and get to earth as soon as we can."
"Bless my comb and brush!" cried the odd man. "I don't know what's going to become of us."
"You will know, pretty soon, if the gas isn't let out!" retorted Tom grimly, and then Mr. Damon hastened to the generator compartment, and opened the emergency outlet.
Finally, by crowding on all the possible power, so that the propellers and deflecting rudders forced the craft down, Tom was able to get out of the grip of the hurricane, and landed just beyond the zone of it on the ground.
"Whew! That was a narrow squeak!" cried Ned, as he got out. "How'd you do it, Tom?"
"I hardly know myself. But it's evident that we're on the right spot now."
"But the wind has stopped blowing," said Mr. Damon. "It was only a gust."
"It was the worst kind of a gust I ever want to see," declared the young inventor. "My air glider ought to work to perfection in that. If you think the wind has died out, Mr. Damon, just walk in that direction," and Tom pointed off to the left.
"Bless my umbrella, I will," was the reply and the odd man started off. He had not gone far, before he was seen to put his hand to his cap. Still he kept on.
"He's getting into the blow-zone," said Tom in a low voice.
The next moment Mr. Damon was seen to stagger and fall, while his cap was whisked from his head, and sent high into the air, almost instantly disappearing from sight.
"Some wind that," murmured Ned, in rather awe-struck tones.
"That's so," agreed his chum. "But we'd better help Mr. Damon," for that gentleman was slowly crawling back, not caring to trust himself on his feet, for the wind had actually carried him down by its force.
"Bless my anemometer!" he gasped, when Tom and Ned had given him a hand up. "What happened?"
"It was the great wind," explained Tom. "It blows only in a certain zone, like a draft down a chimney. It is like a cyclone, only that goes in a circle. This is a straight wind, but the path of it seems to be as sharply marked as a trail through the forest. I guess we're here all right. Does this location look familiar to you?" he asked of the Russian brothers.
"I can't say that it does," answered Ivan. "But then it was winter when we were here."
"And, another thing," put in Peter. "That wind zone is quite wide. The mine may be in the middle, or near the other edge."
"That's so," agreed Tom. "We'll soon see what we can do. Come on, Ned, let's get the air glider out and put her together. She'll have a test as is a test, now."
I shall not describe the tedious work of re-assembling Tom Swift's latest invention in the air craft line—his glider. Sufficient to say that it was taken out from where it had been stored in separate pieces on board the Falcon, and put together on the plain that marked the beginning of the wind zone.
It was a curious fact that twenty feet away from the path of the wind scarcely a breeze could be felt, while to advance a little way into it meant that one would at once be almost carried off his feet.
Tom tested the speed of it one day with a special anemometer, and found that only a few hundred feet inside the zone the wind blew nearly one hundred miles an hour.
"What is it like inside, I wonder?" asked Ned.
"It must be terrific," was his chum's opinion.
"Dare you risk it, Tom?"
"Of course. The harder it blows the better the glider works. In fact I can't make much speed in a hundred-mile wind for with us all on board the craft will be heavy, and you must remember that I depend on the wind alone to give me motion."
"What do you think causes the wind to blow so peculiarly here Tom?" went on Ned.
"Oh, it must be caused by high mountain ranges on either side, or the effects of heat and cold, the air being evaporated over a certain area because of great heat, say a volcano, or something like that; though I don't know that they have volcanoes here. That creates a vacuum, and other air rushes in to fill the vacant space. That's all wind is, anyhow, air rushing in to fill a vacuum, or low pressure zone, for you remember that nature abhors a vacuum."
It took nearly a week to assemble the Vulture, as Tom had named his latest craft, from the fact that it could hover in the air motionless, like that great bird. At last it was completed and then, weights being taken aboard to steady it, all was ready for the test. Tom would have liked to have taken all his passengers in the glider, for it would work better then, but the three Russians were timid, though they promised to get aboard after the trial.
The test came off early one morning, Tom, Ned and Mr. Damon being the only ones aboard. Bags of sand represented the others. The glider was wheeled to the edge of the wind zone and they took their places in the car. It was hard work for the gale, that had never ceased blowing for an instant since they found its zone, was very strong. But the glider remained motionless in it, for the wing planes, the rudders, and equalizing weights had been adjusted to make the strain of the wind neutral.
"All ready?" asked Tom, when his chum and his friend were in the enclosed car of the glider.
"As ready as I ever shall be," answered Ned.
"Bless my suspenders! Let her go, Tom, and have it over with!" cried the odd man.
The young inventor pulled a lever, and almost instantly the glider darted forward. A moment later it soared aloft, and the three Russians cheered. But their voices were lost in the roar of the hurricane, as Tom sent his craft higher and higher.
