CHAPTER XX.

“ALL OUR LIVES DEPEND ON IT.”

Nat staggered toward the door of the pilot-house. Mr. Tubbs, at the wheel, the least affected of the adventurers, turned his head.

“What are you doing to do?” he demanded.

“Get that valve open,” was the brief reply.

“Boy, you are crazy!”

“Maybe, but I’m going to make a try for it, anyhow. All our lives depend upon it.”

“By hooky, if it’s to be done, you’ll do it, and if not, why then, I guess we’ll have to meet death as bravely as we can,” was Mr. Tubbs’ muttered remark, as Nat plunged out of the door.

In the cabin Ding-dong, breathing hard, lay on a narrow bunk. Matco was stretched on the floor, apparently unconscious. Nat gazed at them half stupidly.

“Pretty far gone,” was the thought that came into his dazed mind. Then he plunged on again, reeling as he went, his mind concentrated with bitter intensity on the task that lay before him. Gaining the deck, he found the cold almost too much for him, and he turned back for an instant and donned warmer clothing from the professor’s chest.

Then he doggedly proceeded with his self-imposed task. He noticed that the engine had stopped. The bitter cold had condensed the moisture within it and frozen the lubricating oil.

But Nat wasted no time on these observations. What he had to do must be done quickly if at all.

Gazing upward at the huge bulging curve of the under side of the gas bag, he saw the broken ends of the valve cord fluttering from the bag. They were far above his reach, even if the securing of them would have done him any good.

It was only for an instant that he paused. Then, summoning up every ounce of resolution in his determined mind, he seized hold of the starboard rigging and began clambering up and outward.

Nat climbed by sheer force of will power.

He did not dare to look down into the awful void beneath him—vast and empty as eternity itself. Keeping his eyes steadily fixed on the bulging bag, Nat climbed by sheer force of will power till he was up to the network that encased the bag.

Right here began the most difficult and terrifying part of his task. Hanging desperately above the immensity beneath him, he had to make his way to the upper part of the bag. He did not dare to think of what he was doing. The very notion of it made him feel sick and dizzy. The lad just climbed, fixing his mind on the thought of reaching and opening the valve.

Somehow—to this day Nat couldn’t tell you how—he clambered round under the bulge of the bag and began the easier task of making his way up the tightly rounded sides to the top of the great cylindrical gas container. As the professor had surmised, ice had formed on the outsideof the bag, and made Nat’s endeavor ten times more hazardous and difficult. This ice had clogged the valve ropes, and Nat saw that the only thing to do was, as he had made up his mind, to climb on till he reached the top of the bag.

The possibilities of a slip were awful, and Nat no more dared think about them than he had about the chances of his slipping when he was hanging between earth and sky under the lower part of the bag. He resolutely dismissed them from his mind.

But the physical difficulties of the lad’s self-imposed task were almost overwhelming. There was a sharp pain in his chest, and his limbs felt as if they had leaden weights attached to them. Suddenly a warm stream of something Nat knew to be blood, gushed from his nose; but still he worked his way upward, climbing amidst the network meshes like a sailor on ratlines.

Once or twice he was compelled to pause from sheer exhaustion, and, clinging on with might and main, to spread himself flat on the surface of the gas bag to rest.

If Nat had not been a clean-lived lad all his life, and had not been a hater of smoking and bad company, he would never have been able to endure this ordeal; but somehow, his young vitality won out, and at last he could reach out a hand and touch the valve.

Bracing himself against the rigging, he tugged with all his might. But the condensed moisture had formed ice on the valve, and it stuck.

Nat felt a childish rage take possession of him. Raising his fists, he beat and tore at the valve, while tears of physical weakness and exhaustion streamed down his cheeks.

“I will get you open! I will! I will!” he cried again and again.

But even his frame gave way at last, and suddenly his eyes grew dim and he felt as if a sword had been plunged through and through him.

As everything grew black, Nat, with a last effort of consciousness, clutched at something to save himself from being plunged backward into space.

He caught it, or thought he did, and then his senses went out from him with a vivid flash and a terrible roaring in his ears like the sound of a hundred waterfalls.

Half an hour later, or at ten o’clock, Joe Hartley opened his eyes. At first he hardly knew what had befallen him; but in a few seconds his recollection came back with a rush. He remembered that theDiscovererhad seemed doomed, recalled Nat’s plunge through the door and how he had tried to follow his chum, but had fallen, overcome by exhaustion, at the door.

But now all the chill was out of the air, bright sunlight streamed through the pilot-house ports, and the professor and Mr. Tubbs, both of whom had collapsed on the floor, were sitting up looking about them rather bewilderedly. The professor was the first to speak.

“A miracle has happened,” he declared. “TheDiscovereris out of danger.”

“The barograph shows twenty-five hundred feet,” announced Joe, who had been studying that instrument.

“Where are the others?” asked Mr. Tubbs, rising rather weakly to his feet.

As if in answer to his question, Ding-dong Bell appeared in the doorway between the pilot-house and the main cabin.

“Where’s Nat?” he demanded.

“Isn’t he out there with you?” asked Joe, with a quick leap of his heart.

“No. The only person out there is Matco. He’s so scared that he’s under the ber-ber-bunk.”

“Where is the lad?” demanded the professor earnestly, with a note of anxiety in his voice.

