TOM SWIFT AND HIS HOUSE ON WHEELS

OR

A Trip to the Mountain of Mystery

By VICTOR APPLETON

Author of
"Tom Swift and His Motorcycle,"
"Tom Swift Among the Diamond Makers,"
"Tom Swift and His Talking Pictures,"
"The Don Sturdy Series,"
Etc.

ILLUSTRATED

NEW YORK
GROSSET & DUNLAP
PUBLISHERS

Made in the United States of America

Copyright, 1929, by
GROSSET & DUNLAP, Inc.

"A RACE! WE'LL SEE WHAT YOU CAN DO AGAINST THE HOUSE ON WHEELS!"

CONTENTS

TOM SWIFT AND HIS HOUSE ON WHEELS

CHAPTER I

STRONG WORDS

Tom Swift, with a negative shake of his head, shoved several papers across the table that separated him from a burly, red-faced man whose eyes narrowly observed the young inventor.

"Then you refuse this contract, Mr. Swift—a contract for constructing over one hundred thousand dollars' worth of machinery on which you can make a handsome profit? You absolutely refuse it?"

The red-faced man in his eagerness was leaning forward now.

"Yes, Mr. Cunningham, I refuse!" was Tom's crisp answer. "The Swift Construction Company does not care to handle it."

Mr. Barton Swift, father of the young man who thus calmly turned down what seemed like a good business proposition, nodded in affirmation of what his son had said.

"Is that your last word?" asked Basil Cunningham, who plainly showed his English ancestry, not only in his face and figure but in his general bearing and manner. "This refusal is final?" he inquired.

"Quite final and complete," answered Tom, as he added another document to the pile of those he had pushed toward his visitor. They were blue prints, specifications, and contract forms, but they all went across the table. "The matter is closed."

"But, look here! I say, now!" and Mr. Cunningham began to wax excited, not to say wroth. "I can't understand——"

"Do you mean to say you don't understand English?" asked Mr. Swift, and the smile on the face of the aged inventor took away whatever sting there might otherwise have been in the words. "I thought my son spoke very plainly. He said 'no,' and that's what he means."

"But look here, Mr. Swift! Do you agree with him?"

"Absolutely!"

"And you won't consider the contracts further?"

"The matter is closed, I told you!" and Tom Swift's voice was a bit sharp now.

With an imperious gesture the burly Englishman gathered up his papers and began to stuff them into a leather brief case bulging with other documents. If possible the red of his face deepened.

"Well," he began, "of all the——"

Tom Swift looked up sharply. He was on the verge of saying something that, he himself admitted, he might later have been sorry for when the door of the private office opened and a veritable giant of a man fairly squeezed his way through the doorway.

"What is it, Koku?" asked Tom, not quite pleased with such an interruption at this time.

"Excuse, Master," murmured the foreign giant, whose struggle with a strange tongue sometimes got the best of him. "But new engine him have come an' Mr. Jackson say him got to be lift up—so I lift if you want."

As if to demonstrate his strength, the giant put one finger under the edge of the heavy table around which the three men sat and, with as much ease as if he were lifting a feather, tilted it.

"My word, man! Don't do that!" cried Mr. Cunningham, for one of his feet was close to the leg of the table and he evidently feared the weight would come down on his toes when Koku let go.

"Don't worry," said Tom, with a smile. "Koku won't drop it."

Fascinated by this remarkable exhibition of strength, by which the giant raised several hundred pounds on one finger, the Englishman started to move from his proximity to Koku. But there was no need of alarm, though the timely entrance of Tom Swift's gigantic henchman had evidently stopped a tirade that was on the lips of the visitor.

"That will do, Koku," said Tom, in a low voice. "I will see Mr. Jackson shortly and look at the new engine."

"Yes, Master," murmured the giant, whose whisper, however, was a hoarse bellow in contrast with others.

Koku took himself out and Cunningham, staring at the closed door as though he could not believe what he had seen, continued to stuff his rejected contracts into his case.

"I'm sorry about this," said the Englishman in more subdued tones than he had used before the advent of Koku. "I'm not only sorry, but I'm disappointed and I think I haven't been fairly treated." His anger was rising again, that was evident.

"How do you mean—not fairly treated?" asked Tom sharply.

"Why, dash it all, when I first broached this matter to you I was as much as given to understand that your firm would go ahead and make the apparatus for me."

"You were given to understand nothing of the sort," replied Tom quietly.

"I say I was!" and the Englishman banged his fist hard on the heavy table that Koku had raised with one finger. "I tell you I have been shamefully treated here, and I'm not going to stand it. I——"

Again the door suddenly opened and Basil Cunningham made a move as if to hide beneath the table he had so lately pounded. But instead of Koku, this time the intruder was an aged and decrepit colored man whose whitening, curly hair made a pathetic frame for his black, wizened face. No gentler creature, as a man, could well have been visioned, and Mr. Cunningham, who had evidently been expecting a return of the giant, looked a bit foolish.

"Did yo' all call me, Massa Swift?" asked the negro gently.

"No, Rad, we didn't call," said Tom, with a kind smile at the aged servant who often claimed, regarding the young inventor: "I done nussed him from a baby, dat's whut I done!"

"'Scuse me, Massa Tom," went on Eradicate. "But I thought I done heard a noise in here, an'——"

"We were just talking, Rad, that was all. We have about finished," and Tom looked significantly at the red-faced Briton. "I'll call you if I need you, Rad."

"Yes, sah," and Eradicate shuffled out.

"There is no use in further wasting your time or my own, Mr. Cunningham," proceeded Tom Swift, when the three again faced each other. "My mind is fully made up, and you see that my father agrees."

"I agree fully with my son," added aged Mr. Swift.

"Then I'll have to get somebody else to carry out this contract!" snapped Mr. Cunningham. "I'll go to some firm that knows how to take a big profit when it's offered."

"That's your privilege," replied Tom, smiling. "We don't want it."

There was something so final in his words that Mr. Cunningham knew better than to try other arguments. The last paper was thrust into the case, and the way in which the Englishman snapped the lock showed his anger. He caught up his hat, muttered a "good-day," and hurried out.

"Well, that's that," said Tom Swift, with something between a sigh of relief and regret.

"Tom, you did just right!" exclaimed his father. "I didn't want to interfere, but you gave him the right answer. We want nothing to do with his sort, even though we may have to close down the plant on account of lack of orders."

"We are running a bit short," Tom admitted. "And with all I spent on the talking pictures, with no prospect of any substantial revenue from them for some time, we may be financially up against it soon, Dad."

"Don't worry, Tom. We'll pull through, somehow. You can keep busy, can't you?"

"Oh, yes, I've got to finish my House on Wheels," and Tom fairly spoke of it in capital letters, so near to his heart was this newest invention.

"Ah, yes, Tom, your House on Wheels," and Mr. Swift chuckled a little. "I've been looking it over now and again. Seems as if you had a pretty good thing there."

"I hope it will work out," responded the young man.

"Looks as if you were fitting it up for a trip around the world," went on his father smiling. "Are you?"

"Not exactly, Dad."

"I might make another guess, Tom, my boy," and still the aged man was laughing.

"Well, there's no law that I know of, Dad, to stop you from making guesses," and Tom busied himself over several papers that seemed to need close attention.

"Well, then, Tom, I'll guess that you're going to use your new House on Wheels for a wedding journey. How about that?"

"Who says anything about a wedding trip?" cried Tom, his face almost as red as the Englishman's had been.

"Oh, no one has said anything, Tom," his father answered mildly. "But from the manner in which you and Mary Nestor have been going about of late, looking into furniture store windows and——"

"Oh, there's too much talk going on in this town!" exclaimed Tom, and his father laughed heartily at his son's evident discomfiture.

"Well, wedding trip or world tour, your new House on Wheels appears to be a clever bit of work," went on Mr. Swift. "When will it be finished?"

"Can't say, exactly. Though now that the new engine has arrived, as Koku informed me, I can rush things. I've been waiting for the machinery. That's why I'm glad, in a way, I didn't have to take on the Cunningham contracts."

"Valuable as they were," remarked Mr. Swift.

"Valuable as they were," agreed his son. "And now, if you'll excuse me, Dad, I'll go take a look at that new engine."

"I have some matters to attend to myself," said old Mr. Swift, who, though he had given up active participation in the plant some time before, still maintained a general supervision over certain matters. He left the private office just as Ned Newton, the young financial manager, entered in some haste. Nodding to Tom's father, Ned turned to the young inventor and asked:

"What's this I hear about you turning down Cunningham's work?"

"I don't know, Ned, what you heard, nor how, so I can't reply."

"I was just coming in through the yard when I saw Cunningham getting into an auto with a man who had a face like a rat's. He was a stranger to me; but I knew Cunningham, of course. Say, he was mad, that Englishman! I heard him muttering something about your having refused his contracts and, as nearly as I could make out, he was cussing you up hill and down dale and threatening not only to take his contracts to another firm but to get even with you as well."

"Yes he was angry when he left here," admitted Tom. "But that's all bosh about his going to get even. It was a plain business proposition. Cunningham is a good business man, whatever else he may be, and business men don't look for revenge just because one firm won't do their manufacturing for them."

"Maybe not. It might have been a lot of superheated atmosphere. But I can't understand, Tom, why you didn't take his work. There would have been a good profit in it, you told me, after the preliminary investigation."

"Yes, the profit was there."

"Well, then, what was wrong with such a handsome contract for the very kind of machinery that we are so well equipped to manufacture?"

"If you really want to know, Ned, I'll tell you."

"Of course I want to know."

"Well, then, it's my opinion that Basil Cunningham is a plain, unvarnished, first-water crook!"

CHAPTER II

THE NEW INVENTION

Ned Newton stood for several seconds intently gazing at his chum and business associate after Tom Swift's emphatic rejoinder. Then, feeling that as financial manager of the Swift plant he ought not too easily give up a chance for making money, Ned remarked:

"Well, Tom, I suppose you know your own business best, but you ought to have something to back up your opinion that Cunningham isn't straight."

"I've got enough to convince myself, Ned, though maybe not enough to make you see things the way I do. In fact, I haven't any documentary evidence, but I still maintain that Cunningham is a crook."

"In that case, of course we don't want anything to do with him," agreed Ned. "But what sort of evidence have you, Tom?"

"I may be mistaken," replied Tom, who was willing to give any man the benefit of a doubt; "but I have a very strong suspicion that the delicate machinery Cunningham wanted us to manufacture for him would infringe on the patents of certain English machines used for scientific and optical work."

"Infringement!" exclaimed Ned.

"That's what it would be if we undertook it, and if it were found out we would be liable to prosecution," stated Tom. "Even if we weren't found out, of course I wouldn't undertake such work."

"Of course," agreed Ned heartily. "But are you sure? You have been making some strong assertions against Cunningham."

"I don't believe I'll be called on to prove them in court, for this is just between us," said Tom. "But I looked over the preliminary sketches of the machinery this Englishman wanted us to make for him. At first I was inclined to go on with it. But the other day I saw a notice in an English publication concerning some new scientific machinery just completed and it was almost identical with the blue prints and specifications Cunningham showed me. If we turned out the machinery for him he'd set up a shop over here for making those instruments and it would get us in Dutch once it came out."

"That's right, Tom. I guess you acted wisely in turning him down. He's mad, mad as a wet hen, but let him splutter. That's what he was doing to the Queen's taste when he got in the auto with that rat-faced individual."

"Yes, let him splutter," agreed Tom. "He can't harm us."

However, later on, he was to revise that opinion of the Englishman.

"Of course it's too bad to lose all that good money," mused Ned. "On a hundred-thousand-dollar contract we could probably knock down twenty per cent. at least."

"Yes," agreed Tom, "it would have been picking up a nice bunch of cash. But I'm not going to make patent imitations under cover for anybody. I want nothing to do with fraudulent stuff. We can get enough good contracts, I think."

"Well," remarked Ned, with a shrug of his shoulders, "good contracts aren't going around these days begging some one to take them into their shop. But I dare say we shall pull through."

"Maybe I can get a lot of orders for my House on Wheels when I get it completed," chuckled Tom.

"Nothing doing!" declared Ned, with a laugh. "You'll make only one House on Wheels and I can see you and Mary rolling off in that to the music of——"

"Hey! Where do you get that stuff?" exploded Tom, making an ineffectual reach to punch his chum. "That's the second crack to-day. Dad made one and now you. Where do you get it?"

"Well, since you turned down the Cunningham contract," went on Ned somewhat hastily, producing some papers from his pocket, "suppose we go into this Blakely matter. It isn't such a big thing, but we want to keep the wheels turning."

"Sure," agreed Tom, and the two were soon deep in calculations.

To the old readers of these books Tom Swift needs no introduction. But those to whom this volume comes as their first venture, it may be necessary to say that Tom Swift was a brilliant young inventor who lived with his father in the town of Shopton on Lake Carlopa.

The initial volume, entitled "Tom Swift and His Motorcycle," related how Tom became possessed of a machine that was damaged when Mr. Wakefield Damon, its rider, tried to climb a tree.

That was the beginning of Tom's mechanical activities, for he bought the motorcycle cheap, repaired it, and had some wonderful adventures on it. The tree-climbing incident also served to start the friendship of Tom and Mr. Damon, a friendship that had lasted, though the eccentric man, who blessed everything from his fountain pen to his boots, was much older than Tom Swift.

After his experience with the motorcycle, the young inventor had many startling and dangerous experiences in aircraft, submarines, and in turning out, with the help of his father and with Ned Newton as financial adviser, many strange machines.

Tom's latest invention is told of in the volume just before this one you are now reading, entitled "Tom Swift and His Talking Pictures." He made a machine which brought the images and voices of public performers directly into the home. The making of this machine had taken considerable cash, and though Tom had sold certain rights to a syndicate, the money would not be coming in for some time.

"And that's one reason I was so anxious for this Cunningham contract to go through," remarked Ned, who was talking business matters over with Tom following the departure of the Englishman.

"We'll get other work to do," declared Tom. "To tell you the truth, I'm not over anxious to clutter the shop up with any other stuff until I get my House on Wheels well out of the way."

"Say, just what is this new invention, anyhow?" asked Ned. "I've been so busy I haven't paid much attention to it."

"Well, the name tells just what it is," said Tom. "Briefly, it is a glorified auto—a veritable house that one can not only live in but travel in."

"You mean a house with rooms and a bath and—and—everything?" asked Ned.

"That's it—a bath and everything. Of course, the rooms aren't large, and the beds are to be folded back against the wall when they aren't in use."

"What about eats?" asked Ned.

"There's to be a kitchen with an electric stove," replied Tom.

"Run a stove from a storage battery?" exclaimed Ned. "Say, it can't be done! You'd have to have such a big battery that it would be a job to cart it around."

