The gold-seekers worked hard, and to such good purpose that in three days most of the ship was together once more, and the RED CLOUD looked like herself again. Tom hired a couple of machinists to aid him in assembling the motor, and some of the gas appliances and other apparatus.

"Ha! Bless my rubber shoes!" cried Mr. Damon in delight, as he looked at the big craft "This is like old times, Tom!"

"Yes, indeed," agreed our hero.

"Are you going to give it a preliminary tryout?" asked Ned.

"Oh, yes, I think we can do that to-morrow," replied Tom. "I want to know that everything is in good working shape before I trust the ship on the trip to the frozen north. There are several problems I want to work out, too, for I think I will need a different kind of gas up where the temperature is so low."

"It certainly is cold up here," agreed Ned, for they were now much farther north than when they were in Shopton, and, besides, winter was coming on. It was not the best time of the year to journey into Alaska, but they had no choice. To delay, especially now, might mean that their enemies would get ahead of them.

"We'll be warm in the airship, though; won't we?" asked Abe.

"Oh, yes," answered Tom. "We'll be warm, and have plenty to eat. Which reminds me that I must begin to see about our stock of provisions and other supplies, for we'll soon be on our way."

Work on the airship was hastened to such good advantage the next two days that it was in shape for a trial flight, and, one afternoon, the RED CLOUD was wheeled from the shed out into big field, the gas was generated, and the motor started.

There was a little hitch, due to the fact that some of the machine adjustments were wrong, but Tom soon had that remedied and then, with the big propellers whirling around, the airship was sent scudding across the field.

Another moment and it rose like a great eagle, and sailed through the air, while a small crowd that had daily gathered in the hope of seeing a flight, sent up a cheer.

"Does it work all right?" asked Ned anxiously, as he stood in the pilothouse beside his chum.

"As good as it did in Shopton," answered the young inventor, proudly.

"Bless my pocketbook! but that's lucky," exclaimed Mr. Damon. "Then we can soon start, eh?"

"As soon as we are stocked up," replied the lad.

Tom put the airship through a number of "stunts" to test her stability and the rudder control, much to the delight of the gathering throng. Everything was found to work well, and after ascending to a considerable height, to the no small alarm of the old miner, Tom made a quick descent, with the motor shut off. The RED CLOUD conducted herself perfectly, and there was nothing else to be desired.

She was sent down to earth and wheeled back into the shed, and not without some difficulty, for the crowd, which was now very large, wanted to get near enough to touch the wonderful craft.

"To-morrow I'll arrange about the supplies and provisions, and we'll stock her up," said Tom to his companions. "Now you folks had better go back to the hotel."

"Aren't you coming?" asked Ned.

I'm going to bunk here in the shed to-night, said the young inventor.

"What for?"

"I can't take any chances now that the RED CLOUD is in shape for flying. Some of the Foger crowd might be hanging around, and break in here to damage her."

"But the watchman will be on guard," suggested Ned, for since the hiring of the shed, the young inventor had engaged a man to remain on duty all night.

"I know," answered Tom Swift, "but I'm not going to take any chances. I'll stay here with the watchman."

Ned offered to share the vigil with his chum, and, after some objection Tom consented. The others went back to the hotel, promising to return early in the morning.

Tom slept heavily that night, much heavier than he was in the habit of doing. So did Ned, and their deep breathing as they lay in their staterooms, in the cabin of the airship, told of physical weariness, for they had worked hard to re-assemble the RED CLOUD.

The watchman was seated in a chair just inside the big door of the shed, near a small stove in which was a fire to take off the chill of the big place. The guard had slept all day, and there was no excuse for him nodding in the way that he did.

"Queer, how drowsy I feel," he murmured several times. "It's only a little after midnight, too," he added, looking at his watch, "Guess I'll walk around a bit to rouse myself."

He firmly intended to do this, but he thought he would wait just a few minutes more, and he stretched out his legs and got comfortable in the chair.

Three minutes more and the watchman was asleep—sound asleep, while a strange, sweet, sickish odor seemed to fill the atmosphere about him.

There was a noise at the door of the shed, a door in which there were several cracks. A man outside laid aside something that looked like an air pump. He applied one eye to a crack, and looked in on the sleeping watchman.

"He's off," the man murmured. "I thought he'd never get to sleep! Now to get in and dose those two lads! Then I'll have the place to myself!"

There was a clicking noise about the lock on the shed door. It was not a very secure lock at best, and, under the skilful fingers of the midnight visitor, it quickly gave way. The man entered. He gave one look at the slumbering watchman, listened to his heavy breathing, and then went softly toward the airship, which looked to be immense in the comparatively small shed—taking up nearly all the space.

The intruder peered in through the cabin windows where Ned and Tom were asleep. Once more there was in the atmosphere a sickish odor. The man again worked the instrument which was like a small air pump, taking care not to get his own face too near it. Presently he stopped and listened.

"They're doped," he murmured. He arose, and took from his mouth and nose a handkerchief saturated with some chemical that had rendered him immune to the effects of the sleep-producing that he had generated. "Sound asleep," he added. Then, taking out a long, keen knife, the vandal stole toward where the great wings of the RED CLOUD stretched out in the dim light like the pinions of a bird. There was a ripping, tearing, rending sound, as the vandal cut and slashed, but Tom, Ned and the watchman slumbered on.



CHAPTER X

TOM IS HELD UP

Tom Swift stirred uneasily in his heavy sleep. He dreamed that he was again in his berth in the railroad car, and that the thief was feeling under his pillow for the map. Only, this time, there seemed to be hands feeling about his clothing, trying to locate his inner pockets.

The lad murmured something unintelligible, but he did not awaken. The fumes prevented that. However, his movements showed that the effect of the drug was wearing off. It was intended only for temporary use, and it lasted less time than it would otherwise have done in a warmer, moister climate, for the cold, crisp air that penetrated the shed from outside dispelled the fumes.

"Guess I'd better not chance it," murmured the intruder. "He may not have it on him, and if I go through all his pockets I'll wake him up. Anyhow, I've done what they paid me for. I don't believe they'll sail in this airship."

The vandal gave one glance at the sleeping lads, and stole from the cabin of the craft. He looked at his work of ruin, and then tiptoed past the slumbering watchman. A moment later and he was outside the shed, hurrying away through the night.

Several hours after this Mr. Damon and the old miner were pounding on the door of the shed. Mr. Parker, the scientist, had remained at the hotel, for he said he wanted to work out a few calculations regarding some of his theories.

"I thought we'd find them up by this time," spoke the eccentric man, as he again knocked on the door. "Tom said he had lots to do to-day."

"Maybe they are working inside, and can't hear our knocks," suggested Abe. "Try th' door."

"Bless my heart! I never thought of that," exclaimed Mr. Damon. "I believe I will."

The door swung open as he pushed it, for it had not been locked when the intruder left. The first thing Mr. Damon saw was the watchman, still asleep in his chair.

"Bless my soul!" the old man shouted. "Look at this, Abe!"

"Something's wrong!" cried the miner, sniffing the air. "There's been crooked work here! Where are the boys?"

Mr. Damon was close to the airship. He looked in the cabin window.

"Here they are, and they're both asleep, too!" he called. "And—bless my eyeglasses! Look at the airship! The planes and wings are all cut and slashed! Something has happened! The RED CLOUD is all but ruined!"

Abe hastened to his side. He looked at the damage done, and a fierce look came over his face.

"The Fogers again!" he murmured. "We'll pay 'em back for this! But first we must see to the boys!"

They needed small attention, however. The opening of the big door had let in a flood of fresh air, and this dispelled the last of the fumes. The watchman was the first to revive. The sleep caused by the chemical, sprayed from the air-pump by the vandal, had been succeeded by a natural slumber, and this was the case with Ned and Tom. They were soon aroused, and looked with wonder, not unmixed with rage, at the work done in the night.

Every one of the principal planes of the airship, each of the rudders, and some of the auxiliary wings had been cut by a sharp knife—some in several places. The canvas hung in shreds and patches, and the trim RED CLOUD looked like some old tramp airship now. Tom could scarcely repress a groan.

"Who did it?" he gasped.

"And with us here on guard!" added Ned.

"I—I must have fallen asleep," admitted the watchman in confusion.

"You were all asleep," said Mr. Damon. "I couldn't rouse you!"

"And there was th' smell of chloroform, or something like it in th' shed," added the miner.

"But look at the airship!" groaned Tom.

"Is it ruined—can't we go to the valley of gold?" asked Ned.

Tom did not answer for a few minutes. He was walking around looking at his damaged craft. The sleepy feeling was rapidly leaving him, as well as Ned and the watchman.

"Bless my watch chain!" exclaimed Mr. Damon. "What an ugly, mean piece of work. Can you repair it, Tom?"

"I think so," was the hesitating answer. "It is not as bad as I feared at first. Luckily the gas-bag has not been touched, for, if it had, we could hardly have repaired it. I can fix the wings and the rudders. The propellers have not been damaged, nor has the motor been touched. I think they must have made another attempt to take the map off me," he went on, as he looked at several pockets that had been turned inside out.

