There was a frightened series of grunts close by and some big unwieldy animal went rushing away through the dense undergrowth, crashing along as though badly frightened at this queer thing that had dropped down from the sky.

"Wow! whatever was that, do you know, Frank?" cried the one on the ground.

"I don't know for sure, because I only had the least peep of something that looked like a small elephant making off," replied the other, also alighting.

Andy was already reaching for the repeating rifle, which had been securely fastened in the frame of the monoplane.

"But Frank, they don't have such things as elephants down in South America?" he expostulated.

"Sure they don't," laughed Frank, feeling particularly good over the grand success that had attended their perilous landing. "Nor a rhinocerous, nor a hippopotamus; but they do have the next largest beast, and that's a tapir. He's something like a big pig and not very dangerous, the senor said. That was what we frightened off just now, I reckon."

"Well, here we are on land again and mighty lucky to get down without some sort of a smash. Frank, you don't think anything was broken when we struck, do you?"

"Of course I can't say for sure, but I believe not. But all the same I must give a good look in the morning before we make another start," was the reply Frank returned.

"And now we're just got to stay here all night?" remarked Andy, who still held the gun in his hands.

"That isn't anything. We'll soon have a cheery blaze started that will keep the prowlers away, I guess. Get busy, Andy, and see what we can do. But we'll start it some distance away from our gasoline tank, remember."

"But won't they be apt to see a fire?" asked the other, as he reluctantly placed the rifle down and started to gathering wood, no easy task in the increasing darkness.

"Do you mean Puss and that other fellow?" Frank asked, with a laugh. "Oh, they're a mile or two off, and even if they could see the biggest of fires I'd defy them to get half way here if they took the whole night to cut their way through that mass of trailing vines and brush. Don't bother your head about that crowd, Andy. I hope we're done with them for good."

His reassuring words seemed to have considerable effect on his cousin, who up to recently had himself been a most cheery fellow.

"Well," he said, "we've sure got a whole bunch of gratitude on tap for the lucky way we dropped in here. Chances looked twenty to one it couldn't be done. And I'd like to wager that no other air pilot could have made the ripple so well."

"You're prejudiced, old fellow, because I'm one of the Bird boys," laughed Frank as he struck a match and applied it to the bunch of dead grass he had gathered in the spot selected for their fire.

It was a dozen yards away from the aeroplane and about the same from the nearest line of great bushy trees. Immediately the flame sprang up, dispelling the darkness to some extent.

"Shucks! but that makes a big improvement and no mistake," said Andy, stooping to drop some wood on the fire. "I always like to see what I'm doing. And more than ever when I'm in a strange place. Hark! what was that, do you suppose, Frank?"

A sound had come from the depths of the forest not unlike the wailing of a babe. Frank could give a guess what made it, but he did not immediately say so.

"Say, we must have landed close to some native shack, and that's a baby crying!" Andy declared.

"Hardly," came from Frank. "That's only one of our cat friends giving tongue, perhaps calling to his mate to come and see the funny objects that dropped from the skies."

"Wow! reckon now you must mean a yellow boy, a jaguar! I bet you, Frank, there's a heap of 'em around us right now. How do we know but what every tree hides one of the critters, watching everything we do? I can tell you right now that I don't wander far from this jolly little blaze tonight. And besides, one of us has just got to keep a grip on this gun all the time. I don't hanker after being carried away and made a meal of by a big hungry cat."

"Oh, the fire will scare them away all right, I believe. There isn't an animal that doesn't dread fire. Always keep that in mind, Andy, when trouble comes," said Frank, earnestly.

"I mean to," replied the other, as he once more started to pick up wood, but it could be noticed that while doing so Andy always kept on eye on the alert, as if he really believed what he had said about the chances of their being watched by an army of jaguars.

"There's another sort of cry, Frank," he remarked, presently.

"Yes, and although I couldn't say for sure, I believe it is made by a colony of monkeys, traveling through the woods at night," the other replied, after stopping to listen for a minute to the odd sounds.

"Monkeys!" cried Andy, smiling broadly. "Well, I declare I had forgotten that they have them all through the tropical regions around the Orinoco, the Magdalena and the Amazon. And so that's a menagerie traveling over the treetops, is it? Wish I could just get a look."

"Well, I don't think they're far away," remarked his chum.

"Not for me. I know when I'm well off. This camp looks good enough, without my wandering around in that awful place. Let 'em jabber, and the yellow cats snarl; but Andy Bird stays right at his fireside tonight."

"And I guess you're right," said Frank, as more noises arose all around them.



CHAPTER XVIII.

WHEN FRANK STOOD GUARD.

Pretty soon things began to look fairly cheerful in that lonely glade situated in the heart of the tropical forest. A fine fire crackled and shot up its red flames, lighting up the opening in which the young aviators had so luckily alighted.

Andy was bending over the fire making a pot of coffee, for they had brought along with them the necessary cooking utensils, including a frying pan, not knowing how long they might be adrift in the wilderness, far from the domicile of any human being.

"How do you find it?" he sang out, for his chum had been examining the aeroplane as well as possible under the circumstances.

"Everything seems to be hunky-dory," came the reply. "I'm going to start up the engine now to see if it works without a hitch."

"Don't I hope so," was what Andy said, as he paused in his task to watch.

A minute afterward he gave a little cheer, as the familiar throbbing sound was heard, making the sweetest music that ever greeted the listening ear of an aviator.

"That sounds good to me, Frank!" he cried.

"Nothing wrong about it, thank goodness!" came the reply of the other, as he again shut off power, because they could not afford to waste a drop of their valuable supply of gasoline.

"Well, suppose you drop in here and sample this brand of coffee. What with the cold snack we brought, and which still holds out, we ought to get along right decently, Frank."

"I tell you right now," replied the other, as he came up, "I'm hungry enough to eat anything going; yes, even some of our native cook's worst garlic-scented messes. And that coffee just seems to make me wild. Shove a cup over this way as quick as you know how, brother. Yum, yum, that goes straight to the spot. And this cheese and crackers isn't half way bad, even if it is pilot biscuit."

"Well," said Andy, "ain't you a pilot all right, and don't they feed sailors on this hard tack generally? Sure we've got no kick coming. Everything is to the mustard, and if you asked me my opinion right now I'd say things are coming our way."

"Listen to that chorus, would you?" remarked Frank, as various sounds arose all through the dense timber around them; "they seem to be heading this way sure enough."

At that Andy reached again for the gun on which he seemed to depend so much.

"Well, if any of 'em take a sneaking notion to look in on us, why I'm meaning to use up a few of these flat-nosed cartridges in this six-shot magazine," he remarked, sturdily, as he glanced cautiously around.

"No fear of that now," said his chum, reassuringly. "The danger will come, if it does at all, later on, when we have more trouble keeping the fire going. So after we get this supper down we shall have to gather fuel. It may not be quite so nice to go after it when we see a line of yellow eyes watching all around."

"Oh, shucks! You're just stringing me now, Frank. If I really thought they'd be as bold as that, why I'd climb a tree, that's what."

