Jack Chadwick stepped from the door of the shed where he and Tom Jesson, his cousin—and, like Jack, about seventeen years old—had been busy all the morning getting the Flying Road Racer back into shape, after that wonderful craft’s adventurous cruise along the Gulf Coast of Mexico.

“Almost eleven o’clock,” said Jack, and, thrusting his hand into the breast pocket of his khaki working shirt, he drew out a rather crumpled bit of yellow paper.

“What time did Mr. Pythias Peregrine say he’d be here?” inquired Tom, who, like Jack, was attired in a business-like costume of khaki, topped off with an automobile cap.

Jack, who had been busy perusing the telegraphic message inscribed on the bit of yellow paper, read it aloud.

“Wonder what he can want?” mused Professor Chadwick’s son, in a speculative tone. “Pythias Peregrine is one of the best-known inventors in the country. I guess we all ought to feel honored by his wanting to consult with us, Tom.”

“You bet we ought. Wonder what sort of a man he is. I suppose he’ll be inclined to look down upon us as a couple of kids when he does see us. But—hello, Jack!” he broke off suddenly—“what’s that off there in the sky—over there to the northwest?”

“That speck yonder? It looks like—yes, by ginger, it is—it’s an aëroplane of some sort!”

“That’s what.”

A sudden idea struck Tom.

“Say, Jack, don’t you recall reading about Mr. Peregrine and his aëroplane Red Hawk?”

“Yes, I do, very well indeed. He captured the Jordan Meritt speed and long-distance cup with it.”

“That’s right, and I’m willing to bet the hole out of a doughnut that that is the Red Hawk approaching right now. Pokeville is sixty miles off in that direction, and what more natural than that Mr. Peregrine should take an up-to-date way of paying his call?”

“I do believe you’re right, Tom,” said Jack. “Let’s go in and spruce up a bit, and then we’ll come out and meet him.”

In the rear of the work shed, which housed the Flying Road Racer, was a washroom, and to this the boys hastened to remove some of the grime of their morning’s work. While they are thus engaged, and the aëroplane is winging its way rapidly toward High Towers, it is a good time to tell something about the two lads and their adventures.

As readers of the first volume of this series—“The Boy Inventors’ Wireless Triumph”—are aware, Jack Chadwick was the wide-awake, good-looking son of a man well known for his achievements in science. The name of Chester Chadwick was one of the best known in the world along the lines of his chosen field of endeavor. Tom Jesson, almost as bright a lad as his chum and cousin, was, like Jack, motherless. His father, Jasper Jesson—Mr. Chadwick’s brother-in-law—lived at High Towers, the remainder of which establishment was composed of Mrs. Jarley, a motherly old housekeeper, two under servants, and Jupe, a colored man-of-all-work about the place.

High Towers, Professor Chadwick’s estate, was, as we already know from the address on Mr. Peregrine’s telegram, located near the village of Nestorville, not far from Boston. It was a fine old place, and consisted of a big, rambling house set in the midst of oaks and elms with broad lawns and fields stretching on every side. But the most interesting features of the place were a big lake and a group of sheds, workshops and laboratories in which Professor Chadwick and his son and nephew worked over their inventions.

For Jack and Tom were more like chums to Professor Chadwick than son and nephew. Together the three had devised the Flying Road Racer, the Chadwick gas gun, and many other remarkable devices. From his patents Professor Chadwick had amassed a considerable fortune, thus disproving the popular idea that inventors are, of necessity, shiftless or needy.

The present story opens on a day not long after the three, together with Mr. Jesson, had returned from an adventurous trip in the neighborhood of the semi-savage country of Yucatan. As readers of “The Boy Inventors’ Wireless Triumph” know, Jack and Tom, accompanied by Jupe, had been despatched mysteriously to Lone Island, a desolate spot of land off the mouth of the Rio Grande. Here they had awaited a wireless message from Professor Chadwick, who was cruising on a chartered steam yacht, the Sea King. At last the eagerly expected message came, and the boys set out on a gasolene motor boat to find the Sea King, which, the message had informed them, was disabled.

They found her, and also discovered that she was in peculiar trouble. The rascally governor of the province of Yucatan, off which she lay, had, so they learned, imprisoned Professor Chadwick, Mr. Jesson and some sailors. The boys found that the Sea King carried on board the Flying Road Racer—of which more anon—and they determined to utilize this craft of the land and air in the work of rescue.

How Tom was re-united to his father, the explorer who had been given up as lost in the wilderness of Yucatan for many years, cannot be told in detail here; nor can we go into the surprising incident of the three colored gems contained in a silver casket which caused a lot of trouble for the boys and the others. But all came out well, and wireless played a considerable part in getting the party out of many dilemmas.

It will also be recalled by readers of the volume whose contents we have lightly sketched, that the Flying Road Racer—the aerial auto—had been badly damaged, so far as her raising apparatus was concerned, when she was blown to sea in a hurricane, during which those on board narrowly escaped with their lives. Since their return to High Towers, the boys had been engaged in refitting the craft on new principles, and Professor Chadwick had been busy in Washington in connection with some patents. Mr. Jesson had interested himself in scientific farming, and, at the very moment that the boys had hastened into the shed to make swift preparations to receive what they believed to be Mr. Peregrine’s Red Hawk, he was busy in a corn patch with Jupe, the colored man.

Jack had just given a hasty dab with the brush and comb to his hair, and Tom’s face was still buried in a towel when from the rear of the shed where the corn patch was came the sound of angry and alarmed voices.

“Hyar, you, wha’ fo’ yo’ don’ look out? Wha’ fo’ yo’ mean come floppin’ lak an ole buzzard inter dis yar cohn patch—huh?”

Then, in milder tones:

“My dear sir, I beg of you, be careful. This corn is a particular kind. If you alight here you’ll ruin several hills of it.”

“That’s Jupe and Uncle Jasper,” exclaimed Jack, throwing down the brush and comb and rushing out; “wonder what’s up?”

Tom hastily followed his cousin.

“Sounds as if somebody’s trying to spoil dad’s corn patch,” he murmured, as he ran.

As they rounded the corner of the Flying Road Racer’s shed, the boys came on an astonishing sight—if anything can be called astonishing in this century of marvels.

Above Mr. Jesson’s corn, of which he was justly proud, hovered a beautifully finished monoplane with bright red planes. Its propeller was buzzing like an angry bee—or rather like a dragon-fly, which it resembled with its long tail and bright gossamer wings.

In the air ship was seated a small, rather stout figure, whose countenance was almost hidden by goggles and a black leather skull cap pierced with holes. As this brilliant apparition of the skies swooped over the corn, so low that it almost mowed the feathery heads of the topmost stalks, Jupe made angry passes at it with his hoe.

Mr. Jesson, less strenuous but equally alarmed for his corn, had his arms raised imploringly.

“Yo’ jes git out of hyar, or I gib yo’ one wid dis yar hoe!” Jupe was exclaiming angrily, as the boys came on the scene.

“Why, I—bless my soul—I won’t hurt you,” came reassuringly in sharp, nervous tones from the occupant of the red aëroplane, which, the boys had already guessed, was the Red Hawk, and their visitor, Mr. Peregrine. “I merely dropped to inquire if this is High Towers?”

“Ya’as, dis am High Towers, an’ we got ’nough sky schooners ’roun’ hyar now widout you drappin’ in on our cohn patch,” angrily cried Jupe.

“Jupe! Jupe!” shouted Jack, “be more respectful. That’s Mr. Peregrine!”

“Don’t cahr ef he is Jerry Green,” grunted Jupe, “he don’ wan’ ter fustigate dis yar cohn patch wid dat red bug oh hisn.”

“Don’t be alarmed—won’t hurt it—very sorry—watch!”

With these jerky sentences, the occupant of the monoplane pulled a lever and turned a wheel on the side of the body of his machine. Instantly it rose, as gracefully as a butterfly, skimmed above the corn patch, circled around the boys’ astonished heads, and then dropped lightly in front of the shed which housed its ponderous rival of the skies.

As it came to a standstill the boys ran up to greet its operator, who, although he appeared rather fat and podgy, had already leaped nimbly to the ground.

“This is Mr. Pythias Peregrine?” inquired Jack politely.

“My name—glad to see you—dropped in, as it were—how do you do?—quite well?—glad to hear it.”

“Mah goodness,” exploded Jupe, leaning on his hoe and scratching his woolly head, “dat dar Jerry Green talks lak he had a package of firecrackers in him tummy.”

Mr. Peregrine, having alighted from his Red Hawk, removed his helmet and goggles and mopped his forehead vigorously—for the day was warm, it being about the middle of August. The removal of his headpiece revealed him as a round-faced, good-natured looking man, with a rosy complexion and deep-set, twinkling blue eyes. Having taken off his goggles, he replaced them by a pair of big horn-rimmed spectacles, which, somehow, gave him an odd resemblance to an amiable bull-frog. Indeed, his explosive way of talking was very much at variance with his rotund figure and appearance of “easy-goingness.”

“Naturally want to know what I came to see you about? Of course. Father at home?—No. Recollect you said in your telegram he was in Washington. Very warm, isn’t it?—It is.”

“I got on the long-distance telephone as soon as I received your message,” rejoined Jack, finding it rather hard to keep a straight face as Mr. Peregrine rapidly “popped” out the above sentences. “He said he recalled you very well as an old scientific friend, and that anything that we could do to aid you we were to do. Both my Cousin Tom and myself will be very glad to help in any way you may require. By the way,” as Mr. Jesson came up, “this is my uncle, and Tom’s father, Mr. Jasper Jesson.”

“Jasper Jesson, eh? Noted explorer?—Yes. Lost in Yucatan?—You were. Did I read about it in the papers?—I did. Columns of it. Was it interesting?—Very. Glad to meet you, sir. Glad to meet you.”

He and Mr. Jesson shook hands cordially. Mr. Jesson expressed his surprise at the manner in which Mr. Peregrine had been able to handle his Red Hawk when the corn patch was threatened.

The inventor from Pokeville waved his hand airily.

“Was there ever any need for you to be alarmed?—None at all, my dear sir, none at all. Very simple—Red Hawk, fine little air craft.— Fast?—Very.—Your corn in danger?—Never for a moment.—Sorry I alarmed you, though.”

The somewhat eccentric man went on to tell how he had set out from Pokeville an hour before, and had winged his way to High Towers in fast time. He had used the lake, which lay at the foot of the hill on which they stood talking, as his guide. From above it was visible at a distance of several miles.

“You spoke in your telegram of wishing to see us in regard ito some invention?” hinted Jack, at this juncture.

“Did I?—Of course I did,” sputtered out Mr. Peregrine, using his customary way of expressing himself. “A most interesting thing, too. Well, the fact is, that I’m at a standstill.—Invention won’t work—heard a lot of you boys—thought I’d get you to help me out.—Pay well—very grateful.”

“So far as the last feature is concerned, don’t mention it,” said Jack, “if we can help you out at all, Mr. Peregrine, it will give us great pleasure. But what is this invention of yours?”

Mr. Peregrine cocked his head on one side and paused a short time before answering. At length he spoke.

“It’s a vanishing gun,” he said, forgetting for once to add another explosive sentence.

“A vanishing gun!” gasped the boys, while Mr. Jesson looked astonished and Jupe muttered: “Wha’ de matter wid dis yar Jerry Green and his perishing gun?”

“Yes, a vanishing motor gun,” repeated the inventor—“working on it for the government. Big thing—designed for defense against aëroplanes—having lot of trouble, though—need help—will you come?”

“Why—why,” said Jack, in some perplexity, “I think we might; but, Mr. Peregrine, can’t you explain a little more in detail?”

“Impossible now—hard to tell about gun intelligently till you can see and examine it. Why not come over to-morrow?—Not long trip—soon show you gun—like to have your opinion on it, anyway.—Lot depends on it—government offers big prize for successful one.”

“I think you can quite well go. Jack,” said Mr. Jesson, “Jupe, here, and I can look after the place till you get back. I know your father would like you to help Mr. Peregrine.”

“Then it’s settled,” declared Jack, who was equally anxious to see Mr. Peregrine’s invention, “we’ll be over as early as possible.”

“Many thanks,” said the inventor warmly, looking really relieved, “with you to help, I’m sure we can get it to work all right. One thing more—your Flying Road Racer—may I look at it?”

“Surely,” rejoined Jack, “it’s in this shed. Come in, Mr. Peregrine. Mind that step. There, that’s the Flying Road Racer!”

Jack’s face flushed proudly as he indicated what looked like an ordinary automobile, with a silvery aluminum body shaped like a cigar and a propeller at one end. A framework rose above the body, which was fitted with comfortably padded seats. On this framework was a neatly folded mass of material of a lightish yellow shade.

“But how can it fly?—Don’t see any wings—planes—anything,” asked Mr. Peregrine, much puzzled. He had expected to see, from the newspaper accounts he had read of the wonderful craft, a sort of monstrous flying machine. Instead, he beheld only an odd-shaped automobile of great size, with some fabric folded on the top of the framework like a giant bolt of cloth.

“You see that folded mass on the top,” explained Jack, smiling at the inventor’s perplexity; “well, that’s the gas envelope by which we fly. When we wish to make an ascent we put water in the gas tank and the moisture causes the radolite crystals to expand into vapor. When this is done we turn the gas into the bag by twisting this valve.”

He indicated a brass tap on the dashboard, which bore, also, a number of instruments and lubricating devices, besides this and other valves.

“Well, the bag is so folded that it expands without trouble as the gas rushes in. When ready to fly, we connect the engines with that propeller instead of with the ordinary auto transmission. And then we——”

“But—but—but——” exclaimed the inventor eagerly, “how do you keep your machine on the ground while the bag is filling?”

“Easily,” smiled Jack. “I invented a form of anchor like a mushroom type. One of these is cast out on each side. The harder the Flying Road Racer tugs the deeper the edge of these anchors is embedded in the earth. When we wish to rise we pull ‘trip-lines’ attached to each anchor and—up we go!”

“Wonderful!” exclaimed Mr. Peregrine. “Wouldn’t I like a ride in your machine some day?—I would.”

“You shall certainly have one,” rejoined Jack, “both on the road and in the air.”

Mr. Peregrine was pressed to remain to the noon-day meal, but he refused, saying that he must return to his home in time to put the vanishing gun in shape for the boys’ visit the next day.

“Can I promise you a surprise?” were his last words, as he started the Red Hawk skyward, “I think I can.—Good-bye.”

Whirr-r-r-r-r-r-r-r-r-r! The Red Hawk leaped skyward, bearing its lone navigator swiftly aloft. In ten minutes it was a dot, and finally was obliterated altogether.

“Well, what do you think of him?” asked Tom, as they turned away and began to walk toward the house.

“That he is an eccentric man, but very clever,” rejoined Jack. “I’m quite anxious to see this wonderful gun of his.”

“So am I,” said Tom, with equal eagerness, “if he has invented one that will shoot straight upward on an absolutely vertical line, he has a marvelous invention. Several inventors have been at work on the problem of getting out a gun that will really be effective against aëroplanes, but none has yet been found.”

“Well, I hope we can give Mr. Peregrine some good suggestions,” said Jack, as they reached the house and Mrs. Jarley announced that lunch was ready.

On returning to the Flying Road Racer’s shed that afternoon, the lads’ ears were saluted by a buzzing, roaring sound that they instantly recognized.

“Somebody’s started up the motor!” exclaimed Jack, in a voice in which anger mingled with astonishment.

“That’s right,” echoed Tom indignantly, “wonder who on earth it can be?”

“Come on, let’s hurry up and find out,” and Jack started on a run for the shed.

As he reached the door, clouds of blue smoke met him. The vapor almost choked him. Whoever was tampering with the motor had neglected to pay much attention to the lubricating devices, with the result that the fumes of burning oil filled the air.

“Oh, hello, Jack Chadwick. I—you see—I thought you wouldn’t mind me looking at your machine,” exclaimed a lad of about Jack’s own age, as the indignant young inventor burst into the shed with Tom close on his heels.

The lad who spoke was a rather thick-set youth, with a pronounced squint in his eyes which did not improve his mean and crafty face. Beside him was another boy, a little younger, dressed in a loud gray suit with a bright colored necktie. He was smoking a cigarette.

“Say, you Sam Taylor, put that thing out,” cried Jack, as he entered the shed and took in the scene before him.

“Oh, I suppose you are one of those sissies who get sick when they smoke,” sneered Sam Taylor, in an aggravating tone.

“I’ve never tried it, so I don’t know,” snapped Jack, “but if you want to ruin your health you’d better do it elsewhere than in this shed. And you, Zack Baker,” he went on, turning to the other lad, “what are you doing in here? You might have waited till you were invited.”

In the meantime Tom had stopped the motor and was draining the flooded engine.

“No need to get so mad,” retorted Zack, “as I told you, we thought we’d just drop in and see how the thing worked.”

“Yes, and you might have ruined it,” snapped out Tom indignantly. “I like your nerve in marching in here without speaking to us.”

“Oh, well, don’t get so cross about it. No harm done,” struck in Sam Taylor, who had prudently thrown away his cigarette; “what’s the use of getting all worked up over it?”

“I’m not worked up,” replied Jack, with a flushed and angry face, “but I don’t want you fellows prying about here.”

“Don’t be alarmed. We won’t steal your precious invention,” said Sam, in his sneering tones. “Come on, Zack, we’ve seen all we wanted to see, anyhow.”

“Yes, come on,” said Zack, with a rather uncomfortable look on his face, “we know better than to stay where we are not wanted. Anyhow, I’ve got something that will surprise you fellows. I’ll bet it’ll beat you at flying, even if you do get Mr. Peregrine to help you out.”

With this remark, which he considered quite crushing, Zack swung out of the shed, followed by his pasty-faced companion. Once outside they made their way to the front gate of High Towers and mounted their bicycles, on which they had ridden out from the village for the purpose, as we have seen, of examining the invention of Jack Chadwick and his cousin.

“Wonder how they knew anything about Mr. Peregrine?” said Jack, when he had thoroughly examined the Flying Road Racer and found that it was undamaged.

“Oh, Zack’s folks used to live near Pokeville,” rejoined Tom, “and as for their knowing that he had called on us, I reckon he and Sam saw the Red Hawk flying over and guessed at its destination.”

“That must be it,” said Jack, picking up a wrench and tightening a bolt on the Flying Road Racer’s frame, “but they’re the very last chaps I want snooping round here trying to find out how the Flying Road Racer works.”

“Which reminds me,” said Tom, “that Zack spoke of some invention of his that would surprise us. Wonder what it can be?”

“I’ve no idea,” began Jack, and then broke off suddenly, “yes, by ginger, I have, though; I do recall hearing, last time I was in Nestorville, that he and Sam were working on some sort of mechanical flyer.”

“Gee whiz! I’d like to see it,” laughed Tom. “I’ll bet it can’t fly any more than an old bullfrog.”

“I’m not bothering about it one way or the other,” rejoined Jack, “and now, as the machine is all fixed up, what do you say if we try it out on a trial spin?”

“The very thing,” said Tom, “it’ll feel good to be riding in it again. Wait till I run up to the house and get the dust coats, and I’ll be with you.”

While Tom was gone Jack started up the engine and ran the odd-looking air-and-land machine out of the shed. With its heavy uprights and the big folds of the empty gas bag on top, the Flying Road Racer looked even odder when outside than it had within its shelter. But that, despite its cumbersome appearance, it was capable of good speed, was soon shown when the boys had swung down the driveway and out upon the smooth road leading to Nestorville.

“Going into the village?” asked Tom, noting the direction in which his cousin was driving.

“Yes. I want to get some copper wire and some bolts. After that we can take a spin out into the country.”

As he spoke Jack pressed the accelerator, and the rather ponderous car leaped forward like a scared wild thing. The dust rose about it in clouds, for the weather had been hot and dry for some time. But the road was straight and Jack did not decrease the speed. Instead, it rather increased as they flew along.

They had crossed a bridge on the outskirts of Nestorville and were still proceeding at a good pace, when something came into sight which caused Jack to slow down. It was a cloud of dust, but so thick that it effectually concealed whatever was causing it.

“Another auto coming, I guess,” conjectured Tom.

Jack shook his head.

“I don’t think so,” he said, “it’s coming too slowly for that. Maybe a flock of sheep or—Jiminy crickets!”

Out of the dust cloud, which a vagrant puff of wind swept aside, had suddenly emerged a most curious looking object. It resembled nothing so much as a large bee or horse-fly. But it was of metal, and of quite a size. In a series of extraordinary leaps and bounds, zigzagging from one side of the road to the other, it advanced toward the astonished boys.

“What on earth is it?” gasped Tom, as Jack slowed down the auto to a crawl.

“It’s Zack’s flying machine. That’s what it is,” exclaimed Jack, “ho! ho! ho! If that isn’t a crazy-looking machine!”

Indeed, the object now coming toward them with wobbly leaps and hops, was a most curious-looking affair. Its metal wings flopped up and down with great speed, and underneath it could be seen a sort of legs, with wheels on them in place of toes or feet. In between the wings sat Zack, with an alarmed look on his face. In the road behind him was a small runabout auto in which sat Sam Taylor, encouraging him. But Zack paid no attention. In fact, it was taking all his energies to manage his odd machine.

“Well, whatever else it will do, it won’t fly,” declared Tom, “and you’d better look out for it, Jack. I don’t believe he has it under control.” Indeed it didn’t appear so. Zack could now be seen striving with levers and wheels, and the motor of the odd machine gave out a continuous volley of sharp reports.

“Stick to it, Zack!” called out Sam encouragingly from his auto, in which he slowly followed the wild evolutions of Zack’s mechanical bug— for so it could, with propriety, be called. But Zack paid no attention to him. Instead, he began shouting to Jack:

“Pull out of the road! Pull out of the road! I can’t control it.”

Jack maneuvered the Flying Road Racer till its outside wheels overhung a ditch at the side of the road. He had just completed this move when Zack’s machine, its wings beating faster than ever, actually left the ground and soared into the air.

“Hooray! That’s it, Zack! You’re flying!” shouted Sam enthusiastically, although it is doubtful if he would have cared to change places with his crony.

But although Zack had begun to soar, his flight soon ended. At a height of about four feet from the ground the machine wobbled and then crashed to earth. Zack strove in vain to stop it as it drove, snorting and popping, full at the Flying Road Racer, which Jack could not steer further off the road.

“Look out!” cried Jack, “you’ll be into us. You’ll——”

The sentence was never completed. As Jack uttered it, Zack gave a wild yell and tried to jump out of his uncontrollable invention. The next instant the machine, its wings flapping and its motor buzzing furiously, struck the front of the Flying Road Racer a glancing blow and then turned completely over, burying its luckless inventor in a ruin of twisted rods and bent wings.

“Good gracious! He’s killed!” cried Jack, in horrified tones.

“If he is it will be your fault,” shouted Sam, shaking his fist at the two Boy Inventors; “you did it on purpose.”

“Did what on purpose?” demanded Jack rather angrily, climbing out of the car to the ground.

“Why, got in my way and made me lose control of my flying machine,” struck in a new voice.

It was that of Zack, who, at the same moment, crawled out from under the ruins of his queer invention.

He was scratched and shaken, but not injured, as could be readily seen when he stood up.

“I hope you are not badly hurt, Zack,” said Jack, in a mild tone.

Zack’s face was crimson with anger and mortification.

“It’s all your fault!” he roared. “I’ll get even on you. You just see if I don’t.”

“Don’t talk nonsense,” said Tom quietly, “it had nothing to do with us. I guess your machine was no good. That’s what the trouble was.”

“Oh, it was, was it?” sputtered Zack furiously, regarding the remnants of his craft, “well, you just mind your own business. If it hadn’t been for you coming along and spying on me—”

“Spying on you! Well, I like that!” cried Tom, unable to suppress his indignation. “Who was in our shed this morning looking around to see what you could see?”

“Pshaw! A whole lot you could show me,” sneered Zack.

“Or me, either,” struck in Sam, who had descended from his runabout and stood beside Zack. “I tell you what,” he went on, doubling up his fists, “I’ve a good mind to—to—”

“Well, to what?” said Jack, waxing indignant in his turn.

“To sue you for damages or something. Zack and I were partners in that machine, and now it’s all smashed.”

“That was because you expected too much of it,” said Jack quietly. “It was impossible for it to fly, anyway. You have been working on the wrong principle.”

“You mind your own business, Mister Know-it-all,” yelled Zack furiously. “I guess you aren’t the only fellows around here who can invent anything. By rights, I ought to make you pay for the damage you’ve done.”

“Well, just hark at that,” cried Tom, “as if we had anything to do with your old tin hornet collapsing. You were foolish ever to get into it.” Zack could control his fury no longer. He gave a sudden step forward and aimed a vicious blow at Tom. The latter had no wish to get into a fight with Zack, so contented himself with stepping aside. Not landing his blow as he had expected, had the effect of almost throwing Zack from his feet. He saved himself from a tumble only by an effort.

“Look out!” laughed Jack, “you’ll have another tumble if you aren’t careful, Zack.”

“Oh, you make me tired,” grunted the infuriated lad. But he turned away and tried no further hostilities.

