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THE AEROPLANE BOYS ON THE WING

or,

Aeroplane Chums in the Tropics

BY JOHN LUTHER LANGWORTHY

1912

The further trials and triumphs of the venturesome aeroplane lads are set forth in a particularly thrilling manner in the third volume of this series, now on sale everywhere, and which is entitled, "The Bird Boys Among the Clouds; or, Young Aviators in a Wreck."

CONTENTS

CHAPTER

I. ON THE WAY BACK FROM THE GAME

II. FRANK'S WAY

III. SOMETHING ABOUT THE BIRD BOYS

IV. A STARTLING DISCOVERY

V. A WARM FIVE MINUTES

VI. IN SEARCH OF A CLUE

VII. ANDY RECEIVES A SHOCK

VIII. THE MESSAGE

IX. UNDER TROUBLED SKIES

X. NIPPED IN THE BUD

XI. OUT OF THE FRYING PAN INTO THE FIRE

XII. A GREAT SURPRISE

XIII. THE "DEVIL-BIRD"

XIV. THE AIRSHIP LAUNCHED AT LAST

XV. AN UNPLEASANT SURPRISE

XVI. THE AIR CHASE

XVII. THE CAMP IN THE TROPICAL JUNGLE

XVIII. WHEN FRANK STOOD GUARD

XIX. FIREBRANDS AND JAGUARS

XX. THE AEROPLANE BOYS ONCE MORE AFLOAT

XXI. THE LAST LITTLE HOT AIR BALLOON

XXII. RESCUED

XXIII. HOMEWARD BOUND—CONCLUSION

THE AEROPLANE BOYS ON THE WING

or, Aeroplane Chums in The Tropics

* * * * *

CHAPTER I.

ON THE WAY BACK FROM THE GAME.

"But the Bird boys won the prize of a silver cup!"

"What if they did? It was by a hair's breadth, Mr. Smarty!"

"And their monoplane was proven to be faster than the big biplane you built, Puss Carberry!"

"Oh! was it? Don't you be too sure of that, Larry!"

"Didn't it land on the summit of Old Thunder Top ahead of you and Sandy, in the race that afternoon? Tell me that!" and Larry Geohegan bristled up to the recognized bully of Bloomsbury, while a dozen fellows clustered around on the deck of the big power boat, listening eagerly to this war of words.

They were on their way home from a very exciting game of baseball that had been played at Cranford, across the lake. And after ten innings of hot work the nine from Bloomsbury had won. But not until they had changed pitchers, upon tying the score in the ninth, after coming up from behind.

Puss and Larry both wore the uniform of the home players, and there were others on the boat who also belonged to the team. In fact, the staunch vessel had been placed at the disposal of the baseball club for this day, by Commodore Elliott, the rich owner.

Larry had never been one of the adherents whom Puss could call upon to back him up when he tried conclusions with a hostile faction; in fact, Larry had always been an admirer of Frank Bird, who was recognized as the most persistent rival the bully had ever encountered in his whole career since coming to Bloomsbury.

Puss allowed a contemptuous expression to take possession of his face, and even shrugged his broad shoulders, after a nasty fashion he had, that often angered the one he was arguing with more than words could have done.

"Aw! rats!" he said, in a disagreeable, rasping voice. "Everybody knows that I'd won that same race only for trouble with my engine. Frank was lucky, just like he generally is when he goes in for anything. Look at him today, being called in to pitch in the tenth! We had 'em badly rattled, and they were on the toboggan sure. Yet Frank, the great hero, gets credit for winning that game. Didn't the Bloomsbury crowd cheer him to the echo, though, and want to ride him on their shoulders? Wow! it makes me sick, to see such toadyism!"

"What's all this big noise about, fellows? Didn't I hear my name mentioned?" asked a tall lad with a frank face and clear brown eyes, as he pushed forward.

It was Frank Bird himself, who had been talking with his cousin Andy, and several other fellows, in the bow of the launch, and by accident heard the voices that were raised in dispute.

Percy Carberry, known among his comrades simply as "Puss," did not flinch when he found himself face to face with the boy he detested so thoroughly. They had never as yet actually come to blows; but Puss believed that his muscular powers were far superior to those of his more slender rival, and just now he was in a particularly bitter frame of mind.

"Oh! so you're there, are you?" he sneered "I was just telling your good friend Larry here that I considered you a greatly overrated substitute pitcher; and that luck had as much to do with our winning that game today as anything you did."

Frank Bird laughed in his face.

"Sure," he declared, cheerily. "I was a mighty small factor in the victory, for I only played in one short inning. If I'd faced those hard hitters of Cranford nine times I reckon it'd be hard to tell what they'd have done to my poor inshoots and curves."

"But you held them in that inning, Frank, you know you did!" cried
Larry.

"Mere accident, my boy. Happened to be the weak end of their batting list!" observed Frank, as if determined to agree with his enemy, and thus spike his guns.

"Is that so?" demanded "Elephant" Small, who did not happen to be on the nine, because of his customary slow ways. "Perhaps you'll be saying that dandy two-bagger you whanged out, that brought in the winning run, was also an accident?"

"Well, I must have just shut my eyes, and struck. I seem to remember hearing a sound like a shot, and then they all yelled to me to run; so I did, going on to second in time to see Peterkin gallop home," and Frank looked as sober as a judge as he said this. The others saw the joke, however, and, led by Larry, burst out into a laugh that made Puss and his loyal backers scowl.

"If that bingle was an accident, don't we wish we had a few more players who could shut their eyes and meet Frazer's terrible speed balls and curves in the same way!" one fellow exclaimed.

"So say we all of us!" another cried.

Puss realized that the majority on board the Siren were against him. But he was not given to taking water; even his enemies, and he had many in Bloomsbury, could hardly say that Puss was lacking in a certain kind of grit; while stubbornness he possessed in abundance.

So he just shut his white teeth hard together, and looked scowlingly around the bunch of fellows. And many of them felt a little chill when those cold gray eyes rested upon them; for they knew of old what happened when Puss Carberry made up his mind to mark a boy for future attention.

Frank still stood there by the side of the boat, smiling. Perhaps his very apparent unconcern served to make the other still more angry. There had been bad blood between these two lads for a long time, and more than once it threatened an eruption, which somehow or other had up to now been stayed.