"Not a storage battery," explained Tom. "My House on Wheels is to be operated like some of the new, big jitneys, by a gas-electric motor. There's a gasolene engine of twelve cylinders, and, by the way, it's just arrived from Detroit, so Koku told me. Well, that motor operates a dynamo which furnishes the current that drives the auto, operates the stove and other appliances."

"Then you don't take power directly from the gasolene engine?" asked Ned.

"Only in case of emergency; that is, if the electric motor goes on the fritz. By using my gasolene motor to generate the current to run the car I get a much smoother flow of power, and there are other advantages."

"Does the dingus look anything like a house?" asked Ned.

"I object to your calling it a 'dingus,'" laughed the young inventor. "But in outward appearance it is like a small house."

"With doors and windows?"

"Yes, and even window shutters. Aside from an entrance back of the driver's seat, there is only one door, however, and that is at the rear."

"How about a pair of steps?" asked Ned, thinking to stump his chum.

"I've provided for those, too. There are steps at the rear for easy access to the interior, as my catalogs will say. Only, to keep small boys from hitch-hiking on them, the steps fold up out of the way when the House on Wheels is moving."

"Then you're really going to tour in it?" asked Ned.

"Sure!"

"Going to be pretty heavy, isn't it?"

"Oh, around two tons, I guess."

"It's no flivver, at any rate. But won't it move like a canal boat?"

"Canal boat! Do you want to insult me?" cried Tom. "On good roads she'll do fifty or sixty miles an hour."

"Whew!" whistled Ned. "Guess I'd better go and take a look at this thing."

"Come on," invited Tom.

He was preparing to lead the way out of his private office to that part of the shop where he was constructing the new invention, when Mr. Jackson, the manager, entered with an air that caused Tom suddenly to ask:

"What's the matter?"

CHAPTER III

NED'S SUSPICIONS

"Have you given any orders about unpacking the new engine that just arrived from Detroit?" asked Mr. Jackson of Tom Swift.

"You mean the twelve-cylinder engine for my House on Wheels?" the young inventor inquired.

"That's the one."

"Why, no. Koku informed me only a little while ago that it had come. But I couldn't come out to look at it because that Cunningham chap was in the office. Why, is it being unpacked? And by whom?"

"It is, and by a couple of strange young men who say you just put them on the pay roll yesterday to help with your new invention. They went at the work as though they knew what they were about, but I thought I'd speak to you."

"I'm glad you did!" exclaimed Tom. "I've hired no new hands, young or old, for a long time. I wouldn't without consulting you."

"That's what I thought. But these fellows seemed to know what they were about, and I didn't like to tell them to lay off."

"There's something crooked here!" exclaimed Tom. "This must be looked into. Come on!" he called to Ned Newton.

As the three walked along a corridor that led to one of the main shops where Tom's latest achievement in a mechanical way was in process of construction, the young inventor closely questioned Mr. Jackson.

"Had they got the motor out of the packing case when you left them?" Tom was anxious to know.

"Not yet. It's a pretty big piece of machinery and won't be unpacked in a hurry."

"Then we may be in time!" Tom ejaculated.

"Time for what?" asked Ned.

"To stop any funny work."

"Whew!" whistled the financial manager. "As bad as that? Whom do you suspect?"

"You never can tell," was Tom's reply. "Ever since I've been in this business I've had to fight crooks and sharps. And I didn't like the way Cunningham acted after I turned down his proposition."

"He sure was mad," declared Ned. "But do you think he knew anything about your House on Wheels, and might try to put sand in the motor bearings or hire some one to do it?"

"You never can tell," said Tom again. "Though if it was Cunningham, it was pretty quick work."

"Crooks very often need to act quickly," observed Ned.

Tom hurried forward and was the first of the three to enter the shop. In one corner was a heavy case and opening it were two men, the only occupants of the place just then. At the sound of Tom's entrance they turned, straightened up and looked apprehensive. And well they might, for Ned cried:

"The rat-faced man, Tom! Look! The one who was with Cunningham!"

He pointed to one of the two whose countenance, especially in his appearance of fright, did resemble that of a rat. An instant later he and his companion dropped the tools they had been using and leaped from a near-by open window.

"Stop them!" yelled Tom. But the rascals were too quick, and when the young inventor and his friends reached the casement the two were running across the yard toward the main gate which was, just then, open to let in a truck.

"Stop those men!" yelled Tom, seeing several of his workman, as well as Eradicate and Koku, loitering in the yard.

Not stopping to ask questions, several hands gave chase. The old colored man joined in with a yell of:

"I'll get 'em fo' yo', Massa Tom!"

But his will was better than his deed, for his aged limbs refused to take him over the ground fast enough. As for Koku, the giant would only need to get within hand grasp of the rascals to put a stop to their flight. But, like most big men, Koku was slow in getting started, and the two plotters were beyond the gate before any of their pursuers were within catching distance.

Tom and Ned leaped out of the window also, but reached the gate only in time to see the two plotters disappearing down the road in an auto that, evidently, was in waiting.

"Come, on, Tom! Chase 'em!" cried Ned. "Get out your electric runabout and we'll overtake 'em!"

"Not a chance," Tom replied. "My runabout is having its batteries charged and all the other fast cars are away on the other side of the works. No, they've got us beat. I only hope they haven't damaged my new motor."

"I think they didn't have a chance to do that," said Ned encouragingly. "But who were they, Tom?"

Neither the young inventor nor any one else around the shop, including Mr. Jackson, knew. The two men, one of whom looked like a rat, had appeared at the main gate early that morning, it was learned on checking up. They presented an order signed, apparently, by Tom Swift, authorizing them to come in. It was a rule that any but the regular workmen must have such an order to gain entrance to the plant. But this order was forged.

So the two got in and falsely stating that they had come from the Detroit plant of the concern which had made Tom's new motor, they gained access to the shop where it had been left by a truck from the freight office.

Had it not been that Mr. Jackson saw the men at work and wondered enough about them to tell Tom, they might have carried out their plans, whatever they were. That the plans were based on an intent to work Tom Swift or his possessions some injury, could not be doubted.

A hasty survey, however, showed that the motor had not been taken from its case, so it was not damaged.

"What was the game, Tom?" asked Ned, when orders had been given to admit no more strangers to the plant on any pretext.

"Well, I'll say Cunningham, as a guess."

"You mean he put these men up to wrecking your motor after you turned him down?"

"That's the way it looks to me, Ned. Of course it may have been some of my other enemies. But since you recognized the rat-faced chap, why, it looks suspicious to me."

"But what would be Cunningham's object? He didn't want you to make him a House on Wheels, did he? Or sell him any stock in the enterprise of manufacturing them?"

"No, he didn't mention the matter. I didn't even know that he knew I had such a thing in mind, much less almost completed."

"Well, he found out in some way."

"Very likely. And when I refused to help him make machinery to turn out infringements on English patented apparatus, he turned nasty and decided to make me sorry."

"So it looks, Tom. Lucky you caught the plot in time."

"That's due to Mr. Jackson's foresight. It was a narrow escape. Half an hour later and that motor would be fit only for the scrap-heap. Look here!"

Tom held up a small bottle of a very powerful acid—one capable of eating into and corroding the hardest steel.

"I picked that up where one of the scoundrels dropped it," Tom said. "They evidently wanted to get at some of the valves on the cylinders. A few drops of this acid in each one and the walls would have been so scored that even reboring would not have made them fit to use again."

"A dirty trick!" exclaimed Ned. "I wish we could have caught them."

"So do I, for the sake of what may happen in the future."

Leaving Koku and Eradicate on guard over the new motor, Tom took Ned to where the chassis and body of the House on Wheels were being constructed. It was the first time Ned had seen the new invention and at a glimpse of it, standing in the middle of the shop where it was receiving its final coat of paint, the young manager exclaimed:

"Say, that's a peach!"

"Glad you like it," commented Tom.

The house stood up on a framework corresponding to the chassis on which it would later be mounted. Tom opened the back door and a pair of steps, hitherto concealed in a recess, unfolded, let down, and could be used for entering the little dwelling.

There were four rooms within, two containing folding cots that made comfortable beds. One room of those remaining was used as a kitchen. The other was a living room, though if needful the two bedchambers could also be utilized for this purpose, when the cots were folded away.

"And that's the electric stove, is it?" asked Ned, pointing to the apparatus.

"That's it. And here's the pantry, the ice box, and so on," added Tom, indicating the various conveniences.

"Pretty slick!" was the enthusiastic comment of Ned Newton.

"But where do you work the thing from?"

"The motor goes out there," and, going to the front of the house, Tom showed where the big machine was to be mounted under a regulation auto hood. "This little compartment will contain the driver's seat and the controls," he went on, showing a space divided by a partition from the sleeping quarters.

The kitchen was in the rear of the House on Wheels, and in front of that was the combined sitting and dining room, the sleeping quarters being forward.

"Putting the kitchen in the rear insures the odors being carried away as the machine moves along," explained Tom.

"Then you're going to cook as you travel?" asked Ned.

"Sure!" assented Tom.

"That is you are—or some one else," chuckled Ned.

"What do you mean?"

"I mean that my suspicions are confirmed," went on Ned, with a laugh, and taking care to get beyond Tom's reach before making his next remark. He added: "I know where the first stop will be for this traveling House on Wheels!"

"Where?" asked Tom, unsuspiciously.

"Honeymoon Lane!" yelled Ned, making a leap to escape his chum.

CHAPTER IV

SURPRISING NEWS

After all, Tom Swift had sense enough to take good-naturedly the chaffing to which Ned Newton subjected him.

The young inventor could not but admit that his latest invention, coupled with the fact that he and Mary Nestor had been more than ordinarily chummy recently, would lead to the suspicion that there might soon be a closer relationship between them than heretofore.

Mary and Tom had know each other a long time. Once her family and Tom were marooned on Earthquake Island, and Tom had managed, under great difficulties, to rig up machinery and send a wireless message. Mr. Nestor had held a great opinion of the young man's ability and skill ever since.

"I'll Honeymoon Lane you if I get hold of you!" threatened Tom as he and Ned left the shop where the House on Wheels was nearing completion.

Various matters occupied the attention of the two young men for the remainder of the day. Ned, charged with keeping track of the finances of the company, was busy with negotiations looking to the securing of manufacturing contracts that would keep the plant running. He was a little disappointed that the Cunningham proposition had been turned down, but he could but agree with Tom that to take a contract about which there was any suspicion of wrongdoing would be poor policy.

As for Tom Swift, once he saw that the chassis and upper structure of his new House on Wheels was nearing completion, he arranged with Mr. Jackson to get the new motor on the block for a test. This took until nearly night, and then Tom had things in shape for a preliminary tryout of the machinery the next day.

"No need to ask where you're going, Tom," chuckled Ned when, after the evening meal, which, as on many former occasions, he shared with the Swift family, he observed the young inventor getting out the electric runabout, the batteries of which were now fully charged.

"It's none of your business where I'm going!" said Tom with a smile which took any possible sting from the words.

"Well, I'm on the same sort of errand," commented the financial manager. "Mind if I take the roadster and give Helen a little spin?"

"Consider yourself a top and spin away!" chuckled Tom, and a little later he was on his way to see Mary Nestor while Ned piloted the small but speedy car in the direction of his sweetheart's home.

"Well, Tom, what's the latest news?" asked Mary when she had greeted him and they were seated on the porch.

"Oh, nothing much." Tom decided not to tell her about the Cunningham matter or the discovery of the two men tampering with the motor. "The new House on Wheels is coming on pretty well, though."

"That's good. Am I to get a ride in it?"

"Of course!"

"Tell me about it," she suggested, and Tom launched into an enthusiastic description of the interior of the new van-like vehicle, telling of the rooms, the electric stove, the little pantry and ice box until Mary exclaimed in delight:

"I can hardly wait until it's finished!"

"Which won't be long," commented the young inventor. "If the motor tests out all right, and I think it will, all that remains to be done is to put it in place and see how the whole affair works—I mean whether I have designed it properly so that it will keep to the road at high speeds."

Then they talked of other matters until some uneasy movements on the part of Mrs. Nestor, in the house, warned the young man that the hour was getting late and that he had better leave.

"I'll see you to-morrow, Mary," said Tom, as he started down the drive to where he had left the runabout.

"Yes—I guess so," said Mary, and it was not until afterward that Tom noted and remembered the curious hesitancy in her voice. But now he was thinking of other matters.

It was when he was half way along the road that lay between Mary's house and his own home that, passing along a lonely stretch of highway at moderate speed, Tom saw, thrown across the road in front of him, in bold relief by the brilliant rays of the moon, a gesticulating shadow of a man.

The shadow was waving its arms as though in signal to the oncoming motorist to stop, and when Tom sensed this he began to be uneasy and was about to press the lever that would give him full speed ahead.

"I'm not going to be fooled by any trick!" he murmured. "There have been too many hold-ups of late along this road. And if it isn't a hold-up it may be another attempt by Cunningham to annoy me. Look out there!" he yelled as the signaling figure and its accompanying shadow took the middle of the road. "Out of my way or I'll run you down!"

"Bless my accident policy, don't do that!" cried a voice.

For Tom the reaction was so great that his hand slipped from the electric speed lever, unconsciously pulling it toward the stop notch, and the runabout began to slow down.

"Mr. Damon!" cried Tom. "Is that you?"

"That's my name," said the voice of the man and he and his shadow both stepped to one side as the electric car rolled up and came to a stop, with the application of brakes, opposite him. "Thanks for picking me up. I don't know you, and I'm surprised that you could recognize me in the darkness, but——"

"Oh, you know me, too!" chuckled Tom, and then the man cried:

"Bless my opera glasses! It's Tom Swift!"

"Of course!" agreed the owner of that name.

"Well, how in the world did you hear of my accident and come to get me?" asked Mr. Wakefield Damon, for he it was. "Bless my carburetor, but this is remarkable!"

"I didn't hear of any accident," said Tom, "and I'm sorry to learn that you have been in one. I just happened to come past this way. At first, I thought you were a highwayman. But when I heard you bless your accident policy I knew you."

"It's lucky I spoke promptly!" chuckled the eccentric man.

"What happened?" asked Tom, as he made room for his friend on the seat beside him. "Are you hurt?"

"Oh, no. But my auto stalled about two miles back and I couldn't get it going. There wasn't any garage near, and I hated to go to some strange house, rouse them and ask to use the telephone to have a towing car come out to get me. So I started to walk, thinking I might meet some kind-hearted motorist. I never dreamed you would come by."

"It was just chance," said Tom. "But what's the matter with your car, and where is it? Maybe I can fix it for you."

