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 bad 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.