Although some weeks had passed since the much-talked-of race between the rival aeroplanes, piloted by these two boys, in which Frank took his little craft up to the lofty summit of Old Thunder Top ahead of Puss in his biplane, as narrated in the first volume of this series, entitled "The Bird Boys; or, The Young Sky Pilot's First Air Voyage," the latter had never ceased to feel ugly over his defeat.

As usual he had what he considered a good excuse for his arriving second; but few persons ever knew how Puss and his helper Sandy had tried to injure Frank's airship when it was directly beneath them, by deliberately dropping a sand bag, taken along, singularly enough, as "ballast," but with this very idea in view.

"Seems to me you've gotten the big head ever since you happened to drop on that rocky plateau on top of the mountain just three little seconds ahead of me, Frank Bird!" he said, with a steely glitter in his eyes that those who knew him best understood to mean coming trouble.

"Oh! I hope not, Puss," replied the other, with a smile. "I give you my word my hat fits me just as comfortably as ever. It was a close race, and the one who got there first hadn't much to crow about, for a fact. We happened to be lucky not to have any trouble with our new little Kinkaid engine, that was all."

"Huh!" grunted his cousin Andy, shaking his head, and scowling at Puss in turn. "But we had plenty of other sorts of trouble, all the same, sand bags full of it, in fact. They just rained down on us; but then Frank knows how to check up his engine suddenly, and the storm passed by without any hurt!"

Some of the fellows, who happened to know what this sly reference on the part of the hotheaded Andy meant, began to chuckle. Of course such a thing would only serve to make Puss more angry. He chose to believe that they were all only trying to bait him.

Frank in particular came in for his dark looks. And Larry, who had once run in the same company as Puss, so that he knew his whims better than many others, took occasion to give Frank Bird a sly nudge in the side, as he whispered:

"Look out for him, Frank; he's getting near the danger point, sure!"

But Frank did not have to be warned. He had grown tired of warding off this ever threatening danger of a broil with Puss Carberry. Like his cousin Andy, the other had no father; and his wealthy mother had long since given up in despair the idea of controlling the headstrong lad. So that Puss had his way, whenever he wanted to do anything out of the ordinary.

Because Mrs. Carberry was one of his father's patients, and Dr. Bird esteemed her very highly, Frank had postponed the reckoning just as long as he could endure the insults of the bully. But he believed the last ditch had been reached, and was determined to no longer raise a hand to avert the threatening storm.

Puss had turned when Andy spoke, to flash a look in his direction. But it had no effect upon the other, who could be as reckless at times as the next one. Indeed, Frank often had to curb the impatience and daring of his chum.

"Oh! that's what sticks in your craw, does it, Andy Bird?" demanded Puss. "Just because Sandy happened to drop that ballast, thinking we might make better time if we lightened ship, you choose to make all sorts of nasty insinuations about us wanting to knock you out! Shows where your mind is. Another fellow wouldn't ever let such a fool notion get a grip on him. And you'd better put a reef in that tongue of yours, my boy, unless you want to have it get you into trouble."

Andy flared up at once, and would have replied; but Frank calmly stepped in between the two, as though he claimed first right.

"Neither of us have charged you with intentionally trying to disable our aeroplane by dropping that sand bag, Puss," he remarked quietly. "All we say is that it was a queer coincidence you wanted to get rid of your ballast just when we were walking up on you hand over fist, and about to pass under you, to take the lead. That's all!"

Again there was a low laugh from among the boys who stood around listening. To them it was a rich treat to see the recognized bully of Bloomsbury baited to his very face in this characteristic way; and they were enjoying it hugely.

"Well, let me tell you it ain't all, not by a jugful!" exclaimed Puss, his face taking on a purple hue, as it always did when he became enraged. "Both of you fellows have got to stop speaking about that sand bag dropping, or there's going to be a licking in store for you. See?" and he thrust his face close to that of Frank as he said this. Larry Geohegan fairly held his breath. "Now it's coming; don't I know the signs?" he whispered to the boy next him.

Frank continued to stand there, close to the side of the speeding launch. They were about half way across the deep lake at the time. Evening was coming on, for the sun had just reached the distant rugged horizon in the west.

"Do you refer to me when you say that, Puss?" he asked, with that same queer little smile on his face—a look that mystified the other, who could not understand what it meant.

"Yes, both you and that loud-mouthed cousin of yours. Just because luck favored you, and you won that blooming race by a head, you think I can't manage an aeroplane as well as you. Huh! perhaps you don't know that I'm going to take my machine with me when I go down to the cocoa plantation we own along the Amazon, and use it exploring where a white man has seldom been seen. You can just stay here and grow up with the country, while I'm doing great stunts. But as long as I stay here I'm going to stop this talk about trickery and low-down dodges. You're responsible for most of it, Frank Bird. I warn you what's coming to you." "Perhaps," said Frank, pleasantly, "you would be kind enough to tell me also when this awful punishment is going to fall on my poor devoted neck?"

"Any time, hang you! Right now, if you say another word!" roared Puss, doubling up his fists, and making ready for one of his well known and feared bull rushes, that had brought him a speedy victory many a time.

"So? That's comforting; and with all these good fellows around to see how you wipe up the deck with me. Suppose you begin the swabbing act, Puss!" and Frank pretended to throw himself in a position of defense.

The other gave utterance to a hoarse cry of rage, and lowering his head after the manner of a bull, jumped forward. But the agile Frank simply stepped aside; and unable to check himself in time, Puss Carberry shot over the side of the power boat, disappearing in the clear waters of Sunrise Lake with a great splash.

"Oh!" shouted his crony, Sandy Hollingshead, standing there as if petrified; "and Puss can't swim a single stroke, either!"

CHAPTER II.

FRANK'S WAY.

"My goodness, what a splash!"

"Served him right, that's what!"

"He's gone under, fellows! Dove just like a big frog!"

"Stop the boat! He'll drown!"

Half a dozen were shouting in unison, as the boys crowded to the side over which the bully had pitched when Frank avoided his forward rush.

But Frank heard only that startled exclamation from Sandy Hollingshead:

"Puss can't swim a single stroke, either!"