"No, it isn't worth while. I think the points need filing and that isn't easy to do in the dark. If you'll run me to your house I'll stay all night, provided you have room. My wife is away so she won't miss me. It will be time enough in the morning to send a garage man out to get the car."

"All right," assented Tom. Truth to tell, he was tired and did not relish working over a refractory auto at this hour of the night, or rather, morning, for it was now past twelve. "We'll be glad to put you up, Mr. Damon."

"And I'm glad it happened, Tom, for it will give me a chance to see this new House on Wheels of yours. The last time I was over you were just planning it," said Mr. Damon. "I expect, by now, it is making regular trips."

"Not quite so fast as that. But we're about ready for a tryout."

"Then I'm just in time, bless my tooth brush!" chuckled Mr. Damon.

Next morning, Mr. Damon, after a view of the House on Wheels, to which he gave enthusiastic praise, arranged with a garage worker to come and get him and take him to where his stalled car had been left. Tom busied himself over the motor block test and, to his delight, found that the new engine was even better than rated.

"Of course it needs to be broken in," he told Ned. "But that is only a matter of time. I'm going to rush things through now."

Orders were given for an extra shift of workmen to assemble the House on Wheels and put the motor in place. Aside from some refinements and equipment, the big, new car was almost ready for the road. To such good end did the men work that day, urged on and aided by Tom, that by night the motor was in place, connected to the drive shaft and the machine looked almost finished.

"You could almost run it out as it is now," said Ned.

"Not for a couple of days," replied Tom, with a shake of his head. "But at least it looks the part, so I think I'll telephone Mary and see if she can't come over and take a look."

He hurried to the telephone in his workroom and was soon in connection with the Nestor home, as Ned could tell by the talk. Mary was on the wire, and the financial manager heard Tom say:

"What's that, Mary? You're going away? Why—why——"

Then came a pause. Ned knew Mary was speaking, and what she said seemed to be surprising news for Tom Swift, judging by the look on his face.

CHAPTER V

WORK AND WORRY

Some matters of business routine called Ned Newton from the room while Tom was still telephoning, and when the financial manager returned he heard his chum say:

"Well, of course if it's all arranged there isn't anything more to be said, I suppose." A pause. Then: "Of course I'll come over to see you off. But—it's pretty sudden. What's that? Oh, yes, of course." Then the good-bye.

Tom hung up the receiver with leaden fingers, and there was a listlessness in his walk as he went back to where he had been working. Ned tried to assume an air as if he had heard nothing, but it was impossible to ignore the fact that Tom had received some unpleasant news. If he wanted to speak of it—all right. If he didn't——

But Tom blurted it out.

"Mary's going away!"

"Away?"

"Oh, not for good," and Tom laughed nervously at Ned's startled implication. "It's just on a visit to some relatives she had been promising to go and see for a long time. Matters are now arranged and she is going."

"Rather—er—sudden, isn't it?" asked Ned. For Tom had spoken of his call on Mary the night before and had then made no mention of an impending visit.

"Yes, very sudden. She didn't tell me until just now, when I asked her to come over and take a look at the House on Wheels. But she says she will be too busy packing. Very sudden!" and Tom's voice had a new quality in it.

"Any special reason for her rush?" asked Ned, who felt privileged now that his chum had given him the opening.

"Well, yes, in a way. The relatives to whom Mary is going on a visit are giving a house party for one member of the family who is soon to sail for Europe. Unless Mary starts to-morrow she won't see this forty-second cousin, or whatever she is, and it seems there are family reasons why she should."

"Then she's going soon?"

"Takes the train to-morrow morning."

"Going to be gone long?"

"She isn't sure how long. Hang it all! This upsets all my plans!" and Tom moodily paced the floor.

"Oh, well, it isn't forever! Cheer up!" consoled Ned. "She'll be coming back. My girl went away once."

"Yes, I know. But these people—they——"

Tom paused, significantly, it seemed.

"Well, what's wrong with them?" Ned wanted to know.

"Oh, nothing much, except they're fairly bursting with money."

"Well, that's a good thing, isn't it?"

"Not considering what money means and does nowadays. Mary's going out of her depth, so to speak and——"

"Say, look here!" exclaimed Ned. "You needn't worry about your girl. She's got a level head."

"Yes, I know. But when she gets among millionaires she's likely to lose that level."

"I don't believe so. Why, you're no poverty-stricken chap yourself, Tom, though I admit our bank account isn't as big as it will be when the dividends from the talking pictures will come in."

"I'm not one, two, six in money matters compared to the Winthrop family," complained Tom moodily. "They're filthy rich, and it isn't going to do Mary any good mixing up with that bunch."

"You mean she'll come back dissatisfied with the simple life of Shopton and vicinity?"

"That's what I fear."

"Oh, cheer up, disciple of gloom!" laughed Ned. "You'll find Mary just the same when she comes back as she is now. Is she eager to go?"

"That's just it!" complained Tom. "She seems very keen about it."

"Oh, well, a girl likes a change. And it can't last forever."

"No, I suppose not. Oh, well, I'm a grouch not to wish Mary to have a good time. But I did want her to see this House on Wheels," and Tom acted like a small boy who has been kept home from a party.

"She'll see it soon enough," predicted Ned. "And it will look all the better when it's complete and has had a tryout."

"Maybe," was all Tom would say, and then he plunged into work.

Ned expected that his friend would again go over to the Nestor house in the evening, but Tom, with rather a set look on his face, announced that he intended to work until late on his newest invention. However, he did telephone to Mary and arranged to call for her the next morning to take her to the station.

What took place at the train when Mary departed Ned did not know. But Tom came back looking more gloomy than before and plunged into work with a zeal which left his devoted chum far behind.

The Swift plant was a busy place in the days that followed. There was always more or less of routine labor in connection with several machines which Tom and his father had perfected, patented, and had put on the market for general sale.

The latest invention of the young man, excepting the House on Wheels, had been a machine for showing moving pictures in the home, in simultaneous connection with vocal and instrumental effects by radio. It was possible to sit in one's parlor and not only see a distant theatrical performance, but actually hear all that went on. The vision of the actors and actresses was reduced in size, but the pictures were very clear. And the radio, of an improved type, clearly brought every word and every note of music through the air.

This invention, or a share in it, had been sold to a syndicate which, for a time, had fought Tom Swift fiercely. But now matters were straightened out, though there was much detail to finish.

With that, and with overseeing the completion of his House on Wheels, Tom Swift had plenty of work to keep him busy. He was also worrying, as Ned easily guessed.

Though Tom received and wrote letters, the worried air did not depart from him and Ned knew his chum had a sore feeling in his heart. He was disappointed that Mary had not seen the new car before going away.

But if the young inventor was not privileged to listen to Mary's praise, he had the chance to hear the enthusiastic comments of Mr. Damon who came over a few days after his night break-down.

"Bless my safe deposit box, Tom!" exclaimed the eccentric man, "but I regard your House on Wheels as one of the most marvelous inventions of all time!"

"Strictly speaking it isn't an invention," said Tom. "It is merely an adaptation of several existing ones. I've simply taken a small house and put it on an automobile body."

"But you have done it very cleverly," said Mr. Damon. "This is an age of travel, Tom, and everybody is doing it. Now the one great drawback of travel is to find a place to stay at night, for no one likes to journey after dark, unless in a sleeping car.

"So it has come about that there are hotels and you know what a bother it is to arrange for a night's stay. But now you come along with a house in which a person can travel all day, as in an ordinary automobile. Then at night, when getting to a town, instead of having to hunt up a garage and then a hotel, you just pull your bed down from the wall and tumble in. It's great!"

"Well, I thought of that," Tom said. "I'm hoping it will be the success I think it may be."

"Of course it will be!" declared Mr. Damon. "You can book my order for one now, Tom."

"Consider it booked!" and the young inventor smiled for one of the few times since Mary had gone away.

In spite of the fact that the House on Wheels was, to the unobservant, well nigh complete the day Mary Nestor went away, Tom said considerable yet remained to be done, and for another week he and his men labored hard over the structure.

But finally the last coat of varnish was applied and given time to dry. Not all the fittings were in place, but that was a small matter. The big twelve-cylinder motor was connected and the brake test had been satisfactory.

Then one evening, as Ned was about to leave to go to his home, Tom remarked to him:

"Can you spare the time to make a trip with me, Ned?"

"A trip where and how?"

"I don't know just where, but as to how—in the House on Wheels."

"Is she all ready?"

"We'll give her a tryout to-morrow. Maybe the thing won't work as well as I planned, but we'll soon know. If it comes anywhere near the mark I've set, will you go with me?"

"On a trip? Sure!"

"All right," said Tom, pacing the floor of his office. "Well have the tryout to-morrow. After that—well, we'll see!"

CHAPTER VI

THE TRYOUT

Tom Swift took his place in the driver's seat of the House on Wheels. This compartment was not unlike the front seat in any large, van-like truck, except that it was more comfortable and was equipped with a number of dials, indicators and controls.

"Well, Ned, coming?" asked the young inventor, looking down at his chum and smiling.

"I guess so, if you're quite sure she won't blow up."

"If she does, we'll go together!" joked Tom.

It was the day of the tryout, and while some work yet remained to be done on the new machine, it was in shape for a road test. It had been run around the big yard of the Swift plant and had acted in a satisfactory manner. What it would actually do under road conditions and off the level, was something yet to be demonstrated.

The big twelve-cylinder motor had met the block test and had been able to propel the heavy car around the shops. Tom felt sure there was plenty of reserve power, or would be when it had been tuned up.

Ned now climbed to the seat beside his chum. There was room for three in this compartment, but though Mr. Damon had been invited to come over for the initial run, the eccentric man had not appeared.

With Ned on the seat beside him, Tom touched his foot to the button of the self-starter and with a roar the powerful motor sprang into life. Though it was big and had the strength of many horses, so well was it balanced that there was hardly any vibration, which spells the death knell of many machines otherwise perfect.

Letting the motor warm up a bit, Tom carefully tested the various gear and control levers. Then, gently letting in the clutch, the House on Wheels rolled slowly out of the shed where it had been constructed.

"There she goes!" cried Mr. Swift, who was almost as eager as his son over the success of the venture.

"Rolling like an egg!" exclaimed Mr. Jackson, who had had no small share in building the machine after Tom had planned it.

"By golly! She suah am a reg'lar ark!" was Eradicate's comment. "Mistah Noah he'd suah be livin' pretty if he'd had one ark like dat when de flood come! Ha! Ha!"

There was a subdued cheer from the assembled workmen as Tom Swift proved that at least his machine would run smoothly, and with Koku loudly warning idlers away from the gate, the House on Wheels approached the open highway for the first time.

As might have been expected, any activity at the Swift plant was sure to attract attention from the residents of Shopton. Though they were accustomed to seeing many strange machines issue from the big gates, or perhaps fly over the high fence, the matter never lost its interest. So, on this morning, there was a crowd of sightseers.

Nor were they disappointed with the first view of Tom's new wonder. Bright in its gay colors and varnish, the House on Wheels was a sight for those who appreciate fine cars and machinery. Majestically it rolled out on the big rubber-tired wheels and, driving slowly until he was sure of the feel of the control wheel, Tom eased his machine through the gates and straightened it out on the broad road.

"Hurray!" yelled a boy in the crowd. "It's a regular circus wagon!"

"I wish I had one like it!" echoed a companion.

For a little way, so slowly did Tom nurse the motor along, the crowd could keep pace with the machine. Then, when he had the feel that everything was going smoothly, the young inventor pressed the accelerator down a little.

The result was at once apparent. As smoothly as a big locomotive, and with the same hint of power in reserve, the big House on Wheels went ahead so rapidly that the running crowd of boys and girls and men was soon left behind and Tom and Ned had the road to themselves save for an occasional motorist. But as this section was not ordinarily much traveled, they were not bothered by many other machines.

Drivers of cars who passed or approached the House on Wheels stared curiously at it, and more than one was heard to remark to a companion:

"Some advertising stunt, I guess."

"That might not be bad," commented Ned, after one or two repetitions of this.

"What?" asked Tom, who was intent on listening to the hum of the motor to detect a false note or failure of the oiling system.

"Using this for advertising," said Ned. "Many a firm would pay big money to have a sign painted on the sides of this car, calling attention to the merits of Blank's chewing gum or Hank's breakfast food."

"There are no advertisements going on this!" decided Tom. "I'll make my money some other way."

"Even if you have to take on Cunningham's proposition?" teased Ned.

"I'll never have anything to do with that crook!" said the young man as he slowed down to turn a corner which would take them out on the big state highway. "I'll close down the plant before I'll help him infringe on other inventors. I've had that done to me too many times not to know what it means. No Cunningham in mine!"

They were now in comparatively open country, and though there was more traffic on the state road than on the thoroughfare they had left in coming from the Swift plant, there was not enough to worry a driver of Tom's experience.

"You need a hill for a real stiff test," remarked Ned.

"That's the idea, and we'll come to one soon if we keep on going."

"Well, there doesn't seem to be anything to stop you," was his chum's opinion. "Hop right to it!"

They were bowling along at an increased speed when Tom suddenly leaned over and bent forward as if listening, which is exactly what he was doing.

"What's the matter?" asked his companion.

"Sounds like a knock."

They both listened intently, for though Ned did not have Tom's skill in inventiveness he was a good driver.

"There's something wrong," decided Tom, pulling over to the side of the road to be out of the way of passing traffic. "I'm thinking one of the oil feeds is clogged. Yes, she's heating up," he added, as he pointed to the motor temperature indicator which was one of many dials and gages on the instrument board.

The House on Wheels was brought to a halt and then Ned and Tom raised the hood for a look at the motor. There was an unusual wave of heat as soon as the sides were raised, and Tom's quick eye at once found the seat of trouble. A small valve that supplied oil to one of the many working parts was partly closed so that not enough of the lubricating fluid reached the shaft.

They resumed the journey, and Tom ventured to open the throttle a little, though he had no intention of getting up to maximum speed, which should not be done with any new motor until after it has been limbered up for at least five hundred miles.

The House on Wheels responded well and stepped along rather fast.

"This is the life!" cried Ned gaily. "When do we eat, Tom?"

"Not on this trip. I didn't pack in any grub. And you can't turn in and go to bed, either. This is just a preliminary run so I can decide what changes are needed."

"It seems to me that everything is fine," said Ned. "She's running now like a sewing machine."

"Got to try her on a hill yet," was Tom's answer.

"I suppose so. If you go honeymooning in this you'll have hills to climb," observed Ned, and he noticed that Tom did not now resent a reference to a possible approaching marriage.

"We'll soon know what she can do on the up grade," said the young inventor, with a look ahead. "We're coming to a hill now and it grows stiffer the higher you climb. Yes, this will be a good test."