"What good would that do, tell me?" jeered the other. "Why, these cats just live in trees and can leap twenty feet if they can one. Perhaps if you found a hollow tree now you might feel safe, but in the branches of one—never! Why, the monkeys would come and laugh at you. The ground is the best place for us, after all, Andy."

"More coffee in the pot, if you ain't afraid of staying awake," suggested the cook.

"That would just suit me, for you see I'm more afraid of going to sleep than anything else while on guard duty," Frank remarked, soberly.

By degrees Andy realized that this business of camping in the heart of a tropical forest was no laughing matter. Still, they had escaped so many threatening perils that he was beginning to believe they must be under the protecting wing of some favoring god and that success lay just ahead.

They sat up and talked for a long time. Neither would admit being at all sleepy, and yet Frank caught his chum yawning ever so many times.

"Here, you, just make up your mind to turn in and get seven winks," he said, pretending to be giving orders with all the airs of a commanding officer.

"I suppose I'll just have to," came the reply, as the other started to roll up close to the fire, for they had no blankets with them this time. "Do you know I was just thinking about Puss."

"Well, what of him?" asked Frank.

"What if they start to chase us again in the morning? Are we going to put up with that funny business right along? I say no. Let's warn 'em that we're armed and can bore a hole right through their jolly old biplane, upsetting them any time they get close enough. I'm drawing the line on tomorrow, because somehow I feel it in here that it's going to be the greatest day of my life," and Andy laid his hand on his heart as he spoke.

"Yes, that would be our best plan," admitted Frank. "We've already stood quite enough of that funny business, as you call it. They even fired at us. Depend on it, Andy, they won't follow us very far next time."

And Andy, seeing the way his chum's mouth was firmly set, made up his mind that Frank had reached the end of his patience. Contented with the prospects for the morrow he therefore lay down to get some sleep.

"I say, Frank," he called out presently.

"Well, what now?" asked the one on guard, who had possession of the rifle and had taken up his position so that he could have a clear view of the open space all about the camp.

"If one of the prowlers tries to drag me off, remember I've got my leg tied to this stake I knocked into the ground. While he's tugging you can have a bully good chance to knock him over, see?"

"All right," grinned Frank. "I'll remember. But let out a whoop if you feel yourself going. I might be looking the other way."

"You just bet I will," mumbled Andy, curling himself up as near the fire as he dared creep.

And in three minutes Frank knew from the heavy breathing coming from that quarter, that his chum had found no trouble in getting to sleep, regardless of the various sounds welling up from the neighboring forest, and the fears that possessed his boyish soul.

Frank sometimes sat down; and again, feeling cramped in this position, he would rise to his feet, and walk back and forth. But all the time he kept the gun in his possession, with the hammer pulled back, ready for business. And constantly did he maintain a close watch along the nearer border of the undergrowth that lay there, so dense and filled with mystery.

Time passed on.

It seemed as though a thousand things flitted through the active mind of the young aviator as he thus stood guard over the camp. Once again he was back in good old Bloomsbury, where he had spent so many happy days. He could see the faces of his boyhood friends, Larry, Elephant and others.

Frequently he would detect a movement here or there among the trees; and at such times he could easily imagine that some animal belonging to the forest was creeping closer in. The question was, whether simple curiosity urged them to do this thing, or a design upon the occupants of the camp.

Frank had been in other situations calling for considerable pluck, and never failed to meet the emergency, nor did he now.

It must have been some three hours back that Andy lay down to sleep. That had been the limit of time arranged upon; but Frank did not show any signs of intending to awaken the other.

"Let him sleep," he said to himself, as he walked up and down, for by now he was beginning to feel very drowsy himself, in spite of the coffee. "He needs it more than I do. And besides, I'm a little dubious as to what sort of watch Andy would keep. Anyhow, I can stand it a while longer. Hello! what's that mean?"

His attention had been attracted toward a movement in the brush at the nearest point of the forest. It was not thirty feet distant. Could one of those long-bodied muscular jaguars cover that distance in a wild leap? What if without warning he should see a tawny figure flashing through the air, and headed straight for him?

Frank threw the gun up to his shoulder as if to try and see how readily he could cover such a flying form. As he did so he heard a low and ominous growl, which undoubtedly sprang from the very spot where he had just caught that suspicious movement.

He bent his head to look closer, and as he did so an exclamation fell from his lips.

"And that's no owl staring at me, either," he said to himself, as he caught the singular glow of what seemed like two balls of fire, just under the lower growth.

Frank knew what they undoubtedly must be. He had seen the orbs of a cat shine in this phosphorescent way in the darkness. There could be no doubt but that he was being surveyed by one of those savage beasts whose whining he and Andy had heard around the camp for hours.

"And I declare if that purring sound doesn't come from there, too," he muttered, as he sank down upon one knee, the better to aim his rifle. "What was that the old senor was telling me about these beasts? Didn't he say they jerked their tail to and fro like a pendulum, and made a queer noise just before they jumped? If that is so then this fellow is getting ready to leap over right now. Time I was doing something, if I don't want him to drop on my chum like a rubber ball. Well, here goes to take him between those yellow eyes. Steady now, my boy, steady!"



CHAPTER XIX.

FIREBRANDS AND JAGUARS.

"Bang!"

"Wow! are they coming in on us?" shouted Andy, suddenly aroused by the sharp report of the repeating rifle.

He bounded to his feet, and from his manner of action it was plain to be seen that he remembered exactly the condition of affairs at the time of his taking passage for the Land of Dreams.

Frank had aimed straight between those glowing eyes at the time he fired. And as he was perfectly calm at the time, it stood to reason that his bullet went direct to the mark he meant it should.

He saw a yellow object threshing about under the dense growth, and realized that he had given the adventurous jaguar something that was apt to wind up his career as a terror to the monkey hosts of the forest.

But this was not all Frank saw. Another figure had appeared just ten paces farther along, and he realized that a second jaguar had crept out of the copse, evidently bent on charging the camp.

"There's two more, Frank! Oh! my, it's a dozen I guess!" whooped Andy, who had found a better opportunity to see in other quarters.

"Grab a firebrand, quick!" shouted Frank, trying to get a bead on the second slinking figure; and yet hesitating about firing, because of the great risk that must ensue should he only wound the fierce monster.

He saw out of the corner of his eye that Andy made a plunge toward the fire and was snatching a brand out in each hand.

"Wave them around your head, and shout like thunder!" he cried, at the same time starting in to do this latter himself.

Perhaps it was a comical thing in some respects. Andy often laughed over it afterwards; but just then it seemed serious enough. The way both of them let loose with their strong young voices would have made a football cheer captain turn green with envy. They fairly awoke the echoes slumbering in the depths of the forest.

And Andy waved those two torches like a good fellow, back and forth, in and out, weaving them as an expert Indian club athlete might do with his heavy weights, until the rushing flames roared again and again because of their rapid passage through the air.

"They're licked already, Frank!" whooped Andy, as he daringly began to advance with his flaming beacons swinging around and around. "Look at the coward moving back, would you? Talk to me about your guns, they ain't in it with these things, when it comes to scaring off a pack of wild beasts. Scat! you terror, or I'll just swat you one alongside your jaw. Growl at me, will you? There, take that, hang you!"