“If you want us to, we’ll tow your machine back to town,” volunteered Jack, who felt that there was, perhaps, some excuse for Zack’s anger; “we’re going that way.”

“Then go on, and be quick about it,” shouted Sam furiously. “I guess I can tow the machine in just as well as you fellows.”

“Oh, all right. If that’s the way you feel about it, we’ll be getting on,” said Jack. As he spoke he climbed back into the Flying Road Racer, followed by Tom. He backed the machine away from the wreck and noted, at the same time, that the engine hood had been slightly dented by the impact. But the motor itself was not affected and buzzed away in a lively fashion.

As soon as he had the Flying Road Racer clear of the wreckage, Jack set his lever ahead and the big machine moved off, no further words being exchanged between the cousins and the two boys, who now, clearly enough, chose to regard Jack and Tom as their enemies. As the Flying Racer glided away, Sam, yielding to a sudden impulse of fury, stooped down. He picked up a stone and hurled it with all his might at the two occupants of the land-and-air machine.

Had it struck the mark for which it was intended, the consequences might have been serious. But it whizzed harmlessly by Jack’s ear, avoiding him by a fraction of an inch.

“The coward,” cried Tom wrathfully; “shall we go back and give them a good pummeling?”

Jack shook his head.

“No, leave them alone,” he said. “After all, I’m afraid we didn’t appear to be very sorry over the wreck of that contrivance of Zack’s. He had a right to feel mad, I guess.”

“He was a chump for ever thinking that that thing could fly,” was Tom’s angry contribution to the conversation. He looked back and saw Sam standing in the middle of the road shaking a fist at the retreating Road Racer. Zack was bending over the wreckage examining it with care. The next instant a turn in the winding turnpike shut out the scene from view. But that encounter might have had serious results for our two young heroes in the immediate future, although, at the time, they troubled their minds little over it.

Left alone, Zack and Sam managed to attach the wreck of the “flying” machine to Sam’s auto. Then they set out to tow it back to town on its landing wheels. But they took a roundabout way. Neither of them wanted to display their failure to the prying eyes of the villagers. Fortunately for their plans, Zack’s home was on the outskirts of Nestorville, in which settlement his father had a large store. Sam lived in the town itself, and was the only son of indulgent parents—too indulgent, people said, for old Lem Taylor, who was a banker, grudged his son nothing. The runabout car had been a birthday gift to him a few weeks before, and Zack and he, who were inseparables, had done a lot of riding in it since.

As for Zack, he was more or less the tool of Sam, who had a good deal more evil in his nature than had his crony. The rivalry between Zack and Jack Chadwick and Tom Jesson dated back to the days before the two latter went to Yucatan. At school Zack had tried out several inventions which had been failures. Like many other boys—and men—the success of Jack and Tom had embittered him against them to a degree. Then, too, since their return from their wonderful experiences in the tropics, they had become prominent figures in the village, quite eclipsing himself and Sam.

Zack had hoped that his flying machine would aid in restoring him to his former importance; but now that it was wrecked, this hope was gone. In fact, he dreaded coming in for a lot of joking on that score, for he had been free in his boasts about its marvelous qualities. Altogether, then, neither he nor Sam felt in a very pleasant frame of mind as they towed the debris of the “Flying Hornet”—as Zack had thought of christening his machine—back to his home.

“I’ll bet those kids will tell everybody in town about the smash-up, and we’ll get well laughed at,” grumbled Sam, as he cautiously drove along.

“Bother it all, I guess that’s right,” rejoined Zack. “Just like our luck that they came along when they did. However, I got some ideas from our inspection of their Flying Racer when I looked her over, and we’ll rebuild the Hornet as soon as possible.”

“That’s the way to talk,” said Sam approvingly; “by the way, I wonder what Mr. Peregrine was doing at their home this morning?”

“Looks to me as if some new invention was under way,” hazarded Zack; “wonder what it can be now?”

“I’d like to find out. If only we could, maybe we could get even on them some way for ordering us out of their shed. If we don’t look out those kids will be running this town.”

“That’s what. Tell you what we’ll do—we’ll take a run over to Pokeville in your machine to-morrow, Sam. I know where Mr. Peregrine’s house is. We’ll look around some and see what we can find out. I’m not going to let those kids get ahead of me again if I can help it.”

“Nor I, either,” agreed Sam; “conceited young ninnies! If we can only find out what they are up to with Mr. Peregrine, maybe we’ll find a way.”

It may be as well to say here, as these boys leave our story for the present, that like most bullies, they were cowards, too, and when they heard nothing in town to indicate that Jack and Tom had told of their mishap, they decided to allow all their threats to stand as “bluff,” and to let well enough alone for the immediate future, at least so far as the Boy Inventors were concerned.

Jack and Tom sped along on their way to Nestorville pleasantly enough, but just as they were entering the little town there came a sudden ominous cracking sound from the rear of the machine.

“Something’s smashed!” exclaimed Tom, as Jack quickly brought the car to a standstill.

“That’s right,” agreed Jack; “just get out and see what it is, will you, Tom?”

But Tom was already out of the machine. Down on his knees in the dust he got, and soon found out what had happened.

“A stay rod has parted,” he announced; “it’s that one we welded. I guess we didn’t use heat enough.”

“Glad it’s nothing worse,” rejoined Jack; “we’ll make a stop at the blacksmith’s and get it rewelded; he has a machine for that purpose.”

“Wonder how long that will take?” questioned Tom, who had given a glance up at the sky.

“Oh, hardly any time at all. Why?”

“See those black clouds in the north. Looks as if we were in for a storm. The air feels heavy, too.”

“Well, a heavy rainstorm will do a lot of good and won’t hurt us. The whole country’s as dry as an old bone.”

“That’s what. But I was thinking of that stretch of clay road on our way back. If much rain falls that will be as sticky as a tub full of glue.”

“Oh, we’ll be back long before the storm breaks,” said Jack confidently.

But the welding job took a little longer than they thought it would, and as they set out on their return journey the sky was as black as a slate, and little sharp puffs of wind were driving the dust in whirling “devils” through the streets. As they rolled away from the blacksmith’s shop, one or two large drops pattered down on the folded gas envelope above their heads.

The boys didn’t bother about this, however, and sped along while the rain fell faster and faster. At last they reached the stretch of clay road, which was about two miles from their home.

“Have to put on full power,” decided Jack, turning on more of the radolite gas. The motor puffed and snorted as the Flying Road Racer labored through the heavy blue clay, but it didn’t stall and, considering the nature of the going, good speed was made.

But if they succeeded in avoiding being stalled, others were not so fortunate; As they came puffing around a bend in the heavy, sticky road, they saw, through the rain, that a big yellow touring car was stuck in the middle of the highway, and all the efforts of the two men operating were unavailing to force it through the mire.

As the Flying Road Racer came chugging through the mud, one of the men looked around and hailed the boys. His was a somewhat heavy-set figure, muffled in a red rubber rain coat. From under his goggles there streamed an immense red beard. His companion, so far as the boys could see, was slighter of figure and dark, with a small moustache almost hiding a thin-lipped mouth.

“Hey, you kids,” hailed the red-bearded one, in a deep, rather rough voice, “get us out of this, will you?”

“What’s the trouble?” asked Jack, slowing up. Although he was not best pleased at the other’s sharp mode of address, he felt that it was his duty to do what he could to aid two fellow motorists in distress.

“You can see what the trouble is, can’t you?” exclaimed the black-moustached man; “we’re stalled, stuck, in this infernal clay.”

“Got a rope?” asked Jack; “we’ll try and give you a tow out of it. We’re likely to get stuck ourselves, though.”

“Not much danger of that, with such a car as yours,” responded the red-bearded man, fumbling in the tool box of his car in search of a rope, such as most autos carry nowadays for just such emergencies. He finally found it, and came toward the boys’ car, which Jack had stopped. But the engine was still turning over rather rapidly.

“That’s a powerful motor you have there,” said the stranger, placing one foot on the running board and speaking in a rather patronizing tone, which didn’t much appeal to either of the boys; “what make of car is that?”

“It’s our own invention,” responded Tom quickly, rather too quickly, in fact, for the red-bearded man responded instantly, and with a curious inflection in his tones:

“Oh, is that so? I shouldn’t wonder, now, if you two are the Boy Inventors the papers have printed so much about. And this is the Flying Road Racer, eh? Umph! How does it work?”

“That’s rather a secret for the present,” said Jack, who resented the man’s dictatorial tone and inquisitive manner; “anyhow, if we are going to haul you out of this, we’d better start now before the road gets soaked any more.”

“Oh, all right. No offence meant,” answered the red-bearded man, and immediately busied himself attaching one end of the rope to the rear axle of the boys’ car. Then Jack moved ahead, and the other end of the tow line was made fast to the stalled auto.

This done the men got into their car, the red-bearded man taking the wheel.

“Now, then!” he shouted, as he turned on his power.

Jack did the same, and after a minute of indecision the Flying Road Racer began to move ahead, dragging the yellow car after it. In a few minutes both autos were safely through the heavy, sticky clay, and on the hard road beyond.

“Thanks,” said the red-bearded autoist, as the yellow car gained solid ground, “and now you can do us another favor if you don’t mind. Are we on the right road to Pokeville?”

Jack nodded.

“Straight ahead till you come to a place called Smith’s Corners,” he said; “you cross a bridge beyond that and then turn to the right.”

“Know anybody in Pokeville?” asked the black-moustached man; “ever hear of a Mr. Pythias Peregrine?”

“The inventor?” inquired Jack:

“That’s our man—I mean I’ve often heard of him,” said the red-bearded one; “I reckon now he’s got quite a place there. Lots of servants and all that?”

“I’m sure I don’t know,” rejoined Jack, wondering what interest the two men could have in the eccentric inventor.

“Well, don’t you know anything about his habits? Does he live near his workshops?”

“As I said before, I don’t really know much about Mr. Peregrine,” replied Jack, wondering more and more what could be the object of all these questions.

“Then you haven’t heard anything about a new invention of his? Something he is designing for the government?”

It was on the tip of Jack’s tongue to say that they were going over to Pokeville the very next day in connection with this identical thing; but some instinct checked him. He could not have told why for the life of him, but somehow he mistrusted these two men in the yellow auto. So in reply he merely shook his head.

“Well, we’ve got to be getting on,” said the red-bearded one, as the rain came down harder than ever; “many thanks for your help, and good-bye.”

“Good-bye,” responded both boys, and the yellow auto chugged off down the road through the rain.

A minute later Jack started his machine, and whizzed along after them. But badly as the yellow auto had behaved in the mud, it proved a flyer on the road. It maintained its lead, its occupants from time to time turning their heads and looking back at the two lads in the Flying Road Racer. As the boys turned into the gate of High Towers the yellow car was still speeding through the downpour, as if it were on very urgent business indeed.

“What do you think of those chaps?” asked Tom, as they sped up the driveway.

“I hardly know what to say,” said Jack; “they may be just two tourists going through the country, as they implied, or they may be—something quite different. I don’t know why, but I didn’t half like that red-whiskered chap.”

“Nor did I,” was the prompt rejoinder.

“Why?”

“Oh, just like you, I don’t know why. But there was something about both of them that gave me the idea that they are not all that they seemed to be.”

“Same here. They must have had some object, too, in making all those inquiries about Mr. Peregrine. I wonder what it could be?”

“Hasn’t it occurred to you that a man like him, the possessor of a valuable invention, might have some rivals who would like to find out just along what lines he has been working?”

“It certainly has,” rejoined Jack, as he ran the Flying Road Racer into its shed. “I won’t forget to tell Mr. Peregrine about our encounter when we see him to-morrow.”

“That’s a good idea,” assented Tom.

It rained in torrents all that night; but by dawn the sky had cleared, and a bright sun shone warmly. But everywhere about High Towers were plentiful evidences of the abundance of the downpour. The brook that fed the lake was swollen to a torrent, the lake itself had risen some feet, and its waters, usually clear, were muddy and discolored.

The boys were astir early, making ready for their trip to Pokeville. Jupe was set to work with the hose cleaning the body of the Flying Road Racer, while the boys made some adjustments to the machinery. So fast did they work that by the time breakfast was announced they were ready to start.

“I think I will come with you,” announced Mr. Jesson at the last moment. “I’d like to see Mr. Peregrine’s workshops and laboratories, and although he appears to be a trifle eccentric he is a very likable man.”

“I wonder what you’d have said if he’d lighted in your corn patch,” said Tom, with a grin.

This reminded Mr. Jesson that he ought to see how his corn had withstood the rainstorm, and he hastened off to do this, while the boys got the car out of its shed. Among other adjustments the boys had made that morning, was one involving a change of the gas envelope for a new type which they had invented. Mr. Jesson, on his return from his corn, which he announced was unharmed, noticed the change, the former gas bag having been of a yellow hue. The one the boys had folded on top of the framework that morning was quite black in color.

“Another invention?” inquired Tom’s father, indicating the bag.

“Well, not exactly an invention,” replied Jack, “more of an adaptation. You know that the difficulty in making sustained flights in a dirigible has always been evaporation or the condensation of the gas. This bag is made of a rubber cloth which is interwoven with steel wires and coated with a peculiar air-tight varnish. It makes a very strong fabric, and almost does away with the danger of the bag bursting under the expansion of radolite gas at high altitudes.

“Another feature of it is a small ‘subdivision’ as it were, of its interior. In other words, there is a small balloon or envelope inside the main one. This smaller bag is filled with ordinary air. Now then, when we reach a great height and want to keep on going higher, we pump this ordinary air out of the smaller ‘balloonet’ and the machine rises. At least that’s what we expect it to do. You can see; that by alternately pumping it full or emptying it, we will have—or hope to have—a craft that will always maintain an even keel without danger.”

“That sounds like a great idea,” said Mr. Jesson, “but you haven’t tested it out yet?”

“No, but we hope to have an opportunity to do so before long,” said Jack; “and now, uncle, if you are ready we’ll start. The roads are heavy, and I guess we won’t be able to make very good time.”

“Well, why not fly over?”

“We may have to,” was the rejoinder, “but I don’t want to use the gas-making tank or generator again till it has had a thorough cleaning.”

Jupe, to his unspeakable disgust, was left behind, and stood waving a good-bye to the party as they skimmed off. The road to Pokeville was a fairly good one, and they were able to make about thirty miles an hour over it.

At this rate of going it was not long before they rolled through the little cross-roads settlement of Smith’s Corners, beyond which was the bridge, of which they had informed the two automobilists the previous evening. Jack was sending the auto ahead at a good rate down the hill that led to the bridge, when all at once he noticed a sign nailed to a tree at one side of the road:

Jack jammed on the brakes, bringing the heavy car to a stop.

“What are you going to do now?” asked Mr. Jesson, who, as well as Tom, had noticed the sign.

“Why, it strikes me that this is a mighty good time to test out that new gas bag,” announced Jack, with a quizzical look on his face.

“By ginger! You’re right,” agreed Tom; “let’s get busy at once.”

“I hope it works as well as the old one did down in Yucatan,” said Mr. Jesson.

“I hope so,” rejoined Jack.

He bent over the valve which admitted gas to the folded envelope, and Tom, at the same time, adjusted the generator so that the radolite crystals would begin to make the volatile vapor on which they depended to rise from the earth. A hissing sound presently ensued, and the indicator on the gauge showed that all was ready to fill the gas bag.

As the gas rushed into its container, the folds started to round out, and in fifteen minutes the bag began to assume its cylindrical shape. Before the machine became too buoyant, however, Jack and Tom secured it to the ground by the anchors, the “trip-lines” of which were led on board. Then the work of filling went on, and soon the Flying Road Racer—a “Road Racer” no longer—was tugging at her bonds.

“All right,” announced Jack, after a while, and they prepared to “cast off.”

But just as they were about to pull on the triplines and release the anchors, there was a sudden commotion on the road behind them. They looked around and saw a farmer approaching in a small wagon drawn by a dilapidated-looking mule. The mule was careering about, and evidently objected to coming closer to the weird-looking structure—half auto, half flying machine—that was drawn up in the road in front of it.

“Whoa, thar, you obstreperous critter!” shouted the farmer, getting out and hitching his refractory animal.

This done, he came rapidly toward the boys and their—to him—extraordinary machine.

“Waal, what under ther sun be this yar contraption?” he demanded, gazing curiously at the big balloon bag which was swaying and tugging at its bonds.

“It’s a sort of flying machine,” rejoined Jack, repressing an inclination to laugh; “didn’t you ever see one before?”

“Ya’as, I seen one at ther country fair, but it warn’t nuthin’ like this yar.”

“If you’ll wait a minute you’ll see us fly,” said Jack; but the former didn’t seem to hear him.

The countryman’s eyes were riveted on the notice concerning the bridge.

“Gosh all hemlock!” he exclaimed, in a vexed tone, “if that ain’t jes’ ther peskiest kind er luck. I suppose ther crick has swolled frum ther rain an’ ther old bridge has busted at last. Consarn it all!”

“Isn’t there any other bridge?” asked Mr. Jesson.

“Ya’as, but it’s ’bout a mile further daown, and a roundabout way ter git thar, and I’m in a hurry. Yer see Betsy Jane is mighty sick, and I’m goin’ arter ther doctor.”

“Where does he live?” asked Jack, imagining that Betsy Jane must be the farmer’s wife.

“’Cross ther crick a piece. Consarn it, what am I goin’ ter do?”

“Tell you what,” said Tom, “we’ll take you over in our machine, and bring you and the doctor back. You can leave the mule tied here.”

“What, me ride in thet contraption? Not but what it’s mighty good of ye ter offer it—but——”

“If it’s safe for us, it ought to be safe enough for you,” remarked Mr. Jesson.

“By heck! Thet’s so. Waal, since you’re so kind, I dunno if I care ef I do. By gum! won’t ther folks stare when I tell ’em I’ve rid in er airyoplane?”

“But this isn’t an aëroplane,” objected Tom, who was a stickler for facts, “it’s a dirigible.”

“Don’t keer ef it’s digestible er not, so long as yer daon’t spill me aout,” was the rejoinder.

“Oh, you’ll find it digestible all right,” chuckled Jack, “come on. Climb in, Mister——”

“Hank Appleyard is my name, mister.”

“Very well, then, Mr. Appleyard. Put your foot on that step. That’s it. Now then. Are you all right?”

“By bean poles! This is as comfortable as my parlor cheer ter hum,” remarked Mr. Appleyard, with a tug at his gray goatee, as he sank into the softly cushioned tonneau.

He lay back luxuriantly, and drew out a small and very dirty corncob pipe. Before the boys could observe what he was doing he struck a match. At the sound of the lucifer Jack, who was preparing to “up anchor,” turned like a flash. In a jiffy he had grasped the astonished farmer’s wrist and sent both pipe and match flying into the road.

“Dum gast it all! What did yer do thet fer?” expostulated the indignant agriculturist.

“Because that bag above us holds fifty thousand cubic feet of inflammable gas, and we don’t want to go up before we get ready,” snapped out Jack.

The farmer turned pale.

“By gum, an’ I wuz goin’ ter take a smoke! Say, young fellers, I guess I’ll—”

He was preparing to clamber out, but Jack shoved him back in his seat.

“Sit where you are and hold tight,” he exclaimed. “All right, Tom! Heave away! Ah! Up they come! We’re off!”

“Hey, let me out! Let me out! By gosh, this is too dem rich fer my blood! I——”

“HEY, LET ME OUT! LET ME OUT! BY GOSH, THIS IS TOO DERN RICH FER MY BLOOD.”

Farmer Appleyard, pale and trembling, peered over the side of the tonneau and then sank back with a gasp. The earth lay several score of feet beneath him, and the distance was rapidly increasing. The buoyant gas which filled the container, as if it had been an immense black rugby football, had raised the Flying Road Racer so swiftly that it had seemed literally to “flash” upward.

Below was spread the panorama of the countryside, patches of woods, fields, fenced pastures, and farmhouses. From that height they could see quite plainly the ruined bridge and the angry, turbulent waters of the swollen current that had washed it away. All at once the boys’ passengers had a fresh shock. Jack connected the engine with the propeller, and the Flying Road Racer began to forge ahead. Tom, simultaneously, released the clutch that held the rudder rigid while the Flying Road Racer was merely a land vehicle.

Soon they were flying above the swollen stream, and looking back they could see the road by which they had come, and the farmer’s mule kicking and plunging furiously at its halter rope.

“Poor Balaam! I misdoubt he’ll ever git over, this,” breathed Farmer Appleyard.

“Where is the doctor’s house? Can you see it?” demanded Jack presently.

“Yes. It’s that thar white place with the two big spruces in front. My, won’t he be astonished when he sees me comin’ ter summon him by ther sky route!”

“Is your wife very ill?” asked Tom, as Jack headed the Flying Road Racer for the house indicated by the farmer.

“Eh, young feller? My wife! Waal, she’s as well as I be, I guess.”

“But—but you said she was sick,” exclaimed Tom, wondering if the novel air ride had turned their passenger’s brain.

“What, I said my wife was sick?” demanded the farmer incredulously.

“Why, of course you did, and that you were going for the doctor.”

“Waal, so I am. Fer Dr. Bates, the best horse doctor round here.”

“A horse doctor!” gasped Tom, “but what about Betsy Jane, your——”

“Old gray mare. Ther pesky critter had ther colic, and——”

But a roar of laughter from Jack and Mr. Jesson, who had listened to the conversation, interrupted him. They were still laughing over their comical mistake when Jack brought the Flying Road Racer to the ground in a pasture at the back of Dr. Bates’ house. Sure enough, a sign on the front porch, which they had glimpsed as they descended, said:

And pretty soon out came Dr. Bates himself, his round red face a comical mixture of alarm and amazement at this unexpected apparition of the skies. Explanations were soon made, and the “vet” prevailed upon to return in the air ship to the spot where Farmer Appleyard had left his mule, the farmer promising to drive the horse doctor back by the lower bridge.

“Well,” laughed Jack, as, after bidding farewell to the grateful farmer and the wondering horse doctor, they took the air once more, “I’ll bet that’s the first time an air ship has been used to convey a horse doctor.”

Tom made a queer noise in response.

“What’s the matter?” asked Jack.

“I’m giving a ‘horse laugh’ over Betsy Jane,” rejoined Tom, in high good humor over their adventure.

It was decided after a brief consultation not to deflate the gas bag and drop to earth, but to fly straight on to Pokeville. Jack knew the direction in a general way, and kept the Flying Road Racer headed for a white steeple which appeared on the distant horizon. He believed that this marked the site of the village they were in quest of.

The trip with the farmer had delayed them somewhat, and it was almost eleven o’clock as they drew near the little town for which Jack was aiming. As they got close to it a cluster of white tents with a crowd of people about them could be seen on the outskirts of the place. Gay flags hung above the canvas structures, and even at the height that the air travelers were—about five hundred feet—they could hear the sounds of music.

“It’s a circus!” cried Tom.

“So it is,” said Mr. Jesson, “and look—what is that?—surely a balloon they are sending up!”

Sure enough, as he spoke the boys became aware of a huge, dirty-looking sphere with black smoke rolling from its narrow mouth. It was still tied to the ground apparently, but even as they watched there came the sharp report of a saluting cannon. Instantly the balloon was released from the earth, and shot rapidly skyward, reeling and careening. The manner of its inflation was plainly, judging by the smoke from its mouth, by hot air. The balloon, in fact, formed a part of the free show given by the circus to draw the crowds, and was a common enough feature of small traveling shows.

“Look, there’s somebody swinging below it!” shouted Jack suddenly.

The figure he indicated was a small one, and as they drew closer they could see that it wore red tights gaily spangled. It was suspended from the hot-air balloon by a trapeze, and held on by gripping the ropes on either side of its insecure seat. Under the trapeze hung an object not unlike an immense umbrella closed up. This, the boys knew, was a parachute, and that as soon as the balloon had risen to a sufficient height, the aëronaut would cut the parachute loose and fall by it to the ground.

“Phew!” exclaimed Tom, “I’d hate to do a parachute jump like that.”

“Yes,” said Mr. Jesson, “I was reading only the other day of a parachute jumper whose parachute failed to open. He fell more than a thousand feet to the earth and was dashed to bits.”

“Let’s go closer to the hot-air balloon and watch him when he cuts loose,” suggested Jack.

The others agreed, and the Flying Road Racer was headed for the hot-air balloon, which was rising rapidly. But the Boy Inventors’ dirigible craft had no difficulty in keeping up with it. Soon they were quite close to it, and sweeping around the great pear-shaped bag in big circles. And now they observed something that they had not seen before.

The aëronaut was a boy of not more than twelve years old. His face was white and pinched, and he looked terrified. As the balloon swung higher, there was borne upward from below repeated pistol shots.

“That’s the signal for him to cut loose,” exclaimed Tom. “I know. I’ve seen lots of ascents like this one.”

“Well, why doesn’t he?” demanded Jack.

“For a very good reason,” said Mr. Jesson, who had been observing the young aëronaut closely; “he’s scared to death.”