With Frank Bird to think was to act. The two things were almost synonymous in his mind. Forgotten was the fact that the imperiled lad had been endeavoring to strike him in the face at the time of his submersion in the waters of Sunrise Lake.

Not a single word did he utter, but throwing off his coat, he made a leap over the side of the boat, already slowing up as the power was cut off.

"Frank's gone back after him!" cried one.

"And he'll get him, too," another hastened to say; for they understood that when the leader of the team known as the "Bird boys" attempted anything he usually got there, as some of them said "with both feet."

Meanwhile Frank was swimming with all his might toward the spot in the foamy wake of the boat, where he knew the unfortunate Puss must be battling for his life.

It seems strange that occasionally a boy may be found who has never taken the trouble to learn how to swim. In the country this is a rare occurrence; which would make the neglect of such an athletic fellow as Puss seem more remarkable.

He was threshing about in the deep water like a cat that has fallen overboard; and managing to keep partly afloat after a fashion; though it would have been all over with him long ere the power boat could be turned around and arrive at the spot where he struggled, gasping for breath, and sucking in much water.

Frank was wise enough to understand that it is always desirable to approach a drowning person from the rear, so that a grip may be taken before the would-be rescuer's presence is discovered. Once let those frenzied fingers clutch hold of him, and the chances of a double tragedy would be good.

So Frank was keenly on the watch as he swam toward the splashing and gurgling that announced Puss Carberry's fight for his life.

He could see him by now, and never would Frank be apt to forget the look of absolute terror he discovered upon the agonized face of the bully. Puss had detected the presence of some one near by, and was trying to shout, as well as stretch his appealing hands out, though not with much success.

He actually went under while Frank looked; and the heart of the would-be rescuer almost stood still with a terrible fear that that was the end.

But he kept on, and in another moment a head once more bobbed up, with Puss threshing the water frantically. Once he had gone down. According to what most people said, he would possibly vanish twice more, and after that never rise again.

If anything was to be done, there was no time for delay. Frank was within ten feet of the struggling figure when it came up. He immediately dove, and managed to rise to the surface behind Puss. Then, just as the other was floundering beneath the surface of the agitated water again, Frank caught hold of his sweater close to his neck, and held on with might and main.

He had a serious job of it, for the half-drowned lad made a desperate attempt to turn around, doubtless with the intention of throwing his arms around his rescuer. This was just what Frank was desirous of avoiding. He simply wanted to keep the head of Puss above water until the boat could come and willing hands be stretched down to relieve him of his burden.

So he kept treading water and fighting Puss off as best he was able. It was no easy task, since he still had his baseball shoes on; and swimming in one's clothes is always a difficult proposition. But Frank knew no such word as fail and continued to strive, keeping one eye on Puss and the other on the approaching power boat.

"Steady now, Puss!" he kept saying, again and again, trying to instill some sense in the head of the frantic boy, who still believed he must be going down again. "Keep your breath in your lungs and you'll float! Don't kick so; I'm going to hold you up till the boys come. It's all right, Puss; you're safe!"

All the same Frank was mighty well pleased when the launch did swing close alongside and half a dozen hands reached out to clutch hold of them both.

"Puss first, fellows!" he said, with a half laugh. "I can crawl in myself, I guess." But they would not hear of it, so willing hands lifted him up as soon as the other dripping figure had been deposited in the bottom of the boat.

Frank made light of the adventure, after his usual style.

"Oh, come, let up on that!" he remarked, when some of the fellows were patting him on the back and calling him a hero and all such things that were particularly disagreeable to Frank. "It was just a cinch to me, you know. I'm half a water spaniel, anyway. Besides, if it hadn't been for the way I riled him, Puss wouldn't have fallen overboard. Drop it, please."

By the time the boat reached the landing near the dock where the lake steamer touched, Puss seemed to have discharged his cargo of water, swallowed unintentionally.

He made his appearance, with several cronies clustered about him. Frank was not the one to hold a grudge. Besides, he had come out of the affair with flying colors and had nothing to regret. So he strode up to Puss at once, holding out his hand.

Every boy on board crowded around, eager to see how the bully would behave, for they knew his natural disposition and wondered whether any sort of miracle had been wrought in his disposition because of his recent submersion.

"I hope you're feeling all right now, Puss," Frank said, pleasantly. "I wanted to ask your pardon for treating you so roughly; but knowing you couldn't swim, I was afraid that if you closed with me we'd both go down."

"But you struck me once right in the face, you coward!" exclaimed the other, as he put his still trembling hand up to where a bruise of some sort could be seen.

"Yes, I admit it," returned Frank, quickly; "and that was what I wanted to apologize for. You grabbed me and it was the only way I could break your hold. I've been told by life savers that often they have to strike a man and knock him senseless to save themselves from being dragged down. You must understand that it was no time to be particular. I had to save myself in order to help you!"

The other stared hard at him. Evidently Puss had not yet entirely recovered after his close call. At any rate it was positive that he could not understand how he actually owed his very life to the speedy action of this boy whom he hated so bitterly.

They saw him shake his head, much as a dog might that is worrying a rat.

"Well, you only undid your own dirty work. You pushed me in and then you got cold feet. For fear that I'd drown and you'd be hung you jumped in to do your usual grandstand act of hero! Didn't I hear these softies calling you that right now? No, I don't want to touch your hand. Keep your friendship for those who can appreciate it. There's a long account between us that's going to be settled some fine day."

And with these ungrateful words Puss Carberry strode off the boat, surrounded by his cronies, who were doubtless pleased with the course of things.

"Well, did you ever hear of such base ingratitude in all your born days?" exclaimed Larry Geohegan, making a gesture of supreme disgust.

"And to think of the skunk saying Frank pushed him in!" echoed Elephant, "when he actually risked his life to save the cur. Ain't I glad now I didn't carry out my first impulse and jump after Puss, even before Frank went. Why, maybe he'd have even said I tried to drown him!"

The idea of that proverbial slow coach of an Elephant ever doing anything on the spur of the moment was really too much for the rest of the boys and a general roar went up. "Don't bother your heads about me, fellows," remarked Frank, quietly, when the laughter had ceased again. "That was just about the kind of treatment I should have expected to get from Puss Carberry. Still, I'm not sorry I did it. Life would seem very tame without that schemer around to try and liven things up for me. But I hardly expected him to accuse me of pushing him in when all I did was to step aside and avoid a blow at his hands. Forget it, please."