To the astonishment of Frank, Andy, who had rushed straight at one of the retreating animals, suddenly hurled a blazing brand straight at the jaguar. In his palmy baseball days Andy had never amounted to a great deal as a pitcher; but all the same he made a beautiful throw right then and there.

The whirling, blazing fagot of wood struck the slinking beast full in the side. Frank threw up his gun, ready to shoot should the jaguar, as he feared might be the case, leap at his chum. But there proved to be no need. Instead, the brute was evidently alarmed at this novel weapon, something entirely beyond his ken.

Frank heard him give a snarl that told of mingled rage and fright. Then he made a spring, but away from the fire, and into the dense undergrowth from whence he had just issued so bravely.

Looking around Frank saw that the glade was deserted of four-footed foes. The whirling torches had done the work.

"Bully for us!" shouted the excited Andy, ready to dance in his delight over the success of his labors. "Didn't we send 'em a flying, though? Perhaps they just dare to come snoopin' around here again, when they're not asked! Frank, I guess you nailed that critter, all right. Dast we look and see?"

"Sure we will," returned Frank, instantly. "Pick up another bit of burning wood. Then let me go just ahead of you, so that I can shoot if I have to."

They thus boldly advanced toward the spot where Frank had first sighted the blazing yellow orbs.

"I can see something there!" declared Andy, who possessed sharp eyes.

"Yes, it's the beast, all right. But I can't say for sure whether he's down on his back, or crouching for a spring. Careful, not so fast, Andy." And Frank kept covering the object with his rifle as foot by foot they kept on.

"He's lying on his side! He's a dead duck, all right!" sang out Andy, waving his fire vigorously to and fro.

"You're right, he's stone dead!" observed the other, a touch of natural pride in his voice; for it was no mean feat to kill so ferocious a beast as a jaguar, after seeing only his two eyes shining in the darkness beyond the fire-light.

Frank stooped down, and catching hold of one of the dead animal's hind legs, started dragging it toward the fire.

"Hold on there," said Andy; "don't tell me we're going to have a steak off that old cat? I can stand for a good deal, but I'd go hungry a long time before I'd eat any of him!"

"Don't worry about that," laughed Frank. "But think what a bully old rug his hide will make some day. I'm going to try and take it off, if I can, while you're getting breakfast in the morning. It's worth while."

Andy looked as though he doubted the ability of his chum to accomplish the feat; but then he was counting without his host; for when the chance came Frank deftly removed the pelt, and kept it for a reminder of his hazardous shot.

Andy insisted on taking his turn at playing guard, when he found out what time it was. First of all Frank saw that the fire was revived, with plenty of fuel handy. Then, after giving his chum a few last instructions, he consented to lie down. But his sleep could not have been very sound, for frequently he would raise his head, and take a look around; seeing nothing suspicious he would again lie down.

So the night passed away.

Frank was on deck an hour and more before the dawn came. He felt too anxious concerning the possibilities of the coming day to sleep much.

So Andy started to get breakfast, such as it was, before the night had really gone. He excused himself by saying that while he was not at all hungry, the operation had to be gone through with, and the sooner he was at it the quicker they might be free to mount upward.

Frank knew what a terrific load was on his chum's mind, and how he thrilled with suspense, now that they were so near the realization of his highest hopes or worst fears.

And so he too set to work to remove the jaguar skin, for it would make a pretty decent rug, if it could be properly preserved.

Morning was just breaking as they sat down to partake of the simple meal. Neither of them seemed to care for much. It was indeed no time for feasting, or making merry, when the day had probably dawned that was to settle their mission, one way or the other.

"One thing good," remarked Andy, hopefully, "there doesn't seem to be any strong wind blowing this morning."

Frank had been studying the lay of the land in the glade.

"I tell you we're going to have all we can do to squeeze up out of here without scraping against any tree before we can rise above them," he observed, presently.

"But don't you think we can do it?" demanded his chum, anxiously watching his expressive face.

"I think it is possible," came the slow reply; which after all gave Andy new cause for distrust; since his cousin was so cautious a fellow that he seldom if ever gushed over anything; at the same time he never expressed doubts when he felt positive.

"But!" cried Andy, "there's no other way to fly; we couldn't take the aeroplane to another place; and I reckon there isn't a cleared field within ten miles of here."

"No, it must be done right where we are. Now, I'm going to measure the opening to find out its widest dimensions. Then we will take the monoplane as far back as we can, and make all arrangements for a rapid start. But to rise above those trees, even the shortest of them, is going to call for considerable management, and some great good luck in the bargain."

"But, Frank, you've done it before," declared Andy. "You know you made lots of short starts that beat all the records. That's your best hold. And, Frank, we've just got to get out of here. Everything depends on it."

"Sure," responded Frank, cheerily enough; "and we'll manage somehow, never fear. Now to foot off the space. Count to yourself, and we'll compare notes when I get to the other side. This looks the widest range, according to my eye."

So they both started off, Frank placing one foot close in front of the other, and Andy keeping alongside in order to do his own counting. In this way they passed from one side of the glade to the other; and Frank was secretly pleased to find that the distance was considerably more than he had judged possible.

Besides, the trees happened to be much lower on this side, which fact would be of considerable benefit to them when they started to make the run, and rise.

Frank was still muttering the number of feet to himself, and had arrived within something like five yards of the nearest trees, when, without the slightest warning, he heard Andy let out a screech that could have but one meaning.

He had surely sighted something that spelled peril to one or both of the Bird boys. Frank had wisely kept the rifle in his hand, and instinct caused him to throw this up to his shoulder, though as yet he had not the slightest suspicion as to what the nature of the danger might be, nor the quarter in which it lay.



CHAPTER XX.

THE AEROPLANE BOYS ONCE MORE AFLOAT.

"Frank! Oh! Frank!"

More than a few times had it fallen to Frank Bird to drag his cousin and chum, Andy, back from some impending danger. Now the shoe seemed to be on the other foot.

Even as he looked hastily up, startled by these sudden cries, Frank felt his arm seized in a frenzied clutch, and himself jerked backward.

"What is it, Andy? Here, hold on, let my arm free, and tell me!" he exclaimed.

"Look there; and you were going to walk right up against it! Oh! Frank, what a horrible monster!" Andy replied, in trembling tones, as he strove to point toward something that he had seen just in the nick of time.

"Whew! I should say you were right! Ain't he a dandy, though? And if I saw him at all, I thought it was a great big vine hanging from that tree! Ugh! look at him stretch his mouth, would you? Andy, thanks to your sharp eyes I'm here, instead of in his slimy folds. I guess he could crush an ox. They say nothing can stand the pressure, once they get a couple of folds around."

"Is it a python?" gasped Andy, his horrified eyes glued on the spectacle of the slightly swaying ten feet of snake that hung from the limb of a great tree, in part as thick as Frank's thigh.

"About the same thing," replied Frank. "Down here they call them anacondas, and in other parts of the world they're boa-constrictors. I guess the whole bunch belongs to the same family of squeezers. But that fellow is in our way."

"Well, yes, if you're still determined to run the aeroplane across lots toward this side of the opening," Andy remarked with a shudder. "Why, perhaps that old chap might get gay, and grab hold, just when we expected to go sailing off. That would be a calamity, not only for him, but the Bird boys in the bargain."