The first part of the hill was taken in fine fashion, somewhat to Tom's delighted surprise. He had imagined the machine might labor, especially while new and stiff. But up went the House, never faltering.

Then, after a little comparatively level stretch, the hill took a sudden upward climb. For the first part of this the machine did well, there being no undue strain. But suddenly, when about half way up, there was a little jar, a sort of nervous shiver, and the motor stopped dead.

So quickly did it happen that Tom had no time to apply the brakes and Ned cried:

"Were backing downhill, Tom!"

"I know it!" responded the young inventor, a grim look on his tense face.

CHAPTER VII

THE RACE

The House on Wheels was half way up a steep slope when the motor stopped and the heavy, and somewhat clumsy car—clumsy because of its bulk—began to go backward. Of course there were brakes. Tom had provided a double set, and they would hold. He had tested them under severe strains. But it took a moment for both the young men to realize what had happened and to decide what to do.

Of course there was only one course of action after Tom had quickly discovered that the stoppage of the motor was not momentary, and that it could not be galvanized into action by the self-starter. The thing to do was to jam on the brakes, which the young inventor did before the backward motion of the House had gained it such momentum that it could not be checked.

"Whew!" whistled Ned, as he felt the machine come to what seemed like a reluctant stop. "That was a close call!"

"Oh, no," said Tom, half smiling. "I could have let her get up even more speed than she had, rolling backward, and yet have brought her to a stop with the one set of brakes."

"On this hill?" Ned was a bit incredulous.

"Yes, or on a steeper one. I want to try her on some mountain."

"Maybe you'll get the chance," Ned remarked.

"What do you mean?" asked Tom, for there seemed to be something his chum was holding back. But as, just then, a peculiar buzzing sounded from beneath the motor hood, Tom decided to investigate that before asking any questions.

The brakes were holding the House on Wheels midway up the rather steep hill, but on getting out of the driver's seat, which the two young men did very soon after the accident, their first care was to block the rear wheels with a log of wood which they dragged from a near-by thicket. After seeing that this would keep the car from rolling back downhill, even if the brakes should let go, Tom fastened a rope to the log and the other end of the cable to the rear of the House on Wheels.

"What's the idea?" asked Ned. "Going to use that as a drag going downhill on the other side?"

"No. But haven't you often noticed that where motorists have to stop on a hill, and use rocks or logs to block them, they go away after getting a new start and leave the obstructions in the road?"

"I've seen that many a time," agreed Ned, "and I've bawled 'em out for it more than once. The trouble is that they aren't there to hear what I think about 'em."

"That's just it. Well, I may want to start up without having to release my brakes suddenly, hence the log of wood. And as I don't want to leave you behind to roll the log out of the way, I fastened on this rope. We'll pull the log behind us up to the top of the hill, where it is level, and then we can stop and take it off."

"Good idea!" commented Ned. "Now let's see what's wrong. I do hope it isn't anything serious."

"No, it can't be," decided Tom. "The motor was too severely tested for that. It's just some little dingus that's out of order—maybe a broken oil pipe or a loose wire."

It was the latter that proved to be the seat of the trouble when a careful check-up had been made. In the haste with which the House on Wheels had been assembled, this little item was overlooked. It required but a short time to put the ignition cable back in place, and then, having run the motor for some time, listening to the smooth purr of it, Tom announced that he was satisfied there would be no further trouble.

It was when they were ready to start on again that Tom's wisdom in blocking the wheels was demonstrated. For there was no need of a sudden letting in of the clutch, after racing the engine in gear to get momentum and speed enough to make a flying start uphill. The brakes were already released. The log prevented the House on Wheels from rolling backward, and the machine started slowly up the grade as if taking off from a level. The log was pulled along by means of the rope, and did not remain in the road a menace to following travelers.

"She's coming up in good style," commented Ned, as he observed the increasing speed of the machine even though the grade of the hill grew greater.

"Couldn't be better," agreed Tom, with a satisfied smile. "All the power I need and then some! When she gets broken in I expect great things of her."

"Looks so," murmured Ned.

In a short time they were at the top of the hill and a long, level road lay before them. They made a momentary stop to cast off the blocking log and then went on.

"I'm going back and take a look inside," said Ned after a while. "I want to see how she rides."

There was a passage leading from the driver's seat to the interior of the House, and Ned was soon making his way through the various "rooms" as they might be called, though compartments would probably be the better term. He sat in the small chairs, let down one of the cots and stretched out on it and sat at the table, pretending to eat, though, as yet, there was no food aboard.

"How is it?" asked Tom, as his chum reappeared in the communicating passage.

"Slick as oil!" was the enthusiastic comment. "Rides like an ocean liner."

"That's good. Then there's nothing wrong in the construction. I was afraid she might sway too much."

"There is a little swaying," admitted Ned. "But I think that will be smoothed out when you get a load in."

"I guess so," agreed Tom. "Well, come out here and try your hand at it."

"What do you mean?" Ned wanted to know.

"I want you to drive for a while. You've driven lots of cars, and I want you to get the feel of this. It seems a trifle stiff to me, and I want to see if you get the same impression. I can loosen the gear up a bit if it is."

"You mean you want me to drive your House on Wheels?" asked Ned.

"Sure! Why not?"

"I may wreck her."

"So might I. Accidents are always likely to happen. But I've got to get some other impression than my own as to how she holds the road, takes corners, and the like, and you're the best one I know to give me the information I need. Besides, you'll be coming on trips with me, and I can't always be at the wheel."

"Me come on a trip with you in this?" chuckled Ned. "Well, I like that!"

"What do you mean? Why wouldn't you come?"

"On yours and Mary's honeymoon trip? Excuse me!"

"Say, cut that stuff out!" and Tom seemed serious. "Who's said anything about a honeymoon?"

"Nobody—nobody's said a word. At least, you and Mary haven't," admitted the financial manager. "But actions speak louder than words. And I thought that's why you were getting this canal boat in shape."

"Nothing of the sort!" exclaimed Tom sharply. "I mean—of course—that is, I—Oh, heck! Come on out here and take the wheel!"

"All right!" agreed Ned. "But don't blame me for what happens."

"I won't," and Tom steered the machine over to the side of the road to bring it to a stop out of possible traffic while he changed places with his chum.

After proceeding at a moderate rate for a mile or two, in order to familiarize himself with the brakes and controls, Ned let out a little more gas and the House on Wheels shot ahead on the smooth, level concrete highway which the two had practically to themselves.

"How does she feel, Ned?" asked Tom, as they sped along.

"Fine."

"And how does she handle?"

"Light as a cork! There's no steering strain at all."

"I'm glad of that. I wanted to make sure of it."

"But take her yourself," urged Ned, guiding the House to the side of the road in case any motorists were following. "You haven't had the wheel when you had a chance to let out. Go ahead."

"All right," agreed Tom Swift.

He had not long been in the driver's seat, and was working up speed, when from behind came a long, shrill whistle. For a moment the young men thought it might be one of those signals connected to the exhaust pipe of some speeding motorist. But a look into the rear vision mirror showed a fast freight train approaching. Then, for the first time, Tom and Ned noticed that they were running parallel to railroad tracks and close to them.

On came the fast freight, and the engineer seemed either to be trying to attract the attention of the occupants of the peculiar car or else saluting them. Then Tom cried suddenly:

"I know what he wants!"

"What?" asked Ned.

"A race! And he's going to get it. Come on, steam baby!" yelled Tom, noting that he was now even with the locomotive. "We'll see what you can do against the House on Wheels!"

CHAPTER VIII

CUNNINGHAM ON THE WIRE

Three sharp whistles from the locomotive seemed to indicate, on the part of its driver, an acceptance of the challenge. In answer Tom gave three toots of his own horn and the race was on.

No better speedway could have been devised for a test of the comparative powers of the fast freight and Tom Swift's House on Wheels than the concrete highway and the steel track along which the respective machines were now rushing. There was not another automobile in sight along a stretch of several miles, and no other train on the railroad. It seemed to have been made to order.

"Think you've got a chance, Tom?" yelled Ned. It was necessary to yell, for the puffing, panting locomotive was so close that its exhaust almost drowned one's voice. Nor was the House on Wheels altogether quiet, for there was a subdued rumble and roar at its present high speed which made talking anything but easy.

"I've got a good chance!" answered Tom, with a grim tightening of his lips as his hands grasped more firmly the steering wheel. "I'm going to beat this baby."

"It's a fast freight, Tom, the fruit express. It has the right of way over everything except passenger trains. It's the crack freight of this road and makes almost as good time as some of the through passenger trains."

"Can't help that," replied the young inventor. "I'm not going to sit back and take his smoke!"

Indeed, there seemed to be little danger of this. For though the freight had crept up on the House on Wheels when she was gaining headway, the two machines were not long on even terms before Tom's House began to pull away.

But if he thought to gain an easy victory, he was mistaken. A quick glance showed that the fireman was busy shoveling coal under the boiler of the freight engine. Out belched volumes of black smoke and the increased staccato of the exhaust showed that not only was the throttle being opened wider but that the link motion was being taken up, making a corresponding quicker cut off of steam at one end of the cylinders and a duplicate fast expulsion on the other end.

"She's creeping up on us, Tom," observed Ned, looking back when, after a little run, they had distanced the freight.

"We've got to expect that. But I've got something in reserve yet. Though I daren't let the House out for all she's worth, I can still get the accelerator down a few notches without damage. The race isn't over yet."

Tom had taken part in many speed contests, and he knew how to jockey with the best of them. He purposely let the freight slowly crawl up on even terms with him. This was due not only to the increased speed of the freight but also to Tom's slight slackening of his pace.

"I'll fool this bird!" he told Ned.

And when the engine was again up in front, so that the pilot was in line with the bumper of the House on Wheels, Tom turned on more gas, after a momentary cut-off, and again shot ahead.

He and Ned could almost see, in fancy, the chagrin on the faces of the engineer and fireman as they were thus gently mocked. But the railroad men were good sports and were not going to give up easily.

Again there was a frantic shoveling of coal, and there must have been a more advantageous adjustment of the draft, or perhaps a forced one was turned on, for suddenly the safety valve popped, which, at the speed the engine had already attained, showed an increased pressure of steam.

"He's coming right after us!" cried Ned, as they swayed along.

On no other road but this concrete highway would it have been safe to run the House on Wheels at the speed she was going. And few drivers other than Tom Swift would have been capable of handling the heavy machine with such skill and judgment.

The race was now on in earnest. Tom knew that it would not be safe to push his motor much faster. Not that it was not capable of a higher rate, but it would need to be broken in somewhat before he dared risk it. On the other hand, the locomotive was not thus limited. So if it was not yet at its maximum, there would be no danger in pushing the mechanism to that point. And if the maximum was greater than Tom's temporary one, then he would lose.

However, though forced draft was used, the big freighter appeared to have reached the limit. For perhaps half a mile she held her own on even terms with the House on Wheels. Then Ned asked:

"Can you do a bit better, Tom?"

"I'm going to risk it," was the quick answer.

The House slowly began to draw ahead and there was no replying response on the part of the locomotive. Foot by foot Tom and Ned drew away. They had a glimpse of the fireman desperately shoveling coal, but to no purpose.

Gradually the gap that separated the two widened, and though brakemen on top of the cars yelled and seemed to urge their mates to greater efforts, it was not to be.

Tom Swift pulled away and won the race by a good margin. Not much too soon, either, for when he was several lengths ahead the railroad branched away from the highway it had been paralleling for several miles and disappeared into the woods.

In recognition of the beating by a better rival, the engineer saluted with three long blasts, to which Tom responded with like signals from his horn.

"Well, that's that!" remarked Ned, as they slowed down, for they were approaching another steep hill.

"Yes," assented Tom. "It's all over and I'm satisfied. The House on Wheels couldn't have done better. Not a strain and not a bearing overheated," he added, as he brought the machine to a gradual stop and made a hasty examination.

"Going to take the hill?" asked Ned.

"No, we'll give her a rest and drift back," was the answer. "She has done her duty and there's no use putting on too much strain."

"That's right," agreed Ned.

He had alighted from the driver's seat with Tom to stretch his legs, and as the two were climbing back into the compartment they saw a sporty runabout flash past them. Two men, one young, were in it and they seemed much interested in the House on Wheels at the side of the road. One of them leaned out and looked back.

At the sight of his face Ned exclaimed:

"Did you notice him, Tom?"

"No. Who was he?"

"That rat-faced chap who got into your shop and tried to put this motor out of business."

"No!"

"I'm sure of it! Come on, let's chase after 'em!" proposed Ned eagerly. But Tom Swift shook his head.

"We haven't a chance," said the young inventor. "They've got a much faster machine than mine and a good start. The House wasn't designed to race runabouts, though it can hold its own in a fast freight race. Let him go, whoever he is."

The trip back to the Swift plant was without incident, except that when Tom and Ned left the concrete highway and got into the heavier traffic they were somewhat delayed by the crowding around and near approach of other motorists who showed much curiosity regarding the strange, big machine.

"How was it, Tom?" asked his father, as they turned in through the big gates of the plant.

"Couldn't have been better, Dad," and he gave a short account of the tryout trip, including the race.

"Dat's fine!" commented Eradicate who, with the freedom of an old family servant, had been listening. "Better put her to bed now, Massa Tom, an' let her hab a good night's rest. Dat's what I used to do wif de race hosses down in ole Virginny."

"'Tisn't a bad idea," returned Tom, with a smile. "Give the motor a thorough examination and test for any possible strains," Tom told one of his men, who came out to help put the House on Wheels into the special garage that had been built for it. "I pushed the motor pretty hard, for a new one, and I want to be sure it's in good shape."

"I'll look after it thoroughly, Mr. Swift," promised the man.

Scarcely had Tom and Ned reached the private office, where some matters awaited their attention, than the telephone bell rang. Answering it, Tom showed some amazement when he learned the identity of the man at the other end of the wire.

"This is Basil Cunningham, Mr. Swift," came the loud, somewhat rasping tones of the burly Englishman. "We'll let bygones be bygones, if it's all the same to you. I want you to take my contract and I'll add a special ten per cent. bonus if you will rush it through for me."

For a moment Tom Swift was too surprised to reply. But he gathered his wits together in a few seconds and called back:

"I wouldn't take your contract, Mr. Cunningham, for even an additional bonus of twenty per cent!"

"You won't?"

"No!"

"Is that your final answer?"

"It is."

"But look here, Mr. Swift," and Cunningham's voice was almost whining now, "what objection have you to making these machines for me?"

"Will you tell me what you intend to use them for?" countered Tom.

"No, I will not!" was the answer snapped back quickly. "It isn't any of your affair!"

From the manner in which Cunningham banged the receiver on the hook, Tom felt that the Englishman was in a towering rage. Ned could only guess at half of the conversation, but Tom gave it to him in detail a little later.