The boys, observing the spangled air traveler more carefully, now perceived that Mr. Jesson was correct. The little fellow turned a pitiable face toward them. What made his situation worse was that the hot air in the balloon was evaporating, and if he did not jump quickly it would be too late. Jack shouted words to that effect to the lad. But the panic-stricken boy only clung tighter to the ropes of his trapeze, and shook his head pitifully. It seemed as if he dared not look downward at the empty void between himself and the earth.

“Drop on the parachute!” shouted Tom; “if you don’t, the balloon will fall with you!”

As his cousin spoke, Jack maneuvered the Flying Road Racer yet closer to the hot-air balloon. Big wrinkles now appeared in the bag of the circus balloon, and it began to sag downward more rapidly.

“Great ginger! That kid is paralyzed by fright!” exclaimed Tom, his own face pale; “what are we going to do?”

“Save him if we can,” breathed Jack, “but how?”

“Can’t you get alongside that balloon and take him off?” interrogated Mr. Jesson.

“It will be fearfully risky.”

“True; but we can’t let him be dashed to earth without attempting to save him.”

“I have it,” exclaimed Tom; “I’ll get out the light grappling iron. I’ll throw it and try to entangle it in the parachute. Then we can pull the balloon alongside and get that boy off.”

“A capital idea,” said Mr. Jesson; “how close can you get, Jack?”

“I’ll come as close as I dare,” was the reply. Below—far, far below—the crowd, with upturned faces, watched the maneuvering of the great air craft. This was indeed a spectacle they hadn’t bargained for. The tension was too great for speech. A death-like silence hung over the throng.

Behind one of the white tents two men stood, also gazing upward. But there was no pity nor suspense on their faces. Instead, they cast furious glances at the drama of the skies being unfolded before them.

“I told you that kid would lose his nerve!” snarled out one of them, a heavy-set man in a loud checked suit, in whose bright red necktie an imitation diamond, as big as a walnut, glistened.

His companion slashed at his high boots with a whip he held in his hand.

“I’ll fix him for this,” he growled, “and I’d like to fix those pesky butters-in on board that dirigible, too.”

In the meantime, the dirigible, under Jack’s skillful handling, had been maneuvered quite close to the hot-air balloon. Tom, with the light grapple in one hand, and its attached rope in the other, stood ready to make a cast.

“Now!” shouted Jack suddenly, as the gas envelope of the Flying Road Racer almost bumped against the flabby bag of the hot-air balloon. The grapple whizzed through the air, and so skillfully had it been thrown, that its flukes caught and became entangled in the pendent parachute under the trapeze, to which clung the terrified boy.

“Haul in!” shouted Jack, and Tom and Mr. Jesson belayed heartily on the rope. As the trapeze swung alongside the body of the dirigible, Tom reached out and seized the lad. The little fellow had partially recovered his nerve and was able to help himself, and in a moment more he was safe on board the Flying Road Racer.

What a cheer came up from below! The crowd had seen a unique rescue in mid-air—a triumph of the wonderful resource and achievement of the twentieth century—and it went wild. Hats were thrown up and women sobbed and laughed in the same breath.

As for the young air navigators, they were the coolest people in that neighborhood. Tom cut the balloon loose, and it went sagging and wallowing off, dropping in a field a short time later. In the meantime, Jack began to send the Flying Road Racer earthward, using the depression planes in doing so.

The boy they had rescued speedily found his tongue, and when he did he told them a story that made them flush with indignation. He had been hired out to the circus, he said, by his father some years before. From that time on his life had been one of misery. Urged on by the ringmaster’s whip, he had learned to ride bareback and do some other tricks, but this had been his first trip aloft. The way in which he shuddered as he spoke of it, showed that only the utmost cruelty could have prevailed on him to make an ascent on the hot-air balloon.

The regular parachute jumper had been injured—disabled for life—by a fall at the last “stand” the circus had played. As the boy, who said his name was Ralph Ingersoll, was light and active, he had been ordered to take the parachute performer’s place, by the brutal men to whose care he had been consigned. Terrified by threats of a terrific beating, the boy had consented, with what results we know.

“Oh! If it hadn’t been for you, I would have been killed,” he exclaimed, clasping his hands and gazing gratefully at his rescuers.

“Never mind, Ralph,” said Mr. Jesson, whose indignation had been aroused by the lad’s recital, “we’ll see what we can do to stop any further ill treatment of you.”

“Oh, then you are going to take me back to the circus!” cried the boy, a look of real terror coming over his thin, pale face.

“Well, for the present, yes,” said Mr. Jesson, “but we will have your case investigated, and the law——”

“No law will save me if you take me back,” cried the boy, crouching in a spasm of fear, “they’ll kill me—beat me to death, or do away with me in some way before you can save me.” As he spoke, the Flying Road Racer reached the ground, and the crowd came rushing and surging about it. Through the press, the two men who had so angrily watched the Boy Inventors’ plucky rescue came shoving their way. A look of black rage was on both their faces.

“Now, then,” shouted the man with the whip, as he pushed his way to the side of the Flying Road Racer, “what’s all this mean? What right had you to interfere with this lad?”

“The right that everyone has to save a human life,” rejoined Mr. Jesson firmly, standing between the angry man and the boy, who crouched behind his protector in an agony of fear.

“Oh, that’s all very fine; but you spoiled our show. Come on now, Ralph, you young sneak. I’m going to fix you for getting cold feet.”

“Hold on a minute,” said Mr. Jesson calmly. “It’s evident to me from this boy’s story that you have treated him brutally. You could be proceeded against for the way you have abused him.”

“None of your business, is it, Mister Smart Alec?” demanded the man with the red necktie and the diamond. “I’m Josh Sawdon, the boss of this show, and I demand that boy. He was given us by his father to train.”

“That’s right,” declared his companion, with a vicious crack of his whip, “and we are going to do it, too. Come on, mister, give us that boy.”

“Have you got any papers to prove your right to him?” asked Mr. Jesson calmly.

“No, we ain’t,” sneered Sawdon, “at least, we ain’t got none to show you. Come on, now—give us that boy, or——”

“Well, or what?”

Mr. Jesson stared calmly at the man, who had stepped threateningly toward him. Sawdon stopped short. Something in the direct look of the bronzed explorer checked him.

“I am satisfied that you have no right to this lad,” said Mr. Jesson, in calm, even tones. “I am even better satisfied that you have used him shamefully. Therefore, we will take him under our protection till the matter can come up in the courts.”

“Hooray!” yelled the crowd, whose sympathies were plainly with the aerial party.

Sawdon sprang forward furiously. Behind him came the man with the whip. He “clubbed” his weapon and aimed a vicious blow at Mr. Jesson’s head. But Tom caught the descending wrist in a steel grip. He gave it a quick wrench, and with an “ouch!” of pain the fellow dropped the whip.

In the meantime Sawdon set up a shout for his assistants. In a moment a score of canvasmen and performers came running from every side, armed with tent pegs. The crowd scattered right and left before the attackers.

“We’ll have to get out of this quick,” exclaimed Mr. Jesson, in a low voice to Jack.

The boy nodded. At the same instant he started the propeller. Up shot the Flying Road Racer like a stone out of a sling. Sawdon, who had just sprung at its side, was flung over in a heap, with his companion of the whip on top of him. As the big machine rose a roar of rage went up from the circus hands. But they could do nothing but shake their fists.

Suddenly Tom bethought himself of something which they had forgotten in the excitement. Putting his head over the edge of the car he shouted downward to the crowd:

“Is this Pokeville?”

“Naw, this is Westerlo!” was yelled back from below; “Pokeville’s six miles to the west.”

Jack changed his course, and before long they came in sight of a small town, which really proved to be Pokeville. They descended in the village, much to the alarm of some of the inhabitants, and inquired the way to Mr. Peregrine’s home.

A handsome structure with a pillared portico, standing on a hill about a mile off, was pointed out to them as the home of the inventor.

“No use flying there,” decided Jack; “we’ll take to automobiling again.”

Accordingly, the Flying Road Racer’s gas envelope was deflated, and once more “an auto,” she sped off toward Mr. Peregrine’s house. As they left the village, a car coming in the opposite direction almost crashed into them as it rounded a corner. It was going fast, but not too fast for Jack and Tom to see that it was a yellow vehicle, and that one of its passengers had a big red beard. It was the same car that they had pulled out of the mud the previous evening, whose occupants had been so curious about Mr. Peregrine and his habits.

Jack was conscious of a vague sense of uneasiness at the presence of these mysterious men in Pokeville.

During the trip from Westerlo to Pokeville the case of Ralph Ingersoll had been discussed in all its bearings, and it had been decided that, for the present at any rate, he was to make his home with the boys. Ralph appeared a bright little fellow, and his evident fear of being sent to some institution decided Mr. Jesson not to carry out his first intention.

Besides, Jack and Tom had argued that the lad would be useful to them around their inventions, and they needed an assistant, anyway. So, to Ralph’s great joy, matters were arranged as described above. But Mr. Jesson warned Ralph that, in the event of the circus people proving a legal right to him, he might have to be returned to them. This idea; however, proved so disquieting to the lad that the kind-hearted explorer forebore to press it.

Ralph declared that he had no knowledge of his parents, but that he had been placed with the circus men at an early age. Thus all that he could recall of his past was misery and privation.

As they turned into Mr. Peregrine’s grounds, the inventor himself came toward them. Even at a distance they could see that he was perturbed and excited. His face was flushed, and as soon as he got within speaking distance he began to talk, almost more explosively than usual.

“My stars! I’m glad you’ve come!” he exclaimed. “Queer doings—strange men—frightened them off—but afraid they’ve seen more than I want ’em to.”

“Jump in and tell us about it as we drive to the house,” said Mr. Jesson; “we, too, have had some odd adventures on our way here.”

Just then Mr. Peregrine caught sight of Ralph Ingersoll, who still wore his gaudy tights.

“Bless my soul—what’s this?—circus—bing-bang—through a hoop—whoop-la!” he exclaimed.

“Not exactly,” said Mr. Jesson, with a smile at the inventor’s rapid-fire speech; “but I’ll explain later on. First tell us about the strange men. Possibly we can throw some light on the matter. The boys told me about encountering two men on the road last night, who asked about you, and whom we saw again just now.”

“One of them with a red beard—long one—other chap had black moustache—eh?”

“Yes, that describes the fellows as accurately as we could size them up for their goggles,” struck in Jack, who meanwhile had started the machine again. He drove it up to the front door of Mr. Peregrine’s home, and when they had all alighted a man was detailed to take it to the barn. Within they found a good lunch awaiting them, and Mrs. Peregrine came to meet them with a smile of ready welcome.

As all the passengers were rather grimy, they first had a good wash, and Ralph was provided with a suit which had belonged to Mr. Peregrine’s son, now a lad of nineteen and away at college. During the meal Mr. Peregrine described how, on visiting the shed which housed his invention that morning, he had surprised a strange man with a red beard peeping through a window at it.

“I must tell you,” he continued, “that a powerful syndicate has tried to purchase my invention; but I have refused to sell. Since that time I have been harassed in many ways, and I am afraid that this is their latest move against me.”

When Mr. Peregrine was very much in earnest he dropped his odd way of talking, and there was no doubt but that he was very serious now. His wife, too, looked troubled. Clearly his enemies were powerful, and determined enough to cause the inventor considerable alarm.

“But surely your invention is patented, and you have nothing to fear on the score of their stealing your ideas?” asked Mr. Jesson.

“That’s just it,” said the inventor, with a troubled look; “I have taken no steps in the matter of a patent yet, as I feared a leak somewhere. These people who are after my vanishing gun are aware of this, too, as they have spies in Washington.”

“Well, that does make the matter serious,” agreed Mr. Jesson, and then, as Mrs. Peregrine looked rather alarmed, the subject was changed.

After lunch Mr. Peregrine asked if they would care to see his invention and try to ascertain what the trouble was with it.

“We can’t look it over too soon for me,” exclaimed Jack.

“I do hope you’ll be able to suggest something that will get me over the sticking point,” responded Mr. Peregrine, as the party donned their hats and, following him, made their way to the shed where stood the gun of which so much was expected.

The boys could hardly restrain their curiosity while Mr. Peregrine unlocked the door of the shed, which was furnished with quite an elaborate system of protection. Besides the heavy locks of a novel variety, it was fitted with a burglar alarm connecting with the house.

The door being opened, the boys saw a strange-looking piece of apparatus. Imagine a dull gray-colored submarine boat on wheels of solid steel with wide tires, and you have something of an idea of what they gazed upon. The cigar-shaped body of this odd vehicle was apparently of steel with riveted plates, and about twelve or thirteen feet in length. “Amidships,” so to speak, was a low sort of hood, pierced with slits. From the top of this projected a slender rod of steel tubing with a small, square, boxlike terminal on its top.

“But where does the gun part of it come in?” asked Jack, much mystified.

Mr. Peregrine smiled, and then, motioning to them to come closer, he indicated, what they had not before noticed, a break in the continuity of the “shell” of his invention. This was in the form of a band, completely encircling the diameter of the fore part of the machine. In two places in this band, at opposite points, appeared round openings.

“There,” said the inventor, pointing to this band and the two holes, “is the vital part of my invention. You see those holes?—yes—well, they are the muzzles of my vanishing guns.”

The group about the inventor nodded; but as yet they had only a very vague idea of the details of this strange invention.

“That slender shaft of tubing rising from the conning tower,” said Mr. Peregrine, who in his enthusiasm had lost his jerky manner of talking, “is nothing more nor less than a periscope; you know what that is, I presume.”

“A device which will show whatever is occurring outside, while the operator of the machine to which it is attached remains hidden,” said Jack.

“Correct. But this is an improved periscope. It gives the operator of the ‘gun carriage’ a wide view of the sky in every direction. But to explain my invention more fully I must invite you inside.”

So saying, the inventor opened a door in the side of the steel structure, which they had not previously noticed. Taking Jack by the arm, he gave him a half shove into the interior of the steel cigar.

As the space within was small, Mr. Peregrine explained that he would have to show the points of his invention to one of them at a time. When Jack was inside the inventor closed the door and, turning a switch, caused a flood of light to illuminate the interior of the wheeled cylinder. Jack found that they were standing within the conning tower. Through the slits he could see out into the shed, but his attention was speedily distracted by Mr. Peregrine.

The inventor indicated a seat, and invited Jack to occupy it. The boy was informed that he was seated in the operator’s position. In front of him was a sort of desk with a white top. This was divided into squares. The inventor explained that the white surface represented the expanse of sky commanded by the periscope.

“The instant an aëroplane is seen to enter one of those squares, each of which, as you see, is numbered,” he explained, “I press one of these buttons which are correspondingly marked.”

He reached up to a sort of switchboard above the periscope desk, and pressed one of the numbered buttons on it. A whirring sound followed.

“What’s that?” demanded Jack.

“That noise is caused by the cylindrical band which you observed on the fore part of the machine,” said Mr. Peregrine; “two guns, controlled by electricity, are set in that band. By pressing this button one of them is automatically aimed at the square of sky which the periscope shows is occupied by a supposedly hostile aëroplane.”

Jack nodded. It was plain to him that the band which they had noticed revolved on an axis, and that the muzzles of the ‘vanishing gun’ revolved with it.

“The guns fire explosive shells,” went on the inventor, “and when they burst in mid-air they do damage extending over a wide area. This is an essential feature of the machine, for of course it would be impossible, actually, to hit an aëroplane fair and square except by chance.”

After showing Jack several more unique features of his strange invention, Mr. Peregrine took the boy “forward” into the gun chamber. Jack then saw just how each gun’s magazine of six shells was worked, and how the steel cases on the walls were especially designed for reserve ammunition. The boy could not help feeling the warmest admiration for the inventive genius that the eccentric designer of this queer, modern implement of warfare had displayed.

“But it seems to me that you have solved every problem in connection with this invention, Mr. Peregrine,” said Jack, after he had inspected the storage batteries and engine, designed to supply motive power to the vehicle which housed the vanishing guns.

“Yes,” rejoined the inventor, with a return to his odd, jerky manner, “everything solved—all complete—guns work—everything all right—but won’t go.”

“Won’t go?” questioned Jack wonderingly, “how do you mean?”

“What I say—can’t get it to move—wheels won’t go round.”

The inventor went on to explain that, although he had solved almost all the problems in connection with his wonderful device, one of the most important was still unmastered—namely, the means of locomotion for his invention. To be of any use at all in the field, it must be able to move, and move fast.

Now, although the inventor had provided a gasolene engine of considerable power, still he had not, up to date, been able to make the wheels revolve. Till he could do this, therefore, his invention must be considered a failure.

“It’s this that I wanted you to help me out on, Jack Chadwick,” he said, after he had jerkily explained his trouble; “can you do it?”

Jack looked rather dubious.

“Your machine is so enormously heavy,” he said, “that I’m afraid it is going to be a difficult matter.”

“Not so heavy as it looks,” responded the inventor, tapping the plates; “these are not steel, as you may think, but a mixture of vanadium and aluminum. The machine is practically bomb-proof. Any explosive dropped from an aëroplane would have to be more deadly than any at present known to do it much harm.”

Jack inspected the driving motor, a six-cylinder affair located behind a bulkhead, which cut it off from the conning tower, although the motor controls and the steering apparatus led into that compartment. The young inventor made a thorough and careful examination of the motor, and of the means by which it was geared to the driving shaft.

Then he started it up. Sure enough, as Mr. Peregrine had said, it refused to move the driving wheels. Jack stopped it and made a further examination. Following this, he made some more tests and a series of calculations. Mr. Peregrine watched him with some anxiety. A good deal depended on the lad’s opinion. At length Jack spoke.

“I think we can overcome your difficulty,” he said.

Mr. Peregrine looked as if he would have liked to embrace him.

“You can?—Good!—Fine!—But how?”

“Well, for one thing, your gearing is wrong. We’ll have to change that. Then we shall have to put a carburetor on each cylinder instead of on one only, as at present. That alone will give you more power. Such a change, combined with the improved gearing I spoke of, should solve the trouble.”

“You think so—you really do?—Then my troubles are over!”

“Not just yet,” smiled Jack; “there is quite a lot of work ahead of us, but I think I can promise you that I can make it move at a fair speed.” After making a further examination, and noting down the changes he wished to make. Jack and Mr. Peregrine emerged from the queer machine. The others then took turns in examining it, although it is doubtful if Mr. Jesson or young Ralph understood its principles very clearly.

“Do you think you can make it go?” Tom asked of Jack, in a low voice, after the former had been through it, and Mr. Peregrine had explained his stumbling-block.

“I think so,” said Jack, “but I don’t want to brag. You and I will have to make a trip to Boston as soon as possible, to get several supplies and fittings. As soon as we have those we can go right ahead.”

“That’s the idea,” agreed Tom enthusiastically, but the next moment he broke off abruptly, and pointed to a small window at the back of the shed.

“There was a man with a red beard peeping in at us through that window an instant ago,” he exclaimed.

“It must have been one of the spies that Mr. Peregrine fears; one of the men we met on the road,” exclaimed Jack, and without a thought of the consequences he dashed out of the shed, followed closely by Tom.

As the two boys got outside, they saw a man with his head bent low, darting across the greensward surrounding the construction shed.

“Hi! Hold on! Stop!” shouted Jack.

But the fellow kept on without turning his head. He was evidently making for a lane which ran at the rear of Mr. Peregrine’s grounds. But a high fence separated him from it, a fence which surrounded the estate on all four sides, for Mr. Peregrine had no liking for uninvited visitors.

“He’ll have to stop when he gets to the fence,” panted Tom; “my, but he can run!”

“Yes, and maybe he can show fight, too,” rejoined Jack; “but I guess we can master him.”

“Unless he is armed.”

“He wouldn’t dare to try anything like that here,” was Jack’s reply.

They now perceived suddenly that the man whom they were pursuing had no intention of scaling the fence without assistance. He was making for a spot where a number of empty packing cases that had contained apparatus were piled.

“Pshaw! He’ll escape us after all,” exclaimed Jack angrily, as he saw this.

Even as he spoke the man reached the boxes and scrambled up on them. In the twinkling of an eye he was over the fence, waving an ironic farewell to the boys as he dropped from view on the other side. When Jack and Tom gained the boxes and, in their turn, clambered up on them, there was no trace of the man. But a vanishing cloud of dust far down the lane showed that, in all likelihood, the yellow auto had been waiting for him at the same spot by which he must have entered the Peregrine estate.

The inventor, with Mr. Jesson and young Ralph, had been inside the “war auto” when the pursuit started, so that they were not aware of what had taken place. But on emerging from the metallic wheeled cylinder, they missed the two lads, and came out of the shed to see what had become of them. Their astonishment on learning of the fruitless pursuit may be imagined.

“I wish you could have caught the man,” said Mr. Peregrine; “this plot is deeper than I thought—it’s desperate—and well planned.—Do you think they saw much?”

“Why, from that window he must have seen everything,” said Jack; “and I notice now that one of the panes of glass is broken. He must have been able to overhear considerable of our conversation, too.”

Mr. Peregrine fairly groaned.

“In that case my rivals know of my troubles,” he said, and then, overmastering his depression, he resumed, in a more cheerful tone, “but Pythias Peregrine will fight—yes, sir—to the last ditch—they shan’t steal my invention if I can help it.—They are rich and powerful, yes—but I’ll give them a battle.”

“That’s the way to talk, sir,” said Jack, “and if we can help you win out, we’ll do it. As soon as your machine can move you can take out a patent on it, and then you can laugh at that rascally gang.”

The inventor’s face glowed. He clasped the hands of Jack and Tom impulsively.

“Don’t know what I’d have done if it hadn’t been for you,” he exclaimed; “if only you can make my machine go I will be under obligations to you that I can never repay.”

“Never mind about thanking us till we have accomplished what we hope to do,” laughed Jack, in reply; “and now I think that we had better make arrangements to run over to Boston to-morrow. I’ll spend this afternoon making out a list of the parts I shall need. I’m afraid that they will be quite expensive.”

“I don’t mind a bit about the expense,” declared the inventor eagerly, “if only you can make my machine work.”

The remainder of that afternoon was spent by the two lads looking over Mr. Peregrine’s machine and making careful calculations. No more was seen of the inventor’s enemies, and the night passed without incident, although one of Mr. Peregrine’s employees was posted as a night watchman, and the burglar alarm connecting with the shed that housed the invention was reenforced by additional wiring.

Bright and early the next morning they set about making ready for their trip to Boston. It was a run of seventy-five miles and the roads were not over good, so that they were anxious to get as early a start as possible.

While they were going over the Flying Road Racer, “grooming” the machine, as Jack called it, Mr. Peregrine came up to them.

“I have another mission which I wish you would perform for me while you are in the city,” he said.

The boys looked up from their work.

“What sort of a mission?” asked Jack.

“Well, you see, I’ve been thinking over matters carefully. I have come to a conclusion.—My lawyer, Mr. Bowler, is in Boston—I’ll give you the address later.—I want you to take to him the model of my machine, the blue prints, and a note asking him to take immediate steps to patent my invention.”

“But I thought that you were not ready to patent the machine yet. That you were afraid that by doing so your plans would be forestalled,” objected Jack.

“That’s just the point on which I have changed my mind. I’m certain now that you can make my machine go, and there is no object in holding back the patent any longer. I dare not send the model by express for fear that the plotters may steal it in some way.”

“I think you are right,” said Jack, after a moment’s reflection.

“Very well, then, while you are finishing up your work I’ll wrap the model up. It will have to be packed carefully as it is quite fragile.”

So saying, the inventor walked off to his study to get the model, by which he set so much store, ready for shipment. This did not take long, as the box which was to contain it was already constructed. Very soon he rejoined the boys, with the package in his hands. Mr. Jesson, who was to remain at Pokeville that day to visit some experimental gardens in the vicinity, accompanied him. He added his cautions to the inventor’s injunctions to be very careful of the fragile model.

“You can rest assured that we’ll take good care of it,” was Jack’s reply, “and it will be safe in Boston by noon.”

Had the lad only guessed the dangers ahead of him and the risks he was to run, he would not have spoken so confidently.

At last all was ready, and the model carefully deposited in the back of the machine. Jack took his seat at the steering wheel and started the engine. With a whirr and a bang it was going, and the next instant, with a wave of their hands, the two boys were off on what was to prove an eventful journey. Little Ralph accompanied them. The lad had begged so hard to go that they had not the heart to refuse him, and, after all, as Tom put it, he was so small that he hardly made any difference, anyway.

Although there was no necessity for great speed, the boys were anxious to get their errand accomplished and deposit the model safely in Boston. Then, too, Jack was looking forward, on his return, to making Mr. Peregrine’s invention practicable.

The day was pleasant. The sun shone down hotly, but the two lads in the auto did not notice the heat as they rushed along smoothly in the big machine. They passed through Pokeville at a good rate of speed. So fast, in fact, that they did not notice a man with a red beard who was lounging in front of the hotel. But if they did not see him, he took due note of them.

“There go those two kids,” he muttered; “wonder where they are off to now. It might be a good thing to follow them. I’ve got a scheme. I’ll call up Peregrine’s house and find out where they are going. It may turn out to be worth while taking after them.”