"All right. Then he's got to get his," Frank observed.

"What are you going to do?" demanded the other, nervously.

"Take a crack at his head," came the reply. "Once let a flat-nosed bullet from this little Marlin hard shooter smack him on the coco, and there'll be a funeral in the anaconda family."

"But for goodness' sake make sure work of it, Frank. What if you just wounded the monster? He'd come whirling along at us like a hurricane. And I'm sure he must be thirty feet long, if he's a dozen. Look at the thickness of his neck, would you? Be mighty careful, for his head's swinging a bit, you notice. That was what made me get sight of him. Say, Frank!"

"Well, hurry up. He may take a notion to move off, and I'd lose my chance, Andy."

"How'd it do for me to get some fire, and shoo him away?" suggested his cousin.

"Don't know how it would work," replied Frank, smiling a little, however, at the faith Andy seemed to have in a blazing brand, now that he could look back to his late experience with the jaguar. "Never heard that snakes were afraid of fire. And besides, there's no need. Now keep quiet, and watch. You'll see something worth while; but be ready to jump clear."

He had already dropped down on one knee. The Marlin stock rested against his cheek, and his eyes sighted along the barrel. Andy fairly held his breath, his startled eyes glued on that swaying head of the monster.

Then came the sharp report as Frank pulled the trigger. He instantly jumped back, and by a rapid motion of his hand sent another cartridge into the chamber, the clever mechanism of the gun proving that it was built so as never to fail in an emergency.

Andy had accompanied his chum in that backward movement; but never for an instant did he remove his eyes from the strange spectacle that was taking place there in front of them both.

Undoubtedly the well aimed bullet had crashed through the fearful head of the suspended anaconda. Instantly it released its many coils above, and a tremendous length of writhing snake could be seen whipping over the ground. Nothing in the way of small vegetation could stand in the path of those powerful springy coils, as they shot this way and that.

"Oh! my!" gasped the astounded Andy, as he moved farther back, so as to avoid any chance contact with the flying destructive force that was leveling everything in the glade for twenty feet around. "Did you ever see anything to equal that? Talk to me about your harvesting machines, here's one that's got 'em all beat to a frazzle. Ain't he ever going to give up the ghost, Frank? Guess these anacondas must have the nine lives of a cat!"

"Well," remarked Frank, "you must have forgotten that among boys it's said that a snake won't die till sundown. I've seen one's tail wiggle hours after we thought the thing was stone dead. There, he's moving off into the forest, and a good riddance. While I'd like to measure the serpent just from curiosity, we've got no time to waste waiting for him to kick the bucket."

"That's right," assented Andy. "And as for going anywhere near such a whirlwind, you'd have to excuse me."

They watched the dying anaconda gradually vanish in the depth of the forest; and both boys were glad that it had turned out that way, since they were anxious to depart from the place.

"Don't I wish I'd had my little camera along, so I could have snapped a shot at that dandy chap! The fellows would believe me then, when I told about what happened to us here. And anyway, Frank, I don't think we'll forget this camp, do you?"

"Well, hardly," replied his chum, smiling broadly. "Because we've sure had enough happen to us here to make us remember. But I'm glad to find there's going to be more space for the run than I thought at first."

"We'll need every inch of it," declared Andy, as he looked dubiously at the tops of the lower trees about the place where the snake had held forth. "Don't I wish we'd brought a few sticks of dynamite along, though."

"For goodness' sake, what would we want with dynamite? Think you could have blown up that snake, do you?" asked Frank, as they started to cross the glade toward the waiting monoplane.

"Oh! shucks, no. I was thinking how we could plant 'em under a bunch of those trees and enlarge the gap!" declared Andy.

At that Frank burst out into a hearty laugh.

"What a fellow you are for wild notions. Think of us blowing up the forest to make an aviation field! I reckon, however, seeing that you haven't got the dynamite, Andy, we'll have to do the best we can. Take hold here and we'll push the machine just as far back as it will go. Perhaps we can gain a few yards at this end that will count in the long run."

Frank was particularly careful about every little detail. He knew just what he had to depend on. In the past he had made it a pet hobby to rise in as short a space as possible; and now this faculty seemed destined to prove a valuable asset in their speedy climbing up.

"All ready?" he asked, grimly.

Andy took one last look at the face of his chum. He saw that Frank's mouth was compressed in that firm way that stood for so much; and somehow Andy's wavering confidence returned in full measure. When Frank Bird looked like that, things always had gone according to his will; and they must now!

"Yes, I'm fit, Frank," he said, quietly. "Let her go when you're ready!"

In the many times that the two boys had made ascents, Andy could never remember that his pulses throbbed with one-half the suspense they did now. Not even on that never to be forgotten initial performance, when for the first time they felt the strange sensation of leaving the solid ground in a flying machine, had he been so excited, so nervous, so filled with alternate hope and fear.

Frank had taken every possible precaution. He had thoroughly studied the ground, and made sure that no obstacle would be apt to cause the running gear of the aeroplane to swerve, and thus throw them off their course.

All he could do was to start the machinery, get a rise at the quickest possible second, and be ready to shut off power if he realized that the feat they were about to attempt were impossible, so as to avoid smashing the planes against a tree.

"Then here goes!" he said, calmly.

Andy held his breath as he heard the engine start off at a tremendous speed. He felt as though a giant hand had plucked them from the spot where the aeroplane had been planted for the start. Across the glade they went speeding. His heart almost jumped into his mouth he believed, as he felt the little craft start to leave the ground, as Frank manipulated the planes, and elevated them so as to catch the air under the broad blades.

They were rising rapidly now! Would they manage to clear those terrible treetops that stood like a grim barrier in their path?

Higher yet did Frank throw the planes, so that they actually seemed to be climbing straight upward, according to the vivid imagination of Andy; who, clutching the upright at his side, waited for what was going to happen.

It was too late now to retreat! They had gone too far to stop, and try again! No matter whether for good or ill, their kite had been tossed to the winds of heaven, and they must abide by the consequences.

Andy gave one little squeal, for it could not be termed anything else under the sun. This was when they shot past the most prominent branch of the tree that happened to stand directly in the way of the rising aeroplane. Andy believed that the wheels below must have actually brushed through the foliage, for he always declared that he heard a fierce "swish" as they passed.

Had they caught even one little bit, something dreadful might have happened, and the precious aeroplane, on which everything depended, meet its sad fate; not to speak of the nasty fall the Bird boys would have suffered.

But Fortune was once more kind to the young adventurers. They passed safely through the peril, and were speedily fully launched upon the wide open expanse of space!

"Hurrah!" shouted the exultant Andy; but it might be noticed that his voice was a bit husky, even as his face seemed chalky white.

"A close shave," remarked Frank; who himself had been rigid while they were thus taking such desperate chances; "but we made it, thank goodness! I hope that will be a lucky token of what the day has in store for us."

"Amen!" echoed his chum; and there was no levity in his tones, either.

The sun was just rising. Below them lay the dense foliage of the almost impenetrable forests, from which they had just made this almost miraculous escape. And both young aviators, as if by common consent, started to sweep the horizon around with their eyes.