"Why do you think he is so secretive about what the machines are to be used for?" the young financial manager wanted to know.

"Because there's a nigger in the woodpile—that's my opinion!"

"You still think Cunningham intends to infringe?"

"I do. The fact that he comes back to me after my first refusal shows that he has tried to get other concerns to take up his work and has failed."

"It would seem so," agreed Ned.

"Well, this all goes to show that my first impression is right," went on Tom. "Cunningham is a crook, I'm sure."

"Then we're better off leaving him alone," commented Ned.

They were about to go over some business papers again when the telephone rang once more.

"You answer, Ned," directed Tom. "If it's Cunningham say I will have no further communication with him!"

Ned picked up the instrument, listened a moment, and then cried:

"What's that? Who are you? What do you mean? Don't be a coward! Give me your name!"

"What's the matter?" asked Tom when Ned, by impatiently jiggling the receiver hook, indicated that the person at the other end of the wire had hung up. "Who was talking, Cunningham?"

"I don't think so. But it must have been one of his men. For he said: 'Tom Swift will regret not taking this contract! He'd better watch out!' I tried to make him tell who he was, but he wouldn't."

"So," said Tom musingly, and with a little smile, "they are beginning to threaten, are they? Well, I'm ready for them!"

CHAPTER IX

DISMAL MOUNTAIN

"Well, Ned, I guess that's about all!"

"Unless you want to put in another piece of bacon," was Ned Newton's rejoinder to his chum's implied question.

The two were sitting in the House on Wheels, about a week after the sensational race with the freight train. In the intervening time much work had been done on the new invention. The motor was thoroughly gone over, tuned up, and minor adjustments made. The furnishing of the interior of the House was completed, from kitchen articles to bed linen, and the vehicle was now equipped for a long or short journey, as the owner desired. Ned's particular province was the pantry, and he had furnished it, as Tom said, "with enough grub to last a month."

Following another and more severe tryout of the machine after the freight train race, Tom had suggested to his chum that they go on a week's crosscountry tour to further test the House on Wheels under varying conditions.

"Have you any particular object in view?" asked Ned.

"Well, I thought maybe I'd surprise Mary," was the answer.

"Surprise her?" questioned Ned. "What do you mean?"

"We could call on the Winthrops where she is staying."

"Good idea. But where is it?"

"Just outside Chesterport."

"Chesterport!" exclaimed Ned, with every indication of excitement. "You mean Chesterport in this state?"

"Sure. Why not? What's wrong with it?"

"Nothing. Only—Well, say, what are you going to do after you surprise Mary in Chesterport?"

"After that we can keep on touring, if you like. We can go as far beyond Chesterport as you like."

"We won't have to go far," murmured Ned, and there was a strange look in his eyes. "Why didn't you tell me before that Mary had gone to Chesterport?"

"I didn't attach any importance to it, for one thing," answered Tom. "And, for all I know, I may have mentioned it to you a dozen times."

"No you didn't, or I'd have remembered it."

"What did you mean by saying we won't have to go far beyond Chesterport?" asked Tom. "What's there of such importance?"

"It's queer you never heard of it," murmured Ned, looking over some papers he hastily took from his pocket.

"For the love of Pete! Heard of what?" cried Tom, a bit exasperated by his chum's curious manner.

"Dismal Mountain! The peak of mystery!" exclaimed Ned. "If you haven't made any other plans after you pay Mary a visit, what's the matter with keeping on to Dismal Mountain?"

"Nothing the matter, as far as I can see," admitted Tom. "But it is the first time I've ever heard of the beast and I'd like a little information. Why is the mountain dismal and what's the mystery about it?"

"It's dismal because of the mystery," was the reply. "And as for what that is, smarter lads than you have asked the question and haven't been answered."

"Oh, cut it out! Be yourself!" advised Tom, with a laugh. "Get down to brass tacks and let's have a little first hand information."

"That I can't give you, much as I'd like to," said Ned, with a serious air, not at all in keeping with Tom's bantering words. "All I know about Dismal Mountain is what I've heard or read, but that's plenty. I've made a few notes here, and——"

"I should say you had!" exclaimed Tom, looking at the documents his chum pulled from his pocket. "Looks like an election ballot."

"Well, they're mostly clippings from papers," went on Ned; "though I have made some notes myself of what folks have told me. Look here! Those are some newspaper clippings."

He spread a sheaf of them out on the table in the living room of the House on Wheels where this talk was taking place. The House was in the garage, but was all ready to run out at a moment's notice.

Tom saw that the clippings bore various heads, such as: "Dismal Mountain Smokes Again," "Dismal Mountain Claims Another Victim," and this appeared to be an account of a man who had disappeared somewhere in the fastness of the forest around the place.

"You don't need to read them all," advised Ned. "I can shorten it by summarizing it for you. Dismal Mountain is some distance south of Chesterport—just how far I don't know. It's in a lonely section of the country, away from any town or city, though there are people living not far from the foot of the mountain.

"Some of these folks say the mountain is haunted. Others hold that it is the resort of present-day moonshiners and bootleggers. I think that comes as near the mark as any. Another version is that the strange sights and sounds that are seen and heard are made by the moonshiners or bootleggers to scare would-be investigators away."

"I can well believe that," murmured Tom. "What else?"

"Well, there's another theory that a squad of bandits or road agents make the glens of Dismal Mountain their hiding places," went on Ned. "They lie in wait there and hold up trucks carrying big loads of valuable merchandise, such as bales of silk. There may also be hijackers on the mountain—men who make a practice of raiding the trucks sent out by bootleggers. Of course the latter being engaged in breaking the law themselves, can't call on the law to protect them. So the hijackers have it easy."

"Sounds like a right bad sort of a place," commented Tom.

"It's fully as bad as it sounds," declared Ned. "Not long ago, as you can see by this clipping, there was a train hold-up not far from Dismal Mountain. Some of the bandits are believed to have fled to that place and may still be in hiding."

"This is getting worse and more interesting!" exclaimed Tom Swift. "I only hope you aren't stringing me," he added, with a sharp look at his chum.

"Indeed I'm not kidding you!" expostulated Ned. "You can read it there for yourself. Of course I don't guarantee the truth of any of this, but if I'm fooled, so are the papers."

"It looks authentic," admitted Tom, when he had glanced through several clippings. "At least there have been a number of crimes committed in the vicinity of this Dismal Mountain, and it may hold the criminals."

"That's what I think," said Ned. "And when I heard just now for the first time that you are going to Chesterport, which is the nearest town of any size to the mountain, I thought it would be a good chance to visit the mysterious place."

"You're right!" exclaimed Tom. "I'm glad you mentioned this. I wouldn't have missed it for the world. It's queer I never heard about the mountain of mystery before, and yet it isn't a hundred miles away."

"It is only recently that all these stories became public," stated Ned. "Besides, you were so busy working on your talking pictures and since then on this House on Wheels that I don't blame you for not having heard of this Dismal Mountain."

"It's going to be just the thing!" cried Tom, his face lighting with pleasure. "With Mary away, I needed something to stimulate me and keep me from going stale. This will do the trick! Let's see if we can't run down this mystery!"

"I'm with you!" echoed Ned.

He was putting away his clippings and other information and Tom was going to ask about the roads to Dismal Mountain and the possibility of taking the House on Wheels when they heard a noise at the outer door of the garage where the new machine stood. Then the handle was cautiously tried.

"Look!" whispered Ned, touching Tom on the arm and pointing to the latch that was slowly being raised.

CHAPTER X

JEALOUSY

Together Tom Swift and Ned Newton watched the door of the garage being cautiously opened. There was something peculiar in this. In the first place, no one who had a right to swing the door would have been thus cautious about it. In the second place, no one was supposed to be in that part of the shop just now except Tom and Ned. The young inventor had given orders that he was to be left undisturbed with his financial manager to make a final inspection of his new machine.

Rightly arguing that no one who had a right to be there would try to enter in this manner, Tom Swift decided to find out who was opening the door, and in such a manner as to capture the intruder if possible. Accordingly, he made a sign to Ned to keep quiet and then began creeping toward the door in as stealthy a manner as it was being opened, which was a fraction of an inch at a time.

Ned, seeing his chum's intention, followed him, and the two were close to the door when, unfortunately, Tom stumbled over a piece of wood left by one of the workman. The noise, though slight, was enough to alarm the person on the other side of the door. It was at once pulled shut and footsteps could be heard in hasty retreat outside.

"After him!" yelled Tom, caution now being useless, and he and Ned made a dart for the opening. They swung back the door, but it had stuck a little, and the two youths were just in time to see a crouching, running figure some distance away.

"Catch him!" cried Ned.

It was easier said than done. When Tom and Ned reached the place where they had caught a glimpse of the running figure there was no sign of the fugitive. Though an alarm was at once raised and a search made, no stranger was discovered on the place.

"Well, what do you make of it?" asked Tom, when the two had returned to where the House on Wheels stood.

"Hanged if I know what to make of it," Ned replied. "Whoever it was thought no one was in here, and they thought they could either steal your House or else damage it."

"It would be hard to steal it," replied Tom. "But it wouldn't take much to wreck it. Looks as if some of the old gangs were after me, or else some new one."

"I'm inclined to the latter theory," said Ned. "And the newest one who would logically have it in for you is Cunningham. Isn't that the case?"

"I suppose so. Yet I can't understand a man of his business ability—and I must admit he is shrewd—being foolish enough to risk an attack such as this might have been."

"Unless he is so angry that he hasn't any common sense left," suggested Ned.

"That may be it, yes. Well, the sooner we get started away from here the better it will be for us."

"Do you think you'll escape your enemies, Tom, by starting on a trip in the House on Wheels?" asked Ned.

"Not exactly! We've had experiences before in being trailed by those who wanted to injure me or my father. But it isn't as easy for them to get at me when I'm on the move. I can keep them guessing."

"There's something in that," admitted Ned. "Well, I won't be sorry to be on the move, either."

It was two days after this, following a tryout of the House on Wheels fully loaded and equipped, that Tom and Ned started on what they thought was to be a pleasant little excursion, but which turned out to be the beginning of a series of strange events.

"I'll let you know when I get to Chesterport, Dad," said Tom, when bidding his father good-bye.

"Yes, do," urged the aged inventor. "This is a different machine from any you have traveled in, and I should like to know how it behaves. We might make some money out of putting them on the market."

"I'll think about that."

Ned made his farewells to Helen Morton and then, amid a chorus of good wishes on the part of Mr. Damon and the shop force, the two young men started off in the strange machine which attracted much attention all along the road.

"Off to Chesterport!" gaily exclaimed Ned, as he sat beside Tom in the driver's seat.

"And the mountain of mystery!" added the young inventor.

They reached Chesterport about the middle of the afternoon, but instead of proceeding up the main street to the residence of the Winthrops, who, Tom had told Ned, occupied a mansion in an exclusive part of the town, the House on Wheels, under the guidance of its inventor, was headed into a vacant lot near an automobile garage.

"What's the idea?" inquired Ned, in surprise. "Something gone wrong?"

"No. Why?"

"Why don't you run her up in front of the Winthrop's and call on Mary in style?"

"That's just it, Ned. I'm afraid the Winthrop family wouldn't like this kind of style. And it might embarrass Mary. You see, the Winthrop people are old-fashioned, conservative people, dating back to the Massachusetts Bay Colony, or something like that. Up to a few years ago the older Mrs. Winthrop would never ride in anything but the family carriage. She did grudgingly consent to an auto, in time. Her daughter-in-law isn't much more liberal, and I'm afraid if we dashed up and stopped in front of their place with this rather gaudy affair, the ladies might have a fit and conclude that I wasn't the sort of person Mary ought to marry."

"I see!" laughed Ned. "Well, maybe the House is a bit too much like a circus van to park in front of a proud old lady's house. I see your point. But what are you going to do?"

"Oh, we'll leave the House here under the eye of this garage man and then you and I will hire a taxi and call on Mary in style."

"Count me out. I'll stay with the House."

"Nothing doing! You go with me!"

The young men had been wearing old garments, for they had anticipated having to do some work on the car. But there was a miniature bathroom in the House on Wheels and after washing and changing to fresh garments, the two young men hired a taxi from the garage, near which they had left the House on Wheels and went calling.

"Oh, I'm so glad to see you!" Mary exclaimed impulsively at the sight of Tom and Ned. "Why didn't you send me word you were coming?"

"We didn't decide to come until so short a time ago," Tom answered, "that we didn't really have time."

"He wasn't sure his old House could make the grade," chuckled Ned.

"Oh, then you have the wonderful House with you!" cried Mary.

"Yes, er—I—now—what pocket did I put it in, Ned?" asked Tom in mock anxiety, as he searched through his garments. "I know I had it when we came in, but——"

"Think you're smart, don't you?" mocked Mary.

Grace Winthrop came in just then to be introduced, and she and Ned paired off quite well, "considering everything," as Tom said afterward.

The story of the trip was told and both girls asked to be taken for a ride in the House on Wheels, a petition that was quickly granted. Grace Winthrop shared none of her grandmother's inhibitions against modernism!

"Oh, boys, you're just in time!" exclaimed Mary, as they were having some lemonade out on the shady piazza. "Aren't they, Grace?"

"In time for what?" Tom wanted to know.

"The dance!" answered Mary. "We're having one to-night. You can stay, can't you, Tom? And you, Ned?" She looked appealingly at Tom.

"Afraid not," he answered. "We have a number of engagements, and our schedule——"

"Oh, Tom Swift!"

Mary's disappointment was so genuine that Tom, who had been a little stiff with her at first, relented and said:

"We haven't dress suits with us."

"It's an informal dance," Grace made haste to say, and after being urged a bit more the two visitors consented to come to the affair that evening. They refused an invitation to dinner, as both Tom and Ned wanted to see how it would be to get their own meal on the electric stove in the House on Wheels.

The dance was a great success. Ned found Grace Winthrop a gracious hostess, and he did not seem to miss Helen much.

In fact, he was having such a good time that it was not until late in the evening that he noticed Tom sitting by himself out on the porch and looking in one of the long windows at the dancing floor. Among the couples foxtrotting about were Mary and a young fellow named Floyd Barton to whom Ned had been introduced.

"What's the matter, Tom?" asked Ned, who had come out for a breath of air. "Hurt your foot?"

"Hurt my foot! No! What makes you ask that?"

"You aren't dancing."

"I haven't had much chance!" was the somewhat grumpish answer, and Ned saw his chum's gaze following Mary and her partner. To do him justice, Barton was a fine dancer.

"Oh, ho!" mused Ned to himself, as he took in the situation. "Poor old Tom is jealous!"