An examination of the door showed how the lock had been forced, and the adventurers could easily guess the rest. But who the midnight vandal was they could not tell, though Tom and the others were sure it was some one hired by the Fogers.

"They wanted to delay us," said Tom. "They thought this would hold us back, but it won't—for long. We'll get right to work, and make new planes and rudders. Fortunately the framework isn't hurt any."

Once Tom got into action nothing held him back. He hardly wanted to stop for meals. New canvas was ordered, and that very afternoon some of the damaged wings had been repaired. In the meanwhile the stores and provisions that had been ordered were arriving, and, under the direction of the miner and Mr. Damon were put in the RED CLOUD. Tom and Ned, with the help of a man they hired, worked diligently to replace the damaged planes and rudders. Mr. Parker came out to the airship shed, but he was of little use as a helper, for he was continually stopping to jot down some memoranda about an observation he thought of, or else he would lay aside his tools to go outside, look at the weather, and make predictions.

But Tom and the others labored to such good advantage that in three days they had repaired most of the damage done. Luckily the vandal had cut and slashed in a hurry, and his malicious work was only half accomplished. There was no clue to his identity.

No trace was seen of the Fogers, and Tom hardly expected it, for he thought they were in Sitka by this time. Nor were any suspicious persons seen hanging around the shed. The adventurers left their rooms at the hotel, and took up their quarters in the airship that would soon be their home for many days. They wanted to be where they could watch the craft, and two guards were engaged.

"We'll start to-morrow," Tom announced gaily one evening when, after a hard day's work the last of the damaged planes had been repaired.

"Start fer th' valley of gold?" asked the miner.

"Yes. Everything is in good shape now. I want to go into town, to send some messages home, telling dad we'll soon be on our way, and I also want to get a few things."

"Shall I come?" asked Ned.

"No, I'd rather you'd stay here," spoke Tom, in a low voice. "We can't take any more chances of being delayed, and, as it's pretty well known that we'll sail to-morrow, the Foger crowd may try some more of their tricks. No, I'll go to town alone, Ned. I'll soon be back, however. You stay here."

Both Tom came nearly never coming back. As he was returning from sending the messages, and purchasing a few things he needed for the trip, he passed through a dark street. He was walking along, thinking of what the future might hold for him and his companions, after they reached the caves of ice, when, just as he got to a high board fence, surrounding some vacant lots, he heard some one whisper hoarsely:

"Here he comes!"

The young inventor was on his guard instantly. He jumped back to avoid a moving shadow, but was too late. Something struck him on the back of his head, and he felt his senses leaving him. He struggled against the feeling, and he realized, even in that exciting moment, that the thick collar of his heavy overcoat, which he had turned up because of a cold wind, had, perhaps, saved him from a broken skull.

"Hold him!" commanded another voice. "I'll go through him!"

The packages dropped from Tom's nerveless fingers. He felt himself sinking down, in spite of his fierce determination not to succumb. He felt several hands moving rapidly about his body, and then he struck blindly out at the footpads.



CHAPTER XI

OFF FOR THE FROZEN NORTH

Tom Swift felt as if he was struggling in some dream or nightmare. He felt strong hands holding him and saw evil faces leering at him.

Then gradually his brain cleared. His muscles, that had been weakened by the cowardly blow, grew strong. He felt his fist land heavily on some one's face. He heard a smothered gasp of pain.

Then came the sound of footsteps running—Tom heard the "ping" of a policeman's night-stick on the sidewalk.

"Here come the cops!" he heard one voice exclaim.

"Did you get it?" asked another.

"No, I can't find it. Cut for it now!"

They released the young inventor so suddenly that he staggered about and almost fell.

The next moment Tom was looking into the face of a big policeman, who was half supporting him.

"What's the matter?" asked the officer.

"Hold-up, I guess," mumbled the lad. "There they go!" he pointed toward two dark forms slipping along down the dimly-lighted street.

The officer drew his revolver, and fired two shots in the air, but the fleeing figures did not stop.

"How did it happen?" asked the policeman. "Did they get anything from you?"

"No—I guess not," answered Tom. He saw the packages containing his purchases lying where they had fallen. A touch told him his watch and pocketbook were safe. The precious map was in a belt about his waist, and that had not been removed. "No, they didn't get anything," he assured the officer.

"I came along too quick for 'em, I guess," spoke the bluecoat. "This is a bad neighborhood. There have been several hold-ups here of late, but I was on the job too soon for these fellows. Hello, Mike," as another officer came running up in answer to the shots and the raps of the night-stick. "Couple of strong-arm-men tackled this young fellow just now. I saw something going on as I turned the corner, and I rapped and ran up. They went down that way. I fired at 'em. You take after 'em, Mike, and I'll stay here. Don't believe you can land 'em, but try! I came up too quick to allow 'em to get anything, though."

Tom did not contradict this. He knew, however, that, had the men who attacked him wished to take his watch or money, they could have done it several times before the officer arrived.

"It was the map they were after," thought Tom, "not my watch or money. This is more of the Foger's work. We must get away from here."

The policeman inquired for more particulars from Tom, who related how the hold-up had taken place. The young inventor, however, said nothing about the map he carried, letting the officer think it was an ordinary attempt at robbery, for Tom did not want any reference in the newspapers to his search for the valley of gold.

Presently the other policeman returned, having been unable to get any trace of the daring men. The two bluecoats wanted to accompany Tom back to the airship shed, for his own safety, but he declared there was no more danger, and, after having given his name, so that the affair might be reported at headquarters, he was allowed to go on his way. His head ached from the blow, but otherwise he was unhurt.

"Those fellows have been keeping watch for me," the lad reasoned, as he walked quickly toward the airship shed. "They must have been shadowing me, and they hid there until I came back. Andy Foger and his father must be getting desperate. I think I know why, too. That little dig I gave Andy about his map is bearing fruit. He begins to think it's the wrong map, and he wants to get hold of the right one. Well, they shan't if I can help it. We'll be away from here in the morning."

There was indignation and some alarm among Tom's friends when he told his story a little later that night.

"Bless my walking-stick!" cried Mr. Damon. "You'll need a bodyguard after this."

"I'd just like t' git my hands on them fellers!" exclaimed the old miner. "I'd show 'em!" and a look at his rugged frame and his muscular arms and gnarled hands showed Tom and Ned that in the event of a fight they could count much on Abe Abercrombie.

"I am glad there will be no more delays, and that we will soon be moving northward," spoke Mr. Parker, a little later. "I am anxious to confirm my theory about the advance of the ice crust, I met a man to-day who had just returned from the north of Alaska. He said that a severe winter had already set in up there. So I am anxious to get to the ice caves."

"So am I," added Tom, but it was for a different reason.

They were all up early the next morning, for there were several things to look after before they started on the trip that might bring much of danger to the adventurers. Under Tom's direction, more gas was generated, and forced into the big bag. A last adjustment was made of the planes, wing tips and rudders, and the motor was given a try-out.

"I guess everything is all right," announced the young inventor. "We'll take her out."

The RED CLOUD was wheeled from the big shed, and placed on the open lot, where she would have room to rush across the ground to acquire momentum enough to rise in the air. Tom, whenever it was practical, always mounted this way, rather than by means of the lifting gas, as, in the event of a wind, he would have better control of the ship, while it was ascending into the upper currents of air, than when it was rising like a balloon.

"All aboard!" cried the lad, as he looked to see that the course was clear. Early as it was, there was quite a crowd on hand to witness the flight, as there had been every day of late, for the population of Seattle was curious regarding the big craft of the air.

"Let her go!" cried Ned Newton, enthusiastically.

Tom took his place in the steering-tower, or pilothouse, which was forward of the main cabin. Ned was in the engine-room, ready to give any assistance if needed. Mr. Damon, Mr. Parker and Abe Abercrombie were in the main cabin, looking out of the windows at the rapidly increasing throng.

"Here we go!" cried the young inventor, as he pulled the lever starting the motor, There was a buzz and a hum. The powerful propellers whirred around like blurs of light. Forward shot the great airship over the ground, gathering speed at every revolution of the blades.

Tom tilted the forward rudder to lift the ship. Suddenly it shot over the heads of the crowd. There was a cheer and some applause.

"Off for the frozen north!" cried Ned, waving his cap.

Tom shifted the rudder, to change the course of the airship. Mr. Damon was gazing on the crowd below.

"Tom! Tom!" he cried suddenly. "There's the man with the black mustache—the man who tried to rob you in the sleeping-car!" He pointed downward to some one in the throng.

"He can't get us now!" exclaimed Tom, as he increased the speed of the RED CLOUD, and then, taking up a telescope, after setting the automatic steering gear, Tom pointed the glass at the person whom Mr. Damon had indicated.



CHAPTER XII

PELTED BY HAILSTONES

"Yes, that's the man all right," observed the lad. "But if he came here to have another try for the map, he's too late. I hope we don't land now until we are in the valley of gold." Tom passed the telescope to Ned, who confirmed the identification.

"Perhaps he came to see if we started, and then he'll report to Andy Foger or his father by telegraph," suggested Mr. Damon.