In accordance with this resolve the red-bearded man entered the hotel and closeted himself in a telephone booth. Adopting a feigned voice he represented himself as a friend of Jack’s, and asked where the boy had gone. Mr. Peregrine who, like most inventors, was rather unworldly, immediately replied that the boys had gone on a trip to Boston on important business.

“To Boston,” exclaimed the man to himself, as he hung up the receiver; “if that’s the case, I’ll wager it’s got something to do with the vanishing gun. Hold on a minute! By Jove, I recollect now that Peregrine’s patent lawyer has offices in that city. It’s ten to one that those boys are going there on some business connected with him.”

He lost no time in finding his companion, who was puffing at a black cigar and reading the morning paper. He hastily told him what he had seen, and suggested that they take after the boys at once in the yellow auto.

This plan was soon put into execution, and although they had not much hope of overtaking the lads, the two men reasoned that possibly some accident might favor them. At any rate, they knew that the rich men who employed them to keep track of Mr. Peregrine’s affairs would want to know of the object of this Boston trip, which was clearly an important one.

The bridge which had halted the boys the day before was repaired by this time, and the Flying Road Racer crossed the rather flimsy temporary affair without difficulty. About half a mile beyond the road turned sharply. As the boys swung around this turn they almost ran into the midst of quite an assemblage of men and horses and gaily painted wagons. In a flash Jack realized that they were probably in for some trouble, for he had no difficulty in recognizing this outfit as being the traveling circus from which they had rescued Ralph.

The road was too narrow to turn around in. There was nothing to do but to keep on. Jack hastily told Ralph to conceal himself under a pile of wraps in the tonneau, and with a beating heart he sounded the electric horn, hoping that the circus wagons would turn out and he could get through without difficulty.

But, as ill luck would have it, the rear wagon was driven by the very man with whom they had had the trouble, and beside him sat the fellow who had wielded the whip. They looked around at the sound of the horn and recognized the two lads in a flash. Their next move was to turn their wagon deliberately across the road, effectually blocking the thoroughfare. Then the be-diamonded man shouted to those ahead:

“Say, boys! Here’s the two kids that stole Ralph. Don’t let ’em get away till we’ve evened things up.”

Jack had, of necessity, stopped the Flying Road Racer when the wagon was pulled across the road. He was conscious of a sharp feeling of alarm as the two men clambered down from the wagon and were joined by half a dozen others, all hard-featured, bad-looking men.

“Now we’ve got you where we want you,” growled the big man, shaking his fist vindictively at Jack; “get down out of that benzine buggy and give up your watches and money. Then I’m going to give you the worst hiding you ever had in your lives.”

“I’m not so sure of that,” rejoined Jack, with a calmness he was, in reality, far from feeling; “let us get past, please.”

“Ho! ho! ho! so you think you’re going to get off scot free, do you? Well, you’re mistaken, you young jackanapes. Come on now, get out of that rig.”

As he spoke the man came close to the side of the Flying Road Racer and began tugging at Jack’s arm. But he had hardly laid hands on him before an astonishing thing occurred—astonishing to the ruffian, that is.

Jack’s fist shot out swiftly, and with considerable force. The next instant the fellow, who had been hit fairly between the eyes, staggered back and, tripping on a rock, fell over.

But his companion of the day before, who still wielded a whip, sprang forward from the other side of the machine and aimed a blow at Jack from behind. Tom caught the fellow’s wrist as it descended, and twisted it till he yelled with pain. An angry murmur ran through the crowd of circus men. Several of them detached themselves from the main body, and made an onslaught on the Flying Road Racer.

The boys defended themselves valorously; but there is little doubt that the battle would have ended in their defeat, if it had not been for a sudden happening that diverted the attention of the showmen.

This was nothing more nor less than a shout from some of the men who were lingering about the more distant wagons.

“Old Wallace has escaped!” they cried at the top of their lungs.

At the same instant the boys saw the huge, tawny form of a big lion launch itself from one of the forward wagons. Men scattered and ran right and left, the two fellows who had attacked the boys being among the first to make off.

The lion, having gained the ground, stood stock still for an instant, lashing his tail angrily. The creature seemed undetermined what to do. In the meantime the entire assemblage of showmen had vanished. Not one remained on the scene. The horses attached to the wagons began to rear and plunge in terror.

As for the boys, they were fairly paralyzed for a moment; but not for long. The escape of the lion had caused the horses attached to the wagon which had been drawn across the road to swing inward in alarm. This left a clear passage ahead for the Flying Road Racer.

Jack’s mind was made up in a flash. Putting on full power he drove the big car ahead. The lion saw it coming and gave an angry roar, and was about to spring at the boys when the front of the speeding machine struck the great brute. With a howl of pain and fright the creature rolled over helplessly, pawing the air with its claws, but with all the fight taken out of it.

Ralph, who had crawled out of his place of concealment as the car moved forward, fairly gasped when he saw what had happened.

“That’s old Wallace, the man-eating lion,” he exclaimed; “they got him cheap because of his bad disposition.”

“Well, I guess his disposition is considerably quieted down by this time,” laughed Jack, as the chastened king of the jungle went limping off down the road.

“The same thing applies to that bunch of circus men, I guess,” chimed in Tom.

All three of the lads had to laugh as they saw the lately belligerent show folks decamping down the road at a lively rate. They did not return till Wallace had wandered off across some meadows. The lads learned later that the lion was killed by a farmer the next day as it was attacking some cows, and that the circus men had to pay heavy damages. However, at the time, they did not linger in the vicinity, but resumed their journey as speedily as possible.

Ralph was pale and trembling from his narrow escape, and he had good reason to be, for it is easy to guess what his fate would have been if he had come once more into possession of the rascally circus crew.

Before long they came to a point where the road forked. A signboard standing there directed travelers to Compton, five miles, and Wynburg, three miles.

“I guess we’ll go through Compton,” decided Jack, taking the road that turned to the right, “it’s a little longer way round, but it’s a better road.”

Their way now lay under a high arch of interlacing tree boughs that met above the track. It was cool and pleasant, and when they reached a little brook the three lads decided to get out and eat some of the sandwiches and pie they had brought with them. They made a merry meal of it there under the trees, washing down their lunch with water from a small spring which supplied the brook.

They had just finished and were thinking of resuming their journey, when a sudden sound broke into the stillness of the woodland road—a series of sharp puffs.

“It’s an auto,” exclaimed Jack, who readily recognized the sounds.

“And it’s coming this way, too,” decided Tom.

Less than five minutes later the approaching automobile swept into view. The boys felt rather uneasy when they saw it, for they knew it instantly to be the identical yellow machine used by Mr. Peregrine’s enemies. Nor was their alarm at all allayed by the fact that the front seat was occupied by two men whom they well knew had no good intentions toward the inventor.

Worse still, the model and the accompanying papers of explanation were exposed to full view in the tonneau in case the men should stop and make an investigation. Tom made a move to cover the box containing the precious bit of apparatus, but Jack checked him. He knew that their only chance of escaping interference from the men now approaching them was to act as if they were merely out on a pleasure jaunt.

He counseled both Tom and Ralph to appear composed.

“There’s a chance that they won’t bother us at all,” he said, “although it does look as if they must have followed us from Pokeville.”

“How could they know which road we took,” asked Tom, “if that was the case?”

“Easy enough to trail our peculiar-looking tires,” was Jack’s reply.

He spoke in a low voice, though, for at that moment the yellow auto rolled up alongside and, as Jack had feared, the red-bearded man, who was driving, brought his machine to a standstill beside the boys’ Flying Road Racer.

“Well, once more we meet,” said he, as he shut off the gas and the spark; “out on a trip?”

The man did not have his goggles on this time, and now that his face was exposed Jack saw that it was a mean and crafty one. Two small eyes, set close together and gleaming brightly, seemed to search the lad’s heart as they were fixed on him.

Jack thought it best, however, not to let his suspicions appear on the surface. So he answered calmly enough:

“Yes, we are out for a short run through the country. We are thinking of turning back now, though.”

“Is that so?” was the rejoinder. “Well, we are going on. Got a bit of wire you can let us have? The insulation on one of ours is worn through.”

“I think we can spare you a piece,” said Jack, thinking that this would be a good way to get rid of the men. He rummaged in the tool box and soon produced what was wanted. The red-bearded man thanked him and, having adjusted his engine, he and his companion drove off.

“Well, what do you make of that?” exclaimed Jack, in some wonderment; “the fellow was just as cool as if we hadn’t chased him across Mr. Peregrine’s estate yesterday.”

“I’m glad you didn’t refer to that,” said Tom; “it might have made trouble; and our first duty now is to get the model safely to Boston. We can settle up accounts with those chaps later. By the way, I guess it was a mere accident—their meeting us here.”

Jack looked rather perplexed.

“I don’t know exactly,” he said, with a dubious shake of the head, “and yet they didn’t seem to have any idea that we were on an important mission.”

“Unless they were foxy enough to cover up anything they knew about our having the model right here with us,” said Tom.

“At any rate, it will be best to wait here a while and let them get on ahead a good ways,” decided Jack; “the further off from those chaps we are the better content I am.”

“That’s so,” agreed Tom; “after all, if we get into Boston before dark it will be plenty of time. I do wish we hadn’t run across those fellows, though—or rather, that they hadn’t run across us. It’s made me feel rather uncomfortable.”

In accordance with Jack’s plan the three boys lingered on the woodland road for an hour or more, by which time they judged that the men would have got a good distance ahead. Then they resumed their journey. A short time later they passed through Compton and learned there that the yellow auto had passed through about an hour before.

“Looks as if they were going to Boston, too,” said Jack; “well, there’s one good thing, we know that they are ahead of us and not sneaking about trying to put up any tricks.”

As he had no wish to overtake the yellow car. Jack drove pretty slowly after they passed through Compton, which was set in the midst of quite a wild section of country, thickly wooded and hilly. The roads were fairly good, however, and the journey was without incident till suddenly, at a spot where a rough-looking track branched off from the main road, they were confronted by a sign:

Underneath, in smaller letters, were the words, “Take This Road,” with a rudely painted hand pointing toward the wood road.

“That’s odd,” commented Jack, as he stopped the machine; “they didn’t say anything to us in Compton about the main road being closed.”

“It is queer, certainly,” mused Tom, who had got out of the car and was examining the sign; “and, see here, Jack, the paint on this is quite wet.”

“I wonder if this can be some trick,” pondered Jack seriously; “and yet if it isn’t, we might get into serious difficulties by sticking to the main road.”

He got out of the car and joined Tom on the roadside. An examination of the wood road followed. It was even rougher at a closer view than it had appeared to be at first. It was grass-grown, too, and evidently but little used. But Jack’s quick eyes soon noted something.

An automobile had been along it. The fresh tracks were plainly discernible.

“The yellow auto took the wood road,” he decided; “maybe we are wrong in suspecting a trick, after all. Tell you what we’ll do, Tom, we’ll explore the main road a bit, and if we find it torn up further along we’ll take the wood road.”

“That’s a good idea,” agreed Tom, “but we don’t want to leave the Flying Road Racer unguarded.”

“No, that’s right,” said Jack; “Ralph could remain on guard while we went ahead on foot a ways. If you hear or see anything suspicious just shout to us, Ralph,” he enjoined, as he and Tom struck off down the main road to investigate. Just beyond where the sign that had stopped them was nailed up the road took a sharp turn, and bushes grew right down to the sides of the track.

Thus, a few steps took them out of sight of the Flying Road Racer and Ralph, who was quite proud of the trust reposed in him. They trudged on for a few hundred yards, but there was no sign that anything was the matter with the road.

“It’s just as I thought,” said Jack, “it’s a trick. We ought never to have left the machine back there. We——”

“Help!”

A shrill boyish cry of fear and alarm was borne to their ears from behind.

“It’s Ralph! Come on, Tom! Run as you never ran before!” shouted Jack, dashing off in the direction of the cries.

The boys ran fast; but when they arrived panting at the side of the Flying Road Racer there was no one there. Ralph had vanished as utterly as if the earth had swallowed him up, and the boys quickly realized another disastrous fact.

One look into the tonneau showed them that the model had been taken. The lads, although they knew it was useless, searched the adjoining bushes and woods for a trace of Ralph, and wakened the echoes with their shouts. But no trace of the boy or the model could be found. Indeed, they had not really expected success.

It was a bitter moment when, standing by the sign that had worked all this havoc, the two lads looked in each other’s faces and admitted that they had been tricked. Worse still, although they were certain that the men in the yellow auto had done this thing, they had not the slightest clue as to where they had vanished with Ralph and the model.

Jack felt his heart sink. Tom’s face bore a look of utter dejection. What would Mr. Peregrine say? It did not make the burden any the lighter to realize that in a measure the fact that they had left the Flying Road Racer practically alone was responsible for their disaster.

For a short space of time the lads were too thunderstruck to speak. Jack was the first to find his voice.

“What on earth are we going to do? How can we ever explain?” he quavered.

“If we hadn’t left the machine alone with Ralph we might have managed to fight the rascals off,” lamented Tom.

“Well, there’s no use crying over spilled milk, as dad says. The thing to do now is to decide on our next move.”

“Shall we go back and tell Mr. Peregrine what has happened?”

“No. There’s a bare chance that we may be able to recover the model and the papers and rescue Ralph.”

“You have a plan, then?”

Jack nodded.

“Not much of a one, though,” he hastened to say, “but it’s the best I can think of right now. Those fellows must have gone a short way up this wood road after putting up that sign to fool us. Maybe they watched us from the bushes. At any rate, we know that, wherever they have gone, they must have taken the wood road.”

“You mean to follow them up along the same road, then?”

“No, we’d stand no chance of overtaking them. My plan is to stick to the main road. I’ve an idea the wood road joins it again further on. At any rate, the main road will bring us to the vicinity of a telephone and we can notify the authorities to be on the lookout for that yellow auto.”

“I guess that’s about all we can do,” agreed Tom ruefully.

The Flying Road Racer was started again, and after about half an hour’s run the boys found themselves in a small town called Old Bridge. There they learned that the yellow auto which they were pursuing had passed through about half an hour ahead of them. The men in it had inquired the road to Boston. The storekeeper, who gave the boys this information, declared that he had seen no boy in the machine with the two men. “They were going like blazes,” he volunteered. “That’s a clue, at any rate,” declared Jack, as they set off for the police station to which the storekeeper had directed them; “we know that the men are bound for Boston.”

“A whole lot of good that does us,” grumbled Tom; “we might as well expect to find a needle in a haystack as find two men, who wish to remain concealed, in a large city.”

The Old Bridge police force—which consisted of three men and a captain, was notified of the happening on the road, and the chief promised to have a thorough search of the woods in the vicinity made, and notify the boys in Boston if he came across any clues. For Jack had made up his mind to keep on to the city and lay the whole case before Mr. Bowler, the lawyer.

“He will know better what to do than we do,” he said, “and may be able to suggest some plan for recovering the model and poor Ralph.”

It was with heavy hearts and doleful countenances that the young inventors soon afterward drove into the city and, having put the Flying Racer up at a garage, set out on foot for Mr. Bowler’s offices.

They found him to be a large, rather stern man, who plainly was exceedingly put out by their news. However, he communicated at once with the police, and was assured that a sharp lookout would be kept for the yellow auto.

“What do you think of notifying Mr. Peregrine?” inquired Jack.

“I don’t think the time is yet ripe for that,” was the reply, which rather relieved the boys’ minds; “Mr. Peregrine, as you have doubtless observed, is a very nervous man, and I don’t wish to cause him a shock until we are sure we have done all we can to recover his property. Allow me to say,” he added, “that you did a very unwise thing in leaving that machine unguarded. However, I suppose you are not so much to blame as might appear on the face of it.”

“Just as if we didn’t feel badly enough already,” said Jack, as they left the office. Mr. Bowler had promised to notify Mr. Peregrine in a non-committal way of their arrival, but to withhold the news of their misfortune for the present. It was also arranged that the boys should stop in Boston for a day or so, in order to try and identify the men, or pick up some clue of value. Mr. Bowler promised to explain the cause of their continued absence to Mr. Peregrine over the long-distance telephone.

Under ordinary circumstances the lads would have devoted at least a part of their time in Boston to sight-seeing. But they were in no mood for this, and, having registered at a quiet hotel, they went at once to their room to talk matters over. But, as might have been expected, their deliberations did not lead them to anything definite. In fact, the more they discussed the case, the more hopeless did it appear to become.

They ate a melancholy enough supper in the hotel and, after disposing of the meal, sallied forth; more because there didn’t seem anything else to do than in the hope of picking up any information concerning the missing model. They walked through gaily lighted streets, and after a while reached a part of the city that was not so well illuminated, and where evidences of squalor and poverty began to abound. The thoroughfares were narrow and dark, and the houses more like rookeries than decent dwelling-places.

In and out of dark doorways, sordid, ragged men and women slipped in a furtive sort of fashion.

“My, we are in the slums with a vengeance!” exclaimed Jack.

“Yes, let’s go back. I don’t much fancy this part of the city, and some of those men look desperate enough for anything.”

In fact, several of the bloated, red-faced beings they had encountered had stared speculatively at the two well-dressed, clean-cut lads, as if wondering what they could be doing in such a part of the city. Moreover, Jack and Tom each had quite a sum of money in his pockets, and it was really tempting fate to walk about in such a section with well-lined pocketbooks.

So they turned to retrace their steps. But in the narrow, badly lighted streets, they inadvertently took a wrong direction, and before long they found themselves in a still more ill-favored section.

“I wish we could see a policeman,” remarked Jack, looking about; “I hardly like to ask the way of any of those ruffianly looking men we’ve passed.”

“Nor I,” was Tom’s rejoinder. “Well, let’s keep right on our way, and hurry up, and we are bound to get out of this neighborhood before long.”

Accordingly they quickened their pace. They were passing a dark doorway leading into a particularly rickety-looking rookery, when a man, who was coming out of it hastily, almost collided with them. He wore ragged clothes, but something about him seemed strangely familiar to Jack. The next instant he knew what it was.

The man, who had a flaming red beard, was the same fellow who had driven the yellow auto.

Jack made an impulsive leap for him.

“I want to speak to you,” he began; “you——”

But the man, after casting a hurried, half-alarmed look at the two lads, dodged back into the doorway like a rabbit into its burrow. Without considering the risk he was running, Jack dashed after him into the dark, ill-smelling hallway of the tumble-down building.

“Stop!” he shouted at the top of his voice, but the sound of rapidly retreating footsteps was the only sound that came back to him from the thick velvety darkness of the hallway.

“Tom, run out and get a policeman, and come back as quick as you can!”

Jack flung the words back as he leaped forward and stumbled against the bottom step of a flight of stairs. Higher up he could hear his quarry scuttling off in the darkness like a rat.

“You’re going after him?”

“Yes. I must. We’ve got a chance to get on the trail of these rascals right now, and I don’t intend to miss it.”

There was a snap in Jack’s tones as he spoke that convinced Tom it would be useless to argue. He hurried out to get an officer of the law while Jack plunged blindly up the staircase, stumbling at every other step. Ahead of him he could still hear the retreating footsteps.

In his anger at the behavior of the rascals who had stolen the model and kidnapped young Ingersoll, Jack gave little thought to the grave danger he was running. Guided by the sound of the unseen man’s flight he bounded up the stairs at top speed, barking his shins and bruising himself as he stumbled and slipped in the darkness.

One—two—three landings he passed, and then he came to what appeared to be the top story of the old house. At any rate, above his head was a square of star-spangled sky, framed apparently by a skylight. Jack reached out a hand and encountered the rungs of a ladder. Clearly it led to the roof, and the man he was pursuing had used it to reach the top of the rickety old edifice.

“Well, here goes!” exclaimed Jack; “it’s taking a big chance, but if I lose him now I might as well bid good-bye to the chance of ever getting on his tracks again.”

While this thought flashed through his mind he was rapidly scaling the ladder. In a jiffy he was on the roof of the tenement. But not a trace of the man he was following could he see. All at once, however, he spied a sort of raised doorway on what appeared to be the roof of an adjoining house.

A space of some three feet separated the two houses, but Jack jumped across it without hesitation. From the fact that the man was not in sight, and there was no other place down which he could have vanished. Jack argued that he must have descended by this scuttle.

A ladder, similar to the one he had just ascended, led down from the scuttle to the interior of the house into which he believed the red-bearded man had vanished. Jack descended this, and found himself on a landing illumined by a smoky lamp. Opposite to where he stood was a door.

While he stood there, still hesitating, he heard from within the room a cry that thrilled his blood.

“Don’t! Oh, don’t! I’ve told you all I know! I have, really I have!”

“Heavens! That’s Ralph’s voice!” gasped Jack; “those rascals have got him prisoner in there and are trying to find out something more about Mr. Peregrine from him. Oh, if Tom will only hurry with that policeman! I guess I’ll go back and meet him and——”

Crash! Jack felt a sudden stinging blow on the back of the head. A hundred brilliant lights danced in front of his eyes, and then came what seemed to be the bursting of a bomb within his head. At the same instant everything went black.

“Humph! That’s the time I fooled you nicely,” muttered a voice, as a figure stooped over the unconscious boy and raised him from the floor.

It was the red-bearded man, by name Jake Rook, who, instead of descending the scuttle as Jack had imagined, had been hiding behind a stack of chimneys. He had seen Jack vanish into the scuttle, and had crept softly after him without the boy having any notion that danger was behind him.

“Get the police after me, eh?” he growled, still holding Jack’s limp figure in his arms; “not yet, young man, nor soon, either, if Jake Rook knows his business.”

So saying, he half-lifted, half-dragged Jack toward the door and rapped on it three times in a peculiar manner. It was instantly opened, and the rat-like face of the black-moustached man appeared. The instant his eyes lit on Jack’s pallid countenance, as he lay supported in the other’s arms in the doorway, he gave an exclamation.

“By hooky, Jake! One of those kids! How on earth?”

“Never mind questions now. I’ll explain it later. Help me get him inside. Hurry now. The other kid’s gone alter the police.”

“Jove! How did they locate us?”

“Don’t know. Accident, I guess. I ran right into ’em as I was coming out of the doorway next door.”

While they were speaking the two men dragged Jack into the room and flung him on a rough bed in one corner of the place. Already huddled miserably on the wretched pallet was the figure of Ralph Ingersoll. His face was pale and scared, and he had a bruise on his forehead, received the day before when he had gallantly attempted to fight off the two rascals in the yellow auto.

“It’s Jack Chadwick!” he exclaimed, as the men flung their unconscious burden down; “how did he come here? What dreadful thing have you done?”

“You shut up,” warned Jake Rook savagely; “listen, now, Rad.”

So saying he launched into an account of just how he had encountered the two boys and how he had tricked Jack into walking into a trap. While he was doing this Ralph, despite the risk he ran of being brutally treated by the men, got some water from a tin jug in one corner of the room and bathed Jack’s forehead. But the boy’s eyes remained closed, and his heavy breathing showed that he was far from recovering consciousness.

“The question now is, what’s the next best move?” queried Radcliff, as Jake Rook concluded his recital.

“Well, we’d best lie quietly here for a while. You see the police will be in the next house in a few minutes. They’ll search it and maybe this one, too.”

“In that case we’d better get out of here.”

“No, I’ve got a better plan.”

“What’s that?”

For reply Jake Rook gave his beard a tug and off it came, revealing him as a clean-shaven fellow with a heavy bulldog jaw. Next he removed a wig, and no one would have recognized him, even had they had a far longer acquaintanceship with him than had Jack or Tom.

“You’re a wonder, Jake,” exclaimed his companion admiringly; “well, what now?”

For answer Jake Rook stepped to the wall. He fumbled for a minute and then pulled back a section of the wainscotting, disclosing a sort of dark closet within.

“You get in there with the two kids, and if they try to make a holler you know how to keep them quiet. Hark!”

“Someone’s on the roof!”

“That’s right. In with you. Quick, now, they’ll be here in a minute.”

The two men picked up Jack and carried him to the opening, thrust him in. Ralph was bidden to follow, and he was far too terrified to make any objections.

“If he makes a sound you know what to do, Rad?” said Jake Rook, with a sinister look at the trembling boy.

“I know, all right,” muttered the other, producing a revolver from his hip pocket and tapping it suggestively.

Jake Rook’s disguise was thrown into the hole in the wall also, and then the panel was slid into place again. This done, it would have defied the keenest eyes to tell that there had ever been an opening there. As the panel was slid shut the vastly altered Jake Rook tiptoed softly across the room to the door and listened intently. He was just in time to hear somebody descending the ladder.

Instantly he slid across the room and threw himself on the couch, drawing the dirty blankets up to his chin. He had just done so when a sharp rap sounded on the door. Jake instantly began to cough in a painful manner.

“Ugh-ugh-ugh! Who’s there?”

“Open this door at once!”

“Ugh-ugh, I’m sick in bed. Open it yourself. What is it? Ugh-ugh-ugh—what do you want?” As he spoke the door was flung open and two policemen, with Tom just behind them, stepped into the room.

“Who are you?” demanded one of them of the figure on the ragged bed.