"See anything of it?" asked Andy, eagerly.

"I thought I did away over yonder toward the mountains; but I guess it must be a big bird hovering high up, a condor perhaps," Frank replied.

"Well, there isn't any sign of the biplane, that's sure," Andy went on in a relieved voice. "Perhaps they didn't have as good luck in landing as we did, and had a nasty spill. Don't I hope they busted some of the planes, or part of the little old Gnome engine, so we won't have to be bothered with 'em again?"

Frank made no remark. While as a rule he refused to let anything like bitterness dwell in his heart, still, this was a case where everything was at stake; and if the bothersome revolutionists kept chasing them in the biplane they were apt to give a great deal of trouble. And secretly he could echo Andy's wish that the biplane might be temporarily crippled, so as to be unfit for flying.

"Now, what's the programme?" asked Andy, when they had covered several miles.

"We've just got to head for the mountains yonder," replied his chum. "You know, he declared it was a valley that lay among the mountains; and it must be, to be surrounded by high cliffs. Once we get among the hills, we'll sail back and forth, combing the whole region, and hoping sooner or later to discover his queer prison."

Andy lapsed into a state of silence; but he kept watching ahead as they drew gradually nearer the uplifts. Doubtless but one thought held dominion in his mind, and this was that somewhere amidst those same mountains the father whom he loved so dearly was waiting, and hoping for an answer to his appeals for aid.



CHAPTER XXI.

THE LAST LITTLE HOT AIR BALLOON.

"Did you ever see a wilder region?" asked Frank, about the middle of the morning, when they had alighted on a broad, level plateau, so as to allow him to look over some little matters connected with the engine, that he believed needed attention.

Andy had been using the binoculars pretty much all the time they were aloft, but without any success. Many times be began to think he had sighted something that looked like cliffs rising up, and a wild hope had seized upon his devoted heart; but upon Frank bringing the airship in that quarter, in answer to his frantic appeals, it had proven to be a false clue.

Cliffs they saw in plenty, but as yet none enclosing a valley so as to imprison an unfortunate aeronaut, whose runaway balloon had dropped with him into its depths.

Still, the day was not nearly half over. And the monoplane behaved splendidly; so that they could hope to continue the search as long as their supply of gasolene held out.

"I'll never give up hunting," Andy declared, as he stood there, watching his chum potter with the engine and examine things in general. "No, not as long as this fine little machine stands by us. We can get more gasoline if necessary, for we brought a good supply aboard the boat. When we've gone as far as we dare down this way we'll make another start further on."

"I'm with you, Chum Andy, and you don't need to be told that," observed Frank, quietly, while he worked on.

"As if I didn't know that and counted on you through thick and thin," declared the other, with a look of sincere affection.

"Well, now we're ready to go up again," remarked Frank; "and there's no use asking if you feel like it. So pile in and we'll make a flying start from the top of this rocky plateau."

"What a difference from our last start," observed Andy, with satisfaction, for they were on an elevation with a valley far below, and the air was decidedly bracing for the tropics.

"I should say it was," laughed Frank. "Do you know what it puts me in mind of?"

"I bet you're just thinking of when we won that race to the summit of Old Thunder Top, where nobody had ever been able to climb before, and how we had to make our start for home from that little plateau, plunging off into space."

"Just what I was," declared Frank. "But here we have a longer swing and it's going to be a snap of a launch compared with some we remember."

"Ugh!" grunted Andy, "will I ever forget the one this morning. But let loose, my boy. I had just sighted a likely looking place away over yonder, at the time you said we ought to take advantage of this fine landing stage, to look things over. Just head her that way when we get going, will you?"

"Sure; anything to oblige," assented the other.

The launch was just as easy as they had anticipated. Indeed, Frank seemed to have gotten this part of the programme down to a fine point and could accomplish it apparently as well as a Wright or a Curtiss.

Ten minutes later and the monoplane was soaring toward the region which Andy had denominated as a "likely spot."

"Look at that big bird watching us from that pinnacle yonder!" exclaimed Andy, as he lowered the glasses for a moment.

"I see him," replied his comrade. "And there's no doubt now but what that is a condor of the Andes. He thinks we must be some sort of bird, which we are, of course, and is wondering whether he ought to flap his wings and go up higher or hide behind that church steeple of rock."

"I only hope he don't take a measly notion to fight us, that's all," remarked the other, as he glanced anxiously toward where the Marlin was secured to the framework of the airship.

"No danger of that," Frank continued. "A condor is like our vulture or buzzard, a scavenger; and he lacks the bravery of the bald-headed eagle that attacked us when we came near his nest on the tip of Old Thunder Top. Look there, he's off, Andy, and at a good lively clip, too. Good-bye, old chap, and good luck!"

Andy had lost all interest in the great bird of the western Andes. He was focusing his attention upon the place that he had marked as a likely spot.

"Frank," he said, presently, in a husky voice, "could you drop a little lower and slow down some?"

"That's easy," replied his chum, readily enough. "What has struck you now, Andy?"

"It looks more and more promising to me," came the slow reply, as Andy kept the glasses up to his eyes.

"Then you can glimpse something like cliffs?" asked Frank.

"Yes, and there's no doubt about that part. I'm waiting now to see if the wide valley is wholly enclosed!"

"And if it is, you think—"

"It must be the place! Oh, Frank! What if we are near the spot? Would he still be alive, or has he given up the fight? That condor perched up on the pinnacle—was he only waiting for the time to come when he could fly down? Perhaps—oh! what is that moving yonder? Look, Frank, Frank, something is coming up above the top of the mountain! Can you see it? If you could only take the glasses and tell me, for my hands are shaking so I can't hold them!"

"Brace up, Andy. I can see what you mean without the glasses. There, now it has risen above the line of rocks—something that bobs to and fro like no bird ever flew—something that floats, now this way and now that, just as the wind blows. Andy, upon my word I believe it is, it must be—"

"Oh, say it for me, please, because I just can't find words!" cried the other.

It was a wonder that in their tremendous excitement something disastrous did not happen to the aeroplane, but Frank had wisely cut off some of the power, so that they were just making fair headway at the time.

"It is a little parachute balloon, just like the one that carried that message into the cocoa grove of Carlos Mendoza!" ejaculated Frank.

"Then it means that we have found the valley prison!" gasped Andy.

"Sure, that's a fact. The cliffs yonder are on one side of it!" Frank cried.

"And Frank, don't you see, the fact that another of those little messengers of hope has just come up out of the valley shows that he is alive!"

"You just bet he is, Andy; and we're going to be with him in three shakes of a lamb's tail!" declared the other.

Andy could not utter another word; he was too full of emotion. So he just sat there and stared and waited, his heart doubtless thumping against his ribs as it had never done before.

Of course, when Frank gave utterance to that boast he did not really mean it, and only had the encouragement of his chum in view. He knew that it was apt to prove a difficult task, landing in that enclosed valley, where the vegetation must be of a tropical order.

First of all they must circle around over the wide expanse to take in its features and discover the prisoner. Then Frank could lay his plans accordingly.

Gradually they began to see more and more of those marvelous cliffs. They seemed to stretch in an unbroken cordon completely around the valley. If they were as near like adamant as they looked it would take a man years to cut steps to the lofty top, even though he were given proper tools for the work.