He walked off with his cousin Andy, who had been boiling over at the time the rescued Puss made his astonishing accusation.

"Wouldn't that jar you some now?" remarked Andy, after his customary fashion.

"I suppose you're referring to the way Puss turned on me after I went and got my baseball suit wet just to give him a helping hand?" laughed Frank, good naturedly. "Oh, I don't bear any malice. Perhaps he was still a little stunned by that knock I gave him. But I thought he was going to get his arms around my neck, you see, and then it would be all up with us both. It worked, too, for he was as limp as a dishrag from that time on. Remember it, Andy, in case you ever jump over after Puss."

"Me after that snake? Why, hang it, I'd see him in Guinea before I'd ever lift a hand to save him! I tell you I'd—I'd—" stammered the indignant Andy.

"I don't believe it of you," declared his cousin, quickly. "You may think you'd stand by and see him drown, but that's all gammon. I know you too well to believe you're half as vindictive as you try to make out. But did you hear what he said about going down there to South America, visiting a plantation his mother partly owns and taking his biplane along with him?"

Andy was all excitement now.

"Sure I did," he said. "And ten to one he learned somehow that we thought of going down in that region for another purpose. It would be just like Puss and that sneak of a Sandy Hollingshead to try and beat us out. That fellow wouldn't mind a trip to the other end of the world if he thought he could get your goat, Frank. He hates you like poison. Pity you didn't feel a cramp just when you were swimming to him—not enough to endanger your own life, you see, but sort of make you stop short."

"Shame on you, Andy," remarked Frank. "I hope I'll always carry myself so that I won't be afraid to look at myself in a glass. But what do you know about that place—didn't he call it a cocoa plantation or something of the kind?"

"Yes," replied the other moodily; "I was told that his mother owned two-thirds of some such place along the Amazon or somewhere down there. But let them go. It's a tremendous big country and there isn't the least danger that we'll ever butt into them, if we should decide to take a run down."

"Still," observed the taller lad, thoughtfully, "you never can know. I've heard travelers say that sometimes the world seems to be very small; when you meet your next door neighbor on the top of some Swiss mountain. Puss may know nothing about your plans and this is perhaps only a coincidence, as they say. Since he has had such poor luck getting to the top of our mountains around here he wants to try his hand on those poor South American Andes."

Andy's father had been a professor in one of the colleges, who, having taken up aeronautics, had made many balloon voyages in quest of scientific information, so that his name had become quite famous. Then, about a year before, he had been lost when attempting to solve the air currents on the Panama Isthmus, where the government had thirty thousand laborers digging the big ditch.

Nothing had ever been heard of the professor from the day he started from the Atlantic side of the isthmus, intending to cross the mountains and land on the Pacific beach. And it was becoming a positive mania in the mind of Andy, who lived with his guardian, Colonel Josiah Whympers, to some day go down there and follow in the track of his lost father, in the hope of discovering his sad fate.

It was with this idea in mind that he had united his forces with Frank's inventive genius and helped build the monoplane with which they had won the race to the top of the neighboring mountain, during Old Home Week at Bloomsbury.

And every day he was thinking more and more of what strange things the future might have in store for him, if he ever started on that exploring venture.

CHAPTER III.

SOMETHING ABOUT THE BIRD BOYS.

"How about coming over tonight?" asked Frank, as the boys halted at the gate of Dr. Bird's place, where Andy had gone to get his wheel, since he lived some little distance away.

"I'd like to first rate, Frank, because there are some things I want to talk over with you. But I promised Colonel Josiah to get at his books tonight and straighten them out. It'll take me all evening, I reckon."

"Oh, well," remarked Frank, "see you in the morning anyway. This breeze will have worn itself out by then, perhaps, and if we feel like it we can take a little trip somewhere in the 'Bug,' as you like to call our dandy little aeroplane."

"I hope so," replied Andy, eagerly. "It's been some days now since we were up, and I'm more than curious to find out if that new arrangement of yours is going to help us any in getting a quick start."

"Does the colonel still persist in having old Shea sleep outside the shed?" asked the other, as Andy pushed in to get his wheel out from under a side porch, where he had thrust it before starting off to the baseball game.

"Sure," came the reply. "When Colonel Josiah once starts on a thing it would take an earthquake to stop him. I tried to tell him that there was no danger of our monoplane being injured now that those two men who robbed the jewelry store were locked up at police headquarters, waiting for some formality to start them on the road to a ten-year sentence; but he only shook his head and said Shea had nothing else to do and might as well be earning his salt."

The incident to which Andy referred was related at length in the preceding volume of this series, "The Bird Boys; or, The Young Sky Pilots' First Air Voyage," and had created a ten days' sensation in the quiet little lake town of Bloomsbury.

Two rogues had robbed the extensive jewelry establishment of Mr. Leffingwell and carried off the loot in a couple of suit cases taken from the store. Unable to get clear away on account of a quick chase, they had hidden in the vicinity of the town. One of them, named Jules, had been an aviator at some time in his near past over in France, and learning that the Bird boys had built a monoplane, which was even then ready for a flight, they had attempted to steal the same, with the intention of giving their pursuers, who were hunting the woods for them, the laugh.

But their well laid plans were spoiled through the vigilance of the Bird boys and the quick wit of Frank in particular. The consequence was that both men were eventually captured by Chief Waller and his officers and still languished in the town lock-up, awaiting the day of trial.

"Oh, well!" laughed Frank, as his cousin wheeled his bike out to the front gate, where he could mount better, "it makes mighty little difference, because, from what I've seen of Shea, I imagine he sleeps on his post. I'm glad we didn't let him inside, because, like all Irishmen, he is fond of his pipe and might have set fire to the shed. It's dangerous smoking where there's a lot of gasoline about."

"Of course we've got that Puss Carberry and his mean crony, Sandy Hollingshead, to consider. They tried to injure our machine once and might again, especially after what happened today," said Andy, throwing one leg over his saddle and standing there a minute.

"Oh, I guess not, Andy. They understand that we're keeping tabs of that hangar, with its precious contents. Besides, they've got their hands full of other matters, if what Puss said about that big trip to the Amazon country is true."