“Ugh-ugh—oh, my cough!—My name’s Tattered Terry. I was selling papers up to a week ago, when I took sick. Ugh-ugh, how my cough hurts!”

“Guess we’re on the wrong scent,” said one of the policemen.

Then he turned to the huddled figure of the man on the couch.

“Did you hear any disturbance here to-night? We’re looking for a boy who entered the place next door and has vanished.”

“Ugh-ugh-ugh,” and Jake Rook was shaken by what seemed to be a paroxysm of coughing, “if he’s in the next house, why don’t you look there?”

“We have, but there’s no trace of him,” burst out Tom; “are you quite sure you’ve heard nothing unusual?”

“Ugh-ugh. Oh, my poor lungs! Not a thing, my boy, not a thing. Ugh-ugh—is that all you want to know?”

“I guess that’s all,” said one of the policemen. Turning to Tom, he continued: “Are you quite sure he went in next door?”

“Yes, oh, yes, I’m certain of it. I’d know the house by those peculiarly shaped lower windows. Oh, what can have become of him?”

“Well, he’s not here, that’s certain,” said one of the policemen and, with Tom in despair at the disappearance of Jack, they bade the seeming sick man a gruff good-night and left the room. But Jake Rook did not arise immediately. Instead, he lay very still till he was sure that the police had visited the other dwellers in the rookery. Then he sprang from the bed and hastened to the panel. In a second he flung it open and released Radcliff.

“Phew!” panted that worthy, as he stepped out into the room, followed by Ralph, who looked more woebegone than ever, “it’s like a furnace in there. I don’t think we could have stood it much longer.”

Ralph, who felt sick and dizzy from his confinement in the stuffy hole, reeled over to the cot and sank down on it wearily, while the two men once more lifted Jack across the room. His body was limp, and his face still white and deathlike. Jake Rook gave a startled look at him.

“He’s taking a long time to come to,” he growled; “I hope I didn’t hit him too hard.”

“What do you mean?” exclaimed Radcliff, a rather scared look coming over his countenance.

“Why, that—that——Hark! What’s that?”

Somewhere below in the house somebody was shouting something at the top of his lungs. What was it, that alarmed cry, coming in that high-pitched voice?

Radcliff stepped to the door and opened it. The cry was plain enough then. It was being caught up and echoed by a score of frightened voices throughout the tumble-down tenement.

“Fire! fire! fire!”

On the bottom floor of the rickety old tenement a lamp had exploded. Already the flames were spreading to the stairways.

“We’ll have to get out by the roof!” exclaimed Radcliff, in a nervous tone; “this place will burn like a haystack once that fire gets a good start.”

“That’s right! Come on, we’ve no time to lose. Here, you,” and Jake Rook seized Ralph roughly by the wrist and began dragging him out of the room.

In the meantime Radcliff dived under the cot and secured the model of the vanishing gun machine and the papers which had been hidden there. Having done this, he started after Jake Rook. Already the street below was full of shouts, and the acrid reek of smoke was filling the hallway.

“Come on! We’ve no time to lose,” admonished Rook, rushing through the doorway, still holding Ralph in an iron grip.

But the boy hung back, pleading piteously. His eyes were on Jack’s unconscious form, which lay just as it had been flung across the cot.

“But, Jack—you’ve left Jack!” he cried. “Surely you don’t mean to leave him behind!”

“You shut up and come on, or I’ll take steps to make you,” was the gruff reply, and the next moment Radcliff closed the door of the room, and dragging Ralph after them the two ruffians effected their escape from the burning house.

“And you could find no trace of him?”

It was the next morning in Mr. Bowler’s office, and that man of the law was seated at his desk with Tom Jesson beside him. Tom had just finished telling of the events of the preceding night. The lad was pale and his eyes were red from lack of sleep, but there was a ring of determination in his voice as he replied to Mr. Bowler’s query.

“I’ve told you all there is to tell, sir; but if Jack Chadwick’s on top of the earth I’m not going to give up the search till he is found.”

“That’s the right spirit, my lad,” commented Mr. Bowler, “but at the same time we appear to be up against a stone wall. The last you saw of him was when he vanished into that house. There is no question in my mind but that the men who have harassed you seized him to save themselves from the police. But the question is, what have they done with him?”

“That’s just it,” said Tom despairingly, “there isn’t a single clue to go upon. As you say, we’ve run into a stone wall. But knowing Jack as I do, I’m sure that we’ll get track of him again somehow.”

But the lawyer did not appear so hopeful.

“This gang, or rather the agents of the rich men who are trying to secure this invention, appear to have a far better organized and desperate plan of campaign than we imagined,” he said; “however, I will engage detectives and, in the meantime, we must notify Mr. Peregrine. The news can be kept from him no longer.”

Tom agreed to this, although he knew that the inventor would be driven almost frantic by the news that his vanishing gun model was in the hands of his enemies.

“Now, while I get Mr. Peregrine on the long-distance ’phone,” said the lawyer, “suppose you go over to the garage where you left your machine and bring it around here. We have a lot of ground to cover if we are to get on the track of those rascals, and that will be the quickest way to get about.”

And so it was arranged. While the lawyer got into communication with the inventor Tom fetched the Flying Road Racer around from the garage where they had left it. He found Mr. Bowler waiting for him with the information that Mr. Peregrine had taken the news of his loss more calmly than he had expected.

“By the way,” he went on, “Mr. Peregrine informed me also of something that you should know. It appears that your young friend, Ralph Ingersoll, is being eagerly sought for by the circus men from whom you took him. They seem to have some strong reason for wishing to get him back, and even went to the length of offering a large sum for his recovery, which Mr. Jesson of course refused. He told them, so he informs me, that if they had a legal right to the boy they could obtain his custody through the proper channels.”

“I doubt if they could find him through any channels now,” said Tom, with a grim smile that ended in a sigh as he thought how Jack, too, was now mysteriously missing.

Mr. Bowler, who knew quite a good deal about autos, tried to divert Tom’s mind from his troubles during the ride to police headquarters by discussing the points of the Flying Road Racer with the young inventor. But Tom only replied listlessly. His thoughts were centered on his missing chum and cousin.

There was no news of the yellow auto or of its two operators at police headquarters. This hardly surprised Tom, who had concluded that such clever rascals as Rook and Radcliff had shown themselves to be, would surely have had sense enough to cover up their tracks.

As they were leaving the building one of the two policemen who had helped Tom in his search the night before was coming in. He stopped Tom and spoke to him.

“Here’s a funny thing,” he said; “you know that house next door to the one where your friend vanished? Well, it burned down last night. The flames swept right through it from cellar to garret. Left nothing but the brick shell.”

This news did not particularly interest Tom. He had no idea that Jack had been left behind in the burning building by his captors and, therefore, had no reason to be concerned in the matter.

“It is an odd coincidence,” he said, in reply, as he passed on; “I’m glad we made sure that my cousin wasn’t in the place or I’d be worried.”

“Well, I hope you find him soon,” rejoined the other; “you can depend on it, that if he’s in Boston we’ll get a line on him somehow.”

Although Tom was by no means so sure of this, he thanked the bluecoat, and presently was seated in the Flying Road Racer once more with Mr. Bowler beside him.

“Too bad,” said the lawyer, “although I really hadn’t much expectation that we’d learn anything new. These men we are pitted against are much slicker and smarter than we thought.”

“Do you think that the red-bearded man and his companion are the principals in this thing?” asked Tom, as the machine moved off.

“No; they are simply the tools of a powerful syndicate in New York, composed of wealthy but unscrupulous men, who are far too cunning to undertake the actual rascality. The thing that is bothering me is—are they still in Boston or have they left with the stolen model?”

“And what bothers me,” said Tom, rather sharply, “is what has become of my chum?”

The lawyer looked at the boy beside him. When first he had met Jack and Tom, under circumstances of which we know, he had felt rather inclined to despise them for the way in which they had let the precious box slip out of their custody. He had undergone a change of feeling, though, since he had seen that both boys were as keen-witted and resourceful as their foes were unscrupulous and rascally.

“There, there, Tom,” he said kindly, “don’t mind me, and don’t feel annoyed because I seemed for a minute to think more of that box than of your cousin. I tell you what we’ll do,” he went on; “there’s nothing like a good spin along a country road to clear one’s head and enable one to do some stiff thinking. Suppose we take a little run out of town?”

“I think that’s a good idea, sir,” agreed Tom, and soon the Flying Road Racer was spinning through the suburbs, and then out upon a country road which ran through a charming landscape, dotted here and there by farmhouses surrounded by woods and fields. The lawyer appeared to be thinking deeply, and Tom did not interrupt him. Instead, he attended strictly to his driving, keeping his eyes on the road ahead. They took a spin of twenty-five miles or so, and then on Mr. Bowler’s suggestion they turned back.

They ran back toward the city at a fair speed; but they had not gone more than a few miles before Tom, his eyes fixed on the road, became aware of an astonishing thing. The thoroughfare was straight and level, and out of a cloud of dust ahead there suddenly emerged an automobile. It was coming toward them at a slow gait.

There was nothing very astonishing in this, of course, and in itself it formed no reason for Tom’s startled exclamation. The surprising thing about the approaching car, that Tom first noticed, was that nobody was driving, or occupied its seats, and the next amazing feature of the oncoming car was its color. It was a bright yellow—and we know that Tom had a peculiar interest in yellow touring cars just then.

“Look, sir! Look,” he cried to Mr. Bowler, “if that isn’t the same car those fellows used it’s the twin of it, and more astonishing still, it has no driver.”

“Bless my soul, nor has it! There’s some mystery here.”

Tom slowed down the Flying Road Racer and began to climb out on the running board. At length he brought his machine to a standstill, operating the controls with one hand. He had caused the machine to halt so that it was at one side of the road, offering no obstacle to the driverless car which was slowly approaching them.

“What are you going to do?” demanded the lawyer, as Tom, holding on with one hand, leaned far out from the running board of the Flying Road Racer.

“Find out what this all means, sir,” was Tom’s rejoinder.

Hardly were the words out of his mouth when the driverless car passed them. As it did so Tom made a flying leap for its running board. He landed safely, clinging on to the side of the machine. Then, while the lawyer watched with astonished eyes, the boy clambered into the vacant driver’s seat and, shutting off the power, applied the footbrake, bringing the car to an abrupt stop.

“Well, of all astounding things,” exclaimed Tom as, having brought the car to a stop, he examined it carefully. It was undoubtedly the same car which had been used by the men who had caused all their troubles. But what had become of them? How did the car come to be running itself? How had it kept on a straight course?

The last of these questions was answered when Tom discovered that, attached to the steering knuckles, was a device which, by an irony of fate, he and Jack Chadwick had invented and marketed. This device was in pretty general use and was known as the Automatic Steersman. It consisted of stout springs attached to each steering knuckle, and connected with the “helm” of the auto in such a manner that, provided the wheel was not turned, the car would automatically be kept on a straight course. The device had been thought out by the boys as an aid to beginners in auto driving; but it had been found so useful that many skilled drivers had adopted it. This, then, explained how the car had kept to the road with no one at the wheel.

But the deeper mystery of how it came to be where it was, and minus its occupants, was far from a solution.

“There’s something mighty out of the ordinary in all this,” decided Tom Jesson, in a puzzled tone, as he stood beside the machine on the dusty road.

“This is the most puzzling thing yet.”

Tom uttered the words as Mr. Bowler, who had alighted from the Flying Road Racer, joined him at the side of the yellow car.

“It certainly is,” he rejoined; “it’s piling mystery on mystery. Where can the car have come from?”

“Not very far, that is, by itself,” rejoined Tom instantly; “you see this automatic steerer would only keep it on the road on a straight course. It couldn’t help it to negotiate any turns.”

“That’s so. When did you first sight it?”

“As it came over the top of that hill yonder. I propose that we drive along the road and see if we can’t pick up some clue to the mystery.”

“An excellent idea. If, as you say, the car can’t have come far, we ought soon to encounter something that will put us in possession of some knowledge of what has happened. Suppose you drive your Flying Road Racer, as you call it. I’ll follow in this yellow machine.”

“Very well,” agreed Tom, who knew that the lawyer could drive and had a car of his own, for Mr. Bowler, in chatting with Tom, had informed the boy of this fact.

Tom walked back to the Flying Road Racer, while the lawyer got into the yellow car and turned it around with a dexterity that showed he was no greenhorn at driving an auto. Tom in the lead drove slowly, keeping his eyes wide open.

“You watch the right-hand side of the road. I’ll watch the left,” he shouted back to Mr. Bowler.

“Very well,” was the lawyer’s reply, and in this way the two autos rolled slowly along the road and over the brow of the hill, over which the yellow car of mystery had appeared. Beyond the rise the road took a dip, but was quite straight.

At the bottom of the dip was a bridge spanning a small creek. The road at each side of the bridge was sandy and soft, and the autos puffed rather heavily through it. All at once Tom checked the Flying Road Racer; he then raised his hand above his head to signal Mr. Bowler to stop the yellow car also.

“Have you found something?” asked the lawyer eagerly, as he applied the brakes and cut off power.

“Yes. Look here in the sand at the side of the road. There are footmarks and—yes, by ginger!—there’s been a struggle of some kind here, Mr. Bowler.”

“Let us get out and examine the footprints more carefully,” suggested the lawyer.

Accordingly both the man of law and the boy got out of their machines and the next minute were bending intently above the maze of footmarks that Tom had noticed. It seemed plain enough that, as the boy had surmised, there had been a struggle there. No other explanation would fit the case. The grass was trampled down and twigs broken from the bushes in the vicinity of the tangle of footmarks.

“Well, I guess you are in the right about there having been a struggle here,” said the lawyer, “but we are not any nearer to knowing who engaged in it, what it was about, or anything else that might do us some good. I’m inclined to think——Bless my soul, boy, what’s the matter?”

Tom had flung himself forward with a joyous shout. His leap landed him on the edge of the thicket right alongside some object he had descried. He stooped swiftly and lifted it with a cry of triumph.

It was a square wooden box that the boy held up, and the keen-witted lawyer instantly guessed what it was.

“The model box!” he exclaimed.

“Yes! Hooray! We must be close on their tracks now.”

But oddly enough, as Tom with a flushed face set down the box and prepared to open it, the lawyer by no means seemed to share his satisfaction. It was incomprehensible to him that the men who had stolen the model would have thrown it away like that.

He was not surprised, therefore, when Tom, having opened the lid and peeped into the box, gave vent to a cry of chagrin.

It was perfectly empty.

“Just as I thought,” said the lawyer, rather grimly; “however, the finding of that box establishes one thing clearly enough.”

“And that is?”

“That those two rascals have been here. May be close to us now.”

Tom glanced about somewhat apprehensively. He recollected that, not so very long before—when they had left the machine on the wood road—the two rascals had been closer to them than they thought for. This might be the case now.

“I wish we had some sort of a posse at hand to make a thorough search of the woods,” he said.

“So do I,” was the rejoinder, “but you can depend upon it that those fellows are not lingering here since we arrived on the scene.”

It was at this moment that Tom made another discovery—a cap that lay in some bushes almost at his feet! He picked it up with a cry, having recognized it as the one that Mr. Peregrine had given to poor Ralph.

“They—they’ve had Ralph here with them, Mr. Bowler,” he exclaimed excitedly; “just look here. This is his cap—or rather one that was given him till he could get an outfit to replace his circus clothes. I wonder if it is possible that he——

“Hello! What’s that?”

“Sounds like a groan,” decided the lawyer, as, from the bushes that clustered against the bridge supports, the moaning sound came once more.

“That’s somebody in pain,” exclaimed Tom, shoving his way through the undergrowth that clothed the steep bank thickly.

“Be careful, my boy. You don’t know that this isn’t a trap,” cautioned the lawyer; “those men may be——”

He didn’t finish the sentence. A joyous cry from Tom cut it short. The boy had reached the edge of the creek, and in a clump of alders there he found something that made him utter a shrill cry of delight.

“What is it? What have you found?” demanded the lawyer, peering down.

“Why, I’ve found Ralph, Mr. Bowler. Poor lad, I’m afraid he’s hurt, though. Can you help me to get him up the bank?”

“Can I? Of course I can,” and the dignified lawyer plunged down to where Tom was standing. He found the boy stationed above the recumbent form of a small, frail boy, who was bleeding from a cut on the head. The lawyer made a swift examination of the wound and then told Tom to dip his handkerchief in the water of the creek, and when this had been done he bathed the wound carefully.

As the cold water touched him, Ralph, who had been moaning feebly, opened his eyes and seemed to be trying to speak.

“Not now, my lad,” ordered the lawyer, and then to Tom: “He is not badly hurt. I have examined him and no bones are broken.”

“But the cut on his head?”

“Nothing very serious. Now give me a hand and we’ll get him up the bank and into one of the machines. Then we’ll make as fast a run as possible for a doctor.”

Tom lost no time in carrying out the lawyer’s instructions, and by dint of scrambling and clambering, the two managed to get the wounded lad up the bank. This done, he was placed in the tonneau of the Flying Road Racer, and the two machines sped on once more.

Not more than half a mile further on they reached a village called Boonton. On inquiring, they were soon directed to a doctor’s house, and Ralph, who, after a brief period of consciousness, had again lapsed into insensibility, was placed in the physician’s hands for treatment. Tom was almost dying with anxiety to ask the lad some questions which might put him on the track of Jack, but the physician forbade his patient being bothered for the present.

“But I will allow you to talk to him this evening,” he said, and with this Tom and Mr. Bowler had to be satisfied. The physician, whose name was Tallman, had a sort of small private hospital in one wing of his house, and in a room in this Ralph was put to bed and made as comfortable as possible.

“The boy appears to have been half starved,” said the doctor, “and that has weakened his system so much that he cannot resist pain like a healthy person.”

Whereupon Tom related all he knew of Ralph’s story, not omitting to tell of the rough hands into which the boy had fallen the day before.

“What is his name?” asked the doctor.

“Ralph,” rejoined Tom, and was not slow to notice an odd look pass over the physician’s face. It seemed almost as if the name called up a familiar recollection to him.

“Do you know any one of that name?” asked Mr. Bowler, who, like Tom, had seen the interested expression of the medical man.

“I did once, many years ago,” was the reply, “but I have no idea that this lad can be any relative of his. After all, Ralph’s a common enough name.”

Jack Chadwick opened his eyes and looked languidly about him. His ears sang with the noise of a hundred waterfalls, his brain throbbed cruelly.

“Where on earth am I? What has happened?” he thought dully, as his eyes took in the unfamiliar and squalid surroundings.

“Oh, how my head hurts!” was his next thought. “What can be the matter? I must have——”

Just then recollection rushed back with the force of the incoming tide. The boy recalled how he had followed Jake Rook up the stairs of the tenement house, how he had crossed the roof, and finally, how he had heard Ralph’s cry for help. At that point recollection stopped.

He sat up, feeling sick and giddy. An almost overwhelming nausea was upon him, too. But he overmastered the feeling and rose unsteadily to his feet.

“What a filthy room!” he mused, looking about him by the light of the smoky lamp. “I’d give a good deal to know how I got in here. By the feeling of my head I must have fallen, or been dealt a blow or something. And where’s Tom? He went for the police and—hullo! what’s that? Smells like something burning.”

The acrid smell of the flaming lower floors of the tenement had, in fact, penetrated Jack’s nostrils, although, of course, he didn’t dream for an instant that he was in a fire trap of the worst kind. But suddenly, as he sat there trying to collect his wits, he became aware of shouts and cries and the clanging of bells and shrieking of whistles.

“There must be a fire somewhere,” he thought, recognizing the clangor of the bells and the screaming sirens of the fire engines; “maybe that’s what delayed Tom. If there’s a fire close by there must be a lot of police there. Anyhow, I’ve got to get out of this.”

He arose dizzily and crossed to the door. As he flung it open a great cloud of suffocating smoke struck him full in the face, almost depriving him of breath.

Jack reeled back, slamming the door. A thrill of horror was in his veins. His heart beat thickly, but his blood was icy cold.

“The fire’s here! In this house!” he gasped, “and if I don’t get out pretty quick I’ll be roasted alive!”

He hastily surveyed the room. On one side was a window. It suggested a means of escape other than the door, which was impassable on account of the smoke outside. Jack’s awakening had come several minutes after the departure of Jake Rook and his companion with young Ralph. The flames had now eaten their way up two flights, and the noises he had heard from the street were the shouts of the firemen fighting the blaze and the rattle of the apparatus as it clattered up.

Hastily opening the window, Jack looked out into what, at first, seemed to be a black void. The feeble stream of lamplight from the room, however, presently revealed a wall opposite to him, pierced with windows. One of these was immediately across from the casement out of which he was gazing. The distance across the shaft did not appear to be more than a few feet—possibly three or four. If he only could find some way of spanning the shaft he might yet save himself!

He cast a rapid glance about the room. Its furniture was scanty enough not to require a very long investigation to itemize it. There was a rickety table, on which stood the smoky lamp, two decrepit chairs and the frowsy cot. But none of these seemed to Jack to be what he wanted.

While he still hesitated he felt a crash beneath him. The house shook and Jack knew that this betokened the fall of one of the lower floors. At almost the same instant the panels of the door began to blister, and smoke rolled into the room through a crack under the portal. The boy could now hear distinctly also the roar and crackle of the flames, and it was suffocatingly hot.

“I must do something and do it quick, too,” he exclaimed.

But what? He thrust his head out of the window and shouted at the top of his voice. But above the roar and confusion in the street his feeble cries did not travel far.

He looked about him despairingly. Was there nothing he could do? Nothing to save himself from a fiery tomb?

All at once he gave a glad cry. He had seen something that gave him a gleam of hope. From under the fusty blankets on the bed he had just glimpsed the protruding end of a plank. It gave him an inspiration.

Throwing back the greasy coverings of the cot he found that it was formed by placing planks across trestles, and one of these boards was just about the right length for the purpose to which he designed to put it.

His weakness forgotten in his excitement, the boy lugged the board across the room and thrust it out of the window. It just reached the opposite casement, resting its outer end on the sill beyond by a perilously narrow margin. But it was his only means of escape, and Jack didn’t hesitate an instant to clamber up on the board and begin the passage across the shaft.

Before he set out to crawl across his frail bridge he cast a backward glance into the room he was leaving. As he did so the flames burst through the panels of the door, and he was conscious of a puff of heat like that from the open door of an oven.

As he moved along and neared its center, the board cracked and bent ominously. It was not particularly thick, and Jack was no lightweight. The cold perspiration stood out on his face as he thought of what would happen if his slender support was to snap under him.

He did not know how great a fall he would have, but was well convinced that a tumble from the plank would mean death, swift and terrible. In this frame of mind he crept on. It seemed an eternity before he grasped the other window sill.

The boy had just gripped the projecting ledge of stone with his hands when he felt his support drop from under him. The swaying motion imparted to it as he crept across had caused the end that rested on the opposite window sill to jounce off. The next instant Jack was hanging by his finger tips, with space under his boot soles.

He tried to draw himself up, but, weakened as he was by ill treatment, he was unable to do so, and, worse still, he felt his strength fast leaving him. A cold sweat of horror broke out on him. Was he doomed to a terrible death, after all?

All at once his foot encountered something. It was a water pipe running up the side of the house and passing close by the window, to the sill of which he was clinging with such desperation. If he could only reach that pipe he might be able to save himself yet. The thought put new strength into his rapidly weakening grip, and he began to creep along the sill toward the pipe by moving his hands alternately. It was a fearful strain, and anyone in less perfect physical condition than the young inventor could never have done it. But do it somehow Jack did, and at last, by reaching out with one hand, he was able to grip the pipe.

Then came the most perilous part of his whole enterprise. He must hold on to the pipe with one hand while he let go of the sill with the other. And then, too, there was a chance that the pipe might not be securely fastened and might give way under his weight.

But it was no time to hesitate. In fact, every second his strength was oozing from him. With a prayer on his lips Jack clutched the pipe and made the swing. To this day he cannot tell how it happened, but he succeeded somehow in landing on the pipe, gripping it firmly with both hands. It was then a comparatively easy matter for the boy to draw himself up to the window sill and scramble over it.

He found himself in a cool, pitch-dark place, only faintly illumined by the flames from the house across the shaft. Jack felt in his pocket and was delighted to find that he had some matches there, although his money had vanished—the prudent Radcliff having picked his pockets while the lad lay unconscious in the secret recess.

He struck one of these matches, and as it flared up it showed him that he was in a large bare room with a pile of sacks in one corner and some barrels. The place was evidently a storehouse of some kind, but the boy did not stop to investigate much. Instead, he crossed to a door and gave the handle a tug. It refused to yield.

“It’s locked,” groaned Jack, tears almost rising to his eyes in his disappointment.

He beat on the portal and shouted with all his might, but no answer came. In fact, had he known it, he was in a warehouse in which nobody lived. At last, tired out by all he had gone through, the boy desisted from his efforts to attract attention. Thoroughly exhausted, he lit another of his precious matches and made his way to the pile of sacks. He sank down on them, noticing that they exhaled a pleasant aroma. He wondered what it was. Presently he realized,—coffee.