"Perhaps," admitted Tom. "Anyhow, we're well rid of our enemies—at least for a time. They can't follow us up in the air." He turned another lever and the RED CLOUD shot forward at increased speed.

"Maybe Andy will race us," suggested Ned.

"I'm not afraid of anything his airship can do," declared Tom. "I don't believe it will even get up off the ground, though he did make a short flight before he packed up to follow us. It's a wonder he wouldn't think of something himself, instead of trying to pattern after some one else. He tried to beat me in building a speeding automobile, and now he wants to get ahead of me in an airship. Well, let him try. I'll beat him out, just as I've done before."

They were now over the outskirts of Seattle, flying along about a thousand feet high, and they could dimly make out curious crowds gazing up at them. The throng that had been around the airship shed had disappeared from view behind a little hill, and, of course, the man with the black mustache was no longer visible, but Tom felt as if his sinister eyes were still gazing upward, seeking to discern the occupants of the airship.

"We're well on our way now," observed Ned, after a while, during which interval he and Tom had inspected the machinery, and found it working satisfactorily.

"Yes, and the RED CLOUD is doing better than she ever did before," said Tom. "I think it did her good to take her apart and put her together again. It sort of freshened her up. This machine is my special pride. I hope nothing happens to her on this journey to the caves of ice."

"If my theory is borne out, we will have to be careful not to get caught in the crush of ice, as it makes its way toward the south," spoke Mr. Parker with an air as if he almost wished such a thing to happen, that he might be vindicated.

"Oh, we'll take good care that the RED CLOUD isn't nipped between two bergs," Tom declared.

But he little knew of the dire fate that was to overtake the RED CLOUD, and how close a call they were to have for their very lives.

"No matter what care you exercise, you cannot overcome the awful power of the grinding ice," declared the gloomy scientist. "I predict that we will see most wonderful and terrifying sights."

"Bless my hatband!" cried Mr. Damon, "don't say such dreadful things, Parker my dear man! Be more cheerful; can't you?"

"Science cannot be cheerful when foretelling events of a dire nature," was the response. "I would not do my duty if I did not hold to my theories."

"Well, just hold to them a little more closely," suggested Mr. Damon. "Don't tell them to us so often, and have them get on our nerves, Parker, my dear man. Bless my nail-file! be more cheerful. And that reminds me, when are we going to have dinner, Tom?"

"Whenever you want it, Mr. Damon. Are you going to act as cook again?"

"I think I will, and I'll just go to the galley now, and see about getting a meal. It will take my mind off the dreadful things Mr. Parker says."

But if the gloomy scientific man heard this little "dig" he did not respond to it. He was busy jotting down figures on a piece of paper, multiplying and dividing them to get at some result in a complicated problem he was working on, regarding the power of an iceberg in proportion to its size, to exert a lateral pressure when sliding down a grade of fifteen per cent.

Mr. Damon got an early dinner, as they had breakfasted almost at dawn that morning, in order to get a good start. The meal was much enjoyed, and to Abe Abercrombie was quite a novelty, for he had never before partaken of food so high up in the air, the barograph of the RED CLOUD showing an elevation of a little over twelve thousand feet.

"It's certainly great," the old miner observed, as he looked down toward the earth below them, stretched out like some great relief map. "It sure is wonderful an' some scrumptious! I never thought I'd be ridin' one of these critters. But they're th' only thing t' git t' this hidden valley with. We might prospect around for a year, and be driven back by the Indians and Eskimos a dozen times. But with this we can go over their heads, and get all the gold we want."

"Is there enough to give every one all he wants?" asked Tom, with a quizzical smile. "I don't know that I ever had enough."

"Me either," added Ned Newton.

"Oh, there's lots of gold there," declared the old miner. "The thing to do is to get it and we can sure do that now."

The remainder of the day passed uneventfully, though Tom cast anxious looks at the weather as night set in, and Ned, noting his chum's uneasiness, asked:

"Worrying about anything, Tom?"

"Yes, I am," was the reply. "I think we're in for a hard storm, and I don't know just how the airship will behave up in these northern regions. It's getting much colder, and the gas in the bag is condensing more than I thought it would. I will have to increase our speed to keep us moving along at this elevation."

The motor was adjusted to give more power, and, having set it so that it, as well as the rudders, would be controlled automatically, Tom rejoined his companions in the main cabin, where, as night settled down, they gathered to eat the evening meal.

Through the night the great airship plowed her way. At times Tom arose to look at some of the recording instruments. It was growing colder, and this further reduced the volume of the gas, but as the speed of the ship was sufficient to send her along, sustained by the planes and wings alone, if necessary, the young inventor did not worry much.

Morning broke gray and cheerless. A few flakes of snow fell. There was every indication of a heavy storm. They were high above a desolate and wild country now, hovering over a sparsely settled region where they could see great forests, stretches of snow-covered rocks, and towering mountain crags.

The snow, which had been lazily falling, suddenly ceased. Tom looked out in surprise. A moment later there came a sound as if some giant fingers were beating a tattoo on the roof of the main cabin.

"What's that!" cried Ned.

"Bless my umbrella! has anything happened?" demanded Mr. Damon.

"It's a hail storm!" exclaimed Tom. "We've run into a big hail storm. Look at those frozen stones! They're as big as hens' eggs!"

On a little platform in front of the steering-house could be seen falling immense hailstones. They played a tattoo on the wooden planks.

"A hail storm! Bless my overshoes!" cried Mr. Damon.

"A hail storm!" echoed Mr. Parker. "I expected we would have one. The hailstones will become even larger than this!"

"Cheerful," remarked Tom in a low voice, with an apprehensive look at Ned.

"Is there any danger?" asked his chum.

"Danger? Plenty of it," replied the young inventor. "The frozen particles may rip open the gas bag." He stopped suddenly and looked at a gage on the wall of the steering-tower—a gage that showed the gas pressure.

"One compartment of the bag has been ripped open!" cried Tom. "The vapor is escaping! The whole bag may soon be torn apart!"

The noise of the pelting hailstones increased. The roar of the storm, the bombardment of the icy globules, and the moaning of the wind struck terror to the hearts of the gold-seekers.

"What's to be done?" yelled Ned.

"We must go up, to get above the storm, or else descend and find some shelter!" answered Tom. "I'll first see if I can send the ship up above the clouds!"

He increased the speed of the motor so that the propellers would aid in taking the ship higher up, while the gas-generating machine was set in operation to pour the lifting vapor into the big bag.



CHAPTER XIII

A FRIGHTENED INDIAN

The violence of the hail storm, the clatter of the frozen pellets as they bombarded the airship, the rolling, swaying motion of the craft as Tom endeavored to send it aloft, all combined to throw the passengers of the RED CLOUD into a state of panic.

"Bless my very existence!" cried Mr. Damon, "this is almost as bad as when we were caught in the hurricane at Earthquake Island!"

"I am sure that this storm is but the forerunner of some dire calamity!" declared Mr. Parker.

"I'm afraid it's all up with us," came from Abe Abercrombie, as he looked about for some way of escape.

"Do you think you can pull us through, Tom?" asked Ned Newton, who, not having had much experience in airships had yet to learn Tom's skill in manipulating them.

The young inventor alone seemed to keep his nerve. Coolly and calmly he stood at his post of duty, shifting the wing planes from moment to moment, managing the elevation rudder, and, at the same time, keeping his eye on the registering dial of the gas-generating machine.

"It's all right," said Tom, more easily than he felt. "We are going up slowly. You might see if you can induce the gas machine to do any better, Mr. Damon. We are wasting some of the vapor because of the leak in the bag, but we can manufacture it faster than it escapes, so I guess we'll be all right."

"Mr. Parker, may I ask you to oil the main motor? You will see the places marked where the oil is to go in. Ned, you help him. Here, Abe, come over here and give me a hand. This wind makes the rudders hard to twist."

The young inventor could not have chosen a better method of relieving the fears of his friends than by giving them something to do to take their minds off their own troubles. They hurried to the tasks he had assigned to them, and, in a few minutes, there were no more doubts expressed.

Not that the RED CLOUD was out of danger, Far from it. The storm was increasing in violence, and the hailstones seemed to double in number. Then, too, being forced upward as she was, the airship's bag was pelted all the harder, for the speed of the craft, added to the velocity of the falling chunks of hail, made them strike on the surface of the ship with greater violence.

Tom was anxiously watching the barograph, to note their height. The RED CLOUD was now about two and a half miles high, and slowly mounting upward. The gas machine was working to its fullest capacity, and the fact that they did not rise more quickly told Tom, more plainly than words could have done, that there were several additional leaks in the gas-bag.

"I'll take her up another thousand feet," he announced grimly. "Then, if we're not above the storm it will be useless to go higher."

"Why?" asked Ned, who had come back to stand beside his chum.

"Because we can't possibly get above the storm without tearing the ship to pieces. I had rather descend."

"But won't that be just as bad?"

"Not necessarily. There are often storms in the upper regions which do not get down to the surface of the earth, snow and hail storms particularly. Hail, you know, is supposed to be formed by drops of rain being hurled up and down in a sort of circular, spiral motion through alternate strata of air—first freezing and then warm, which accounts for the onion-like layers seen when a hailstone is cut in half."