The other sighed.

"I only wish I was as sure of going down there as Puss seems to be," he observed. "I don't know how it is, but something queer seems to be drawing me that way. Day and night I have pictures rising in my mind. I've read every scrap concerning the Isthmus and northern coast of South America, until I guess I'm as well posted on such things as one who had been there."

"Yes," said Frank, softly, "and I'm afraid you let your mind dwell too much on that subject, old chum. It's more than a year now since your father disappeared. And the chances of your ever finding what became of him are like searching for a lost diamond in the sand of the seashore. It's affecting your mind, Andy. You look all fagged out. I wish you could cheer up and be something like your old self."

But the other only shook his head sadly.

"I don't believe I ever can, Frank, until I've had my chance to go down there and make a good try to find all that is left of my poor father. Just as you say, it seems almost silly to think that I could ever succeed, but no matter, I've got it arranged in my mind and the colonel is coming around slowly."

"Well," Frank hastened to declare, "you know if it ever does get to the point that you do go down to make that search, I'm with you. My father would never throw any obstacle in the way, I'm dead sure. And Andy, of course we'd take our aeroplane along. Think how many trips we could make in her over country that no one could ever penetrate on foot."

Andy was too full for further words. He simply turned and squeezed the hand of his cousin; but the look of affection which he gave Frank told what was in his mind just then.

Frank watched him go spinning along the road and then with a sigh turned into the house.

The day had been replete with excitement for him. First there was the keenly contested game with their rivals across the lake and a tie in the ninth inning, which gave the Bloomsbury boys a chance to win out in the tenth. His pitching had held the enemy safe, and in their half of the inning Frank had made the hit that brought the game to a conclusion. As a rule the home club took the last chance at the bat, but the Cranford manager had chosen differently on this occasion, for some reason of his own, and with disastrous results.

Then, on the way home, had come that little diversion aboard the launch, when his old enemy, Puss Carberry, in attempting to strike him, had miscalculated and gone plunging into the lake, himself being unable to swim.

Frank had nothing to regret in connection with his leap after the struggling lad and his subsequent saving of Puss. True, the latter chose to crush down the natural spirit of gratitude that should have made him accept the hand Frank offered later. But Frank felt that he could afford to smile at such an exhibition of a small nature.

At the supper table his father and Janet, his sister, just home from boarding school a couple of weeks back, plied him with questions concerning the game. Of course, the girl had been present and had seen her brother carry off the honors on the diamond; but there were lots of things she wanted explained.

And before Frank knew it he was asked point blank what had happened on the way across the lake, for Janet had been aboard another boat, it seemed.

"Marjorie Lee told me she heard that you jumped overboard to save some one, she didn't just know who?" was what Janet said, and the good doctor pricked up his ears as he looked inquiringly toward the boy of whom he was so proud.

Frank turned red and then laughed.

"Oh, pshaw!" he said. "I had hoped that would be kept quiet. But some of the fellows like to talk too much."

"Who was it you jumped over after? They said you held him up until the boat got around—that he could not swim a stroke, and must surely have drowned only for your prompt action. It couldn't have been Cousin Andy, because he can swim nearly as well as you. Tell us, Frank," Janet persisted.

So Frank found himself compelled to relate the whole circumstance. In his usual generous manner he tried to gloss over the conduct of Puss and spoke as though the other had tumbled overboard during a little boyish roughhouse business; but Janet knew of the enmity between the pair, and she could read between the lines.

Frank spent a couple of hours after supper in poring over a book Andy had loaned him. And it might easily be assumed that it had to do with the birds, animals, fauna and inhabitants of that great country lying north of the equator, down in Central and South America.

It was about nine o'clock when his father called to him. The doctor had just come in from a few last visits and looked anxious.

"Frank, I'm in a peck of trouble," he said, with a whimsical smile, "and I wish you could help me out, though I dislike putting you to so much trouble."

"Oh, don't mind that, dad, one little bit; you know I'm only too glad to be of any assistance to you. What's gone wrong now? Machine laid off again and garage closed? But you won't need it till nine tomorrow, will you?"

There was a world of affection in the very way Frank used that word "dad." It might seem disrespectful coming from the lips of many boys, but to the ears of the good doctor it was as sweetest music.

"That's the trouble, Frank. I do need some means of getting around tonight the worst kind. Fact is the car broke down just as I got it in the yard. Same old trouble, and will take an hour to fix it up. And all at once it dawned on me that I had forgotten to take the medicine out to Farmer Lovejoy, which I surely promised tonight. It lies under the seat of the machine. Slipped my mind entirely when I was out. And Frank, there may be a serious turn to that child's sickness unless that medicine gets there within the next hour or so."

"Don't say another word, dad," declared Frank, jumping up and getting his cap. "My wheel is in fine shape and with a good lantern I can make the run in a jiffy. Only too glad to be able to help out. The packet is under the seat in the car and you left that in the side yard? All right, I'm off!"

CHAPTER IV.

A STARTLING DISCOVERY

It did not take Frank many minutes to get started on his little trip.

As he had said, his wheel was in good shape, with neither tire needing any pumping up. And even his acetylene headlight had only to be attached, which task took but a short time.

"I declare!" he exclaimed, as he rested his wheel against the gate and turned back, "that would have been a rough joke on me if I'd gone spinning off and only remembered after I'd almost got there that I forgot to take the package of medicine out of dad's little runabout. So much for having my brain full of that wonderful scheme of Andy's."

He found the medicine, and as the packet turned out to be small enough to be stowed away in one of his coat pockets, Frank so disposed of it. Then wheeling his machine out into the road he took a last look at the lantern, to see that the water might not be dripping on the carbide too rapidly to combine the greatest efficiency. After that he swung into the saddle, starting off with the perfect freedom that proclaims the rider a master of his wheel.

Once he passed out of town Frank made good progress. He had a ride of several miles before him, ere he could expect to reach the farmhouse of Jason Lovejoy, one of his father's oldest customers and friends.

There was no help from the moon, because the sky had clouded up and screened the young queen of the skies. But Frank needed no other light than the brilliant glow that spread out along the road ahead of him coming from his lamp.

It happened that he passed the home of Colonel Josiah Whympers, the retired and lame traveler, in whose care Andy had been left by the will which his father had made before starting on what had proven his last air voyage.

