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 a.s.sistance 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 gla.s.s 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 pa.s.sed 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.