"That is right," broke in Mr. Parker, who was listening to the young inventor. "By going down this hail storm may change into a harmless rain storm. But, in spite of that fact, we are in a dangerous climate, where we must expect all sorts of queer happenings."

"Nice, comfortable sort of a companion to have along on a gold-hunting expedition, isn't He?" asked Tom of Ned, making a wry face as Mr. Parker moved away. "But I haven't any time to think of that. Say, this is getting fierce!"

Well might he say so. The wind had further increased in violence, and while the storm of hailstones seemed to be about the same, the missiles had nearly doubled in size.

"Better go down," advised Ned. "We may fall if you don't."

"Guess I will," assented Tom. "There's no use going higher. I doubt if I could, anyhow, with all this wind pressure, and with the gas-bag leaking. Down she is!"

As he spoke he shifted the levers, and changed the valve wheels. In an instant the RED CLOUD began to shoot toward the earth.

"What's happened? What in th' name of Bloody Gulch are we up ag'in'?" demanded the old miner, springing to his feet.

"We're going down—that's all," answered Tom, calmly, but he was far from feeling that way, and he had grave fears for the safety of himself and his companions.

Down, down, down went the RED CLOUD, in the midst of the hail storm. But if the gold-seekers had hoped to escape the pelting of the frozen globules they were mistaken. The stones still seemed to increase in size and number. The gas machine register showed a sudden lack of pressure, not due to the shutting off of the apparatus.

"Look!" cried Ned, pointing to the dial.

"Yes—more punctures," said Tom, grimly.

"What's to be done?" asked Mr. Damon, who had finished the task Tom allotted to him. "Bless my handkerchief! what's to be done?"

"Seek shelter if the storm doesn't stop when we get to the earth level," answered Tom.

"Shelter? What sort of shelter? There are no airship sheds in this desolate region."

"I may be able to send the ship under some overhanging mountain crag," answered the young inventor, "and that will keep off the hailstones."

Eagerly Tom and Ned, who stood together in the pilothouse peered forward through the storm.

The wind was less violent now that they were in the lower currents of air, but the hail had not ceased.

Suddenly Tom gave a cry. Ned looked at him anxiously. Had some new calamity befallen them? But Tom's voice sounded more in relief than in alarm. The next instant he called:

"Look ahead there, Ned, and tell me what you see."

"I see something big and black," answered the other lad, after a moment's hesitation. "Why, it's a big black hole!" he added.

"That's what I made it out to be," went on Tom, "but I wanted to be sure. It's the opening to a cave or hole in the side of the mountain. I take it."

"You're right," agreed Ned.

"Then we're safe," declared Tom.

"Safe? How?"

"I'm going to take the RED CLOUD in there out of the storm."

"Can you do it? Is the opening big enough?"

"Plenty. It's larger than my shed at home, Jove! but I'm glad I saw that in time, or there would have been nothing left of the gas-bag!"

With skilful hands Tom turned the rudders and sent the airship down on a slant toward the earth, aiming for the entrance to the cave, which loomed up in the storm. When the craft was low enough down so that the superstructure would not scrape the top of the cave, Tom sent her ahead on the level. But he need have had no fears, for the hole was large enough to have admitted a craft twice the size of the RED CLOUD.

A few minutes later the airship slid inside the great cavern, as easily as if coming to rest in the yard of Tom's house. The roof of the cave was high over their heads, and they were safe from the storm. The cessation from the deafening sound of the pelting hailstones seemed curious to them at first.

"Well, bless my shoelaces! if this isn't luck!" cried Mr. Damon, as he opened the door of the cabin, and looked about the cave in which they now found themselves. It was comparatively light, for the entrance was very large, though the rear of the cavern was in gloom.

"Yes, indeed, we got to it just in time,'" agreed Tom. "Now let's see what sort of a place it is. We'll have to explore it."

"There may be a landslide, or the roof may come down on our heads," objected Mr. Parker.

"Oh, my dear Parker! please be a little more cheerful," begged Mr. Damon.

The adventurers followed Tom from the airship, and all but the young inventor gazed curiously at the interior of the cave. His first thought was for his airship. He glanced up at the gas-bag, and noted several bad rents in it.

"I hope we can fix them," Tom thought dubiously.

But the attention of all was suddenly arrested by something that occurred just then. From the dark recess of the cavern there sounded a fearful yell or scream. It was echoed back a thousand-fold by the rocky walls of the cave, Then there dashed past the little group of gold-seekers a dark figure.

"Look out! It's a bear!" shouted Mr. Damon. "A bear! It's an Eskimo Indian!" yelled Abe Abercrombie, "an' he's skeered nigh t' death! Look at him run!"

As they gazed toward the lighted entrance of the cave they saw leaping and running from it an Indian who quickly scudded out into the hail storm.

"An Indian," exclaimed Tom. "An Indian in the cave! If there's one, there may be more. I guess we'd better look to our guns. They may attack us!" and he hurried back into the airship, followed by Ned and the others.



CHAPTER XIV

THE RIVAL AIRSHIP

Well armed, the adventurers again ventured out into the cave. But they need not have been alarmed so soon, for there were no signs of any more Indians.

"I guess that one was a stray Eskimo who took shelter in here from the storm," said Abe Abercrombie.

"Are we in the neighborhood of the Alaskan Indians and Eskimos?" inquired Ned.

"Yes, there are lots of Indians in this region," answered the old miner, "but not so many Eskimos. A few come down from th' north, but we'll see more of them, an' fewer of th' pure-blooded Indians as we get nearer th' valley of gold. Though t' my mind th' Indians an' Eskimos are pretty much alike."

"Well, if we don't have to defend ourselves from an attack of Indians, suppose we look over the airship," proposed Tom.

"It's too dark to see very much," objected Ned. But this was overcome when Tom started up a dynamo, and brought out a portable search-light which was played upon the superstructure of the RED CLOUD. The gas-bag was the only part of the craft they feared for, as the hailstones could not damage the iron or wooden structure and the planes were made in sections, and in such a manner that rents in them could easily be repaired. So, in fact, could the gas-bag be mended, but it was harder work.

"Well, she's got some bad tears in her," announced Tom as the light flashed over the big bag. "Luckily I have plenty of the material, and some cement, so I think we can mend the rents, though it will take some days. Nothing could have been better for us than this cave. We'll stay here until we're ready to go on."

"Unless the Indians drive us out," said Abe, in a low tone.

"Why, do you think there is any danger of that?" inquired Tom.

"Well, th' brown-skinned beggars aren't any too friendly," responded the old miner. "Th' one that was in here will be sure to tell th' others of some big spirit that flew into th' cave, an' they'll be crowdin' around here when th' storm's over. It may be we can fight 'em off, though."

"Maybe they won't attack us," suggested Ned, hopefully. "Perhaps we can make them believe we are spirits, and that it will be unlucky to interfere with us."

"Perhaps," admitted Abe, "though my experience has been that these Indians are a bad lot. They haven't much respect for spirits of any kind, an' they'll soon find out we're human. But then, we'll wait an' see what happens."

"And, in the meantime, have something to eat," put in Mr. Damon. "Bless my knife and fork! but the hail storm gave me an appetite."

In fact, there were few things which did not give Mr. Damon an appetite, Tom thought with a smile. But the meal idea was considered very timely, and soon the amateur cook was busy in the galley of the airship, whence speedily came savory odors. The electric lights were switched on, and the adventurers were quickly made comfortable in the cave, which so well sheltered the RED CLOUD. Tom completed his inspection of the craft, and was relieved to find that while there were a number of small rents, none was very large, and all could be mended in time.

Abe Abercrombie took a look outside the cave after the meal had been served. The old miner declared that they had made a good advance on their northern journey for, though he could not tell their exact location, he knew by the character of the landscape that they had passed the boundaries of Alaska.

"A few more days' traveling at the rate we came will bring us to the Snow Mountains and the valley of gold," he said.

"Well, we won't average such speed as we did during the hail storm," said Tom. "The wind of that carried us along at a terrific pace. But we will get there in plenty of time, I think."

"Why; is there any particular rush?" asked Ned.

"There's no telling when the Fogers may appear," answered the young inventor in a low voice. "But now we must get to work to repair damage."

The hail storm had ceased, and, with the passing of the clouds the cave was made lighter. But Tom did not depend on this, for he set up powerful searchlights, by the gleams of which he and his companions began the repairing of the torn gas-bag.

They worked all the remainder of that day, and were at it again early the next morning, making good progress.

"We can go forward again, in about two days," spoke Tom. "I want to give the cement on the patches plenty of chance to dry."

"Then I will have time to go out and make some observations, will I not?" asked Mr. Parker. "I think this cave is a very old one, and I may be able to find some evidences in it that the sea of ice is slowly working its way down from the polar regions."

"I hope you don't," whispered Ned to Tom, who shook his head dubiously as the gloomy scientist left the cave.

The weather was very cold, but, in the cavern it was hardly noticed. The adventurers were warmly dressed, and when they did get chilly from working over the airship, they had but to go into the well-heated and cozy cabin to warm themselves.