"Guess Andy's gone to bed," he mused, as he saw the house wrapped in darkness, for it was now after half past nine.

Frank cast a glance back toward the big field where the shed stood in which the great little monoplane, in which they had won their victory during Old Home Week, was stored. But he could just barely make it out, owing to the distance and the faint light of the moon coming through the clouds.

Naturally the hearts of both lads went out toward the gallant aircraft which had answered every call made upon it for speed and endurance. It was equipped with an engine of the latest make, weighing only a third as much as the average aeroplane motor and a triumph of modern scientific discovery. Since the Bird boys had constructed that monoplane themselves, after patterns obtained elsewhere, surely they had reason to be proud of their work and the gallant victory which had come to them.

Frank pedaled on, thinking nothing of the trip. He was accustomed to being abroad at night with his wheel, and, indeed, had taken many a twenty-mile run by the light of his lamp alone.

What was there to fear? Bloomsbury was a peaceful community. Rarely did anything occur to indicate that a spirit of lawlessness was abroad. Occasionally the police had some trouble with wandering tramps, but Chief Waller's strong point seemed to lie in that direction, and as a rule hoboes gave Bloomsbury a wide berth. The word had gone out that they made stragglers work when caught there, and nothing could be more horrible in the eyes of these "Wandering Willies."

After passing Andy's home it was not more than twelve minutes before Frank found himself approaching the quiet farmhouse where he was to leave the medicine.

The doctor had told him to ask a number of questions with regard to the little sufferer, and Frank was well enough up in medicine to know what to say when he learned how matters were going.

A big watchdog boomed his hoarse bark upon the night air, as Frank dropped off his wheel at the gate where the mail box was fastened.

"Hello, Kaiser! Good dog! Don't you know me, old fellow? Come here and be friends, Kaiser! It's all right! I'm coming in!"

Frank knew how to use a wheedling voice that a dog instantly recognized as belonging to a friend. Besides, instinct doubtless told Kaiser that any one who had evil intentions would come sneaking around and not in this bold fashion.

At any rate, the big mastiff began to wag his tail, and though he still barked, it was by way of a welcome now. Frank fearlessly opened the gate and walked in. The guardian of the farm came up to him, sniffing, and Frank, without hesitation, rubbed his hand over the shaggy head of Kaiser.

So side by side they advanced to the house. Already a door had opened, showing Farmer Lovejoy with a lamp in his hand. Evidently they had been anxiously waiting for the coming of the good doctor, and were possibly beginning to worry because he had failed as yet to show up with the medicine he had promised.

"It's you, Frank, is it?" asked the farmer, as the lad drew near the stoop.

"Yes, sir," replied the boy, cheerily. "His machine broke down and I had to come on my wheel. But father said it was very important that you have this medicine tonight. He expects great things of it by morning."

"Well," said Farmer Lovejoy, warmly, "that was right nice of you to come all this way on your wheel, Frank. But I guess it's on'y what we'd expect from Doc Bird's boy. I saw ye make that trip up to the top of the mountain in your airship, Frank. I tell ye it was wuth seein'! Won't you come in? The missus'd like to see ye."

"Why, yes, I will; because dad asked me to explain something to you and also get some information about Sue. A few minutes will make little difference," Frank said.

But, although he did not suspect it just then, even seconds came very near being of the greatest importance.

Perhaps he spent all of ten minutes in the Lovejoy home and in that time learned what his father wished to know. The old farmer came to the door with him, shaking hands warmly.

"Once again I say I'm obliged to ye, Frank," he remarked, with feeling, "for comin' away out here to fetch the medicine. It may be the means of savin' our gal to us, who knows? But I've got faith in your father. If anybody kin fetch our Sue around he will. Good night, lad. Kaiser, mind your manners. This is one of the best friends we've got."

"Oh, that's all right, sir," declared Frank, quickly, as he patted the shaggy head of the big mastiff. "We understand each other, don't we, old boy? He knew my voice, because a dog never forgets a friend, and I've played with him many the time. Good night, Mr. Lovejoy. Keep up your spirits. Dad says Sue is going to get over this all right in a little time."

Once again on the road he turned his face toward home. After all, this six or seven-mile run was only a good touch of exercise, and he would sleep all the sounder on account of it. Besides, Frank loved nothing better than to do something for the parent who all his life had been so indulgent to him.

As he pedaled along, keeping his eyes well ahead, so as to glimpse any vehicle that might loom up in his path, he was thinking of what Andy had in mind. While the project was as yet rather uncertain, Frank seemed to feel that his cousin could never be wholly satisfied that he had done his duty by his father until he had spent some time down on the Isthmus trying to get some traces of the lost aeronaut.

"I reckon I ought to know something of Andy's persistence," he said to himself, with a chuckle. "And now that he's got this bee in his bonnet there'll be no peace until he tries the scheme out. Sure I'm with him from the word go. It makes me shiver all over with expectation just to think of what glorious times we two chums might have—hello! there's something ahead, and I'd better slow up!"

It proved to be a farm wagon, pulled by two tired nags, and headed for home, after a day in the town market. The driver was asleep on the seat, leaving to the sagacity of his animals the successful navigation of the road.

Perhaps some movement of the horses or else the bright light of the acetylene headlight falling on his face aroused the man, for he sat up as Frank was about passing.

"Hello! is that you, Frank Bird?" he asked, leaning forward to look closer at the rider of the bicycle.

"Sure; just been up to your neighbor's, Lovejoy's, with some medicine for his Sue," returned the boy, recognizing the farmer.

"How is the gal gettin' on?" called the other, over the canvas top of his seat.

"Fine. No danger, dad says!" answered Frank.

"That's good!" he heard the sympathetic neighbor remark, as he moved on.

Five minutes later and Frank once more found himself approaching the Whympers place. As before, the house was in complete darkness, as if the inmates were long since abed. Frank knew that the old man kept early hours, seldom sitting up, for he read much during the day, having nothing else to look after.

Then, as was only natural, the eyes of the bicycle boy turned once again with more or less affection toward the quarter where he could just dimly make out the long, squat shed out in the field, in which the precious monoplane was stored.

As he did so Frank uttered an exclamation of surprise.