CHAPTER XI

TRAILING THE MYSTERY

The next day, after a late, lazy sleep in the bunks of the House on Wheels, Tom Swift and Ned Newton, in fulfillment of a promise made the night before, called to take Mary and Grace for a ride in Tom's latest invention.

Tom and his chum called in a taxi to take the girls out to the House on Wheels, for the young inventor rightly guessed that Mrs. Winthrop would not appreciate the sensation that would be caused should the big auto stop in front of her house.

"Hello!" Mary called to Tom and Ned as she came downstairs with Grace to meet them. "Did you have a good time last night?"

"Fine!" answered Ned, who had thoroughly enjoyed himself.

"Are you all ready?" asked Tom, trying to smile but not making a great success of it. He seemed anxious to avoid answering the question. But Mary was not to be put off.

"I asked if you had a good time last night, Tom Swift," and Mary's voice had a new quality in it. "Aren't you going to answer me?"

"Oh, I beg your pardon. Of course! It was a lovely affair. And I must say you danced very well, Mary—you and Mr. Barton."

There was something in Tom's tone that made Mary look sharply at him, but she said nothing more then.

"Well, are you all ready for the thrill of your lives?" asked Ned, to cover the little moment of embarrassment that followed the interchange between Mary and Tom.

"Does the machine go very fast?" asked Grace.

"Not at all," Tom made haste to say. "It isn't a racer, by any means. It's just a comfortable way of traveling, that's all. There won't be any particular thrill."

"I'm eager to see it since its completion," said Mary, and Ned noticed that her manner toward Tom had changed a bit.

However, once they were started, the party was gay enough and Ned thought perhaps his chum's natural jealousy would wear off. He learned, by judicious questions put to Grace Winthrop, that Floyd Barton was a rich young man of the neighborhood who had been paying Mary much attention since her arrival in Chesterport.

"Mr. Barton thinks Mary is a lovely girl," said Grace to Ned.

"Well, he is certainly right," was the answer. "So does Tom Swift."

"Oh, well, that's different. Mr. Barton is just a very good friend. Of course I know that Tom and Mary are engaged. But a girl must be nice to those who are nice to her."

"Then you'd better start right in on me!" challenged Ned, and the two laughed.

This was more than Mary and Tom were doing just then. They seemed to be talking seriously on the rear seat of the taxi, Ned and Grace occupying the auxiliary folding seats ahead.

However, once the House on Wheels was reached, the air cleared a bit. Both girls went into raptures over the House, though Mary had seen it before, when it was almost completed. They reveled in the appointments and said the kitchen was "just darling," using so many other adjectives to praise the other sections that Tom and Ned felt quite set up over having had a hand in turning out the machine.

The House on Wheels was taken for a spin into the country with the girls as guests, and the party remained out all day, eating "on board," if that be the proper term. In the evening, when the return to Chesterport was made, Tom and Mary seemed to have patched up their little differences. Ned had an inkling as to what was at the bottom of the trouble when he overheard Tom say:

"Well, but you didn't need to dance every number with him, did you?"

"I didn't! I danced with you three times! If I had known you were coming I'd have saved more for you."

"I'm sorry I didn't send you word," murmured Tom.

"So am I," replied Mary, and then they talked of other things.

But that Tom still felt jealous pangs was evident the next day, for the boys remained over for a lawn party Grace had arranged in honor of Mary. There was no dancing this time, for the affair was held out of doors. But Floyd Barton was there, with other young men, and even Ned, in what few moments he spent away from Grace Winthrop, could not help noticing that Mary was very often in the company of the young Chesterport man.

However, she gave Tom some attention and called him to her side when she had to preside at a little game. She seemed very sweet and gracious, but there was a lowering look on Tom's face that did not altogether vanish, Ned noticed.

At the close of the lawn party Mary accompanied Mr. Barton to the gate to bid him farewell. When she came back Tom further showed the canker that was eating him.

"Can't you stay over one more day?" Grace Winthrop was asking Ned, who had announced that their plans called for starting off the next morning.

"I'd like to," Ned replied. "But of course——"

"We're going to pull out first thing to-morrow!" broke in Tom, with more bruskness than seemed necessary.

"Oh, in that case then you won't be here," said Mary, and her voice was tantalizingly cool. "I thought you were having a good time."

"We are!" exclaimed Ned.

"Too good," said Tom. "I guess you're having a good time too, aren't you, Mary?" His question was rather pointed.

"Who, me? Oh, yes! Grace has entertained me lavishly, and——"

"I guess she hasn't been doing all the entertaining," and Tom pretended to be much interested in a troublesome hangnail.

"Oh, of course her friends have been awfully sweet to me," said Mary, purposely misunderstanding. "Well, if you boys won't stay, you won't! Where are you going, Tom?"

"Oh, off on a little exploring trip," and he glanced toward Ned to make sure he would not mention Dismal Mountain, since they had agreed it would be better to keep their plans secret. "Got to try out the House under all sorts of conditions."

"I suppose so," agreed Grace. "Well, can't you stop off again on your way back?"

"We'll try," was all Tom would promise, though Ned was enthusiastic when he said:

"I sure would like to!"

"Do try, then," urged Mary. "I'm having such a lovely time on this visit that I want every one else to have fun, too. And you have been working hard, haven't you, Tom?"

"A bit, yes."

"Well, now you'd better take a rest on this trip. Don't think about business and don't run into any danger. Will you?"

She crossed the room and stood near him, while Ned and Grace went outside.

"Will you, Tom?"

"Will I what?"

"Be careful to keep out of danger."

"Oh, I—Who'd care if I did get into danger?" His voice was hard.

"Who'd care? Well, I like that, Tom Swift! Wouldn't your father care, and my father and mother, and Ned and Koku and Eradicate and—lots of folks?"

"Anybody else?" asked Tom, with a half smile.

"Of course, you silly boy! I would! Is that what you wanted me to say?"

It would seem from Tom's pleased answer that it was.

So the little rift in the heavens appeared to have passed.

"All hands on deck!"

Ned Newton heard this hail from the depths of drowsy slumber as he turned over in his cot the next morning.

"What's the row?" he asked sleepily.

"All hands on deck!" repeated Tom. "Come on, if we're going to get started."

"What's the matter?" yawned Ned, parting the curtains and peering out. "Are you the little early bird after the earlier worm this morning?"

"Somewhat. But we've been loafing long enough. Let's get on the move if we're going to."

They washed, dressed and had breakfast, and then, having paid their garage bill and taken on a supply of gas and oil, they set out down the main road of Chesterport, having said good-bye to the girls the night before.

They were on the road to Branchville, beyond which was the beginning of the hills that rose to their limit in the peak known locally as Dismal Mountain.

"I hope we run across a batch of moonshiners, some train bandits, and half a dozen road agents!" declared Tom, as he grasped the steering wheel.

"Ah, ha!" mused Ned. "The little green bug is still biting him!"

CHAPTER XII

THE WARNING

Though not a very great distance separated the vicinity of the mountain of mystery from Chesterport, Tom and Ned decided they would occupy two days on the trip. By hard driving they might have covered the trail in a day and a night, but there was no special need of haste. Then, too, Tom Swift did not want to push the motor of his House on Wheels to the safe limit even, for he wanted to get it well broken in and limbered up before trying any stunts with it.

"This is the life!" sang Ned, as they rolled along the level highway. "Eh, Tom?"

"It sure is! Makes a fellow glad to be alive!"

"This is one of the best things you ever turned out of your shop," went on Ned, indicating by a comprehensive motion of his hand the vehicle in which they were riding.

As they motored along, their big car attracted much attention, not only from passing machines but on the part of persons in towns and villages through which they passed.

Noon came almost before the two travelers realized it, and, being then on a country road with no settlement in sight, they pulled off the highway, stopped under some trees and near a little stream, and prepared to have lunch.

The pantry had been well stocked, and Ned and Tom, being used to camping, had no difficulty in preparing a light meal, part of which was set to cooking on the electric stove. In a little while there was a most appetizing odor in the air and either this, or perhaps a sight of the big machine itself, caused a passing man to stop.

He was obviously a hobo, a rather dirty, unshaven and ragged specimen of tramp. Yet his face had an impudent, roguish smile and his manner was ingratiating as he shuffled up in the dust until he was opposite the House, outside of which Tom and Ned sat on stools in the shade. They were waiting for the potatoes to boil.

"How's business, Boss—maybe I ought to say Bosses?" asked the tramp in a hoarse voice. He leered and smiled.

"What do you mean—business?" asked Tom.

"The lunch-wagon business." The tramp seemed surprised at the question. Very evidently he took the House on Wheels for one of those roadside refreshment places.

"We haven't opened up yet," said Ned, carrying on the delusion.

"Smells like you had," commented the tramp, hungrily sniffing. "If that ain't hash and onions cooking may I never eat another meal!"

He was vehement about it. From his looks he did not appear to have eaten a meal recently.

"Is it hash and onions?" he asked.

"Guessed it first shot," commented Tom.

"But I can't see how you can expect to do much business here," went on the hobo. "This road ain't much traveled."

"We're our own best customers," chuckled Ned, and at the man's look of surprise he added enough information to show the nature of the House on Wheels.

"Well, then it's a washout as far as it goes with me," sighed the tramp. "I was goin' to ask if I couldn't do you folks some work for the price of a hand-out, but if yours is a private concern——"

"Oh, I guess we can manage to get you something," said Tom good-naturedly. A little later when he and Ned were eating in the combined kitchen and dining room, they handed the tramp a generous plateful, for which he expressed gratitude.

"Travel much in these parts?" asked Ned, as the hobo was about to shuffle along.

"More or less, Boss."

"Ever been to Dismal Mountain?"

"No, I can't say I have. And, what's more, I don't intend to! So if you folks is aimin' to have me go there to work for what you jest give me, count it out! I'm sorry, but——"

"Nothing like that," interrupted Tom. "I just wanted to know if we were on the right road to get there."

"Yes, you're on the right road," the tramp admitted, with a shake of his head. "But what for you fellers want to go to Dismal Mountain, gets me!"

"What's the matter with the place anyhow?" asked Ned.

"Oh, I don't know's there's much the matter with the place," and the man emphasized the word. "It's the birds that hang out around there."

"Ghosts?" asked Tom, with a smile.

"Ghosts!" exploded the tramp. "I'd rather meet ghosts than some of the guys what hangs out there. Tough babies—an' I don't mean maybe!"

"A rough crowd, eh?" asked Ned.

"Tougher'n what I like," admitted the tramp. "I don't claim to be no saint, but I'm pretty decent compared to some of the hard-boiled eggs that hide around Dismal Mountain."

"Then you wouldn't advise us to go there?" Tom asked.

"It's none of my business, Boss," was the answer. "You know what your own game is better'n what I do. But I wouldn't advise you to take any valuables with you when you go to Dismal Mountain."

"Thanks," murmured Ned. "We aren't wearing any diamonds."

"Some of the guys there'll steal the laces out of your shoes," went on the tramp.

"Just what kind of criminals hang out there?" inquired Tom.

"A kind I never travel with," was the quick rejoinder. "I'm a bum—I don't deny it—and I'm not lookin' for work. But I'd sooner work than pull off some o' the things that those babies do. Keep your eyes open if you go there."

"We will," promised Ned.

The tramp shuffled away, and when the two chums were again alone Ned looked at Tom and asked:

"Think we'd better follow through?"

"Sure! Why not?"

"Well, there are only two of us and if there are some tough gangs up there, or even a small band, we might run into trouble."

"I'm not going to run away from trouble," declared the young inventor. "Maybe it would have been wise to have had at least Koku along. But I'm not going back after him. We'll go on to Dismal Mountain and see what's there. Are you with me?"

"I sure am, Tom!"

They rested after the noon meal, washed the dishes in the near-by brook, to save the supply of water in the auto tanks, and then journeyed on in leisurely fashion. They expected to reach the mountain of mystery the following night.

It was dusk when they stopped the House on the outskirts of a little village and prepared the evening meal. Then, having disposed of that, they decided to go into town for the sake of the exercise and to see if they could buy a paper.

They hired a couple of boys from a house near where they had parked their machine to stand guard over it while they were in town, and one can well imagine with what pride the youngsters accepted the commission.

"We won't let nobody come near it until you come back!" promised the older boy.

"I got my baseball bat if they do!" chimed in his brother.

Stopping for an ice-cream soda in the only store of the town that dispensed this refreshment and having bought a paper, Ned and Tom lingered a while to listen to the somewhat excited and loud talk that was going on amid a crowd of men in the place, evidently the headquarters of the village gossips.

"And they got clean away!" one man declared. "Took every darn cent, too!"

"Did they hurt the guards?" asked another.

"Shot at 'em, but missed. It was all over quick."

"Didn't they see which way the robbers went?" some one wanted to know.

"Off toward Dismal Mountain," another answered.

"Might have known it!" commented several. "That place ought to be wiped out."

"This sounds interesting," remarked Tom to Ned in a low voice. "I'm going to butt in."

Accordingly, he addressed the principal speaker and asked what all the talk was about.

"Highway robbery, that's what!" came the vehement answer. "A couple of men guarding the pay roll of the shoe factory here were held up this afternoon and robbed of about four thousand dollars."

"I just now heard you mention Dismal Mountain," went on Tom. "Is that a hang-out for highwaymen?"

"That and worse," was the reply. "Dismal Mountain is a good place for honest folks to stay away from."

"Well, my friend and I claim to be honest," said Tom, indicating Ned. "But we are on our way to Dismal Mountain and——"

"Don't go!" exclaimed an old man in the store. "I know more about that place than most folks, and my advice to you is not to go there. Unless you're officers aiming to arrest the scoundrels that hide there," he added hopefully.

"No, we aren't officers," stated Ned.

"We were just going there to find out what gives the place its bad name," added Tom. "We would rather like to solve the mystery."

"Well, be warned by me and keep away," went on the old man. "I used to live not far from the place," he added, "and I don't want to see any more such goings on as I witnessed."

"What were they?" asked Ned.

"I couldn't tell you," was the answer, with a dubious shake of the head. "I've seen men go up that mountain and never come down. There were queer noises and queer lights. Nobody that had a valuable horse near Dismal Mountain ever left him in a field over night. If they did he wasn't there in the morning."

"This sounds interesting," said Tom.

"Interesting, young man!" exclaimed the speaker. "It's dangerous! That's what it is! Dangerous!"

There was so much interest in the recent hold-up that the departure of Tom and Ned was little noticed. They went back to the House on Wheels where they found the two boys had been faithful to their trust, and, having paid and dismissed them, the two travelers turned in for the night.

"Well, what about it?" asked Tom of his chum when they arose the next morning and found it raining and blowing. "Shall we lay over?"

"Not on my account," declared Ned. "This storm doesn't seem to be going to amount to much."

"Oh, it wasn't of the storm I was speaking."