And presently they cleared the near side, so that the monoplane floated directly above the valley itself.

"Careful now, Andy!" warned the cautious Frank. "Hold yourself tight while we circle around, dropping lower all the time. Suppose you shout, though I should think he'd have heard the noise of our exhaust before now!"

He had hardly uttered these last words when there came a cry from below.

"Look, look, Frank, there he is! Oh, what a blessed sight that is! My father, and alive after all! See how he runs and waves his hands! What will he say when he knows that it's his boy in this airship come to save him?"

"Call out and tell him!" said Frank, hardly able to control his own feelings, though he knew he must or they might meet with an accident in this supreme moment of victory.

So Andy did shout, calling upon his father wildly and waving his cap to him. The prisoner of the enclosed valley seemed dazed at first. Perhaps he had been deceived so many times by his dreams of being saved that he feared this might prove only another delusion. They could see him stand there and put his hand to his head as he stared. It was so very wonderful, this coming of a modern aeroplane to snatch him from his living grave. And then that voice, how like the one he had never expected to hear again!

But by degrees, as the little Bleriot monoplane sank lower, and the forms could be more plainly seen, he began to grasp the truth. Again he showed the most intense excitement, waving his arms and running to keep up with them.

"Wait," said Frank, presently, as he saw that Andy was so excited he could not carry on an intelligent conversation. "I'm going to speak with him and find out if there's any clear spot where we can land."

"Uncle Philip!" he shouted presently, when Andy had subsided. "This is Frank, your nephew, and Andy, your own son. Is there any clear place where we can land?"

The aeronaut understood, because all this was right in line with the profession which he had been following at the time of his vanishing from mortal sight.

He indicated the quarter where a landing might be risked and upon investigating by hovering over the same, Frank decided that it promised success.

So the aeroplane dropped down and touched ground. It bumped along for a little distance and then Andy, leaping out, managed to bring its progress to a halt. They were in the enchanted valley, from whence those wonderful messages had floated, one of which, by a strange freak of fate, had eventually reached the boy thousands of miles away, for whose eyes it had been intended!

And immediately Andy was clasped in the arms of his father. He knew him despite the long gray beard, which had grown during his many months of confinement, with hope daily choked by despair. His clothing was almost in tatters, and he seemed thin and peaked; but the look upon his drawn face now was of supreme happiness.

Then, after they had in some measure recovered from all this intense excitement, the boys sat down to tell what a miracle had been wrought, bringing the message to the home in far away Bloomsbury. With an arm still encircling the form of his boy Professor Bird listened and asked many eager questions.

"And to think," he said, finally, "that little messenger you saw going up just now was constructed of the very last fragment of the old balloon silk. I made a fire with flint and steel, filled it with hot air and sent it up with prayers, believing that it was my forlorn chance. And then I heard the exhaust of your motor. I feared my mind was giving way under the terrible strain. When I looked up and saw an aeroplane sail into view I fell down on my face, believing I had gone mad. But it was a blessed reality, thank God!"

Plans were soon under discussion looking to leaving the valley as soon as possible. About this time Andy happened to think of something and began to fumble at his pocket.

"Oh, how I hoped and prayed when I bought that, father, that I might have the happiness of seeing you smoke some of it," he said, as he drew out a little packet of tobacco, on which the late prisoner pounced with all the delight of an inveterate user of the weed, who had long been deprived of a pleasure.

"I have been using dried leaves of a wild grape and some other things," he admitted; "but after all they were only vile substitutes. It was thoughtful of you, my boy, to remember my weakness."

And Andy snuggled up close to him as he commenced to puff at his pipe, using a match for the first time in many moons and smiling whimsically when he struck the same, as memory played queer pranks within.

Meanwhile Frank wandered around to survey the scene of the professor's imprisonment and figure how they were ever going to get out with the aeroplane.



CHAPTER XXII.

RESCUED.

"What's the hurry?" asked Andy, when once they began to talk over their plans for leaving the valley.

For once Frank agreed with his chum. They had plenty to eat along with them and it might be just as well to wait for another day. By that time all of them would have recovered to a great extent from the excitement that had told upon them, particularly the professor, none too strong.

So it was finally concluded to stay right where they were until another morning, when one at a time Frank would endeavor to convey them out of the valley, not daring to risk two passengers at once with such a poor field for the start.

The time passed quickly enough, for there were a thousand things to tell on both sides. The aeronaut described his accident and related how he had lived through all the dreary months that had gone. Fortunately there did not happen to be any fierce wild beasts in the cliff bordered valley, and while he had had adventures with venomous serpents, fortune had stood by him.

He showed numerous little contrivances by means of which he had secured game enough to supply his needs. There were nuts in abundance and some wild fruits which, as a scholar, he knew the value of.

Water could be had in plenty, as a lovely stream flowed through the valley, diving down at one end and vanishing in the rocks, to find an outlet such as the human prisoner prayed for daily in vain.

Why, it was evening almost before Andy realized it, so quickly had the hours sped along. How proudly had his father asked all about the monoplane, which he examined with the most intense interest, knowing it to have been mostly made by the two enterprising Bird boys.

Prom the way in which he smiled and nodded his head after this survey it was evident that he was very well pleased with what they had done. And he also made them tell all about that famous race through the air to the hitherto unsealed crown of Old Thunder Top, which he remembered very well.

"And now, let's think of having a jolly little meal," said Frank, as the shadows began to lengthen down below the lofty cliffs, which was a pretty good indication that night could not be far away.

"Count me in," said Andy, jumping up, for it was his duty to get busy when the time came to make a fire and prepare a repast. "I guess we've got coffee for a few times yet, and I smuggled a can of Boston baked beans along when Frank wasn't looking, knowing that father used to be right fond of 'em."

"Coffee! Beans! Why, you fairly take my breath away!" exclaimed the one who for so many months had been deprived of all the comforts of civilization and forced to sustain his life in the most primitive manner.

When supper was cooking the professor made some excuse to wander off. Frank knew, though, what ailed him.

"It's the aroma of that blessed coffee, that's what," he said to Andy, who had looked a little troubled at this action on the part of his father. "It's been so long since he's smelled it that it just makes him wild. I know, because I had a little experience that way myself once, only it was two weeks I had to go without when we were camping and not many months. When supper's ready he'll come with a rush, mark me, Andy."

And he proved to be a true prophet, for no sooner had Andy lifted up his voice to call that the meal was ready than the professor broke through the bushes and hastened to take his place.

Frank lost not a second in filling a tin cup of the amber liquid and handing it to the late prisoner of the valley.

He tasted and then nodded his head.

"Nectar for the gods, my boys!" he declared. "One never knows how little things like this go to make up a portion of one's life until a cruel fate has deprived him of them all. And to think I have a boy so thoughtful as to fetch along a packet of smoking tobacco and a can of the real Boston baked beans. Thank you, Frank, that's a heaping pannikin you've given me, but I suspect I'm equal to the job."

They made a happy trio as they ate and chatted and laughed. Perhaps that was the first hearty laugh Professor Bird had given utterance to since the day he started in his ill-fated balloon from Colon on the Caribbean coast to cross the Isthmus of Panama.