"Why, there's a light over by the hangar!" he burst out. "Now, what under the sun do you suppose that old fool of a Shea can be doing? Oh, my! Look at the flame jump up! Why, as sure as you live I believe the shed's afire! And I can see the figure of a man moving about. This is no accident, but something worse! And it looks as if the little 'Bug' might be going up in smoke in a jiffy unless I can sprawl over the fence here and get on the spot mighty quick!"

CHAPTER V.

A WARM FIVE MINUTES.

"Fire! Fire!"

So Frank shouted, even as he jumped over the fence, and made a bee line for the center of the big field, where the shed lay in which the precious monoplane was stored.

He had hastily leaned his bicycle against the fence as he made the plunge. Nor did he cease to let out constant yells while running across the open as fast as his agile legs could carry him. Twice he tripped over some object and nearly fell, only to recover himself and speed on.

As he ran he kept his eyes upon the low building beyond. In this manner he plainly saw the stooping figure of a man or boy making off in a roundabout way so as to avoid him.

Frank's heart was burning with indignation because of this dastardly attempt to ruin the gallant little airship that had so nobly stood all tests and proven itself a splendid piece of workmanship.

"Oh, the contemptible coward! I'd just like to chase after him and get my hands on him once!" was the thought that passed through his brain.

But he knew he could not. The scoundrel, no matter who it was, must be allowed to escape in order that he turn his attention to the burning shed and try to save the airship from destruction. Once the fire got inside, there was enough of the dangerous gasoline about to insure the speedy burning of the whole flimsy fabric, all but the motor itself.

So Frank kept headed straight for the hangar, trying to shut out the sight of that crouching, fleeing figure. He continued to lift his sturdy young voice in repeated shouts:

"Fire! Fire!"

Those in the house must hear; yes, and the neighbors, too. He might not be able to master the flames alone and single handed, and would need help. Besides, it was only right that Andy, being part owner in the monoplane, should be made aware of its sudden peril.

As he thus drew near the low building he saw that the fire had already gained considerable headway, just as if the incendiary might have used kerosene or some other inflammable fluid, to hasten matters.

Frank's heart grew cold as ice as he contemplated the rapidity with which those hungry flames were crawling up the dry boards that constituted the side of the shed.

But he did not lose his head in this sudden crisis. It was characteristic of Frank Bird that, no matter what the emergency, he was always cool enough to think out the proper thing to be done or else jump at it through instinct.

And Frank had foreseen just some such possible need as this. He even kept several buckets of moist sand handy, where it could be snatched up at a second's warning, knowing that most fires can be smothered, when quenching them with water is out of the question.

"The buckets!" he gasped, as he arrived close to the building, one part of which was now fairly covered with the creeping tongues of ruddy fire. "I must use them on it!"

He had to turn the corner of the shed to get to where they stood. And as he did so he ran plump into a figure that was coming toward him. Just in time did Frank dodge a big fist that shot out. And in that second he recognized in the other Shea, the Irishman who had been hired to keep watch of the shed.

"Hold on, Shea!" shouted Frank. "It's me, Frank Bird. Somebody has set fire to the shed! Grab up a bucket of sand and carry it around here. We can put it out yet if we're busy!"

Shea had evidently only been aroused from a sound sleep by the approaching cries of the boy and was still in a daze. He had discovered the fire, and hearing Frank running toward him, supposed that this must be the one who had done the evil deed.

But he had sense enough to do as he was told now, snatching up one of the sand buckets and following the boy. Frank immediately commenced fighting the flames with a vim. He slapped the wet sand at the creeping fire, and wherever it struck there seemed to come a quick abatement of the conflagration. But it was by this time so extended that as fast as he succeeded in knocking it out in one place it cropped up afresh somewhere else.

His ammunition would not last if this kept up.

"Get busy, Shea!" he cried. "Find something and slap at the fire for all you're worth! Fight it, man, fight it!"

As Frank happened to turn his head to learn what the other was doing he saw something that made very little impression on his mind just then, but which had considerable bearing on the matter later.

A light was speeding along the road, heading away from town, and Frank realized that the firebug had seized upon his convenient wheel and was making his escape.

Later on he might figure out the meaning of this movement. Just then he really had no time to give it a thought, no matter if a dozen wheels were concerned. The fire demanded every atom of his attention.

Shea did get busy. Once he became stirred up, and he proved a valuable helper. He went for the flames tooth and nail, smothered them with his coat, regardless of consequences, after he had slipped that article of wearing apparel off; kicked and tore and fought until it became evident that between them they were certainly making a decided impression on the threatening conflagration.

All this while it seemed to Frank that his heart was in his throat. Not so much because he feared that they would fail to gain the mastery over the fire as that some spark might find ingress to the shed and happen to alight upon a can of the dangerous gasoline.

If such a thing occurred he knew that it would be all over. The hangar must be completely destroyed and, of course, their little darling airship would share in its fate.

So, even though he saw the end of the conflagration in sight, Frank knew he had no reason to breathe easily until every spark had been trampled under foot.

By now he was conscious of loud shouts coming from points near at hand and realized that doubtless Andy as well as others had been awakened by the racket and were coming on the run to assist. Had the safety of the airship depended on their reaching the shed in time, though, its chances would have been next to nothing.

Frank was just stamping on what seemed to be the very last vestige of the fire when Andy came galloping to his side.

"W-what's all this mean, Frank? Where in the wide world did you come from, and who set our hangar afire?" he gasped, almost winded from his exertions, for he had dressed in about a minute, despite his trembling fingers, and was barefooted even then.

"Don't know who did it, but he ran off on my wheel a few minutes ago. I was on the way home—carrying medicine to Susie Lovejoy. Saw flames and gave alarm. Got here on the jump and we managed to get the better of it. But it was a close shave, all right, I tell you, Andy!"

Frank himself had no breath to spare, nor could it be wondered at, considering the recent valiant fight which he had made against big odds.

"So the ornery skunks did try to burn us out, after all!" burst forth the other part owner of the monoplane, bitterly. "Say, where was Shea all this time? What use was he as a watchman?"

"He helped me good and hard at any rate. Only for Shea I'd never have got the better of it, I'm afraid," said Frank, always ready to cover up any little failing on the part of another, though never hesitating to denounce his own shortcomings.