It worked perfectly, and he could direct it almost anywhere. The wind acted as the motive power, the bending and warping wings, and the rudders and weights controlling its force.
"I'm going higher, and see if I can remain stationary!" yelled Tom in Ned's ear. His chum only nodded. Mr. Damon was seated on a bench, clinging to the sides of it as if he feared he would fall off.
Higher and higher went the Vulture, ever higher, until, all at once, Tom pulled on another lever and she was still. There she hung in the air, the wind rushing through her planes, but the glider herself as still and quiet as though she rested on the ground in a calm. She hardly moved a foot in either direction, and yet the wind, as evidenced by the anemometer was howling along at a hundred and twenty miles an hour!
"Success!" cried Tom. "Success! Now we can lie stationary in any spot, and spy out the land through our telescope. Now we will find the lost platinum mine!"
"Well, I'm not deaf," responded Ned with a smile, for Tom had fairly yelled as he had at the start, and there was no need of this now, for though the wind blew harder than ever it was not opposed to any of the weights or planes, and there was only a gentle humming sound as it rushed through the open spaces of the queer craft.
Tom gave his glider other and more severe tests, and she answered every one. Then he came to earth.
"Now we'll begin the search," he said, and preparations were made to that end. The Russians, now that they had seen how well the craft worked, were not afraid to trust themselves in her.
As I have explained, there was an enclosed car, capable of holding six. In this were stores, supplies and food sufficient for several days. Tom's plan was to leave the airship anchored on the edge of the wind zone, as a sort of base of supplies or headquarters. From there he intended to go off from time to time in the wind-swept area to look for the lost mine.
There were weary days that followed. Hour after hour was spent in the air in the glider, the whole party being aboard. Observation after observation was taken, sometimes a certain strata of wind enabling them to get close enough to the earth to use their eyes, while again they had to use the telescopes. They covered a wide section but as day after day passed, and they were no nearer their goal, even Tom optimistic as he usually was, began to have a tired and discouraged look.
"Don't you see anything like the place where you found the mine?" he asked of the exile brothers.
They could only shake their heads. Indeed their task was not easy, for to recognize the place again was difficult.
More than a week passed. They had been back and forth to their base of supplies at the airship, often staying away over night, once remaining aloft all through the dark hours in the glider, in a fierce gale which prevented a landing. They ate and slept on board, and seldom descended unless at or near the place where they had left the Falcon. Once they completely crossed the zone of wind, and came to a calm place on the other side. It was as wild and desolate as the other edge.
Nearly two weeks had passed, and Tom was almost ready to give up and go back home. He had at least accomplished part of his desire, to rescue the exile, and he had even done better than originally intended, for there was Mr. Borious who had also been saved, and it was the intention of the young inventor to take him to the United States.
"But the platinum treasure has me beat, I guess," said Tom grimly. "We can't seem to get a trace of it."
Night was coming on, and he had half determined to head back for the airship. Ivan Petrofsky was peering anxiously down at the desolate land, over which they were gliding. He and his brother took turns at this.
They were not far above the earth, but landmarks, such as had to be depended on to locate the mine, could not readily be observed without the glass. Mr. Damon, with a pair of ordinary field glasses, was doing all he could to pick out likely spots, though it was doubtful if he would know the place if he saw it.
However, as chance willed it, he was instrumental in bringing the quest to a close, and most unexpectedly. Peter Petrofsky was relieving his brother at the telescope, when the odd man, who had not taken his eyes from the field glasses, suddenly uttered an exclamation.
"Bless my tooth-brush!" he cried. "That's a most desolate place down there. A lot of trees blown down around a lake that looks as black as ink."
"What's that!" cried Ivan Petrofsky. "A lake as black as ink? Where?"
"We just passed it!" replied Mr. Damon.
"Then put back there, as soon as you can, Tom!" called the Russian. "I want to look at that place."
With a long, graceful sweep the young inventor sent the glider back over the course. Ivan Petrofsky glued his eyes to the telescope. He picked out the spot Mr. Damon had referred to, and a moment later cried:
"That's it! That's near the lost platinum mine! We've found it again, Tom—everybody! Don't you remember, Peter," he said turning to his brother, "when we were lost in the snow we crawled in among a tangle of trees to get out of the blast. There was a sheet of white snow near them, and you broke through into water. I pulled you out. That must have been a lake, though it was lightly frozen over then. I believe this is the lost mine. Go down, Tom! Go down!"
"I certainly will!" cried the youth, and pulling on the descending lever he shunted the glider to earth.