The half-starved, wholly worn out lad did not hesitate to help himself from one of the sacks that was open. But coffee beans are not very satisfactory fare, even to a half-famished boy.

Besides, Jack was thirsty. His mouth and tongue felt dry as lime kilns.

Small wonder that, in his extremity, the boy thought he should go mad. Luckily, however, exhausted nature asserted herself, and the deep sleep of total fatigue prevented his dwelling on his misfortunes.

It is now time to return to the bedside of Ralph Ingersoll, in the home of Dr. Tallman. It was evening and Tom, as he had promised, had returned to hear Ralph’s story and see what light he could throw on the fate of Jack and the stolen model.

Tom returned alone, Mr. Bowler having received an urgent telephone message on returning home, which commanded his presence at his office that evening. So Tom had driven out alone in the Flying Road Racer to have a chat with Ralph.

He found the lad sitting up in bed, much better, thanks to the doctor’s ministrations, and eager to see his friend. After first greetings had been exchanged, Ralph lost no time in plunging into his story. As our readers know, the lad had been surprised and carried off by the same two rascals who had stolen the model while he was left on guard at the wood road. Apparently, they kidnapped him on account of his desperate resistance. At any rate, he was bundled into the yellow auto, and hurried off down the wood road which, as Jack had surmised, joined the main thoroughfare further on.

Terrified half to death by the men’s dire threats to kill him if he made any outcry, the poor lad told how they had taken him to the room in the old rookery, which, it appeared, was used as a rendezvous for hard characters of all descriptions—which explained the secret hiding-place in the wall.

Tom, who had been warned by the doctor not to excite his patient, thought it best to let the lad tell his story in his own way, and therefore did not put any questions regarding Jack. It can be imagined, then, with what a cruel shock he heard of the lad’s being abandoned to his fate in the burning building, after the flight of Rook and Radcliff with the model and Ralph.

He sank his head in his hands, quite unable to speak for some moments. As he knew, from what the policeman had told him that morning, that the building had been gutted by the fire, he found it impossible to cherish a hope that somehow Jack might have been saved. When he grew calmer Ralph went on with his narrative.

It appeared that after the men had fled from the blazing building they made their way directly to a garage where the yellow car had been put up. This place was not, properly speaking, a garage at all, but a stable in the low part of town, kept by friends of the rascally pair. Here they spent the rest of the night, sleeping in a hayloft.

During their passage through the streets Ralph was given no opportunity to appeal to passers-by. Jake Rook’s threats of what would happen to him if he did alarmed him far too effectually for him to disobey the ruffian’s orders to keep silent.

That morning had been spent by Jake Rook in active work of some sort. At any rate, Ralph said he had gone out early, after writing several letters in a sort of office attached to the stable. As he left the place to post them he had dropped one unnoticed, and, as Radcliff’s attention happened also to be distracted at that moment, Ralph had picked it up.

All that morning and the early part of the afternoon were spent in the stable and then, after Jake Rook’s return, the auto was run out and Ralph ordered to get into it with his two guardians. He dared not offer any opposition and soon the trio, skirting the city by back streets, were driving along a country road.

“We came to a place where there was a bridge,” said Ralph, “and the men stopped the car there. I heard them say they were going to some place up the creek that the bridge crossed.

“They both got out of the car and one of them took the model out of the box and looked at it to see if it had been damaged, for we had come over some pretty rough roads.

“The engine of the car had been left running, though the clutch was out, and I thought that maybe it was my chance to escape. I knew a little about autos, for that circus gang had one once. So I put my foot on what I thought was the clutch pedal, and the machine began to move off. But it wasn’t going very fast and Jake Rook jumped on the running board and pulled me clear out of the car.

“He fell over as he did so, and we both rolled into the road. Before he could get up again the car was out of sight. Rook was so mad that he picked me up round the waist and ran to the rail of the bridge with me and—and that’s all I remember,” said Ralph, bringing his narration to a close.

It cleared up many points which had been enigmas, and Tom told Ralph how they had found him.

“And just to think,” he exclaimed bitterly, “that it wasn’t so very long before that that those ruffians made off up the creek. Oh! If only we could have caught them!”

“Why don’t you look at that letter I picked up?” suggested Ralph presently.

This was a surprise to Tom. In his grief over Jack’s fate he had forgotten all about the letter which Ralph had mentioned.

“That’s right, I’d forgotten you had it,” he said. “It may give us a clew. Where is it?”

“In the pocket of my coat. It’s hanging up over there on that hook.”

Tom lost no time in getting the missive from the garment Ralph indicated. It was addressed, in what was clearly meant to be a disguised hand, to Stephen Melville, No. 289 Wall Street, New York.

Tom tore the envelope open eagerly. Inside was a single sheet of paper, covered with the same half printed writing that was on the envelope. The note was brief and very much to the point:

“Phew! I should say that this does give us a clew!” gasped Tom, having read the note, “but it doesn’t give us any line on poor old Jack, and I’d rather have that than fifty models. Hold on, though! If we can find those men and get them arrested that may help us to trace Jack. I’ll get right back to the city now and notify the police at once. The old Haskins place!” mused Tom. “That must mean some old house or mansion in the vicinity of that creek. I wish——”

But just then the recollection of Jack’s probable fate swept over the lad again and poor Tom fairly broke down. In the midst of his collapse Dr. Tallman came into the room. His face was radiant and he seemed excited.

“Someone wants to talk to you on the ’phone, Tom,” he said kindly.

“To me?” exclaimed Tom, looking amazed.

“Yes, somebody in Boston. The call is from Mr. Bowler’s office.”

Greatly wondering who could be calling him, except the lawyer, Tom hastened to the ’phone, which was in the hall outside the room where Ralph lay.

“Hullo!” exclaimed Tom picking up the receiver, “hullo! Who is it—What—Oh, glory!—It’s Jack!”

And Jack, indeed, it was. The sound of his voice brought into Tom’s heart the most joyous feeling he had ever known. He fairly skipped about with excitement as Jack hastily told him of his escape from the burning building, and how, the next day, he had been discovered more dead than alive by workmen in the warehouse. The men found him in a swoon, but rushed him off at once to the Emergency Hospital, where nourishment and stimulants were administered.

The hospital people communicated with Mr. Bowler as soon as they found out who Jack was; but, through the error of a clerk in his office, the message had not been transmitted properly to his house. When he reached his office that evening, in response to the summons already recorded, his amazement may be imagined when, instead of the client he had expected, the missing Jack Chadwick greeted him.

The joyous news was soon communicated to Ralph, whose peaked face lighted up wonderfully at the glorious intelligence. In spite of Dr. Tallman’s urgent request to him to stay and have some refreshment, Tom insisted that he must get back to Boston without delay. He was crazy with impatience to get the letter Ralph had so cleverly picked up into the hands of the police, and to clasp Jack’s hand again.

Ten minutes later Tom was off on one of the most pleasurable trips of his life; shortly before he had hardly dared to hope that Jack had escaped from the flames alive. He promised to return in the morning. As Dr. Tallman said good-by he added:

“By the way, I think I shall have something remarkable to tell you ere long about this young Ingersoll. He is not by any means just what you think he is.”

With which puzzling words Tom had to be content, for the good doctor refused to say more.

“What a wonderful day this has been,” mused Tom, as he spun along the road, his searchlight brightly illumining the road ahead of him. So intent was he on his pleasant thoughts that he was quite startled when suddenly, into the circle of light ahead, there stepped a human figure. Tom turned out quickly to avoid running over him. But as he did so he heard himself hailed in a sharp voice.

“Hey, mister!”

“Well, what is it?” demanded Tom.

“Give me and my pard a ride inter Boston?” Now, at any other time Tom would have refused such a request, for just at that date holdups of automobilists were frequent. But at the moment, he felt so joyous and at peace with all the world, that he stopped the car and told the men to get in.

As the car came to a standstill two dark figures stepped into it out of the black night.

“Get back in the tonneau,” ordered Tom, “and hold on tight, we’re going to make a fast run.”

“But not the kind of run you expect, Tom Jesson,” came in startling contrast to the whining, tramp-like tones in which he had been hailed from the roadside. “Turn this car around and drive where we tell you.”

The command was enforced by the pressure of something cold to the back of Tom’s neck. With a sharp thrill of fear, the boy realized that it was the muzzle of a pistol that pressed against him, and that the man who had uttered the command to turn about was Jake Rook.

Tom did more rapid-fire thinking right then that he had ever done in his life before. Bitterly he blamed himself, too, for halting the car at Jake Rook’s request. If only he hadn’t done that, how different things might have been!

But Tom wasn’t the sort of lad to waste time in vain regrets. He realized plainly enough that he was in the power of the rascally pair who had made them so much trouble, and that in the event of his offering any resistance things might go hard with him.

He therefore decided to bide his time, and await the coming of some more favorable turn in his fortunes.

“Come on! Turn around and look slippy now!” growled Rook, emphasizing his order by an unpleasant “click” of the trigger of his weapon.

“Where do you want to go?” demanded Tom in as steady a voice as he could command. He was determined not to let the rascals see that he was afraid of them.

“None of your business. Your job is to do what you’re told—see?”

As there was nothing else to do, and resistance would have been infinitely worse than foolish, Tom obeyed. Inwardly he hoped that they would meet another car somewhere along the way that they were going, and in such a case he determined to appeal for aid, cost what it might. He knew that the road was a fairly well traveled one, and decided that, if only he had a decent proportion of luck, they might meet some other machine.

“Now drive ahead! Fast, too!” came the next order, as Tom completed his turn.

Tom started up at as fast a pace as he thought was prudent. He had no intention of wrecking the Flying Road Racer to please his captors. All this time Jake. Rook kept the muzzle of the pistol pressed to the lad’s neck. Tom could feel the disc of steel burning into his flesh, and no one can blame him for shuddering a bit as he realized the sort of man who was at the other end of the weapon.

They drove straight on for a mile or so without encountering a single other vehicle. At last they reached a point where a road branched off from the main thoroughfare.

“Turn off here,” ordered Rook gruffly.

Tom, perforce, changed the course of the Flying Road Racer, and they began to bump along over what seemed to be a very rough and little used road. The white rays of the searchlight showed dark trees on each side of the track, meeting in an arch overhead.

It was like driving through a leafy tunnel. But Tom wasn’t paying much attention to scenery right then. All he realized was that, in the very moment when a way out of all their difficulties seemed to have been found, things had lapsed back into as bad a state as ever. He wondered how Rook and his companion had happened to be on the road, and how they knew he would be coming along it.

As a matter of fact, neither of them had any idea that the autoist they had hailed was Tom till they heard his voice. Then Rook’s plans were made in a flash. The two men had been on their way toward Boonton to get a train into Boston when Tom came along. His advent had made a change in their plans.

The trees along the roadside began gradually to close in. The trunks were closer together. At last they reached a spot where it was impossible to proceed any further in the car. Tom brought it to a stop.

“All right,” said Rook, “that’s as far as the car can come. We’ll have to hoof it the rest of the way. Put out that searchlight and come on.” Tom extinguished the light, and Rook’s companion produced an electric torch. Guided by this, the party set out once more, Tom in advance, with Rook close behind and Radcliff hanging on to one of his wrists. As they proceeded it suddenly flashed across Tom that the men were taking him to one of their hiding-places—quite likely to the very “old Haskins place” referred to in the letter.

“Well, at any rate I may find a chance to get on the track of the model once more,” he thought, as they still pushed forward.

All at once through the trees the white outlines of a huge house loomed up in ghostly fashion. Tom guessed that it must be the Haskins place referred to in the letter he still had in his pocket. He wished now that he hadn’t it on his person. If the men should search him and should find it, they might have a clew to the whereabouts of young Ralph.

The house, as well as Tom could see in the starlight, was one of the old colonial type, with four great, gaunt pillars supporting the upper story. However, he had not much time to pay attention to details before the men hustled him around to a small side door, which one of them shoved open. It led into a small entrance hall, and through what had evidently been the kitchen. Dust and cobwebs were thick everywhere, and Tom saw that it must have been years since the place had any legitimate occupants. It seemed an ideal place for the outlaws who now, it appeared, haunted it.

They passed through the lower regions and up a flight of stairs into a huge and gloomy main entrance hall with doorways leading from it and a grand staircase at one end. The rays of the electric torch shone on gilding and white painted woodwork. But the woodwork was gray with dust and dirt, and the gilding was tarnished and neglected in appearance. It was a melancholy place, rendered doubly so by the conditions under which Tom viewed it.

Turning to the right, Rook, who had now assumed the lead, entered one of the rooms which opened upon the great hall. A huge glass chandelier hung from the ceiling and other evidences of past glories remained. But the wallpaper was peeling off in great blistery, bloated patches, and the rats scampered squeaking in every direction as they entered. Such a noise did the vermin make that Radcliff started and almost dropped his light.

“What’s the matter with you?” growled Rook in no amiable tones.

“Why, those confounded things gave me a start. I thought they were ghosts at first.”

“The only spirits round here come out of a bottle,” retorted Rook in a reckless tone.

“But they do say the old place is haunted,” said his companion with a slight shudder. “In Revolutionary time the redcoats killed a whole family on that staircase, and—hark! what was that?”

He stared nervously about him and something in a distant part of the house creaked and rattled.

“Nothing but a loose shutter, or some of those confounded rats,” was the growling reply of Rook. “Come on, now. Bring the boy into the hack room, where we can be more comfortable.” Radcliff, still showing signs of nervousness, advanced with Tom, and they passed out of what liad been the big drawing-room of the old mansion into a smaller chamber. In this were a table and two chairs, a rough cot and the remains of a meal on the table. A lantern also stood on that piece of furniture, and Rook lighted it.

“Now then, youngster,” he demanded, flinging himself into a chair, “where’s that young Mel—Ingersoll, I mean?”

This was the question which Tom had been dreading. But he assumed a bold front.

“I don’t know,” he said, “and if I did I wouldn’t tell you.”

A black look passed over Rook’s face. His lips, clean shaven now that the red beard had gone, compressed in a thin line. Tom knew from young Ralph’s story that the ruffian had discarded his disguise, and he thought that, villainous as Rook had looked before, he looked ten times worse now.

“Oh, you won’t tell, eh? Well, maybe we can find a way to make you.”

“What do you want to know for?” demanded Tom with a boldness he was very far from feeling.

“Because he’s in a certain party’s way, and we are going to get some money for putting him back where he belongs—with that circus.”

“That would settle the matter,” declared Tom, with seeming irrelevance. “If my life depended on putting him back with those ruffians, I don’t think I’d say. But I don’t know.”

Inwardly Tom was wondering over the mystery that seemed to have injected itself into the case of young Ralph. First the doctor had hinted at some secret, then there was the letter with its vague allusion, and now the rascally Rook seemed to have some knowledge of the lad.

Rook thought a moment, drumming the table with his fingers as if meditating.

“Do you mean to say that you and some other meddling jackanapes didn’t pick the kid out of the creek where we’d left him?” he asked presently.

Tom, who was a shrewd lad, saw by the man’s manner that he was—to use a slang term—fishing. He therefore shook his head.

“I don’t know what you are talking about,” he said, “but I can tell you this—the police of Boston are on your track for abducting my cousin Jack.”

A swift look of alarm sped across Rook’s face. Radcliff’s hand, which he had raised to light a pipe, shook violently. Tom saw that he had scared them, and determined to follow up his advantage. But Rook interrupted him.

“Why, what do you know——” he began, when there came a startling interruption.

Somewhere upstairs a door slammed, and then there was the sound of a stealthy footstep creeping, apparently, toward the stairway. Radcliff started up in wild-eyed terror.

“What is it?” he gasped. “Oh! What is it?” Tom himself was considerably startled, and Rook turned pale.

“I—I don’t know,” he stammered. “Hark!” They listened, hardly daring to breathe. The time, the place, and the ghostly stories that clustered about the old mansion, all combined to make the interruption an alarming one.

“It’s—it’s a ger-ger-ghost!” stammered Radcliff, his teeth chattering.

“Don’t be a fool!” hissed Rook. “There ain’t no such things. It’s a rat or a——”

A fearful yell suddenly broke the breathless silence. It rang through the deserted house in a way to make the blood run cold.

Radcliff could stand no more. With one bound he cleared the table, knocking over the lamp as he did so. Instantly the light was extinguished, plunging the place into total darkness.

The scream was repeated, followed this time by a ghastly sort of chuckle coming out of the darkness. Even Rook’s iron nerve gave way. With what seemed an echo of the spectral yell, he plunged forward, collided with a long, old-fashioned window that opened into the room, and plunged clean through the frame, with a crash of glass and splintering of wood.

Tom felt his scalp tighten with terror. His tongue seemed to cleave to the roof of his mouth. He could not stir from the spot as he heard those fearful steps drawing closer and closer.

All at once, as he stood stock still, his heart pounding till it shook his frame, something happened that changed him from inaction into wild panic.

From the direction in which he judged that the door leading from the large room into the small one must lie there suddenly appeared a spectral figure of seemingly unusual height. It was gleaming white and had an arm outstretched.

With a cry of fear Tom dashed off into the darkness. In his panic he did not know where he ran. As he sped along he could hear the swift pitter-patter of pursuing footsteps.

All at once, as Tom ran, the ground seemed to subside from under his feet, and he felt himself falling—falling forward into space!

In an office on lower Wall Street, New York, overlooking the East River with its bustle of water traffic, sat Stephen Melville, the man to whom Rook’s message had been addressed—a message that, as we know, he had not received. Melville was a man of about forty-five, heavy-jawed, coarse-lipped and bulky-necked, with a big, heavy body. But about the man there was, withal, a suggestion of brutal strength.

On the door of Melville’s office was painted the word “Private.” Without this screened-off sanctum was a busy room full of clerks and stenographers. On the door of this outer office appeared the words: “General Offices of the Artillery Devices, L’t’d.—Stephen Melville, President.”

At the precise moment that we are looking in on the offices of the Artillery Devices, L’t’d, a man whom we have seen before—to wit, Joshua Sawdon, owner of Sawdon’s Circus—shoved his way, and essayed to continue to shove his way, past an office boy, who, however, held up the showman at the rail behind which were the desks of the stenographers and clerks aforesaid.

Mr. Sawdon appeared to be out of temper. Seeing that it was in vain for him to try to get past the boy without sending in his name, he hastily wrote on a bit of paper:

“Young Ingersoll has gotten away. Must see you at once.—Sawdon.”

He folded this and handed it to the boy, telling him to take it in to Mr. Melville and “look slippy.” Then Mr. Sawdon adjusted his diamond, at which the clerks had been gazing in awe, and awaited the great man’s summons. It came quickly.

“De boss ses youse is ter come right in,” said the office boy on his return, with considerably more respect in his tones than he had used before.

Sawdon lost no time in obeying this injunction. As soon as he was inside the private office, Melville motioned him to a chair.

“What the dickens is the meaning of this?” he demanded with a lowering brow, indicating the circus man’s scrawl.

“It’s plain enough, aint it?” rejoined Sawdon. “The kid’s vamoosed, gone, skipped.”

“And I paid you to see that he was kept with the show and in ignorance of everything but the fact that he was a circus slave,” thundered Melville. “How did this thing happen?”

“Well, what are you to do when a bunch of ginks come along in a flying automobile and steal him right out of the air before your eyes?” protested Sawdon, mopping his brow.

“Stop raving and tell me what happened,” demanded Melville angrily.

“Just this,” rejoined Sawdon, “he was kidnapped in the air”; and he went on to explain to Melville how the boys had aided Ralph to escape from the balloon.

“And,” he concluded, “we didn’t get a chance to get a hold of the kid again. First they took him to the home of a guy named Parisgreen, or something like that, an’ then——”

“Hold on,” demanded Melville angrily, but with a note of eagerness in his voice, “this man Parisgreen, as you call him—he lives near to Pokeville?”

“That’s the gook.”

“His name’s not Parisgreen at all then. It’s Peregrine; an inventor, isn’t he?”

“Well, he and those kids invented a way of getting that kid away from us, all right, all right.”

“Where is the boy now?”

“In Boston, I guess. I learned later that that’s where those kids were headed for when we passed ’em on the road. But they had Ralph hidden, else I’d have got him back all right.”

“A nice mess you’ve made of it,” growled Melville angrily. “Well?” he demanded, looking up as the office boy tapped timidly and then opened the door.

“Here’s Mr. Sykes to see you, sir,” he announced.

“Good!” exclaimed Melville. “Show him in. Sawdon, you’ll have to step outside for a while.” The showman obeyed. He evidently stood in considerable awe of Melville, and showed no hesitation in carrying out the curt order. As he stepped out a man of a very different cut stepped in. The newcomer was Jerome Sykes, the silent partner of the Artillery Devices Company. He was a gray-haired man, tall, slender, with the face of a fox, a sharp, inquisitive manner and general air of furtiveness.

As the door closed he gave Melville a crisp nod, and then asked sharply:

“Any news from Boston?”

“None from Rook or Radcliff. I don’t know whether they succeeded in getting a line on Peregrine’s vanishing gun or not; but I’ve just heard some bad news from that fellow you passed.”

“Who is he?”

“His name’s Sawdon. He’s the circus man who was given charge of Ralph Ingersoll. He’s just come in to tell me that the boy has gone, and, curiously enough, the people who have taken him are in some way connected with Peregrine, whose invention we are after.”

“Phew! That’s odd, indeed. But Ralph Ingersoll is your personal affair. What I came to see you about is this; we’ve got to have that device of Peregrine’s or we’re in a hole we won’t get out of.”

“I know that,” said Melville gloomily. “From what I’ve heard it’s the kind of thing the government has been looking for. We know it’s not been patented yet, and if only Rook and Radcliff succeed——”

“You haven’t heard from them?”

“Not a word. But they are reliable men and if it is possible to get hold of Peregrine’s models or papers they will accomplish it.”

“Look here, Melville,” struck in the fox-faced Mr. Sykes, “do you know where to find your men in Boston?”

“Yes. I can lay my finger on them at any time.”

“All right then; you go to Boston yourself at once. If the Artillery Devices Company is going to keep its head above water, we’ve got to have that vanishing gun invention of Peregrine’s. He won’t sell, so it’s fair to take it from him by trickery if we can. Are you able to start for Boston at once?”

“Yes. Right away, practically. I agree with you that something must be done and done quick, too.”

And so it came about that an hour later Melville and Sawdon were sitting in a New York, New Haven and Hartford coach bound for Boston. As the train flew along Melville idly asked Sawdon how his circus was getting along.

“It ain’t getting along at all,” was the gruff rejoinder. “I’ve quit it cold. It seems we had no luck after the boy got away from us. It had been bad enough before that. Then we lost that lion, Wallace. He was a big drawing card.”

“And so you quit?”

“Yes; just ducked right out. I guess my performers were a sore bunch when they found that I’d left ’em in the lurch, but it couldn’t be helped. But what about this kid Ingersoll, as he’s called? Of course, I know in a general way that he’s entitled to something you’ve got, and that you don’t want him to get.”

“Entitled to something I’ve got?” said Melville, with a sneering laugh. “He’s entitled to all I’ve got—only he isn’t going to get it.”

Tom’s fall was not a long one. But he was bruised and shaken by it. Had it not been for the fact that he had tumbled into what had been an old mushroom cellar that was floored with soft mold, he might have been injured seriously. As it was, however, his tumble through the open trapdoor, which he had not noticed in his haste to escape from the phantom that he thought was pursuing him, resulted in no injury to the lad.

Suddenly he heard himself hailed from above.

“Say, you, what’s the trouble?”

“I’ve fallen into a hole of some kind,” rejoined the boy, much astonished at hearing the voice, which was not an unfriendly one.

“Yes, and I came mighty near following you. Wait till I get a light and I’ll see what I can do to get you out of your trouble.”

“Now I wonder who on earth that can be?” thought Tom, as he heard the one who had addressed him retreating down the hallway. “Could it have been he who screeched like that and scared me so?”

Before long the man was back with the overturned lantern, which he had picked up and lighted. As he held it over the edge of the trapdoor through which Tom had tumbled the boy gave a start. The man’s face was painted white, and he had on a suit of loose white material with funny looking black mules stenciled all over it. The man peering over the edge of the hole saw the look of astonishment on Tom’s face, and broke into a laugh.

“Guess you’re wondering what under the sun sort of a chap I am,” he said. “Well, I’m a clown. I was with that show of Sawdon’s, but the rascal quit us cold down yonder, and dug out with everything. He even took our clothes and I had to make shift in this rig. It’s all I had.”

“Oh,” said Tom greatly relieved, “then it was you that ran after me?”

“Sure. But, look, there’s a sort of ladder over there. Climb out, and I’ll tell you how I came to be here, and you can tell me something about yourself.”

Tom lost no time in clambering up the rough contrivance for getting in and out of the mushroom cellar. Then he followed his newly found friend to the small room in which the men who had captured him had first questioned him.

“Reckon I got you out of quite a scrape, didn’t I?” asked the clown, regarding Tom with a quizzical sort of look.

“I should say so,” rejoined the boy gratefully. “If it hadn’t been for you I don’t know what would have happened to me. But you almost scared the life out of me, too,” he added truthfully. “What gave you the idea?”