It was on the third day of their habitation in the cave, and work on putting the patches on the gas-bag was almost finished. Mr. Parker had gone out to make further observations, his previous ones not having satisfied him. Tom was on an improvised platform, putting a patch on top of the bag, when he heard a sudden yell, and some one dashed into the cavern.

"They're coming! They're coming!" cried a voice, and Tom, looking down, saw Mr. Parker, apparently in a state of great fear.

"What's coming?" demanded the young inventor, "the icebergs?"

"No—the Indians!" yelled the scientist. "A whole tribe of them is rushing this way!"

"I thought so!" cried Abe Abercrombie. "Where's my gun?" and he dashed into the airship.

Tom slid down off the platform.

"Get ready for a fight!" he gasped. "Where are you, Ned?"

"Here I am. We'd better get to the mouth of the cave, and drive 'em back from there."

"Yes. If I'd only thought, we could have blockaded it in some way. It's as big as a barn now, and they can rush us if they have a mind to. But we'll do our best!"

The adventurers were now all armed, even to Mr. Parker. The scientist had recovered from his first fright, when he spied the Indians coming over the snow, as he was "observing" some natural phenomenon. Tom, even in his excitement, noticed that the professor was curiously examining his gun, evidently more with a view to seeing how it was made, and on which principle it was operated, rather than to discover how to use it.

"If it comes to a fight, just point it at the Indians, pull the trigger, and work that lever," explained the young inventor. "It's an automatic gun."

"I see," answered Mr. Parker. "Very curious. I had no idea they worked this way."

"Oh, if I only had my electric rifle in shape!" sighed Tom, as he dashed forward at the side of Ned.

"Your electric rifle?"

"Yes, I've got a new kind of weapon—very effective. I have it almost finished. It's in the airship, but I can't use it just yet. However, maybe these repeaters will do the work."

By this time they were at the entrance of the cave, and, looking out they saw about a hundred Indians, dressed in furs, striding across the snowy plain that stretched out from the foot of the mountain in which was the cavern.

"They're certainly comin' on," observed Abe, grimly. "Git ready for 'em, boys!"

The gold-seekers lined up at the mouth of the cave, with guns in their hands. At the sight of this small, but formidable force, the Indians halted. They were armed with guns of ancient make, while some had spears, and others bows and arrows. A few had grabbed up stones as weapons.

There appeared to be a consultation going on among them, and, presently, one of the number, evidently a chief or a spokesman, gave his gun to one of his followers, and, holding his hands above his head, while he waved a rag that might have once been white, came forward.

"By Jove!" exclaimed Tom. "It's a flag of truce! He wants to talk with us I believe!"

"Bless my cartridges!" exclaimed Mr. Damon. "Can they speak English?"

"A little," answered Abe Abercrombie. "I can talk some of their lingo, too. Maybe I'd better see what they want."

"I guess it would be a good plan," suggested Tom, and, accordingly the old miner stepped forward. The Indian came on, until Abe motioned for him to halt.

"I reckon that's as far as it'll be healthy for you t' come," spoke Abe, grimly. "Now what do you fellers want?"

Thereupon there ensued a rapid exchange of jargon between the miner and the Indian. Abe seemed much relieved as the talk went on, until there came what seemed like a demand on the part of the dark-hued native.

"No, you don't! None of that!" muttered Abe. "If you had your way you'd take everything we have."

"What is it? What does he want?" asked Tom in a low voice.

"Why, the beggar began fair enough," replied the miner. "He said one of their number had been in the cave when a storm came an' saw a big spirit fly in, with men on its back. He ran away an' now others have come to see what it was. They don't guess it's an airship, for they've never seen one, but they know we're white folks, an' they always want things white folks have got."

"This fellow is a sort of chief, an' he says the white folks?—that's us, you know?—have taken th' Indians' cave. He says he doesn't want t' have any trouble, an' that we can stay here as long as we like, but that we must give him an' his followers a lot of food. Says they hain't got much. Land! Those beggars would eat us out of everything we had if we'd let 'em!"

"What are you going to tell them?" inquired Mr. Damon.

"I'm goin' t' tell 'em t' go t' grass, or words t' that effect," replied Abe. "They haven't any weapons that amount t' anything, an' we can stand 'em off. Besides, we'll soon be goin' away from here; won't we, Tom?"

"Yes, but—"

"Oh, there's no use givin' in to 'em," interrupted Abe. "If you give 'em half a loaf, they want two. Th' only way is t' be firm. I'll tell 'em we can't accommodate 'em."

Thereupon he began once more to talk to the Indians in their own tongue. His words were at first received in silence, and then angry cries came from the natives. The chief made a gesture of protest.

"Well, if you don't like it, you know what you kin do!" declared Abe. "We've got th' best part of our journey before us, an' we can't give away our supplies. Go hunt food if you want it, ye lazy beggars!"

The peaceful demeanor of the Indians now turned to rage. The leader dropped the rag that had served for a flag of truce, and took back his gun.

"Look out! There's going to be trouble!" cried Tom.

"Well, we're ready for 'em!" answered Abe, grimly.

There was a moment of hesitation among the natives. Then they seemed to hold a consultation with the chief. It was over shortly. They broke into a run, and quickly advanced toward the cave. Tom and the others held their guns in readiness.

Suddenly the Indians halted. They gazed upward, and pointed to something in the air above their heads. They gave utterance to cries of fear.

"What is it; another storm coming?" asked Tom.

"Let's look," suggested Ned. He and Tom stepped to the mouth of the cave—they went outside. There was little danger from the natives now, as their attention was fixed on something else.

A moment later Tom and Ned saw what this was.

Floating in the air, almost over the cave, was a great airship—a large craft, nearly the size of the RED CLOUD. Hardly able to believe the evidence of their eyes, Tom and Ned watched it. Whence had it come? Whither was it going?

"It's a triplane!" murmured Ned.

"A triplane!" repeated Tom. "Yes—it is—and it's the airship of Andy Foger! Our rivals are on our track!"

He continued to gaze upward as the triplane shot forward, the noise of the motor being plainly heard. Then, with howls of fear, the Indians turned and fled. The rival airship had vanquished them.



CHAPTER XV

THE RACE

Astonished and terrified as the Indians had been at the sight of the big-winged craft, high in the air above their heads, Tom and the others were no less surprised, though, of course, their fear was not exactly the same as that of the Alaskan natives.

"Do you really think that is Andy Foger?" asked Ned, as they watched the progress of the triplane.

"I'm almost sure of it," replied Tom. "That craft is built exactly as his was, but I never expected him to have such good luck sailing it."

"It isn't going very fast," objected Ned.

"No, but it can navigate pretty well, and that's something. He must have hustled to get it together and reach this point with it."

"Yes, but he didn't have to travel as far as we did," went on Ned. "He put his ship together at Sitka, and we came from Seattle."

"Bless my memoranda book!" exclaimed Mr. Damon. "The Fogers here! What's to be done about it?"

"Nothing, I guess," answered Tom. "I'd just as soon they wouldn't see us. I don't believe they will. Get back into the cave. We must use strategy now to get ahead of them. There will be a race to the valley of gold."

"Well, he served us one good turn, anyhow, though he didn't mean to," put in Abe Abercrombie.

"How?" asked Mr. Parker, who was still examining his gun, as though trying to understand it.

"He scared away them pesky natives," went on the miner. "Otherwise we might have had a fight, an' while I reckon we could have beat 'em, it's best not to fight if you kin git out of it."

The gold-seekers had withdrawn inside the mouth of the cave, where they could watch the progress of the rival airship without being seen. The Indians had disappeared beyond a snow-covered hill.

The airship of Andy Foger, for such it subsequently proved to be, floated slowly onward. Its progress was not marked with the speed of Tom's craft, though whether or not the occupants of the ANTHONY (as Andy had vain-gloriously named his craft after himself) were speeding up their motor, was a matter of conjecture.

The adventurers held a short consultation, while standing at the mouth of the cave watching the progress of the ANTHONY. It rose in the air, and circled about.

"He certainly IS trying to pick us up," declared Ned.

"Well, we'll start out after him to-morrow," decided Tom. "I think all the patches will hold then."

They resumed work on the RED CLOUD, and that night Tom announced that they would start in the morning. Meanwhile Andy's craft had disappeared from sight. There was no further evidence of the Indians.

"I don't reckon they'll come back," spoke Abe, grimly. "They think we are sure-enough spirits, now, able to call creatures out of the air whenever we want 'em. But still we must be on our guard."

As Mr. Parker was not of much service in helping on the airship he agreed to be a sort of guard and took his place just outside the cave, where he could make "observations," and, at the same time watch for the reappearance of Indians. They had little fear of an attack at night, for Abe said the Alaskans were not fond of darkness.

The cold seemed to increase, and, even in the sheltered cave the adventurers felt it. There were several heavy flurries of snow that afternoon, and winter seemed setting in with a vengeance. The daylight, too, was not of long duration, for the sun was well south now, and in the far polar regions it was perpetual night.