"What then?"

"The warnings we had last night against proceeding to Dismal Mountain. If you——"

"Nothing doing!" interrupted Ned. "I'll go with you to the end of the trail!"

"That settles it. We keep on!" cried Tom.

After a hearty breakfast, they took their places on the front seat and started off. For a time they followed a good concrete road, but it soon branched off, and their way lay along a highway that had once been good but which was so no longer.

As the day advanced, taking the travelers farther on their way, the storm increased. By afternoon and after lunch, which they ate while moving along, they were in the midst of a terrific downpour with a wind which reached at times the velocity of a gale.

"She seems to weather it all right, though," remarked Ned, indicating their traveling House.

"Standing up fine!" agreed Tom, much pleased with the staunchness of his latest invention. "We'll be almost there by night in spite of the storm and the bad road."

Hardly had he spoken than there was a fiercer burst of wind, which dashed the rain like hail against the protecting glass in front. Just then Ned pointed ahead as a loud crash sounded and cried:

"Look out, Tom! Stop! Danger!"

CHAPTER XIII

THE DESERTED HOUSE

Tom Swift, ever on the alert when driving any of his machines, from the humble motorcycle to the more complicated apparatuses of the air or undersea, lived up to his name in bringing the House on Wheels to a quick but skillful stop as Ned Newton uttered the exclamation of warning.

It was just in time, for the front wheels were almost against a big rotten tree that the gale had blown down across the highway leading toward Dismal Mountain. Tom's attention had been taken momentarily by some of his dashboard gages, so he had not seen the sway of the tree before it fell. But Ned's quick eyes had sensed the danger and had given ample warning.

"Close call, that!" commented Tom, as he leaned back after pulling hard on the emergency brake.

"Don't want 'em any closer," agreed Ned, as he looked through the driving rain at the fallen tree. "If we had gone full tilt into that it might have scratched some of the paint off the House."

"Worse than that," assented Tom. "It's lucky you yelled at me when you did."

"Well, what's the next move?" asked Ned.

"Put on our umbrella clothes and see if we can cut that tree away," suggested Tom. "I don't believe we can very well turn around and I don't want to navigate backward."

"No, it won't be easy," agreed Ned. "Well, let's hop to it. I don't believe there's much traffic on this road, but what there is we don't want to hold up."

"Speaking of hold-ups," said Tom grimly, "maybe we could get some of the hold-up residents of Dismal Mountain to come to our help."

"They don't show up in any great numbers," remarked Ned, as he made his way back into the interior of the car to get his raincoat and rubber boots, which Tom had designated as "umbrella clothes."

They were in a lonely part of the country, in the midst of an extensive piece of woods, it appeared, on a seldom-traveled road, about at the beginning of the big peak known as Dismal Mountain. They had seen no habitation for some time, nor had they met any other travelers, which last was not remarkable, considering the state of the weather.

Tom carried a set of emergency tools in his House on Wheels and among these were a couple of axes. In a short time he and Ned, fortified against the elements, which appeared to be doing their worst just now, were attacking the fallen tree with their sharp tools.

Fortunately the tree was pretty well rotted, and though it was large in diameter, the trunk was punk-like in its character and the axes easily bit into it. Chopping out small sections, the two travelers dragged them to one side of the road until at last, after an hour's work, they had cleared a passage for their auto and for any other vehicles that might follow.

"Though if there are any other people foolish enough to drive up here in a storm like this, they ought to be made to chop their own trees," commented Tom, as he got back on the seat.

"It wasn't so bad when we started up here," Ned reminded his chum.

"Oh, I'm not kicking!" Tom made haste to say. "I'm just talking to hear my own voice. Whew, it's going to be a nasty night!"

"It already is one!" declared Ned, for darkness was rapidly falling and they had no idea of what lay beyond them.

"Want to stay here?" asked Tom, always willing to give in on the matter of stopping for the night.

"No, the road's too narrow in case anything else comes along, though I don't believe it will. Let's push on, and maybe we'll get to some decent place where we can pull up."

The motor, which had been stopped while the fallen tree was being chopped away, was again put in motion and once more the House on Wheels began the gradual but steady ascent that led up Dismal Mountain, by this time in the young men's minds, a veritable mountain of mystery.

For about a mile the road was fairly good and firm. After that either the highway had not been kept in repair or the heavy rain was washing it away rapidly, for the House on Wheels careened from one rut into another until it was swaying like a circus camel in the parade.

"Not so good!" commented Ned, as he banged up against the side of the seat after a particularly heavy lurch.

"It is getting a bit thick and heavy," agreed Tom, trying to peer ahead into the gloom which was pierced by two powerful headlights of the auto. But powerful as they were, the gleams of the lamps appeared to be swallowed up in the dark trees on either side of the road and by the surface of the highway itself.

A comparatively light surface is needed to reflect the gleams of any auto lamps properly, as you have noticed when driving first on concrete and then on asphalt. You can see twice as well on the former as on the latter. And in driving through woods on a dirt road, nearly all the illumination is absorbed so that you get the benefit of very little of it.

It was so in the case of Tom and Ned, and though for a little way in front of the wheels they could see where they were going, beyond ten feet all was gloom and darkness.

It was still raining hard and the wind was blowing. Tom had set in motion the wiper of the glass in front of him so the drops did not accumulate and distort his vision. But he needed all the artificial aids he could command on a night like this and under the circumstances.

For the first time it began to be apparent to him and Ned that perhaps they had done rather a foolish thing to come to Dismal Mountain in this large van-like car. It was not exactly the kind of a machine for prospect work, not being small or flexible enough for quick maneuvering.

On the other hand, it was a portable base of supplies and the occupants of it could stop wherever they found themselves and be comfortable, which was more than could be said for a small car. So they kept plugging along.

The motor was pulling powerfully. Tom was glad of this for he knew he would need all the power he could command when they got into the upper slopes where the grades would be stiffer.

On and on, up and up, the House on Wheels was driven until Ned began to wonder where his chum would stop. He did not like to suggest a halt, for there seemed to be no good place to pull up. The road was still narrow. The House took up considerable room and there were places where trees grew so close to each side of the road that it seemed impossible to squeeze the big vehicle through.

But, somehow, Tom managed it, though once both sides of the car lightly brushed great trunks that would have taken hours on the part of a skilled lumberman to fell. However, luck was with the two venturesome travelers.

After a stiff ascent, in which Tom had to drop back to second gear for one of the few times since the trip started, they came to a somewhat level stretch, as was evidenced by the easier pull on the motor. Ned, always enthusiastic, exclaimed:

"Hurray! We're up!"

"Not half!" exclaimed Tom. "Don't fool yourself."

"Oh, gee!" sighed Ned.

"But we may reach a place where it will be wise to stop for the rest of the night," went on Tom, trying in vain to pierce the dark forest ahead and on either side. "The road is wider here and we can pull off it with a chance for something else to pass."

"Nobody but us two are crazy enough to be out here on a night like this," commented the financial manager.

"Guess that's about right," assented Tom. "Still, it's best not to take any chances. I'll go along a bit farther and then we'll pull up and call it a day's work."

The going was better until there was a sudden lurch to one side.

"In a hole!" cried Tom, and he quickly went into second and then into first gear in an effort to pull out.

However, it was not to be. The House on Wheels slowly settled down and not all the power of the motor could stir it. Finally Tom realized that he was only sinking the rear wheels deeper into the mud by churning them around.

"We've got to dig out!" he told Ned.

There was no help for it. Once more they donned boots and raincoats and, hanging a portable electric light over the bogged side, they saw where the right front wheel had sunk into a deep hole. It took the two the best part of an hour to dig a slope in front and fill it with small stones to make a firm surface so the machine could climb out. This the auto did after several false starts, and once more they were on their way.

The road shortly broadened and the trees were cut back from the highway into a small clearing. This opening enabled the two to see better, and in the gleam of the powerful lamps Ned noticed, just ahead, on the right, a big house, from which, however, no lights showed. As the car approached, it could be seen that the place was an old, deserted mansion that had once been the stately home of some wealthy person, for there were extensive grounds.

"Look!" exclaimed Ned.

"I see it," answered Tom. "Nobody home from the looks of it, but we can pull up there and stop for the night. What say?"

"Suits me!"

Accordingly, Tom guided the big car into what seemed to have once been a drive and he and Ned both experienced a feeling of relief. But if they had known to what adventures the deserted house was a preface they might well have hesitated.

"What do you make it out to be?" joked Ned, as the House on Wheels was brought to a stop at one side of the old mansion. "Is it a hang-out of bootleggers or road agents?"

"Take your choice," Tom answered, in equally light vein. "Luckily, we don't have to depend on them for supper. We roll our own."

"And I'm going to roll mine right soon!" added Ned. "Boy, I'm hungry and I don't mean perhaps!"

"Be with you in just a minute," Tom said, shutting off the motor and putting on the emergency brake. He was glad to note that the ground seemed firm beneath the wheels.

As he and Ned were alighting, thinking to have a look around the outside of the deserted house before getting something to eat, Ned uttered a low exclamation which Tom heard above the noise of the rain that was coming down more gently now.

"What is it?" whispered the young inventor.

"Did you hear a noise in there?" asked Ned in cautious tones.

CHAPTER XIV

A STRANGE DISAPPEARANCE

Like game dogs, Tom Swift and Ned Newton froze in their tracks and stood in the rain near the deserted house, waiting for they knew not what. It was a lonesome, dreary place, dense woods being all around them, and ahead, though some miles distant, the sinister summit of Dismal Mountain with its suggestion of mystery. Only the fact that the warm, comfortable and cozily lighted House on Wheels was near by heartened the young men. They were rather tired from their trip, with fighting the elements, and digging the heavy auto out of bog holes.

For several seconds they stood there, Tom seeking to tune his ears to what Ned had said he had heard—a noise in the deserted house. But as no sounds came to him, the young inventor began to believe that his chum was mistaken.

"Guess it was only the storm," he said, still pitching his voice low.

"Maybe," agreed Ned. "Yet at first I was sure the sound came from the house."

"It might at that, and still nobody need be in it," Tom suggested. "In an old, deserted place like this there are always doors to swing, windows to rattle, and shutters to slam."

"I suppose so," agreed Ned. "Well, shall we go in and have a look around?"

"I don't know that it will do us any good or that we can learn anything by going in this old mansion," was Tom's comment. "Yet as long as we're here we might as well go in. If we're going to stay here all night——"

"Stay here all night!" interrupted Ned, in surprise.

"I don't mean in there," and Tom pointed to the dark and silent mansion, "but in our own House. If we're going to camp out here it's just as well to know the character of our neighbor."

"Sure," assented Ned. "Well, come on in and let's get it over with. Then we'll eat. I'm hungry!"

"So am I. Got your flashlight?" and Tom produced one of these handy little portable torches.

"Never go without it when I'm traveling with you," chuckled Ned. "You always end up in some queer situation or other." This was true, as Tom knew from past experience, so he did not comment on it.

A look behind the young men showed them that the auto was where they had left it, the power shut off, the headlights glowing, and also some lights turned on showing the cozy interior.

"I'll sure be glad to get back in it," murmured Tom.

"So will I," echoed his chum.

The deserted mansion the two had discovered half way up Dismal Mountain was like many other tenantless houses in lonesome country districts, only this was rather larger and better.

With the departing of the owner the place had been left to the mercy of the elements and the whims of those who were more or less vandals who took delight in needlessly breaking doors, windows and shutters. Consequently there was no difficulty in getting into the place. The front door gaped wide and, after flashing their lights into and around a spacious entrance hall, Tom and Ned stepped inside.

"I guess this a hang-out for tramps now and then," remarked Tom, as the two advanced down the hallway.

"Shouldn't wonder," agreed Ned. "They've got plenty of rooms at their disposal, anyhow," he added as his light showed many apartments as they continued on their way. Aside from broken boxes and barrels, with here and there a litter of straw or leaves, there was no furniture in the rooms.

Dismal and eerie to the extreme was the deserted house. Paper peeling from the damp walls hung in strips like festoons of Spanish moss. In places the plaster had fallen, leaving gaping holes that were like sightless eyes staring at the intruders.

They went through the first floor, flashing their lights into nooks and corners but discovering nothing. There were some signs of the place having recently harbored such tenants as tramps. In one room a fire appeared to have been burning not long since on an open hearth and some empty tin cans scattered about seemed to give evidence that hoboes had cooked a meal here some time.

"Shall we go upstairs?" asked Ned, when their inspection of the first floor was finished.

"Might as well," decided Tom. "Then we'll know there isn't anything here to annoy us after we get back to the House."

The front stairway was a large and imposing one, sweeping up to a balcony where there was space enough for a fairly large room. From here one could look down into the lower front hall. As Ned followed Tom to this balcony he saw the young inventor turn and gaze intently at what appeared to be a panel in the back wall of the landing. Tom's start was so obvious that Ned asked:

"What's the matter?"

"I thought—I wasn't sure—but I thought I saw one of those oak panels slide as I came up the stairs," answered Tom.

"You thought you saw a panel slide!" exclaimed Ned. "Say, this is like a moving picture mystery."

"Maybe it was only the shadow of your flashlight," went on Tom.

He advanced to the rear wall and tapped on it. The lower part was made up of what had once been beautifully carved, quartered oak panels. But as far as the two adventurers could discover, all of them were in place and none seemed movable.

"It must have been a shadow," said Ned.

"I guess so," agreed his chum.

The rooms upstairs, like those below, were bare and deserted, devoid of furniture, but with the same festoons of drooping wall paper. In some of the chambers there were piles of old bags and leaves in some corners showing plainly that tramps had been sleeping there.

"It was probably these hoboes, who made this place a hang-out, that gave rise to the stories about ghosts and bootleggers on Dismal Mountain," commented Ned, and Tom agreed that this might be so.

The number and arrangement of the upper rooms confirmed the ideas of the young men that this mansion had once been the home of persons who lived in luxury and moved in high society. There were a number of bedchambers, each with a private bath. But the latter rooms were in worse ruin than any other part of the house, for the fixtures had been torn out, probably by those who wanted the lead and brass piping to sell to junkmen. Some of the porcelain bath tubs had been wantonly cracked and broken.

It was when Tom, preceding Ned, walked out of one of the bedrooms into the main hall that the young inventor gave another perceptible start and uttered a low exclamation.

"What's the matter now?" asked Ned, with half a laugh. "See another moving panel?"

"No, but, somehow, Ned, I feel as if we were being spied upon! Don't you?"

"Spied upon! What do you mean?"

"Well, when I came out of that room," and Tom pointed back to it, "I had a distinct feeling that eyes were following me. Didn't you ever have such a feeling?"

"Yes; but not now. I think you're just over-worked and nervous. You did most of the driving, and with that and the storm and getting bogged, it's no wonder you're seeing things."