“Well, you see, it was this way. After Sawdon ducked out I had no place to go to, so I was wandering along the road, thinking that maybe I could give a show some place and pass the hat to get some other clothes, when I saw this old house. It was getting late, so, thinks I, there’s my Walled-off-Castoria. I walked in and went into one of the upper rooms, where I lay down for a snooze. I must have slept a long time, I reckon, for when I woke up I heard voices below.

“I listened with my ears wide open, and what I heard showed me mighty quick that two fellers were carrying out some bit of rascality. So all at once I hit on the idea of being a ghost. I reckon what one of them fellers said about the place being haunted gave me the idea—and so I gave those yells that you heard, and it certainly worked.”

“It certainly did; and I thank you for it,” laughed Tom, “but it scared me as badly as it did the bad men, almost.”

“Well, it’s hard to please everybody, as the feller said when they kicked at his carrying Limburger cheese on the street car. But now tell us what you are doing here, sonny.”

Tom told him as much of his adventures as he thought advisable. When he had finished the clown exclaimed:

“So you’re one of the kids that rescued that boy from the balloon?”

“Ralph Ingersoll, you mean?” inquired Tom.

“Ralph Ingersoll nothing! His name is Melville, and if he had his rights he’d be riding in a benzine buggy, and wearing diamonds and—and eating turkey every day of his life.”

“What do you mean?” asked Tom, with a curious sense that the name of Melville was familiar to him, somehow.

“Just this, and now that Sawdon’s gone back on me I don’t mind telling about it, that Ralph Melville, for that’s his right name, was put in Sawdon’s charge by his uncle, Stephen Melville, a rich manufacturer of guns and artillery and such like things in New York.”

“Why, he’s the man who’s trying to steal Mr. Peregrine’s invention!” exclaimed Tom.

“I don’t know about any very green invention,” said the clown, “but this I do know, that I’m going to tell what I can about that poor kid. He’s been cheated out of his rights—that’s what he has—and I don’t care who knows it.”

“How did you find all this out?” asked Tom eagerly.

“Why, I was in the dressing tent on the night that the Melville kid was brought to Sawdon, who was an old friend of this Stephen Melville. Melville gave Sawdon a big sum of money every month to keep the kid where no one would know where he was. It seems that when Ralph was a little baby his father was killed in a railroad accident, and the news of his death proved the death of his mother, too. There was a will leaving all the wealth of John Melville (that was Ralph’s father) to his boy. But his uncle was to be his gardeen till he come of age. Well, what does his uncle do but get a fake will made up and spirit the boy away.”

“But hadn’t the boy any friends?” asked Tom. “Well, I heard them talking about a Doctor Longman, or some such name——”

“Wasn’t the name Tallman?” asked Tom, recollecting the mysterious hint about Ralph which the doctor had thrown out.

“Yes, that was the name, sure enough. It seems that this Dr. Tallman had another will or something, but Melville said that he had satisfied him that the boy was dead.”

Tom wondered greatly how it was that Dr. Tallman could have had the suspicion—which he evidently had—that the boy he knew only as Ralph Ingersoll was, in reality, the long missing Ralph Melville. But he was not to find this out till later. After some more discussion of Ralph’s strange history, Tom suggested that they should go out and try to find the Flying Road Racer and drive at once to Dr. Tallman’s residence. But his new-found friend, whose name was Dick Dangler, pointed out that in the dark they would have a hard job to find the machine, and might get lost into the bargain.

“My idea would be to wait till daylight, as the fellow said when they wanted to hang him at sunset,” he said in his odd manner. “In the meantime, I’ll skirmish around and try to find something to eat, for by the looks of that table those fellows have food stored away some place. Then we can take a nap till it gets light.”

Tom agreed to this and went to a cupboard in the corner of the room, which they thought might have served the men as a larder. Sure enough, they found some canned chicken, some tinned beef and a box of crackers in the place. But Tom lost all interest in these as his eye caught something which was tucked away in the extreme corner of the cupboard.

As he saw what it was he gave a cry of joy. The next instant he was down on his hands and knees, eagerly investigating his discovery.

It was the long missing model. As Tom clasped it and then fell to gathering up the plans, which had also been placed in the cupboard, he was fairly burning with joy.

“Hurray! I’ve got Mr. Peregrine’s model back,” he kept gleefully repeating. “Now he can go ahead and finish up his vanishing guns!”

Dick Dangler seemed almost as joyous as the boy over the discovery.

“That ghost trick of mine certainly brought good luck all around,” he said.

As he spoke a noise behind them made them look around. Tom almost uttered a cry as he found himself looking straight into the muzzle of a revolver held by Jake Rook. Radcliff had Dick Dangler similarly covered.

“You began crowing too soon, my young rooster,” sneered Rook, with a contemptuous smile. “Now just hand over that model, and hurry up about it, too.”

What was poor Tom to do? It was a bitter thing to have to acknowledge, but once more the rascals had triumphed. Silently, and with brimming eyes, Tom did as he was ordered. Then, still aiming their revolvers at Tom and his friend, the two men backed slowly out of the broken window, through which they had entered, and vanished in the darkness.

It would have been quite useless to pursue them, for even had Tom found them, he would still have been at their mercy. No, he had to admit that he was beaten, badly beaten, too. The fact that it was no fault of his own did not make the disappointment any easier to bear.

Dr. Tallman was standing on his porch the next morning. By his side was Ralph, pale and a bit shaky, but with a glad look on his face. The news of Jack’s safety had heartened him up immensely.

All at once, far down the road a cloud of dust showed that a vehicle of some sort was approaching. It drew rapidly closer, and the two figures on the porch saw that it was a fast red runabout, and carried two persons.

The machine was the lawyer’s own, the yellow car having been taken by the police. The next instant they were recognized as Mr. Bowler, the lawyer, and Jack.

“I wonder where Tom is?” questioned Ralph.

The next minute, after greetings had been exchanged, Mr. Bowler and Jack were asking the same question. Dr. Tallman looked amazed.

“Why, he left here last night for your house!” exclaimed the doctor. “Didn’t he arrive?”

“No; we haven’t seen a sign of him. What can have happened?” exclaimed the lawyer anxiously.

“I’ll bet those rascals are mixed up in it in some way,” cried Jack. “Oh, what can we do to find him?”

“Wait a moment, things may not be as bad as you imagine,” said the doctor.

The words had hardly left his lips before down the road from the opposite direction to that from which the lawyer and Jack had arrived, there came another automobile.

Jack recognized its familiar outlines in a flash.

“The Flying Road Racer!” he exclaimed, and then the next instant, “Tom is in it. Hooray! Where can he have been?”

“And who is that with him?” wondered Mr. Bowler.

“Why—why—it’s a clown!” gasped Ralph, bursting into a laugh. “Why—why,” he exclaimed a moment later, “it’s old Dick Dangler, from Sawdon’s circus, the only man who was kind to me in that whole company; What can he be doing with Tom?”

The Flying Road Racer swept up to the porch, and before its wheels had stopped revolving almost, Tom and Jack were clasping each other’s hands. Ralph, too, was dancing for joy, while, in the background, Mr. Bowler and Dr. Tallman looked on.

Tom’s story was soon told.

“We found the auto as soon as it was daylight,” he said, “but the men who took the model had damaged the engine so that it took me some little time to fix it up. And that’s all, except that here we are, and the model has slipped out of our hands for a second time.”

“Never mind,” said Dr. Tallman consolingly, “maybe you’ll find it again.”

But Tom shook his head disconsolately.

“I guess not, it’s gone for good, I’m afraid, this time. But Dick Dangler here has something he wants to tell you, Dr. Tallman.”

“To tell me?” said the doctor in wondering tones, looking at the eccentric figure of the clown, who was talking apart with Ralph.

“Yes. It concerns Ralph’s identity. If I’m not mistaken, you already suspect him to be more than a friendless orphan lad.”

“Frankly I do,” was the rejoinder. “He has a peculiar mark on his arm in the shape of a wineglass. I never recall having seen such a peculiarity except on one child, an infant named Ralph Melville.”

“Hurray! Glory be!” exclaimed Tom, much to the surprise of the doctor and the lawyer, the latter of whom had started at the name of Melville. “Ralph, you’re rich, or are going to be. It’s all the same! Hurray!”

Of course, until Dick Dangler’s story had been told the rest of the party couldn’t make out Tom’s delight. But it appeared, according to Mr. Bowler, that it would be a difficult matter to prove Ralph’s rights to the Melville fortune and name, and in the meantime much had to be done. The fact that it was Melville who was also concerned in trying to swindle Mr. Peregrine out of his invention was another complication.

A conference was held, at which it was decided that Ralph for the present would remain with Dr. Tallman, his father’s old friend. In the meantime the others would go to Boston and try to get on the track of the patent thieves. Before they departed, however, Dick Dangler was fitted out with an old suit of the doctor’s, and proved to be quite a respectable, kindly appearing man, with a very grave and serious countenance. A clown would have been the last thing you’d have taken him for.

From Boston Mr. Peregrine was fully apprised of the recent exciting happenings, and begged the boys not to run into any unnecessary danger. Mr. Chadwick had returned from Washington, he said, and had expressed his desire that, as the boys had lost Mr. Peregrine’s model, they should do all they could to find it. As for Mr. Jesson, the news from him was that he was perfectly happy, having found a new variety of potato in the Pokeville district.

As Mr. Bowler had a good deal of legal work to attend to, which had been neglected during the last few days, he left the boys to their own devices. Dick Dangler rode with them to the garage where they put tip the Flying Road Racer, and then left them, promising to call at their hotel later in the day.

Having seen the car put up, the two lads started out for Police Headquarters. There they were informed that not a trace had been found of the men who had stolen the model. Tom then related what had occurred in the old mansion.

“So that’s where they have been hanging out!” exclaimed the official to whom he communicated this information. “Well, I’ll send a couple of men out there this very afternoon to search the place thoroughly. We may light on a clew.” He went on to inform them that every station in Boston would be guarded, and that no chance to capture the men, supposing them to be in that city, would be neglected.

“Well, I suppose we will have to be content with that,” said Tom, as they left. “It’s tough to think that those men may be right in the city now and yet we can do nothing.”

“I should think it more likely that they would be in New York,” said Jack. “After what they did in the old mansion it would be my idea that they would try to get as far away from this vicinity as possible, knowing that we are on their trail.”

The boys walked on through the streets, looking into shop windows, and especially into those in which mechanical apparatus was displayed. But this began to pall after a while, and Jack suggested that they take a walk along the wharves. Tom readily agreed, and, arm in arm, they set out to visit one of the most interesting quarters of the Hub.

The “T” wharf, where the fishing vessels lie, particularly attracted their attention, and they were gazing with interest at a smart schooner unloading her finny freight when a familiar voice struck on their ears.

“Why, hullo, boys, what are you doing here?”

They turned and found themselves gazing into the frank, bronzed face of Captain Andrews, skipper of the yacht Sea King, who had shared their adventures in Yucatan.

The captain was unaffectedly glad to see his young shipmates again, and asked them many questions about themselves. He said that he had prospered exceedingly, and now owned two fishing schooners besides a fast, smart motor craft, all engaged in the fishing industry. He was so eager to unfold the story of his progress that he did not at first notice that neither of the boys looked particularly cheerful.

“What’s in the wind, shipmates?” he demanded. “You look as down-in-the-mouth as a hooked codfish.”

“As bad as all that?” laughed Jack. “Well, Captain, there’s a reason, as the advertisements say.”

“What’s up? Heave ahead and spin your yarn. If it’s anything I can help you out of, trust me to do all I can.”

His manner invited confidence, and, seating themselves beside the sea veteran on an upturned box, Jack poured out the story of their troubles.

“Well, if that don’t beat a novel!” exclaimed the captain when he had finished. “And those two rascals are in Boston, do you think?”

“We don’t know,” rejoined Jack. “We’ve really no way of finding out, and the police are as helpless as we are.”

“Oh, the police are always no more use than a lot of babies,” declared Captain Andrews, who clearly had a contempt for that much-maligned body of men. “I’d back you boys against any detective I ever saw.”

“That’s very good of you,” laughed Tom, “but I’m afraid we’ve proved the kind of detectives that don’t detect.”

“Don’t be downcast, lads,” counselled the captain heartily. “When things seem at the worst, it is generally the time that they begin to mend. I’ll spin you a yarn about that, if you like.”

“I wish you would,” said Jack. “It will pass the time away pleasantly.”

“Back fifteen years ago I was mate of the brig Nancy Lee,” began the captain. “We sailed out of ’Frisco on the Fourth of July, bound for the islands on a trading cruise. Two days out we ran into as nasty a sample of weather as ever I saw. We lost our mainmast, and two of the men were killed in its fall.

“Then, when the storm had blown itself out, the captain took sick, and, worse than that, our provisions began to get low. Things went from bad to worse. We did not sight a sail of any kind; the men grew ugly and mutinous. Then one night the ship took fire and——

“Dash my lee scuppers, what’s up now?” exclaimed the amazed captain, as Jack and Tom suddenly leaped to their feet and dashed off, leaving him in the most exciting part of his story.

“It’s those men, there they go—look!” shouted Jack, flinging back the words as he ran.

It was indeed Jake Rook and Radcliff. They turned as they heard the boys shout, and then, recognizing them, took to their heels. The boys ran in and out amid the maze of traffic, and for a time kept the two rascals in sight. But finally in the crush and crowd they lost them, and had to admit that there was but little likelihood of their ever finding them again.

Regretfully they retraced their steps, but on their return they found that Captain Andrews had been called away on business, leaving word with the men on board the schooner that he would visit them at their hotel later in the day.

“We do seem to have the very worst sort of luck,” declared Tom, as the two lads trudged back to their hotel in very low spirits. “If only we could have caught up to those rascals!”

“We made a big mistake when we shouted out as we did,” said Jack. “If we had followed them in silence we might have managed to track them to wherever they have their hang-out.”

Tom reluctantly agreed that this was so. “But, just the same,” he added, “we do have hard luck, and more than our fair share of it.” After lunch they set out for Mr. Bowler’s office, having already telephoned to the police that the men were actually in Boston. Just as they were leaving the hotel, however, they met with an unexpected interruption to their plans. Dick Dangler hurried up to them, his ordinarily grave face flushed and excited.

“I’ve news!” he exclaimed. “Great news!”

“You’ve found those men?” asked Jack and Tom in the same breath.

“No; but I’ve done almost as well. Who do you suppose I’ve seen?”

“Haven’t an idea,” said Jack. “Maybe——”

“Nobody less than Sawdon, and with him was Stephen Melville himself.”

“Stephen Melville here in Boston?” gasped Jack. “He must be going to meet Jake Rook and Radcliff.”

“I don’t know, but I did better than just seeing them. I followed them. Traced them to an old tumble-down livery barn on Emmons Street. They are there now, I guess. Phew! I ran all the way here to tell you, and I’m ’most out of breath.”

“Good work!” exclaimed Jack. “It looks as if the net was closing in about those rascals. Come on, Tom, we’ll hurry to headquarters, get some officers and go down there. We’ll bag the whole gang in a bunch.”

“That’s the idea,” cried Tom, “but, hurry up, we’ve no time to lose. Glory be! I feel better than I have for many a day. Things are coming our way at last.”

In the livery stable on Emmons Street, the same one in which Ralph had been confined, sat four men. They were grouped about a table in a small room in the rear of the place, for the stable was what is sometimes known as “a blind,” and the place was the resort of all sorts of unprincipled characters who had reason to fear the forces of law and order.

On the table was a litter of papers, typewritten specifications and blue prints, but the most conspicuous object was a beautiful model of Mr. Peregrine’s vanishing motor gun. One of the men was Stephen Melville, and the identity of the others may be easily guessed. They were Sawdon, Jake Rook and Radcliff.

“Well, boss, have we earned our pay?” asked Jake Rook, as Melville paused in his interested scrutiny of the model and the plans.

“You bet you have,” he exclaimed enthusiastically, “and as soon as we have a contract with the government I’ll give you a bonus as well. Why, with these plans and this model it will be easy to manufacture a machine unlike the Peregrine one in appearance but exactly like it in principle. What a fool he was not to sell when he had the chance! Now we have all the benefits of his work for nothing.”

“But say, boss,” interrupted Jake Rook, “how are you going to get the stuff to New York? There’s a hunt on for us in the city, and I guess that by this time you are being looked for, too.” For Jake had discovered that his letter had not been delivered, and readily guessed that it might have fallen into Ralph’s hands, and from him passed to the possession of the two lads they had tried so hard to injure.

“I’ve arranged for all that,” said Melville; “the police may guard all the railway stations; but we won’t go by train. I know a man here who has a fast motor boat and isn’t too particular, where there is money concerned. He’ll take us down the coast a way, and then put us ashore. We’ll separate and reach New York by different routes.”

“That’s a rattling good plan,” said Sawdon approvingly; “I guess that this time we’ve got those kids buffaloed for fair. Does this fellow with the boat know that you are going to hire it?”

“Yes, I thought it best to be prepared for emergencies, and so I have arranged for the boat to meet us at the Buttermilk wharf. That’s some distance from the regular shipping piers, and we won’t attract attention.”

“And Dan Darby has the disguises,” added Jake Rook. “Oh, Dan!” he cried, raising his voice. In response a bottle-nosed, red-faced man of the low, rough type shuffled in.

“Well, what is it?” he demanded.

“Have you got those disguises?”

“Sure, they’re upstairs in the loft. Want to put ’em on now?”

“We do,” said Melville; “there’s no knowing how soon some of that outfit may cross our trail, and we don’t want to be caught napping.”

“All right, go right ahead up. Jake knows the way,” said Dan, who, although he posed as a livery-stable keeper, was a notorious rascal of Boston’s underworld.

Half an hour after the four worthies had taken their way upstairs, they reappeared again. But how altered! Jake Rook, who was an adept at this sort of thing, had excelled himself at his work.

Melville’s moustache had been shaven off, and he was rigged out like a bloated, broken-down old cab-driver; Sawdon had the semblance of a hanger-on about a livery stable; Jake Rook appeared to be a peddler; and Radcliff was apparently a seedy, down-at-heels foreigner of the emigrant type, with an untidy black beard.

“Great!” exclaimed Dan, as he viewed them; “your own mothers wouldn’t know you, and that’s the truth.”

At this moment there came a loud knocking at the door of the stable, which was closed and locked. Dan darted to a peephole in the front of the place, constructed for the purposes of spying.

“Great Scott, boys!” he exclaimed the next minute, in a low, tense whisper, “it’s them kids you were talking about, with half a dozen policemen. They’re in plain clothes, but I’d know a bull anywhere.”

Instant consternation prevailed among the conspirators. But Jake Rook, who alone remained cool, spoke up quickly.

“Is the old getaway still working, Dan?” he asked quickly.

“Yes. You know where it is. It leads out on Murphy’s Alley.”

“Good! Follow me, and we’ll fool that bunch yet,” exclaimed Jake, darting to the rear of the stable, while Dan called out in a surprised voice: “Who’s there?”

“It’s the police. Open this door instantly, do you hear?” came a sharp voice on the outside.

“All right! all right!” and Dan shuffled toward the door; “What’s up? What do you want?” he demanded, as he opened it slowly.

“To search this stable of yours. Some suspected criminals have been traced here,” spoke up the leader of the police, a heavy-set man with a crisp moustache.

“Here?” exclaimed Dan, in well-simulated amazement; “criminals in my stable? You must be mistaken.”

“Oh no, we’re not, and this place is too well known for us to be fooled by you. Stand aside.” The man gave Dan a rough shove that sent him spinning to one side and entered the place, followed by the boys and his comrades of the force. But, as we know, the birds had flown. Not a trace of them could be found. The “getaway,” as Jake Rook called it, a secret door in the back of the place leading out on an alley, was too cunningly constructed even to catch their attention.

“There, what did I tell you?” grinned old Dan, when they had finished and found that they had “drawn a blank,” as huntsmen say. “It’s too bad to do anything like this. Why, if it got out, it would give me a bad reputation.”

“You precious old rascal,” exclaimed the detective, “as if you weren’t one of the worst characters in Boston, but too foxy to get into the toils of the law!”

“Oh, my! Oh, my! How you talk!” exclaimed old Dan, looking as if he was really grievously insulted by the imputation that he was not an honest and upright citizen.

“Well, there’s no doubt in my mind that the men were here,” said the officer, turning to the boys; “but they’ve gone, and covered up their tracks mighty well, too.”

“More bad luck,” growled out Tom, gritting his teeth; “and just when we thought we had them, too. I don’t suppose we’ll ever see them again now.”

“It’s not likely,” admitted the policeman; “from what you have said they must be a band of slick fellows, all right.”

“But suppose this man Melville starts to manufacture that vanishing gun thing, can’t he be prosecuted?” asked Dick Dangler.

“Mr. Bowler says that such a slick man as he is would make just enough alterations in the model so that it wouldn’t be possible to prove that it was not his own idea. Such cases are very hard to prove, he says, and cost thousands of dollars. No; if the model is in Melville’s hands, there’s an end of it.”

This speech was the contribution of Jack, who had talked with the lawyer on this very subject. There being nothing more to be done at the stable, they came away, followed by a sarcastic grin from old Dan.

“You won’t never catch an old bird like me by putting salt on his tail,” he chuckled. “I wonder if them fellows took that model they set so much store by? Looked like so much junk to me, but I guess it must be valuable to them all right.” He peeped into the room where the consultation had been held and found that the model and papers had been taken. Jake Rook, in fact, in his dash for the alley had taken the model and stowed it under his coat, while Melville had grabbed up the papers.

The boys were sitting in the hotel that afternoon pondering fresh plans, when there came a sudden summons to the telephone.

“This is Captain Andrews,” came a voice at the other end when Jack answered it. “By the great horn spoon, but I’ve a valuable bit of information for you lads. It concerns those lubbers who stole the patent.”

“Gracious!” cried Jack, “is that so? Where can we see you?”

“You wait there and I’ll be up,” was the reply; “if my information is right those rascals are about to slip through your fingers again.”

“By ginger! not this time, if it’s humanly possible to catch them,” declared Jack earnestly, as he hung up the receiver. “We’ll follow them no matter where the chase may take us.”

And where it was to take them neither of the boys dreamed at that moment, but they were on the eve of one of the most adventurous incidents of their lives.

Captain Andrews burst into the hotel a short time later like a bombshell, scattering bell-boys and guests in his mad rush to reach Jack and Tom, who were awaiting him in a corner of the lobby.

“If you want to catch those fellows you must come with me right away,” he exclaimed pantingly; “they’ve gone to sea in Cap. Flinders’ motor boat. They started half an hour ago; but if we hurry I’ll go after them in mine, and there’s a chance we can overhaul them, or at least keep track of them.”

Of course the reference to Captain Flinders’ motor boat was so much Greek to Jack, but the captain would not explain any more just then.

“Don’t waste time talking,” he exclaimed; “I’ll tell you about it as we go along. Shiver my topsails, but they’ll get away yet if we don’t hurry.”

It was evident enough, from all this, that there was not a minute to be lost, and Jack and Tom, who had their hats on, followed the energetic seaman out of the hotel without an instant’s hesitation. Outside was a row of taxicabs. Jack engaged one of these, and they started off for the “T” wharf at a rattling speed.

As they spun along the captain explained how he had got upon the track of the gang of rascals.

“This Captain Flinders is a regular shark,” he declared; “he’ll do anything for money, and has a mighty bad reputation along the water front. Well, as I was standing on the end of the Buttermilk Wharf where he keeps his boat—the Tarpon, and a clipper she is, too—I saw him meet four precious seedy-looking chaps. One looked like an old cab-driver and the rest were as bad.

“‘What’s in the wind now?’ I thought, and as they came toward me I slipped in behind a pile of bales, for I didn’t want Flinders to see me, and was curious to know what he was doing with that outfit of ragamuffins. Well, as luck would have it, they stopped just the other side of the pile of bales, and I could hear some of what they said. I heard enough to convince me that they were the chaps you were after, in disguise, and then I jumped for a telephone.”

The boys fairly gasped in their eagerness to hear more.

“Were they all there?” demanded Jack.

“Well, there were four of ’em. And they’ve got the model, too. I heard one of ’em, a chap the others called Melville, laughing about the way they’d tricked you by sneaking out of a stable by a secret back door.”

“So the rascals were there, after all,” exclaimed Jack; “well, if that doesn’t beat all!”

“Well, when I came back from ’phoning to you, what should I see but the Tarpon putting out into the stream. Right then and there I started for the hotel and there’s a chance—just a chance—that we may catch ’em yet. You see, from what I heard, they were figuring on not sailing till to-night, but I guess they changed their minds.”

“Jumping Jupiter!” exclaimed Tom, “this is warm work with a vengeance. You didn’t overhear them say where they were bound for, captain, did you?”

“Yes, East Hampton, they said. But here’s the wharf. Come on, pile out. Jack, you pay the cabman while I get the old Sea Gull ready.” When the boys joined the captain once more they found him busied over the engine of a good-looking cabin motor boat about thirty feet in length.