After a brief inspection of the ship the next morning, following a good night's rest, when they were not disturbed by any visits from the natives, Tom announced that they would set sail. The day was a clear one, but very cold, and the gold-seekers were glad of the shelter of the warm cabin.

The RED CLOUD was wheeled from the cave, and set on a level place. There was not room enough to make a flying start, and ascend by means of the planes and propellers, so the gas-bag method was used. The generating machine was put in operation, and soon the big red bag that hovered over the craft began to fill. Tom was glad to see that none of the several compartments leaked. The bag had been well repaired.

Suddenly the RED CLOUD shot up in the air. Up above the towering snow-covered crags it mounted, and then, with a whizz and a roar, the propellers were set going.

"Once more northward bound!" cried Tom, as he took his place in the pilothouse.

"And we'll see if we can beat Andy Foger there," added Ned.

All that morning the RED CLOUD shot ahead at good speed. The craft had suffered no permanent damage during her fight with the hail storm, and was as good as ever. They ate dinner high in the air, while sailing over a great stretch of whiteness, where the snow lay many feet deep on the level, and where great mountain crags were so covered with the glistening mantle and a coating of ice as to resemble the great bergs that float in the polar sea.

"I wouldn't want to be wrecked here," said Ned, with a shudder, as he looked down. "We'd never get away. Does any one live down there, Abe?"

"Yes, there are scattered tribes of Indians and Alaskan natives. They live by hunting and fishing, and travel around by means of dog sledges. But it's a dreary life. Me an' my partner had all we wanted of it. An airship for mine!"

"I wonder what's become of Andy?" spoke Tom, that afternoon. "I haven't sighted him, and I've been using the powerful telescope. I can't pick him up, though he can't be so very far ahead of us."

"Let me try," suggested Ned. "Put her up a bit, Tom, where I can look down. Andy won't dare go very high. Maybe I can sight him."

The RED CLOUD shot upward as the young inventor shifted the elevation rudder, and the bank clerk, with the powerful glass to his eye, swept the space below him. For half an hour he looked in vain. Then, with a little start of surprise he handed the glass to his chum.

"See what you make that out to be," suggested Ned. "It looks like a big bird, yet I haven't seen any other birds to-day."

Tom looked. He peered earnestly through the telescope for a minute, and then cried:

"It's Andy's airship! He's ahead of us! We must catch him! Ned, you and Mr. Damon speed up the motor! The race is on!"

In a few minutes the great airship was hurling herself through space, and, in less than ten minutes Andy's craft could be made out plainly with the naked eye. Fifteen minutes more and the RED CLOUD was almost up to her. Then those aboard the ANTHONY must have caught sight of their pursuers, for there was a sudden increase in speed on the part of the unscrupulous Foger crowd, who sought to steal a march on Tom and his friends.

"The race is on!" repeated the young inventor grimly, as he pulled the speed lever over another notch.



CHAPTER XVI

THE FALL OF THE ANTHONY

Had it not been for what was at stake, the race between the two big airships would have been an inspiring one to those aboard Tom's craft. As it was they were too anxious to overcome the unfair advantage taken by Andy to look for any of the finer points in the contest of the air.

"There's no denying that he's got a pretty good craft there," conceded Tom, as he watched the progress of his rival. "I never thought Andy Foger could have done it."

"He didn't do very much of it," declared Ned. "He hired the best part of that made. Andy hasn't any inventive ideas. He probably said he wanted an airship, and his dad put up the money and hired men to build it for him. Andy, Sam and Pete only tinkered around on it."

Later Tom and his chum learned that this was so—that Mr. Foger had engaged the services of an expert to make the airship. This man had been taken to Sitka with the Fogers, and had materially aided them in re-assembling the craft.

"Do you think he can beat us?" asked Ned, anxiously.

"No!" exclaimed Tom, confidently. "There's only one craft that can beat my RED CLOUD and that's my monoplane the BUTTERFLY. But I have in mind plans for a speedier machine than even the monoplane. However I haven't any fear that Andy can keep up to us in this craft. I haven't begun to fly yet, and I'm pretty sure, from the way his is going, that he has used his limit of speed."

"Then why don't you get ahead of him?" asked Mr. Damon. "Bless my tape-measure! the way to win a race is to beat."

"Not this kind of a race," and the young inventor spoke seriously. "If I got ahead of Andy now, he'd simply trail along and follow us. That's his game. He wants me to be the path-finder, for, since I cast a doubt on the correctness of the map, a copy of which he stole, he isn't sure where he's going. He'd ask nothing better than to follow us."

"Then what are you going to do if you don't get ahead of him?" asked Ned.

"I'm going to press him close until night," answered Tom, "and when it's dark, I'm going to shoot ahead, and, by morning we'll be so far away that he can't catch up to us."

"Good idea! That's th' stuff!" cried Abe with enthusiasm.

"He's a sneak!" burst out Mr. Damon. "I'd like to see him left behind."

Tom carried out his plan. The remainder of the day he hung just on Andy's flank, sometimes shooting high up, almost out of sight, and again coming down, just to show what the RED CLOUD could do when pressed.

As for those aboard the ANTHONY, they seemed to be trying to increase their speed, but, if that was their object they did not have much success, for the big, clumsy triplane only labored along.

"I wonder who he's got with him?" said Ned, as darkness was closing down. "I can't make out any one by this glass. They stick pretty closely to the cabin."

"Oh, probably Andy's father is there," said "and, perhaps, some of Mr. Foger's acquaintances. I guess Mr. Foger is as anxious to get this gold as Andy is."

"He certainly needs money," admitted Ned. "Jove! but I hope we beat him!"

But alas for Tom's hopes! His plan of waiting until night and then putting on such speed as would leave Andy behind could not be carried out. It was tried, but something went wrong with the main motor, and only half power could be developed. Tom and Ned labored over it nearly ail night, to no effect, and through the hours of darkness they could see the lights from the cabin of the ANTHONY gleaming just ahead of them. Evidently the bully's airship could not make enough speed to run away from the RED CLOUD, or else it was the plan of the Foger crowd to keep in Tom's vicinity.

The direction held by Andy's craft was a general northwestern one, and Tom knew, in time, and that very soon, it would bring the ANTHONY over the valley of gold. Evidently Andy was placing some faith in his copy of the stolen map.

"Once I get this motor in shape I'll soon pull away from him," announced Tom, about four o'clock that morning, while he and Ned, aided by Mr. Damon, were still laboring over the refractory machine.

"What are you going to do?" asked Ned.

"It's too late to carry out my original plan," went on Tom. "We're getting so near the place now that I want to be there ahead of every one else. So as soon as we can, I'm going to push the RED CLOUD for all she's worth, and get to the valley of gold first. If possession is nine points of the law, I want those nine points."

"That's the way to talk!" cried Abe. "Once we git on th' ground we kin hold our own!"

It was breakfast time before Tom had the motor repaired, and he decided to have a good meal before starting to speed up his craft. He felt better after some hot coffee, for he and the others were weary from their night of labor.

"Now for the test!" he cried, as he went back to the engine-room. "Here's where we give Andy the go-by, and I don't think he can catch us!"

There was an increasing hum to the powerful motor, the great propellers whirled around at twice their former number of revolutions, and the airship suddenly shot ahead.

Those on the ANTHOMY must have been watching for some such move as that, for, no sooner had Tom's craft begun to creep up on his rival than the forward craft also shot ahead.

But the airship was not built that could compete with Tom's. Like a racer overhauling a cart-horse, the RED CLOUD whizzed through the air. In a spirit of fun the young inventor sent his machine within a few feet of Andy's. He had a double purpose in this, for he wanted to show the bully that he did not fear him, and he wanted to see if he could discover who was aboard.

Tom did catch a glimpse of Andy and his father in the cabin of the ANTHONY, and he also saw a couple of men working frantically over the machinery.

"They're going to try to catch us!" called Tom to Ned.

This was evident a moment later, for, after the RED CLOUD had forged ahead, her rival made a clumsy attempt to follow. The ANTHONY did show a burst of speed, and, for a moment Tom was apprehensive lest he had underrated his rival's prowess.

Suddenly Ned, who was looking from a projecting side window of the pilothouse, back toward Andy's ship, cried out in alarm.

"What's the matter?" shouted Tom.

"The airship—Andy's—two of the main wings have collapsed!"

Tom looked. It was but too true. The strain under which the ANTHONY had been put when the machinists increased the speed, had been too much for the frame. Two wings broke, and now hung uselessly down, one on either side. The ANTHONY shot toward the snow-covered earth!

"They're falling!" cried Mr. Parker.

"Yes," added Tom, grimly, "the race is over as far as they are concerned."

"Bless my soul! Won't they be killed?" cried Mr. Damon.

"There's not much danger," replied the young inventor. "They can vol-plane back to earth. That's what they're doing," he added a moment later, as he witnessed the maneuver of the crippled craft. "They're in no danger, but I don't believe they'll get to the valley of gold this trip!"

Tom was soon to learn how easily he could be mistaken.



CHAPTER XVII

HITTING THE ICE MOUNTAIN

Onward sped the RED CLOUD. For a moment after the accident to Andy's ship, Tom had slowed up his craft, but he soon went on again, after he had satisfied himself that his enemies were in no danger.