Before they went to sleep that night all preparations had been concluded looking to getting out of the trap in the morning. Frank had made his estimations and knew to a nicety just what his engine could do. Once free from the valley he believed they could head direct for the distant Magdalena, carrying two passengers and making short flights. It was true that as yet he had never taken up any second passenger and it entailed an additional tax upon the motor, but he had great faith in the little Kinkaid engine and felt that it would respond nobly to any additional demand made upon it.

But it would be advisable that he carry the professor out of the valley and land him on that plateau where they had made their last halt, ere going back for Andy. Then, from that elevated place they could start on the return trip, with everything favorable for a successful flight.

The night passed at length, though it must have seemed interminable to Andy. Frank knew that often his chum would rise up on his elbow and put out a hand gently, just to touch the form of his sleeping father close to him. And Frank did not wonder at it, for there were times when even he found it difficult to realize that their remarkable mission had actually proven successful.

At length the day came.

They were early astir, for much remained to be done. And there would needs be deft manipulation of the gallant little monoplane by its clever pilot, if two separate flights out of the enclosed valley were to be undertaken.

Finally all was ready.

The professor had really next to nothing he wished to bring away. The valley had grown hateful to him because of his enforced stay and he never wanted to see it again.

He took his place in the seat usually occupied by Andy. His face was grave, for he knew what risks they were running. But surely the lad who had piloted the frail craft through so many perils would not fail now!

"Good-bye, both of you!" said Andy, beaming upon them, as he prepared to assist in the launching. "Please don't forget me down here and let me root, hog, or die for months. Birds of a feather flock together, you know, so come back again, Frank."

Then came the start. It was anything but an easy job to get going in the small space allowed by the character of the valley, but Frank had figured it all out, measured the ground, removed such obstructions as promised to give trouble and had perfect confidence in his ability to make it.

And he did.

After that other ascent in the heart of the tropical forest he declared he did not mean to let anything appal him henceforth.

Once they started circling the valley, low down and just missing the tops of the trees growing there, Andy, sent vigorous whoops after them, and his father answered by waving his hand, for hat he had none.

So, guided by the master hand of Frank Bird, the aeroplane rose above the line of those hateful and cruel cliffs and for the first time since his captivity the man of science saw the blessed outside world again.

There was no trouble landing him on the accommodating plateau, after which the aeroplane started back for its second passenger.

Frank abated his vigilance not a particle. He knew that constant watchfulness must be the price of safety when one is venturing to imitate the birds and soar through the upper currents of the air.

Down into the valley he dropped, the monoplane behaving beautifully. And presently he was shaking the hand of his chum again.

Once more was a start made. Frank breathed easier after it had proven a success, for there were narrow escapes from a collision with some obstacle, and he knew only too well what that stood for.

"Now we're all right, I guess!" sang out Andy, as they came out of the depths and Frank turned the airship in the direction of the distant plateau.

Naturally Andy was as happy as a lark, singing and calling as they glided along, and finding scores of causes for attracting the attention of his chum. Finally Frank had to caution him to slow down and not try to make him look so much.

The trip was made in perfect safety. Indeed, Andy was now so confident of the capacity of the monoplane, as well as the skill of its pilot, that he expressed himself as ready to go anywhere in such a craft with such a driver.

It required some planning to arrange matters so that both Andy and his father could be carried at the same time; but Frank had been figuring on this and fixed it in his mind.

Even after the start he felt more apprehensive than he allowed the others to see, for this was after all an experiment. Aviators have gone up with two passengers and in monoplanes, too, but the limit of their stay aloft had never exceeded two hours, for the strain is very great.

So Frank hoped to find places where they might drop down to rest, thus making the journey in easy stages.

He believed they had plenty of gasoline to see them through, for an additional supply had been carried when starting from the neighborhood of the boat.

But once they were afloat he realized that he had been borrowing needless trouble, for the gallant little aircraft just acted beautifully and seemed to be able to speed merrily along with two passengers almost as well as with but one.

Of course there were many chances for trouble. There always are when traveling in an aeroplane, since the least thing that goes wrong means a descent or a fall.

Frank tried no lofty flight. He kept close above the tree tops, content to make steady progress in the direction where his little compass told him they would find the river.

Once away from the mountainous country and they were able to descend to still lower levels, where the chilly air changed to hot, and there were signs of life among the trees below—birds, monkeys and other natives of the wilds showing themselves at times.

It must have been a glorious sensation to the old aeronaut to be thus speeding along in a modern, up-to-date airship, after his enforced idleness for so long. Again and again did he express himself in that way, as he gazed over the expanse of country, and then allowed his eyes to rest fondly on the form of his boy, more dear to his heart than ever after what had happened.

"I think I see an open place beyond," remarked Frank, after they had been moving something like two hours after leaving the high plateau. "And it might be wise while we have the chance to go down and look things over. Then we will feel fit for another spell of work."

Accordingly the aeroplane was headed downward. They circled the opening once or twice in order that the pilot of the aircraft might get his bearings perfectly, and then he headed for the ground.

Even as they were just approaching the earth Frank heard Andy give one of his customary exclamations, such as announced an important discovery.

"Frank, there's the biplane in the opening!" was what he cried.

Yes, Frank himself had sighted it now, but the discovery came too late to have any effect upon their movements, since they were bound to land, not having room to rise again, even did they wish to do so.

And Frank, as he felt the wheels under the aeroplane touch the earth, also heard a loud cry and some lusty Spanish expletives as a pistol was discharged.



CHAPTER XXIII.

HOMEWARD BOUND—CONCLUSION.

As was his usual habit, Andy jumped before the monoplane had stopped. Frank on his part had no sooner seen that everything was going well than he snatched the Marlin rifle from its fastenings. He realized that they were up against trouble of some sort, for those Spanish exclamations told him there must be one revolutionist at least close by ready to do battle.

"Frank, look out, he's got a pistol!" cried a voice, which he recognized as belonging to Puss Carberry.

Just then he caught sight of a figure rushing forward. It was the same man no doubt whom they had seen with Puss in the biplane. They had evidently broken some important parts in landing and ever since must have been busy trying to mend the same.

"Stop!"

When the advancing revolutionist heard this sharp command and saw that he was being covered by a rifle in the hands of the determined looking pilot of the monoplane, he sized up the situation and then raised his hands in a way that meant he surrendered.

"Drop that gun then!" ordered Frank, and as he did so Puss seized upon it with a snarl of joy.

"Now we'll see how two can play at that game, you skunk!" gritted the other, as he snapped the pistol straight at the head of the man.

"Here, none of that, Puss. You leave him to us. He's our prisoner, not yours!" ordered Frank, horrified at the rage which the other had shown.

So Puss found that he did not have any authority in the matter, and that if he wanted to get assistance from his old-time rivals in order to finish mending his airship and get away from so dangerous a locality he must do what they said.

He told about how he and Sandy had been out for a trial spin two days before. That was when Frank and his chum had sighted them from the river. But that very night some of the revolutionists had made a descent on the home of his uncle, who had a cocoa plantation not many miles away from that of Mendoza, seized him and carried him away, as they also did the little airship.