"Well, maybe that's it," agreed Tom, but his heart did not appear to be in what he was saying. "I am tired. I'll be glad when we have had something to eat and can turn in for a good night's sleep."

"Boy, you let loose an earful that time!" chuckled Ned.

He saw that Tom was flashing his light back into the room they had just quitted and he followed his chum's example. But nothing was seen save the same dismal ruin that confronted them on every side.

Going downstairs behind Tom, when Ned reached the landing where the young inventor had said he thought he saw a panel move, he was suddenly conscious of the same feeling that Tom had mentioned—that of unseen eyes staring at him.

"But it's all bunk!" said Ned to himself. "It's just nerves. I'm not going to speak of it. Tom has enough to worry about now."

However, he cast a quick look over his shoulder and even flashed his torch on the oak paneling, a move which caused Tom to ask:

"What's the matter?"

"Oh, nothing," answered Ned, prevaricating just a little. But he felt he had a right to, since, as he reasoned, Tom Swift had been under a strain for several days getting the House on Wheels in shape for this test trip. There was no sense in adding to his worries, especially as it was such an intangible something that Ned had felt.

Yet he could not get over the sensation that he, too, as Tom had been, was being watched by sinister eyes somewhere within that deserted mansion. Eyes that were evil, that looked evil, and that hoped evil.

"Might have been bats," thought Ned. "Always have been bats in an old house. That's what it was—bats. I'll be getting them in my belfry if I don't get something to eat soon," he thought, with a noiseless chuckle.

Their footsteps echoed and re-echoed through the dark and eerie mansion, but nothing happened, save now and then a distant and ghostly hammering or clattering sound that plainly came from rattling windows, banging doors, and swinging shutters.

"Well," remarked Tom, with a sigh of relief, "we've proved that there's nobody around here to annoy us. Now for a good night's rest."

He stepped out of the front door, closely followed by Ned. The rain was coming down hard and the wind had once more risen to the proportions of half a gale. For a moment Tom and Ned stood on the big front porch. Then Ned remarked:

"We must have got turned around and come out the back way."

"Why so?" asked Tom.

"Because we left the House right where we could see it from the front steps, and it isn't in sight now. We must have got turned around and come out at the back instead of the front."

"This is the front all right," said Tom in a queer voice. "It's where we went in, but the House on Wheels is gone!"

"Gone!" cried Ned. "It can't be!"

"Look for yourself," asserted his chum. "You know where it was. In plain sight with lights going, as we saw just before we went inside. Now it's gone!"

There was no doubt of it. The House on Wheels had vanished!

CHAPTER XV

ON THE TRAIL

Their hearts oppressed with a sense of foreboding which they could not fathom, Tom Swift and Ned Newton hurried down the broad front steps of the old mansion, out into the wind and rain, and hurried toward the clearing where they had left the warm, lighted, and cozy House on Wheels. For a moment they hoped that perhaps the lighting system had failed and that they could not see the big auto because it was shrouded in darkness.

But as they lighted their way by means of their pocket flashlights and reached the spot, near two large, distinctive trees where they had halted the big auto, there was no question about it. Their car had been taken away! It could not have rolled downhill, for it had been stopped on a level spot, and Tom had taken pains to set the brakes.

"Some one came and got it!" exclaimed Tom, when it was certain that the machine had vanished.

"Who was it?" came from Ned.

"Hard to say. But I guess we weren't wrong, Ned, in suspecting that we were being spied upon by unseen eyes in that old house."

"I'm forced to believe that."

"While some watched us inside, to make sure we wouldn't come out and interrupt the theft, others stole the House," declared Tom.

"Looks so," commented Ned. "Gee, but this is tough luck! What are we going to do now?"

"We've got to hit the trail, of course, and see if we can't get it back," was Tom Swift's prompt answer.

Though they were hungry and tired, the two young men did not hesitate. In fact, they could not. Much depended on prompt action, for the House on Wheels could not long have been taken away. Luckily Tom and Ned had on rubber boots and rain coats, and their little electric flashlights enabled them to see the trail. Without them they would have been at a great disadvantage.

But with these gleams, flashing occasionally so as not to wear out the batteries too fast, the two first made sure where the big auto had stood and then began to trail it.

"They first swung around in a half circle and then went off this way," said Tom, pointing to the peculiar marks in the mud left by the tires of the House on Wheels. They were tires especially made for heavy duty and marked with ridges designed to prevent skidding, so the trail was easily followed, particularly as the wet ground took a deep impression.

"It ought to be a cinch to trace her," remarked Ned, as the two young men hurried on, their weariness and hunger forgotten in the excitement of the chase.

"Yes, for a way, anyhow," agreed Tom. "But we may not always have soft dirt roads like this to retain the marks. Though I don't believe there are any concrete stretches in this neighborhood," and he motioned toward Dismal Mountain, up the trail of which the House on Wheels clearly had been driven.

"The ground will be soft for a couple of days after this rain, and we can keep on following," suggested Ned.

"They may get too far ahead of us to leave us a Chinaman's chance," said Tom, with a sigh. "Remember, we're walking, and if the House only crawled it could do ten miles to our one. Besides, they may run her down off this mountain and onto a hard road, and then the tire marks won't be one, two, six!"

On they splashed in the rain and darkness. The road taken by the House on Wheels, as evidenced by the tire marks, led up the mountain and the deserted house, with its gloom, its secrets and its spying eyes, was soon left in the rear of the young men who pressed on, now and then flashing their torches to make sure they were still on the right trail.

"Hark!" exclaimed Tom suddenly, when they had been thus going for several minutes.

"What is it?" asked Ned, coming to a halt.

"Let's listen and try to hear the motor," suggested the young inventor. "I have an idea those fellows, whoever they are, won't push the machine too hard. They may run her only a little way and then lay over for the night."

Accordingly, the two stood there with the rain dripping on them, listening. But the only sounds that came to their ears were those of the storm—the wind and rain, the clattering of tree branches, and the swish of wet leaves.

"No use trying to hear anything," stated Ned, after a pause.

"No, I guess there isn't. We'll keep on."

Again the two plunged forward along the muddy road. They blessed their lucky stars that had given them the forethought to put on rubber boots and coats before venturing around and into the old house.

Tom, also, was glad he had equipped his car with those heavy and peculiarly marked tires, for they were very easy to follow, even under the adverse circumstances of rain and darkness.

In spite of the fact that the noise of the storm would seem to preclude their hearing any sound made by the car ahead of them, Tom and Ned stopped several more times and listened for any faint echo of a motor ahead of them. But they heard nothing.

"Maybe I'm wrong, Ned," said Tom, after a while, pausing at a sandy stretch in the road, where the wheel marks were very plain, "but doesn't it strike you that these tire impressions are fresher than they have been for some time back?"

"Fresher? Anybody would think we were trailing an elephant or some wild animal."

"Well, we are, in a way. But you see the rain has the effect of washing out the marks after a certain time. Now these marks here are sharp and fresh."

"Yes, I admit it," said Ned. "But what of it?"

"Well," and Tom's voice had a note of triumph in it, "to me this means that my House has passed here within a short time—minutes I should say—otherwise the hard rain would have washed down some of the tire ridges."

"Tom, you're right!" cried Ned. "She ought to be close now."

"That's what I think. Come on!"

Once more the two plunged forward. The tire marks continued to become ever fresher until the seekers reached a place where a small road branched off the main highway.

"They went up here!" cried Tom, indicating the trail that led up the branch road.

"Sure enough!" assented Ned, flashing his light on the marks.

Up the road the two fairly ran until, so quickly that it was startling, they came upon the big auto at a standstill in the middle of the highway. The House on Wheels was in darkness, but there it was.

"We've found her!" exulted Tom, but he had the caution to speak in low tones.

"Sure enough," agreed Ned and his voice was hardly more than a whisper. "But what's the game, I wonder?"

That remained to be seen.

CHAPTER XVI

TWO STRANGE MEN

There were two theories to account for the taking away of the House on Wheels. These at once occurred to Tom Swift and Ned Newton as they stood in the rain and darkness near the auto, hardly able to believe their good luck which had brought them to the machine within half an hour of the theft.

One explanation was that the legal authorities of the place—state police or local traffic officers—had come upon the parked House while Tom and Ned were in the deserted mansion. Seeing no one in the big auto, but observing that the lights were on, the authorities might have concluded that there had been an accident or that the car was abandoned and so had decided to drive it some place where it could be held pending an investigation.

Another and more plausible theory, was that ordinary thieves, happening upon the car, had decided to appropriate it for themselves. For it was a car that any one might desire to possess.

As Tom and Ned stood behind the discovered auto, pondering over these matters, it was more and more evident to them that the car had been stolen and abandoned. But had it been abandoned for good, or were the thieves just temporarily away from it?

That last consideration must give them serious pause.

For perhaps a full minute the two stood there, the rain dripping off their hats and coats, while they considered. Meanwhile they were using their ears and eyes to the best possible advantage; their ears particularly. For soon after discovering the auto they had switched off their torches and now stood in gloom. There was no light either in the House on Wheels or at the headlamps, as Tom and Ned ascertained by a quick glance forward.

No sound came from the stranded auto. There was no noise of movement on the part of those who had taken the vehicle away and who might now be in ambush near it.

"Well," questioned Ned in a whisper, "what'll we do?"

"Let's circle the House and see if we can spot anybody," was Tom's answer, just breathed into his chum's ear.

The storm was making so much noise that ordinary sounds on the part of the two would be covered, they thought. Still, they were not going to take any chances and they used the utmost caution in proceeding.

"Come on!" whispered Tom.

"I'm with you!" answered Ned.

Side by side they started around the left of the House, intending to make their way to the front and gain control of the machine. They were not half way to their objective when there was a noise up ahead—a crackling and trampling of the bushes and voices coming out of the darkness.

Tom reached out and caught the coat of Ned who was moving away from him.

"Hold on!" whispered the young inventor, pulling his chum toward him. "Let's see who these birds are before we bump into them."

It was good advice, as Ned admitted by following Tom into a little recess of the underbrush about midway of the auto. Pushing themselves back into the screen of shrubs, the two waited. They were not long left in doubt as to the character or intentions of the men whose voices came to them.

There were two men, as evidenced by the different tones. One said:

"Well, we got her all right!"

"You said it."

From the tones of the voices Tom and Ned judged one man to be big and the other small, and, without sight of them, the hidden ones so distinguished the two speakers mentally.

"It was easy," went on Big, to give him a temporary designation.

"Maybe it was too easy," suggested Small.

"What do you mean?"

"Well, I mean those two lads won't give up their machine so easily. They may come to get it back."

"Let 'em!" chuckled Big. "We'll be ready for 'em."

"I'd feel better satisfied if we had kept on," said Small. "I don't see the sense in stopping here."

"That's what the boss told us to do if we were lucky enough to get the machine," said the other. "And we did."

"Well, if the boss told us to stay here, we've got to, I reckon," admitted Small. "But there's no use staying out in the wet. That's a pretty nifty little outfit this fellow Quick turned out, and I don't see why we can't take it easy in it and have some grub."

"There's no harm in that," agreed Big. "But the chap who got up this dingus is named Swift, not Quick."

"It's all the same," chuckled the other. "And I can't get in out of the wet any too quick and have something to eat. What say?"

"I'll be with you in a little while."

"Why, where you going?" asked Small, and there seemed to be a note of suspicion in his voice.

There was a moment before the reply came and in that moment Tom and Ned made several rapid conclusions. There was no doubt now but what their car had been stolen. These were no state police or local traffic officers who had run the car away for its own safety. They were thieves and had evidently acted from a well-planned motive.

"They know you, Tom, or one of them does," whispered Ned.

"Seems so! By golly! I'd give a good deal to know just who is back of all this!" Tom's voice though low was tense and angry.

"Maybe we can find out," whispered Ned.

"Hush!" cautioned Tom, and at that moment Small spoke again, saying:

"Where you going? What's the game? Why don't you come in with me and help rustle some grub on that electric stove I saw."

"I can't come just now," was the answer.

"Getting cold feet?" demanded the other man sullenly. "Say, if you're trying to double cross me——"

"Don't be a fool!" snapped Big viciously. "It's all part of the game we're playing for the boss."

"Well, maybe it is. But I don't like you sneaking off this way leaving me all alone in case anything happens."

"I've got to go. I've got to go tell the boss."

"You have?"

"Yes."

"Where is he?"

"A little way ahead, waiting. His orders were, if we got the car, to stop here and for me to come on alone and let him know."

"All right, then I reckon you got to do it. But where is the boss?"

"Near the entrance to the castle."

"Oh! Well, all right. Go ahead, but don't leave me alone any longer than you can help."

"Ho! Who's getting cold feet now?" jeered Big.

"Well, you never know what can happen," grumbled Small. "It's a nasty night. Those fellows may get help and trace us here. I'm not afraid of the two, but if they get a gang of police——"

"Forget it! They'll never find us. Besides, where could they get any police on a night like this to come to Dismal Mountain?"

"Well, maybe they couldn't. Anyhow, don't be any longer than you can help."

"I won't," promised Big. "Soon as I let the boss know we've pulled off the trick I'll come back. You can wait inside and be cooking your own grub. I'll eat when I come in."

"All right. Hop to it."

The sound of one man striding away in the darkness through the brush could be heard. The two had evidently gone on ahead after temporarily abandoning the House and had come back to hold their talk in front of the halted machine. Now one was going away and the other remaining.

"What are we going to do now?" asked Ned.

"Let me think a minute," suggested his chum. "Did you hear that remark about the castle?"

"Yes."

"Have you any idea what it means?"

"Yes, I heard something about it when I was looking up the history of Dismal Mountain before I had any idea we'd ever come here. The castle is an old stone building, built to represent its name. It was started by a rich man who had an idea he'd like to live somewhat after the English style. But either he died or his money gave out, for the castle was never quite finished. It's an old, rambling pile of stone near the top of this mountain of mystery."

"Anybody live in it?"

"That I don't know. Probably it's deserted like the old house, but it may be the hang-out of some of the gangs infesting the mountain, and it's very evident that our car has fallen into the hands of one of these same gangs."

"Yes," agreed Tom. "But they won't have my machine long!"

"What are you going to do?"

"Get it back, Ned. There's only one man there now and we ought to be able to easily handle him."

"He's likely to be armed. They both are I should say, and there is no telling when Mr. Big may come back."

"I aim to do up Mr. Small before Mr. Big shows up," replied Tom grimly. "As for being armed, we've got our own automatics."

"That's so!" agreed Ned, who, for the moment, had forgotten that before getting out of the House on Wheels to go to the old house he and his chum had put the weapons in their pockets. "Well, lead on, Tom."