"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.