"Don't you think—that is to say—I know they can't expect anything from us," spoke Mr. Damon, "but for humanity's sake, hadn't we better stop and help them, Tom?"

"I hardly think so," replied the young inventor. "In the first place they would hardly thank us for doing so, and, in the second, I don't believe they need help. They are almost safely down now."

"I don't just mean that," went on the odd man. "But they may starve to death. This is a very desolate country over which we are sailing."

"They must have a supply of food in their ship," declared Tom, "and they have brought their plight on themselves."

"They're in no great danger," put in Abe.

"There are plenty of natives around here, an' if the Fogers need food or aid they can git it by payin' for it. Why, for the sake of th' parts of their damaged airship, th' Eskimos would take th' whole party back t' Sitka and feed 'em well on th' trip. Oh, they're all right."

"Very well, if you say so," assented Mr. Damon. He looked back to watch the ANTHONY slowly settling to earth. It came gently down, proving that Tom knew whereof he spoke, when he had said they could vol-plane down. Before the RED CLOUD was out of sight Tom and his companions saw Andy and his father leave their wrecked craft and venture out on the snow-covered ground. The Fogers gazed enviously after the airship of our hero as they saw him still forging toward the goal.

"I guess Andy's stolen map won't be of much use to him," mused Tom. "Now we can put on all the speed we like," and with that he shifted the gears and levers until the airship was making exceedingly good time toward the valley of gold.

The remainder of that day saw our adventurers pursuing their way eagerly. At times they were flying high, and again, when Abe suggested that they go down to observe the character of the country over which they were passing, they skimmed along, just above the big mountains, which seemed almost like icebergs, so covered were they with frost and snow.

They were indeed in a wild and desolate country. Below them stretched a seemingly endless waste of snow and ice—great forests interspersed with treeless patches, while now and then they sailed over a frozen lake.

Once in a while they had glimpses of bands of Indians, dressed in furs, hunting. At such times the natives would look up, on hearing the noise made by the motor of the airship, and catching a glimpse of what must have seemed to them like some supernatural object, they would fall down prostrate in amazement and fear.

"Airships are pretty much of a novelty up here," remarked Abe with a grim smile.

The weather was new very cold, and the gold-seekers had to get out their heavy fur garments, of which they had brought along a goodly supply. True, it was warm in the cabin of the airship, but at times, they wanted to venture out on the deck to get fresh air, or to make some adjustments to the wing planes, and, on such occasions the keen, frosty air, as it was driven past them by the motion of the craft, made even the thickest garments seem none too warm. Then, too, it was colder at the elevation at which they flew than down on the ground.

Another day found them in a still wilder and more desolate part of Alaska. There were scarcely any signs of habitation now, and the snow and ice seemed so thick that even a long summer of sunshine could hardly have melted it. The hours of daylight, too, were growing less and less the farther north they went.

"Do you think you can pilot us right to the Snow Mountains, Abe?" asked Tom, on the third day after the accident to Andy's airship. "Let's get out the map, and have another look at it. We must be getting near the place now. We'll look at the map."

The young inventor went to his stateroom where he kept the important document in a small desk, and the others heard him rummaging around. He muttered impatiently, and Ned heard his chum say: "I thought sure I put it in here." Then ensued a further search, and presently Tom came out, his face wearing rather a puzzled and worried look, and he asked: "Say, Abe, I didn't give that map back to you; did I?"

"Nope," answered the miner. "I ain't seen it since just before th' hail storm. We was lookin' at it then."

"That's when I remember it," went on Tom, "and I thought I put it in my desk. I didn't, by any possible chance give it to you; did I, Ned?"

"Me? No, I haven't seen it."

"That's funny," went on Tom. "I'll look once more. Maybe it got under some papers."

They heard him rummaging again in his desk.

"Bless my bank-book!" cried Mr. Damon. "I hope nothing has happened to that map. We can't find the valley of gold without it."

Tom came back again.

"I can't find it." he said, hopelessly.

Then ensued a frantic search. Every possible place in the airship was looked into, but the precious map did not turn up.

"Perhaps the Fogers took it," suggested Mr. Parker, who had helped in the hunt, in a dreamy sort of fashion.

"That's not possible," said Tom. "They haven't been near enough to us since I saw the map last. No, the last time I had it was just before the hail storm, and, in the excitement of repairing the ship, I have mislaid it."

"Maybe it's back there in the big cave," suggested Ned.

"It's possible," admitted the young inventor. "Pshaw! It's very careless of me!"

"If you think it's in the cave, we'd better go back there and have a hunt for it," suggested Mr. Damon. "Otherwise we are on a wild-goose chase."

"Don't go back!" exclaimed old Abe. "I think we can find th' valley of gold without th' map, now that we have come this far. I sort of remember th' marks on that parchment, an' we are in the right neighborhood now, for I kin see some of th' landmarks my partner and I saw. I say, let's keep on! We can cruise around a bit until we strike th' right place. That won't take us so long as it would to go back to the cave. Besides, if we go back, the Fogers may get ahead of us!"

"With their broken airship?" asked Ned

"Can't they repair it?" demanded Abe.

"Hardly—up in this wild country," was Tom's opinion. "But perhaps it WILL be just as well to keep on. I have a hazy remembrance of the distances and directions on the map, and, though it will take longer to hunt out the valley this way, I think we can do it. I can't forgive myself for my carelessness! I should have kept a copy of the map, or given one of you folks one."

But they would not hear of him blaming himself, and said it might have happened to any one. It was decided that the map must be lost in the big cave, and if it was there it was not likely to be found by their enemies.

"We'll jest have t' prospect about a bit," declared Abe, "only we'll do it in th' air instead of on th' ground."

It was dusk when the fruitless search for the map was over, and they sat in the cabin discussing matters. The lights had not yet been switched on, and the RED CLOUD was skimming along under the influence of the automatic rudders and the propellers.

"Well, suppose we have supper," proposed Mr. Damon, who seemed to think eating a remedy for many ills, mental and bodily. "Bless my desert-spoon, but I'm hungry!"

He started toward the galley, while Tom went forward to the pilothouse. Hardly had he reached it than there came a terrific crash, and the airship seemed tossed back by some giant hand. Every one was thrown off his feet, and the lights which had been turned on suddenly went out.

"What's the matter?" cried Ned.

"Have we hit anything?" demanded Mr. Damon.

"Hit anything! I should say we had!" yelled Tom. "We've knocked a piece off a big mountain of ice!"

As he spoke the airship began slowly settling toward the earth, for her machinery had been stopped by the terrific impact.



CHAPTER XVIII

A FIGHT WITH MUSK OXEN

"Can I help you, Tom? What's to be done?" demanded Ned Newton, as he rushed to where his chum was yanking on various levers and gear wheels.

"Wait a minute!" gasped the young inventor. "I want to throw on the storage battery, and that will give us some light. Then we can see what We are doing." An instant later the whole ship was illuminated, and those aboard her felt calmer. Still the RED CLOUD continued to sink.

"Can't we do something?" yelled Ned. "Start the propellers, Tom!"

"No, I'll use the gas. I can't see where we're heading for, as the searchlight is out of business. We may be in the midst of a lot of bergs. We were flying too low. Just start the gas generating machine."

Ned hurried to obey this order. He saw Tom's object. With the big bag full of gas the airship would settle gently to earth as easily as though under the command of the propellers and wing planes.

In a few minutes the hissing of the machine told that the vapor was being forced into the bag and a little later the downward motion of the ship was checked. She moved more and more slowly toward the earth, until, with a little jar, she settled down, and came to rest. But she was on such an uneven keel that the cabin was tilted at an unpleasant angle.

"Bless my salt-cellar!" cried Mr. Damon. "We are almost standing on our heads!"

"Better that than not standing at all," replied Tom, grimly. "Now to see what the damage is."

He scrambled from the forward door of the cabin, no easy task considering how it was tilted, and the others followed him. It was too dark to note just how much damage had been inflicted, but Tom was relieved to see, as nearly as he could judge, that it was confined to the forward part of the front platform or deck of the ship. The wooden planking was split, but the extent of the break could not be ascertained until daylight. The searchlight connections had been broken by the collision, and it could not be used.

"Now to take a look at the machinery," suggested the young inventor, when he had walked around his craft. "That is what I am worried about more than about the outside."

But, to their joy, they found only a small break in the motor. That was what caused it to stop, and also put the dynamo out of commission.

"We can easily fix that," Tom declared.

"Bless my coffee-spoon!" cried Mr. Damon, who seemed to be running to table accessories in his blessings. Perhaps it was because it was so near supper time. "Bless my coffee-spoon! But how did it happen?"

"We were running too low," declared Tom. "I had forgotten that we were likely to get among tall mountain peaks at any moment, and I set the elevation rudder too low. It was my fault. I should have been on the lookout. We must have struck the mountain of ice a glancing blow, or the result would have been worse than it is. We'll come out of it all right, as it is."

"We can't do anything to-night," observed Ned.