"But just to think of the meanness of it all," continued Andy, shaking his head in the aggressive way he had. "That Puss Carberry ought to be shut up behind bars, that's my opinion straight from the shoulder, and if I could only find out for sure that he was in this I'd get Colonel Josiah to prosecute him to the limit."

"But we have no proof that it was Puss," remarked Frank. "The fellow who stole my wheel went off along the road away from town. And he went licketty split, too, as if he had business over in Shelby or Newtown. Perhaps it was only a hobo. He may have started the fire by accident, and was trying to put it out when I saw him first. Then, when I shouted, of course, he had to scoot."

"What's this?" demanded Andy, kicking some object, and then seizing hold of his foot, for he had forgotten that he had no shoes on.

Frank uttered a cry and picked it up.

"Look here, don't you recognize this?" he asked, as he held a can up.

It was Andy's turn to give vent to a low exclamation.

"Why, it's our kerosene can, Frank!" he said.

"That's what I thought. And it is kept on a bench just outside the kitchen door, isn't it?" demanded the other, quickly.

"That's a fact. And neither of us ever brought it here. Shea, did you ever see this oil can before?" and Andy dangled it before the eyes of the watchman who had slept on his post.

"I niver did the same, sor," replied the man, as he surveyed the can.

"Then that settles it, Frank. The mean skunk grabbed that can and fetched it over here to spray the wall of the shed with oil and making the fire jump."

"True as you live," said the other. "Do you know, I thought I smelled burning kerosene. And that was why the flames kept crawling up everywhere so fast. Well, it was a good job that we saved the place. And ain't I glad I didn't wait just five minutes longer at Lovejoy's place. Nothing could have helped then, and we'd just have to build another airship. But here comes the colonel stumping along, Andy!"

CHAPTER VI.

IN SEARCH OF A CLUE.

"Heigho! what's all this fuss and feathers about?" demanded the old retired traveler, as he came limping along, with his crutch and cane.

Several neighbors accompanied him, having been aroused by the clamor.

"Same old story, sir," remarked the disgusted Andy, still clutching his bruised toe tenderly. "They've been trying to beat us one way, if they couldn't another."

Frank gave him a nudge.

"Be careful what you say, Andy," he remarked. "There is no proof as yet that any one we knew had a hand in this business. You may get in trouble if you mention names offhand. Go slow now. We'll find out the truth later on, perhaps."

So Andy, taking heed, managed to tell what had happened without directly accusing any one. Nevertheless, it was not difficult for those who listened to guess where his suspicions lay. And perhaps they thought, after all that had occurred in the past, with the hand of Puss Carberry moving the pieces on the chessboard, that Andy was justified in believing as he did.

After a while the excitement died away. The boys had opened the shed and made sure that no lingering spark remained to threaten their beloved little aeroplane with destruction. But it was all right and they feasted their eyes on it, as if they never before realized how precious it had become.

"Getting to be a regular thing, seems to me, these night alarms, boys," remarked one of the neighbors, for not long before they had been aroused in the middle of the night when the two jewelry thieves tried to steal the aeroplane and were baffled in their design by the two boys, sleeping at the time in the shed, so as to guard their flying machine.

"If one watchman ain't enough I'll get three—half a dozen if necessary," declared Colonel Josiah, as he glared at the offending Shea and pounded on the turf with his heavy cane. "But these lads are going to be protected, if it takes my last dollar. I'll get a Gatling gun and train it here, so we can blow the rascals to smithereens if they try such a dastardly job again."

But everybody knew that the genial old colonel did considerable talking and blustering, but was harmless withal.

Shea promised to remain awake the balance of the night. He even went to the house and armed himself with a big horse pistol that the colonel owned and which had many a story connected with its keeping company with the traveler in foreign lands.

"Huh! I've got half a notion to camp right here again, like we did that other time, Frank," said Andy, before they locked the wide doors of the shed. "Here's my cot and blankets, you see, just as I left 'em."

"No need of that, Andy," returned his chum, smiling. "After all this rumpus you couldn't hire that fellow to come back here tonight. He may be ten miles away by now. Wonder if that's the last I'll see of my wheel?"

"Now," continued Andy, "if you're addressing that to me I'd like to prophesy that you'll find the bike somewhere off the road a mile or two away, where the fellow pitched it when he concluded to make a sneak back to town."

"There you go, barking up that same tree again. I never saw such a positive fellow as you are," declared the other, smiling. "Your name ought to be Thomas, for you seem to doubt everything that you can't just understand."

"Well, if not Puss, who, then?" demanded Andy, aggressively.

"I confess that I don't know at this minute," admitted Frank. "But I hope to discover the truth in some way. Remember how that other time, when some one tried to injure us by sneaking in here and cutting the canvas wings of our monoplane all to flinders, I picked up a playing card and we afterwards traced it to the owner?

"Yes," cried the other, instantly, "and wasn't that party Puss Carberry all right?"

"It sure was," laughed Frank. "But forget this thing for now. Perhaps tomorrow we may be able to find some clue that will tell which way the wind blows—it might be the print of a shoe in the earth or something like that. Lots of ways to pick up information, if only you keep your wits at work."

"Yes," returned Andy, "and if it's Frank Bird who's doing the thinking. But perhaps it would be silly in me sleeping out here tonight. I'd better be traipsing back to bed right now, because, you see, I'm only half dressed and it's chilly."

"Good. I'll see you to the house, because I've got to walk home, now that my wheel has gone up the flume," remarked Frank.

"What's the matter with you using mine?" demanded the other. "That plug you put in holds dandy, and there's nothing the matter with it right now. Same old place, under the side porch here. Guess the lamp is on the bum, but you hardly need that. If a cop holds you up, explain what happened."

"All right, I guess I might as well ride as walk. But I hope I get my wheel back. It's nearly new, you know, and cost a heap," Frank remarked, as he dove under the stoop, to presently appear dragging the other bicycle.

"Apply to Puss and Company for further information," called Andy, holding the door open a crack to shoot the words out and then closing it.

Frank, laughing at the obstinate ways of his chum, pushed the machine out to the road and was soon moving along. Evidently he lacked the same confidence in Andy's wheel that he felt in his own, for he made no attempt to speed as he went toward town and home.