Threatened with dire things if he refused to obey, he had been compelled to go up in company with the man who was now their prisoner, a Spaniard, who had once sailed in a balloon and knew something about that type of aviation, though having much to learn in connection with modern aeroplanes.

Sighting our two Bird boys, of course Puss had known who they were. But the man was positive that they must be spies sent out by the government to learn what the revolutionists might be doing up the Magdalena. And he had threatened all sorts of things, Puss declared, unless a hot pursuit were carried on. Secretly Frank was of the opinion that it would require very little urging to make Puss Carberry do his level best to overtake any aerial craft piloted by one Frank Bird, toward whom he had always felt the most bitter animosity.

After about an hour's hard work Frank managed to get the biplane in decent trim for a flight. He was also able to spare the other some gasoline.

Had he been allowed to have his own way Puss would have left the Spaniard in the forest, where he might have died, being unable to make his way to civilization. But Frank would not hear of it. He obtained a solemn promise from the man that he would not make any further effort to obtain control of the biplane, and then Puss was made to take him aboard. Of course, Frank had made sure that the man carried no weapon and that his revolver was thrown away.

They left the glade in the forest soon after the biplane had started. Puss managed to keep close to the others while they headed off toward the northeast. He did not wholly trust the passenger he was carrying and wanted to remain within call of the three who relied upon the monoplane to carry them to safety.

They could even shout out to each other as they sailed along. Thus Puss warned them when they were approaching a camp of the revolutionists as they drew near the region of the river, and they were able to change their course, not wishing to again run the perilous gantlet of gun-fire.

When another descent was deemed necessary it was close to the Magdalena, though many miles south of the town where the cocoa planters lived.

There was no reason why Puss should also descend, save that he wished to be rid of his unwelcome passenger. The revolutionist might now make his way to camp and electrify his fellows with a stirring account of his various adventures. And one could easily guess that they would lose none of their zest in the telling.

Puss did not expect to halt again when the monoplane was brought down. He could make one flight of it now and reach the home of his uncle, where doubtless Sandy was mourning him as lost.

Just as Frank had expected, Puss on saying good-bye tried to appear as though something along the order of gratitude might be striving to gain a foothold in his crooked nature.

"Say, Frank, I'm sorry now I ever tried to do you dirt," he observed, as he held out his hand. "Let's forget the past and start all over again."

"Sure," replied Frank, as he readily took the offered hand; but it lay like a cold toad in his grasp, as Andy afterward expressed it, for Puss insisted on also bidding him good-bye ere he made a start in his biplane.

"Well, now, what d'ye think of that?" said Andy, as they stood and watched the other mount upward and caught the wave of his hand ere he started down river, being fully five hundred feet high. "Did he mean it, Frank? Would you really want to go so far as to trust that snake if the chance ever came again for him to do you a bad turn?"

Frank shrugged his shoulders.

"Say, ask me something easy, won't you?" he remarked. "Because you know how hard it is for a leopard to change its spots. Perhaps Puss has seen a light; but excuse me if I doubt it. Naturally he felt kind of cheap, because we got him out of a bad hole and placed him under obligations. But that will wear off in a short time."

"Right it will," declared Andy. "I give you my word, Frank, that the next time we see him he'll have a fine story all fixed about how he was just going to jump on that Spanish revolutionary fellow, and twisting his gun out of his hand, shoot him down, and then fly away. Oh, don't I know Puss in Boots, though? He'll hate us both worse than ever just because he's beholden to us. Rats! him reform? Not much!"

By the middle of the afternoon they had advanced far enough to know that another lap ought to carry them to town, and of course all of them were anxious to have the journey completed.

"If it could only be written up and sworn to," said Andy, enthusiastically, "I reckon it'd go down in the annals of aeroplaning as the most wonderful stunt carried out up to date. But people won't take our word for it."

"We've got the evidence of it, though, in the person of your good dad, and people may believe what Professor Bird says over his own honored signature, however much they might doubt the yarn of a couple of boys," Frank remarked, as he took a last look, to see that both his passengers were snugly settled, ere starting the motor.

"We're on the home stretch now!" declared Andy, after they had again mounted up into the realm of space and found their course northward.

"Yes," observed Frank, "we're homing pigeons now, if any kind of bird."

"At any rate," laughed the professor, "we're birds of passage, and one of them is mighty glad of the opportunity to get back into the old world again."

In due time they sighted the town, and as before, the greatest excitement followed as they headed across the place, looking to land where the journey had begun—in the yard of the cocoa planter's place.

Of course Senor Carlos was delighted with the success of the mission. For two days the Bird boys were the center of an enthusiastic demonstration. Frank was a little nervous lest they be visited by some of the revolutionists, but such did not turn out to be the case. And on the third morning the little steam yacht once more headed down the turbulent Magdalena, with a heavy rain promising more water to add to the flood, as wet weather had seemingly set in again.

They met with no difficulties on the way down. Apparently the camp of the revolutionists had been moved from its former position at the narrows of the river. It might be those in charge had taken the alarm and feared lest a government force must be on the way to capture them, after being informed about the camp by the spies they had sent up the river.

And Barranquila was finally reached, where they halted only long enough to chat a short time with Senor Jose, who met them as before on the quay and wanted to shake hands with the professor.

Knowing just how anxious the government was to get possession of airships just then, Frank did not want to give them any further chance to confiscate his neat little craft, under some pretense or other. So they left the city at the mouth of the Magdalena and steamed away, bound once more for Maracaibo, where they meant to take steamer for New York, New Orleans or any port in the States.

The last glimpse they had of the river was the flood that was pouring out between the jaws of land marking one of the mouths of the Magdalena and making a distinct yellow area in the salty waters of the tropical ocean.

The beloved little aeroplane had been safely boxed again and was making the homeward voyage in their company. What strange and wonderful things it had been through! Andy declared that they almost passed belief, and he expressed his doubts as to their ever having an opportunity to pilot that same aircraft through atmospheric seas as tempestuous as those they had experienced in the tropics while rescuing the prisoner of the cliff bordered valley. But then Andy was not gifted with second sight and he could not foresee what the wonderful future might have in store for the Bird boys.

They had by this time experienced enough of the fascinating new methods of cruising in cloudland to want to continue. And it stands to reason that other adventures would be lying in wait for lads so constituted.

For the present it must be enough to say they arrived safely at good old Bloomsbury in due time and that the entire population was on hand to greet the party when they stepped from the train. Also, the wonderful little monoplane, the same that had been equal to the test in the race for Old Thunder Top, had to be placed on public exhibition for several days in the town hall, where every man, woman and child in all the country around could examine and comment on the construction of the airship that had brought fame and happiness to Frank and Andy Bird.

In due time Puss and Sandy turned up, minus their biplane, which the government of Colombia had seized on some plausible pretext, though paying liberally for the same. But they were soon at work constructing another, which they claimed would far exceed the one that had been lost.

Professor Bird by slow degrees recovered his health that had been sadly shattered by his experience down in that country. But he declared that his days were over so far as aviation went, and that in the future he must be content to take a back seat and see the honors of the family carried off by the younger generation—the Bird boys.

THE END.