"Only eat," put in Mr. Damon, "and we'll have to take our coffee cups half full, for everything is so tilted that it's like topsy-turvey land. It makes me fairly dizzy!"

But he forgot this in the work of getting a meal, and, though it was prepared under considerable difficulties, at last it was ready.

Bright and early the next morning Tom was up making another inspection of his ship. He found that even if the forward deck was not repaired they could go on, as soon as the motor was in shape, but, as they had some spare wood aboard, it was decided to temporarily repair the smashed platform.

It was cold work, even wearing their thick garments; but, after laboring until their fingers were stiff from the frost, Ned hit on the idea of building a big fire of some evergreen trees near where the ship lay.

"Say, that's all right!" declared Tom, as the warmth of the blaze made itself felt. "We can work better, now!"

The RED CLOUD was tilted on some rough and uneven ground, in among some little hills. On either side arose big peaks, the one in particular that they had hit towering nearly fifteen thousand feet.

Everything was covered with snow and ice, and, in fact, the ice was so thick on the top of the mountains that the crags resembled icebergs rather than stony peaks. The crash of the airship had brought down a great section of this solid rock-ice.

"Do you think we are anywhere near the valley of gold?" asked Mr. Damon that afternoon, when the work was nearly finished.

"It's somewhere in this vicinity." declared Abe. "Me an' my partner passed through jest such a place as this on our way there. I wouldn't wonder but what it wasn't more than a few hundred miles away, now."

"Then we'll soon be there," said Tom. "I'll start in the morning. I could go to-night, but there are a few adjustments I want to make to the motor, and, besides, I think it will be safer, now that we are among these peaks, to navigate in daylight, or at least with the searchlight going. I should have thought of that before."

"Then, if you're not going to start away at once," spoke Mr. Parker, "I think I will walk around a bit, and make some observations. I think we are now in the region where we may expect a movement of the ice. I want to test it, and see if it is traveling in a southerly direction. If it is not now, it will soon be doing that, and the coating of ice may reach even as far as New York."

"Pleasant prospect," murmured Tom. Then he said aloud: "Well if you are going, Mr. Parker, we'll be with you. I'll be glad of the chance to stretch my legs, and what more remains to be done, can be finished in the morning."

Mr. Damon declared that he did not relish a tramp over the ice and snow, and would stay in the warm cabin, but Tom and Ned, with Abe and Mr. Parker started off. The scientist pointed out what he claimed were evidences of the impending movement of the ice, while Abe explained to the lads how the Alaskan Indians of that neighborhood hunted and fished, and how they made huts of blocks of ice.

"We are nearing th' Arctic circle," the old miner said, "and we'll soon be among th' most savage of the Eskimo tribes."

"Is there any hunting around here?" asked Ned.

"Yes, plenty of musk ox," answered Abe.

"I wish I'd brought my gun along and could see one of the big beasts now," went on Ned. He looked anxiously around, but no game was in sight. After a little farther tramp over the icy expanse they all declared that they had seen enough of the dreary landscape, and voted to return to the ship.

As they neared their craft Tom saw several large, shaggy black objects standing in a line on the path the adventurers had come over a little while before. The objects were between the gold-seekers and the RED CLOUD.

"What in the world are those?" asked the young inventor.

"Look to me like black stones," spoke Ned.

"Stones?" cried Abe. "Look out, boys, those are musk oxen; and big ones, too! There's a lot of 'em! Make for the ship! If they attack us we're goners!"

The boys and Mr. Parker needed no second warning. Turning so as to rush past the shaggy creatures, the four headed toward the ship.

But if our friends expected to reach it unmolested they were disappointed. No sooner had they increased their pace than the oxen, with snorts of rage, darted forward. The animals may have imagined they were about to be attacked, and determined to make the first move.

"Here they come!" yelled Ned.

"Sprint for it!" cried Tom.

"Oh, if I only had my gun!" groaned Abe.

It was hard work running over the ice and snow, hampered as they were with their heavy fur garments. They soon realized this, and the pace was telling on them. They were now near to the ship, but the savage creatures still were between them and the craft.

"Try around the other way!" directed Tom, They changed their direction, but the oxen also shifted their ground, and with loud bellows of rage came on, shaking their shaggy heads and big horns, while the hair, hanging down from their sides and flanks, dragged in the snow.

"Right at 'em! Run and yell!" advised the young inventor. "Maybe we can scare 'em!"

They followed his advice. Yelling like Indians the four rushed straight for the animals. For a moment only the creatures halted. Then, bellowing louder than ever they rushed straight at Tom and the others.

The largest of the oxen, with a sudden swerve, made for Mr. Parker, who was slightly in the lead off to one side. In an instant the scientist was tossed high in the air, falling in a snow bank.

"Mr. Damon! Mr. Damon!" yelled Tom, frantically. "Get a gun and shoot these beasts!"

The young inventor and his two companions had come to a halt. The oxen also stopped momentarily. Suddenly Mr. Damon appeared on the deck of the airship. He held two rifles. Laying one down he aimed the other at the ox which was rushing at the prostrate Mr. Parker. The eccentric man fired. He hit the beast on the flank, and, with a bellow of rage it turned.

"Now's our time!" yelled Tom. "Head for the ship, I'll get my electric gun!"

"We can't leave Mr. Parker!" yelled Abe.

But the scientist had arisen, and was running toward the RED CLOUD. He did not seem to be much hurt. Mr. Damon fired again, hitting another beast, but not mortally.

Once more the herd of shaggy creatures came on, but the adventurers were now almost at the ship, on the deck of which stood Mr. Damon, firing as fast as he could work the lever and pull the trigger.



CHAPTER XIX

THE CAVES OF ICE

"Keep on firing! Hold 'em back a few minutes and I'll soon turn my electric rifle loose on 'em!" yelled Tom Swift as he sprinted forward. "Keep on shooting, Mr. Damon!"

"Bless my powder-horn! I will!" cried the excited man. "I'll fire all the cartridges there are in the rifle!"

Which, at the rate he was discharging the weapon, would not take a long time. But it had the effect of momentarily checking the advance of the creatures.

Not for long, however. Our friends had barely reached the airship, with Mr. Parker stumbling and slipping on the ice and snow, ere the musk oxen came on again, with loud bellows.

"They're going to charge the ship! They'll ram her!" yelled Ned Newton.

"I think I can stop them!" cried Tom, who had leaped toward his stateroom. He came out a moment later, carrying a peculiar-looking gun, The adventurers had seen it before, but never in operation, as Tom had only put some finishing touches on it since undertaking the voyage to the caves of ice.

"What sort of a weapon is that?" cried Abe, as he helped Mr. Parker on board.

"It's my new electric rifle," answered the young inventor. "I don't know how it will work, as it isn't entirely finished, but I'm going to try it."

Putting it to his shoulder he aimed at the leading musk ox, and pulled a small lever. There was no report, no puff of smoke and no fire, yet the big creature, which had been rushing at the ship, suddenly stopped, swayed for a moment, and then fell over in the snow, kicking in his death agony.

"One down!" yelled Tom. "My rifle works all right, even if it isn't finished!"

He aimed at another ox, and that creature was stopped in its tracks. Mr. Damon had exhausted his cartridges, and had ceased firing, but Abe Abercrombie was ready with his rifle, and opened up on the beasts. Tom killed another with his electric gun, and Abe shot two. This stopped the advance, and only just in time, for the foremost animals were already close to the ship, and had they rushed at the frail hull they might have damaged it beyond repair.

"Here goes for the big one!" cried Tom, and, aiming at the largest ox of the herd, the young inventor pulled the lever. The brute fell over dead, and the rest, terror stricken, turned and fled.

"Hurrah! That's the stuff!" cried Ned Newton, capering about on deck. He had hurried to his stateroom and secured his rifle, and, before the musk oxen were out of sight he had killed one, which gave him great delight.

"Mighty lucky we drove them away," declared Abe. "They are terrible savage at times, an' I reckon we struck one of them times. But say, Tom, what sort of a gun is that you got, anyhow?"

"Oh, it fires electric bullets," explained our hero. "But I haven't time to tell you about it now. Let's get out and skin one of those oxen. The fresh meat will come in good, for we've been living on canned stuff since we left Seattle. We've got time enough before it gets dark."

They hurried to where the shaggy creatures lay in the snow, and soon there was enough fresh meat to last a long time, as it would keep well in the intense cold. Tom put away his electric gun, briefly explaining the system of it to his companions. The time was to come, and that not very far off, when that same electric rifle was to save his life in a remarkable manner, in the wilds of Africa where he went to hunt elephants.

In the cozy cabin that night they sat and talked of the day's adventures. The airship had been slightly lifted up by means of the gas bag, and now rested on a level keel, so it was more comfortable for the gold hunters.

"I did not complete my observations about the great snow slide," remarked Professor Parker, "I trust I will have time to go over the ground again to-morrow."

"We leave early in the morning," objected Tom.

"Besides, I don't believe it would be safe to go over that ground again," put in Mr. Damon.

"Bless my gunpowder! But when I saw those savage creatures rushing at you, I thought it was all up with us. Are you hurt, Parker, my dear fellow? I forgot to ask before."