“Will you be ready right away?” inquired Tom, “because if not, I guess we ought to ’phone to Mr. Bowler. He’ll be anxious if we are missing without any explanation.”

“All right, boys. You’ll have time for that, but hurry.”

In five minutes the boys were back, and Captain Andrews announced that all was ready. No time was lost in casting off, and in five minutes more the Sea Gull’s bow was headed downstream. A long chase had begun, and one that was to prove remarkable in more ways than one.

“Seems queer, doesn’t it,” remarked Jack, “to think that only a short time ago we were sitting in the hotel, thinking we’d lost the trail for good and all, and here we are, hot on it again, only by sea instead of land.”

“It does,” agreed Tom, who was looking after the engine, while Captain Andrews steered. The motor of the Sea Gull was a powerful, four-cylindered, four-cycle one, developing twenty horsepower. This made the Sea Gull unusually fast for a craft of her class, but the boys recalled that Captain Andrews had told them that the Tarpon was a swift craft, also.

Twilight found the Sea Gull well off shore, and riding a swelling sea. Jack, who was on the lookout, was the first to sight, some five miles ahead of them, another motor craft.

“Can that be the Tarpon?” he exclaimed, pointing.

“Here, take the wheel a minute while I overhaul her,” said Captain Andrews eagerly.

He dived into the cabin and reappeared with a pair of strong binoculars. He focused these on the distant craft, and after a brief scrutiny announced that it was beyond doubt the Tarpon that they had sighted.

“She must have had some sort of engine trouble,” he declared, “or she would have made better time than this.”

“Can we overhaul her, do you think?” questioned Jack anxiously.

Captain Andrews shook his head doubtfully.

“Even if she had to slow down for a time she is creeping ahead now; but maybe, if all goes well, we can keep on her track through the night. For one thing, we know that she is bound for East Hampton, and I could find my way there blindfolded.”

“Perhaps I could fix your engine so that it will give us a little more speed,” volunteered Jack.

“I wish you could, lad,” responded the seaman, taking the wheel from the boy once more.

“I’ll do what I can,” promised Jack.

He fell to work on the motor, and found that by readjusting the carburetor he could coax more speed out of it. By this time it was dark, and, having finished his work on the motor, Jack went forward with the running lights. Soon they were shining out like twin jewels—red to port and green to starboard. Then he set the stern light, and coming back eagerly looked into the night ahead of them.

All at once through the darkness a white light flashed up and instantly vanished, only to reappear again as the Tarpon rose on a wave crest.

“So long as we keep that light in sight we are all right,” declared Captain Andrews, and resigning the wheel to Jack, he went below to prepare supper, which meal they ate in “relays.” Coming on deck after his meal, Jack saw, to his astonishment, that the dancing white light ahead of them was much closer than it had been before he went below. This meant that they were overhauling the Tarpon.

“We’re creeping right up on her,” declared Captain Andrews, when Jack mentioned this fact to him; “we ought to be alongside in half an hour if we keep on at this gait.”

The words sent a thrill through Jack.

“That means a fight,” he said calmly, although his heart beat fast.

“That’s what it does, lad,” returned the doughty captain, “but there are three revolvers below, and we’ve got the law on our side—don’t forget that.”

“No, and I don’t forget that they are five to our three,” added the boy, with a grim smile.

As they crept closer, Tom was apprised of the turn events were taking. He was provided with a revolver, and Captain Andrews armed Jack and himself likewise.

“I don’t approve of firearms; fists is my way of fighting,” he said. “But we are going up against a gang of sea sharks that are desperate, and we may have to fall back on the guns.” Silence fell on the party as they slowly but surely crept up on the bobbing, dancing light ahead. As they came within hailing distance Captain Andrews boomed out a hail:

“Tarpon, ahoy!”

But no answer was vouchsafed.

“Looks as if they are going to cut up rough,” opined the captain; “well, there’s nothing for us to do but heave alongside and board them. You’re not scared, Jack?”

“Not a bit. I’m too hot to get at the rascals who have caused us so much trouble to feel scared of them.”

Captain Andrews spun his wheel over and prepared to bear down on the light, but as he drew up close to it a bewildered look passed over his face. At the same instant Jack spoke:

“Isn’t there something rather odd about that light, captain?”

“Just what I was thinking, lad. It’s low down in the water and—by the great horn spoon! They’ve fooled us. That light’s nothing more than a lantern set adrift in a bait tub!”

And so it was. The wily party on board the Tarpon had certainly played a successful trick on their pursuers. Extinguishing their own stern light, they had set the lantern on a bait tub, dropped it overboard and cast it loose to drift at its own sweet will.

“So, for the last three hours, we’ve been following a will o’ the wisp!” groaned Jack dismally.

“Looks that way,” agreed the captain. “Consarn it all, we might have known that they’d be up to some such trick as that—such a shipload of pirates.”

He shoved back his cap and scratched his head.

“It’s a game of blind-man’s buff from now on, lads,” he said; “do you want to take a chance?”

“While there’s one left we’ll take it,” declared Jack stoutly.

“I wonder how far astray that old tub led us,” mused Tom a few minutes later, when they were once more on their course.

“Impossible to say,” said the captain, “but a light tub like that would drift fast, and their trick will have given those lubbers a big lead on us.”

“Not much doubt of that, I’m afraid,” agreed Jack; “but we may as well keep right on now. Possibly we’ll get track of them at East Hampton.”

With only this hope to buoy them through the long night hours, the trio clung to the marine trail. All of them were too excited to sleep and so they took turn and turn about at steering, attending to the engine and keeping a lookout.

As the first gray warning of dawn came on the eastern horizon, Captain Andrews consulted his log, compass and charts. He declared that they were not far from East Hampton, and that unless something had happened to the Tarpon during the night, she must have landed her passengers there. This was a bitter pill to swallow, but the boys kept hoping against hope while the light grew stronger.

But as the surrounding sea became visible in the summer’s dawn, a cry of delight broke from three throats simultaneously.

Bobbing up and down on the swells not half a mile off lay the Tarpon. She was motionless, except for the action imparted by the waves, and it was evident that something was the matter with her engines.

“Guess they tried to run so fast during the night that they overheated them,” declared Captain Andrews, as he gazed at the other craft.

He turned his wheel, and the Sea Gull began to head toward the Tarpon. At first it appeared that they were not observed, but the next instant they found out differently. Something sang through the air above Captain Andrews’ head.

Jack saw a flash and a puff of smoke from one of the portholes of the Tarpon’s raised deck cabin, and a few seconds later came the report of a rifle. Then, borne clearly across the water, came a megaphoned threat:

“Keep off, or it will be the worse for you.”

Captain Andrews snatched up the Sea Gull’s megaphone. His bronzed face was flushed with rage, and his voice shook with suppressed fury as he bellowed back:

“You infernal scoundrels, what do you mean by firing at us? Are you going to let us board you and give up that model, or do we have to make you?”

“Oh, run along and play,” came back from the Tarpon, in a voice which the boys recognized as Jake Rook’s.

“You keep away from us if you know what’s good for you,” came back in another voice.

“By Neptune, boys,” growled Captain Andrews, “it kind of looks as if they had the upper hand of us after all. I don’t see how we can board them as things are now. It’s no use sticking our heads in a hornet’s nest, and that’s what we’d be doing if——Hello! They are moving again; guess they’ve got their engine fixed. Well, we can stick to their heels, and if they run into a town we can arrive close enough to them to have them arrested.”

“But will they make for a town now that we are so close on their tracks?” wondered Jack.

“Isn’t it more likely they’d land along the coast some place, where there was no risk of encountering the authorities?”

“Jove, lad, I don’t know but what you’re right. Well, all we can do is to tag along and watch our chance.”

“Look, one of them is coming out of the cabin with a megaphone,” cried Tom suddenly.

They watched a figure clamber up on the stern of the boat ahead and raise the speaking trumpet.

“Sea Gull, ahoy!” came the hail.

“Aye! aye! what do you want with us?” bellowed back Captain Andrews, in no amiable tone.

“It’s no use your following us. If it’s the model you are after, we landed it last night while you were chasing that bait tub!”

If a bombshell had exploded in their midst the party on the Sea Gull could not have felt a deeper sense of consternation. The long chase had been for nothing then, and, as Jack had put it, they had indeed been pursuing a “will o’ the wisp.”

Jack was the first to recover from the shock.

“I don’t believe it,” he declared stoutly.

“It would have been like their knavery to pull off just such a trick, though,” struck in Tom; “what do you think, captain?”

“Just this, that a bird in the hand is worth two in the bush,” declared the stout old seaman. “Maybe they did land the model in the night; but in that case what are they doing away down the coast? And again, even if they did land it, I propose to keep on their heels till we bring them to justice.”

The seaman’s words put new heart into the boys, and instead of slackening in their pursuit, they kept up the Sea Gull’s speed which, do what they could, was slightly slower than the speedy Tarpon’s. About an hour after the hail from the Tarpon’s after-deck had come, the craft ahead suddenly changed her course.

“They’re heading in toward land,” cried Jack excitedly.

“Yes; I guess they realize that they can’t shake us and are going to land and make a run for it,” decided Captain Andrews. “Great sea serpents, but they are putting on speed!”

The Tarpon certainly was flying. Great jets of spray shot up on each side of her bow, and the roar of her motor could be heard like the incessant discharge of a whole battery of gatling guns.

Jack sprang down to Tom’s side at the Sea Gull’s engine. He tinkered with the carburetor and speeded up both spark and gasolene supply. Like an arrow from a bow the Sea Gull sprang forward gallantly. Every timber in her shook under the vibration. But like a greyhound after a rabbit, she hung tenaciously in the wake of the Tarpon.

It was a marine race, filled with the keenest excitement. Jack’s heart pounded. The blood rushed hotly through his veins. With burning eyes he straightened up from the engine and gazed ahead. The distance between the two crafts was still the same, the Tarpon maintaining her lead.

“Can’t you get any more speed out of her?” almost groaned Captain Andrews. “If once they reach that coast and land, we’ll have a tough job getting them again.”

“I’m afraid that I can’t do any more with the motor,” responded Jack; “it’s heating up now, and if I force it any more it may stick altogether.”

The coast toward which both boats were heading at racing speed was a wild and desolate-looking stretch of beach, with cliffs towering up to some height from a rocky base, and pine woods and hills on top.

“Like as not old Flinders knows just where he is heading for,” said Captain Andrews, with some uneasiness; “but I don’t like the look of this at all. See those rocks and that shoal water all about us. We may run aground any minute, and at this speed that would mean ‘good-bye, Sea Gull.’”

Jack nodded. He fully saw the dangers of navigation so close to that rocky coast. But Captain Flinders seemed to have no fears. He kept right on without reducing speed, dodging in and out of shoals incessantly. Captain Andrews, with his heart fairly in his mouth for the safety of his craft, followed his every move. He knew that the Tarpon drew more water than his craft, and that where Captain Flinders could go with safety he could follow.

The chase through the watery maze kept up for an hour or more, and then, so far as the Sea Gull was concerned, it came to a disastrous conclusion. Without the slightest warning Captain Andrews’ craft rammed her nose at full speed into a sand bank, and at the same moment the boys and the captain were thrown flat on their backs. Tom was up in a jiffy and shut off the engine. The others were as quick in recovering themselves. But alas for the Sea Gull! Her nose was jammed hard into the sand, and although the engine was reversed and run at full power, it could not move her.

“Well, if the bad luck isn’t holding out to the end!” exclaimed Tom despairingly; “what on earth can we do now?”

“What, indeed?” echoed Jack. “I guess that they win this time.”

“What, giving up already?” exclaimed Captain Andrews. “Why, boys, there’s lots of luck left. I see that the tide is rising. That’s lucky, for it means that at high water we can get the Sea Gull off. In the meantime I’ve got a plan.”

Both boys hung eagerly on his next words. “We’ll take the dinghy and row ashore. It can’t be so very far to some village or town where we can summon the authorities. That will give us a chance to land those miscreants yet.”

“It seems about all there is left to do,” said Tom, who didn’t seem to be very much impressed with the plan.

“Hello, the Tarpon’s dropped her anchor,” exclaimed Jack, pointing to the other craft, which had come to a standstill about five hundred yards off.

“Then there’s no time to lose in getting ashore,” declared Captain Andrews; “we’ve got to beat them to it. Come on, lads, help me get the dinghy over.”

The dinghy referred to was a small, light flat-bottomed boat, carried athwart the stern of the Sea Gull. It took but a short time to get her overboard. In the meantime Jack had dived into the cabin, leaving the task of lowering the small boat to his two companions.

“Come in here,” he shouted, as soon as the boat was over and floating astern. Tom and Captain Andrews obeyed.

To their astonishment they found Jack in his underclothes busily engaged in stuffing his discarded suit with old bits of canvas and anything he could find to give the clothes the semblance of being on a living frame.

“What on earth have you got in mind now?” demanded Tom wonderingly.

Jack explained.

“I was just thinking,” he said, “that there was no use in our all going ashore. Somebody must be aboard to guard the Sea Gull from attack. But at the same time it’s important that those fellows on the Tarpon should think that there is no one here. My plan is that you, Captain Andrews, and you, Tom, row ashore with this dummy of myself sitting in the stern of the dinghy. You can easily dispose of it in some bushes when you get there. Then you make off at top speed for some telegraph office or telephone and summon help, and I’ll stay here on guard.”

“But they may attack you,” objected Tom. “That’s not likely. In the first place, there are three revolvers that I have at hand, and I guess that I could stand off quite a bunch of them if they should venture on an assault. But I guess they won’t.”

At first Captain Andrews would not listen to Jack’s plan; but when the lad represented to him that it might be necessary to have some one on board in case the Sea Gull floated on a rising tide, he changed his mind. The dinghy was brought around to the side of the launch away from the view of the Tarpon crowd, and Jack’s dummy carefully lowered into it.

Then, with Captain Andrews at the oars and Tom supporting the counterfeit Jack, the row to shore was begun. Jack, in the meantime, had found an old suit of clothes which he had put on in place of the garments he had sacrificed.

THEN, WITH CAPTAIN ANDREWS AT THE OARS AND TOM SUPPORTING THE COUNTERFEIT JACK, THE ROW TO THE SHORE WAS BEGUN.

He did not, of course, show himself outside, but from the porthole he watched the dinghy’s progress. He could hardly keep from laughing as he looked at “himself” propped up in the stern.

“That’s a good dummy, if I do say it myself,” he chuckled; “maybe it has more brains than I have, at that,” he added, with a grim smile.

But his attention was speedily distracted from watching the Sea Gull’s dinghy by the fact that from the Tarpon’s side another small boat now shot out. In it were five men—the total ship’s company of the Tarpon.

“Well, that disposes of the theory that the model was landed in the night,” mused Jack, as he watched them row off; “unless a sixth confederate ashore took charge of it.”

His expression suddenly changed to one of anxiety as he saw that the Tarpon’s dinghy was clearly in pursuit of the Sea Gull’s small boat.

“If they catch up there’ll be a fight more than likely,” he exclaimed, “and five to two, and with the two unarmed, is terrific odds. Hello, Tom’s seen them. Captain Andrews is pulling faster now! So are the Tarpon’s, though! It’s a race for the shore!”

Jack fairly glued his face to the porthole as he watched the two boats. A few moments later he gave a sigh of relief as the Sea Gull’s dinghy grazed the beach, and Captain Andrews and Tom sprang out. Jack noted, with a sort of grim amusement, that Tom supported the dummy up the beach, and managed it so skillfully that from a distance it really looked as if it were Jack walking beside him.

A moment later the two figures of Jack’s friends vanished in the brush which grew down to the foot of the cliffs, and the Tarpon’s boat touched the shore. Jack heard her occupants give a yell as they leaped out and ran up the beach, almost in the footsteps of Tom and Captain Andrews. The next instant the brush swallowed them likewise, and Jack was left to conjecture what was taking place behind that leafy curtain. That it was a drama of a pretty strenuous sort he was certain.

The cabin was insufferably hot, and Jack was too restless to remain still. As he knew that no one was left on board the Tarpon, he saw no objection to his emerging on deck for a breath of fresh air. He sat in the cockpit, looking dreamily at the Tarpon swinging at anchor, and wondering how things were faring with Captain Andrews and Tom.

Suddenly his reverie was broken off. The boy sprang to his feet and slapped his hand down on his knee. A sudden idea had come to him—an idea that was an inspiration.

“It’s worth trying,” said the boy to himself; “it’s worth trying. I may find out nothing, and then again—well, it may mean a whole lot.”

Jack secured the door of the cabin, and then divested himself of his clothes. This done he let himself over the side of the Sea Gull and struck out with a long, steady stroke for the Tarpon. It was quite a swim, and the tide ran swiftly. The Maine water is cold, too, but Jack was strong and vigorous and did not mind this in the least. In fact, after his long spell in the stuffy cabin the water felt delightfully refreshing.

It was not long before he reached the side of the Tarpon, and swimming around her finally found a dangling rope by which he hauled himself on board. Once in her cockpit, he started for the cabin door. As he had expected, it was locked. But a big wrench lay by the engine box, and Jack, without hesitating an instant, picked it up and with one blow smashed the lock in.

Then he opened the cabin door and found himself in a compartment bigger than the Sea Gull’s, but in a wild state of untidiness.

“Phew! what a stuffy hole,” thought the lad; “I guess those fellows don’t clean it out once a year. I wonder——”

Jack almost did a back somersault as he broke off his soliloquy. From out of a corner of the cabin something had sprung at him with a fierce growl and a savage display of teeth. It was a bulldog and a powerful brute, which appeared quite determined to drive Jack off the boat.

“Gracious,” exclaimed the boy, as the dog stood snarling at him, its ugly teeth exposed and its hair bristling angrily, “this is a fix. I never dreamed they’d have left a guardian here.”

“Gr-r-r-r-r-r-r-r!” came from the dog, as its nose crinkled up into a fierce snarl.

Suddenly the growl stopped, and the animal gave a spring at Jack’s throat. But, luckily, the boy had picked up the wrench with which he had broken in the door, and was prepared for the attack. As the dog was in mid-spring he raised it and brought the weapon down with crushing force on the animal’s head. The dog seemed to crumple up, and fell in a limp heap at the boy’s feet.

“He’s not dead,” said Jack, after an examination, “but I guess when he comes to he’ll feel pretty sick. I’m glad I didn’t kill him, although it might have been my life or his.”

He stepped over the dog’s body and entered the cabin. Then, without wasting time, he began a search. From the eager light in his eyes it was evident that Jack had an object in view, and was bent on accomplishing it as speedily as possible.

In the meantime Captain Andrews and Tom had been plunging through the brush on the steep cliffside, trying to work their way to the top. This appeared to be a task difficult of accomplishment. For one thing, the ground was loose and scaly, and for another, the brush grew very densely.

They were forced to be cautious in their ascent, too, as any undue noise was likely to bring the rascals who were trailing them about their ears in a hurry. At length they struck a sort of path, and before long gained the summit; But at about the same time that they found the trail their enemies struck it, too, and were close on their heels. Just at the top of the cliff a big rock lay poised beside the path.

Captain Andrews saw that this gave them an opportunity to hold their foes at bay, and he was quick to take advantage of it.

“Tom,” he whispered, “make off at top speed and get help as soon as possible. Jump now!”

“But what are you going to do?” Tom wanted to know.

“I’m going to keep those fellows from getting up, by this path at any rate,” was the response.

Tom knew that it was no time for argument, and although he did not much like leaving Captain Andrews alorie, he made off in all haste across the country. Before long he struck a road, and soon after got a lift in a passing wagon to a near-by village.

In the meantime an exciting scene had been enacted at the cliff top. Tom had not left Captain Andrews five minutes before Jake Rook, in advance of the others, straggled up the trail. As he reached the top he was amazed to hear a voice proceeding apparently from behind a big boulder, which was poised on the summit.

“You’ll have to go around the other way, gentlemen,” said Captain Andrews suavely; “if you advance any further I’m mightily afraid that this rock may roll down on you.”

“See here, Andrews,” came back the voice of Captain Flinders, “you’ve been imposed upon by those boys.”

“I know all about that, Flinders,” came back the reply, “but just you tell your friends there not to come any further this way, or they’ll land in trouble. I guess this rock would make quite a dent in the anatomy of anybody it happened to fall on.”

He shoved the rock suggestively, and it gave an ominous quiver. A hasty consultation followed among the men. It was impossible to dislodge the doughty captain by shooting at him, for he was shielded behind the rock. On the other hand, if they did not reach the cliff summit by that way the gang of rascals would have to make a long detour, and that, for reasons of their own, they were not anxious to do.

But it was the course they had finally to adopt, and Captain Andrews, with a grim smile, heard their retreating footsteps. It was not till they had gone that he realized that, in all probability, the model and the papers had gone with them. He was pondering this aspect of the case when Tom returned. He brought with him the village constable of Rumson, the town he had reached, and half a dozen deputies.

“Whar be them roustabouts?” demanded the constable, as he came up.

“I guess they’ve headed to the south,” said Captain Andrews; “I drove ’em off this trail by threatening to get careless with this rock.”

“Good for you! If they’ve gone south they’ll be bound to come up that path by Rumson Point,” declared the constable; “come on, boys, thar’s a re-ward for ketching them fellers.”

Thus stimulated, the posse set off at top speed for the Point, while Captain Andrews and Tom decided to return to the Sea Gull and find out how Jack was faring. They arranged to meet the constable and his men later on in the village, and learn how they had succeeded.

They found the dinghy as they had left it, and rowed off to the Sea Gull without loss of time. As they neared the grounded boat Jack’s head appeared out of the cockpit, and he waved his hand excitedly.

“He’s got some sort of news,” declared Tom; “wonder what it can be?”

They were soon to find out. As they boarded the Sea Gull, Jack, with dancing eyes, produced the long-missing model. Then, as if to cap the climax, he held up a sheaf of papers.

“Hurray, lad! You’ve done the trick!” shouted Captain Andrews.

“But how—what—where”—stammered Tom. “How?—by taking a swim over to the Tarpon. Where?—in a secret locker under the cabin floor,” laughed Jack. “You see,” he went on, “I had a hunch that it might pay to investigate the Tarpon, for I concluded that it was likely that Melville’s outfit would leave the model there till they found a safe place to take it ashore, and so—I got ’em.”

“And I guess that posse is getting our friends,” cried Captain Andrews. “Hark!”

From the direction of the Point came the sound of several shots and then silence.

“I have an idea that that is the finish of Mr. Melville and his outfit,” said Jack. But Tom interrupted him.

“The Sea Gull is afloat,” he cried.

Sure enough, the tide had been rising during the last hour, and now they could feel a quiver of life in the Sea Gull. The engine was started, and after a short time the craft was backed off into deep water and anchored. Not long after the three friends rowed ashore and made their way into Rumson. They found that village in a state of turmoil. The five marauders had all been captured after a bloodless battle, in which, however, a few shots had been fired by Rook and Melville.

But Rumson was not to have the honor of their presence long. After a brief examination before a local magistrate, they were consigned to the Boston authorities. They were tried for their crimes in that city, and received various jail sentences. Captain Flinders alone escaped on the plea that he did not know what kind of men he had taken as passengers. This was palpably false, but as he aided the State’s case by his testimony, he was released with a stern warning.

After the hearing at Rumson the boys telegraphed the glad news of the recovery of the model and papers to Mr. Peregrine, and notified their parents of the termination of their adventurous quest. The next day they started back for Boston on the Sea Gull, towing the Tarpon behind. Captain Flinders had asked Captain Andrews to look after the latter craft while his case was pending, and the boys’ good-hearted friend could not refuse. The bulldog, now completely subdued, went as a passenger on the Sea Gull, and Jack ultimately bought the animal from Flinders.

At Boston, the inventor, both the boys’ fathers, and Ralph and Jupe in a state of wild excitement, all met the boys, and many and hearty were the greetings and congratulations. After a few days in the city Jack found all the appliances he needed, and in a very short time afterward the Peregrine Vanishing Motor Gun was accepted by the government as a weapon for use against aëroplanes.

But Mr. Peregrine always says that, had it not been for the Boy Inventors, his machine would have remained and rusted in its shed. So with his authority we have linked their names with his invention.

One other thing of interest must be told. The Vanishing Motor Guns are being manufactured by the United States Artillery Devices Company, whose nominal head is now young Ralph Melville. The business was found to be in a bad way, but the contract for building the guns, which came to it after all, assisted in putting it on its feet again. Dr. Tallman, as Ralph’s guardian, had charge of the work of reconstruction. Prosperity has not changed Ralph, and he is as warm a friend of the boys as ever, and never has forgotten his rescue in mid-air. Dick Dangler has a post in the Melville works, and fills it right well.

And so the time has come when, for the present, we must bid good-bye to the Boy Inventors. But we shall meet them again ere long, and learn something more about their mechanical skill and clever daring. The next volume of their adventures will deal with a particularly enthralling subject—that of submarine work. Of the dangers and difficulties our young heroes faced under the water you may read in The Boy Inventors’ Diving Torpedo Boat.