Mr. Tubbs, who had been struggling with his dim memory of events preceding his collapse, spoke:

“I recall it now,” he said. “Nat said he was going to get that valve open”—he paused—“somehow.”

“And you let him go?” demanded the professor.

“I—I didn’t mean to,” stammered the repentant Mr. Tubbs, “but I was so nearly on the verge of caving in, that I couldn’t carry out my resolve.”

“Search the craft thoroughly,” ordered the professor, lines of anxiety showing in his face, “there was only one way to open that valve.”

They looked their questions.

“And that was by climbing around the gas bag and opening it by hand.”

“Good gracious!” exclaimed Joe. “And Nat dared do such a thing!”

“He must have, and succeeded, too,” said the professor in a curiously tense voice, “the opening of that valve was the only thing that would result in our having dropped to a supportable region of the air.”

“But we are dropping no longer.”

The exclamation came from Mr. Tubbs.

“No. The automatic cut-off arrangement would have closed the valve when we had reached a warmer belt of atmosphere,” explained the professor, “but don’t let us lose time talking here. Scatter through theDiscovererand make a thorough search. He may have dropped unconscious somewhere.”

The anxiety with which the search was conducted may be imagined. TheDiscovererwas allowed to drift lazily along while they sought some trace of the missing lad, but the search resulted in nothing.

“There is only one conclusion to be reached,” said the professor in a solemn voice, “poor Nat paid the penalty of his bravery with his life. He——”

The man of science broke off, unable to command his voice, and at the same instant came a cry from above them—a hail from out of the air, it seemed:

“Hello, people!”

“Good heavens! It’s Nat!” fairly shouted the professor, as Nat, whose feet were alone visible round the bulge of the gas bag, clambered nimbly down and dropped from the rigging, beside them.

In his excess of joy, the professor flung his arms around Nat’s neck, much to the lad’s embarrassment, while the rest fairly fought for a chance to grasp his hand. In intervals of joy making, Nat told his story, part of which we are familiar with.

It seemed that when he swooned on the swaying balloon top he instinctively clutched at the first thing his hand encountered, which was one of the valve ropes. The valve, already loosened by his pounding on it, yielded to the sudden pressure upon it and jerked open. At least, this was the only explanation Nat could furnish of the fortunate occurrence.

When he came to himself he said he saw that theDiscovererwas at a reasonable height, and manipulating the cords he again closed the valve.He was too weak to attempt the descent at once, but lay outstretched on the top of the gas bag, regaining his strength. All this time he suffered with a dreadful fear that his friends below might have succumbed to the awful rigors of the upper air. With an apprehensive heart he at last began the climb down and he concluded:

“You may imagine how delighted I was to hear your voices, even if the professor was preaching my funeral sermon.”

The boys broke out into wild yells of enthusiasm.

“Three cheers for Nat Trevor, the bravest boy on earth!” shouted Joe Hartley.

The shouts rang out oddly in the thin atmosphere of mid-air, but they relieved the boys’ feelings. As they died out, Matco appeared at the door of the cabin, and gazed at the scene a moment. Then seeing that Nat was the idol of the moment the Indian ran nimbly along the swaying deck and throwing himself on his knees, placed Nat’s foot on his head.

It was the last straw.

“Say, fellows!” cried Nat with a red face, “that’s about all of this hero business. Let’s have some breakfast and get the engine going.”

And so, what might have been a tragedy, ended in one of the merriest meals ever enjoyed by aerial travelers.

By noon theDiscoverer, none the worse for her involuntary flight into the icy realms of space, was able to resume her voyage over the desolate peaks and abysses of unknown depths, above which the adventurers were now soaring.

“FEATHERED AEROPLANES.”

The professor’s observations that day showed that they were within two hundred miles of where the fabled city ought to lie, always supposing that it really had an existence. But you may be sure that not one of the Motor Rangers doubted that fact.

The course was altered, and theDiscoverer’sbow turned toward some ragged-looking peaks that cut the sky line to the northwest. The country over which they were now passing was, as has been said, desolate in the extreme. It appeared to have been devastated by earthquakes or forest fires, and the vegetation was scanty, while the surface of the ground was split, and scarred and hillocked like a crumpled bit of parchment. But toward afternoon thecharacter of the scenery changed. The mountains grew in gloomy grandeur and were clothed with dense tropical growth. Between the great masses and lofty elevations lay dark and unfathomable chasms, at whose depth only a guess could be made. It was wild and dismal scenery, and, viewed even from above, oppressed the travelers with its sense of lonely vastness.

TheDiscovererwas not making as good time as usual, owing to a stiff headwind. Then, too, the engine had not developed its full power since its freezing up in the upper aerial regions. But the professor announced himself as well satisfied with their progress. Matco gradually got over his first fear of the air travelers and talked to the professor in his rough Spanish, which Nat could hardly understand, so besprinkled was it with mispronunciations and Indian words.

The old Indian was much interested in trying to find out what the white men,—for he no longer thought them gods,—were doing in that part of the country. But the professor deemed it wisest not to tell him. Ultimately they would have to set him free, and if he knew too much of their expedition he might make trouble for them with the other Indians.

It was the middle of the afternoon, and Nat was seated in the cabin reading a book on the Incas, when a hail from the pilot house brought him to his feet. Joe, who was at the wheel, was calling him.

“Nat! Nat! Come out here—quick!”

Nat lost no time in obeying. As he joined Joe the latter excitedly pointed ahead of theDiscoverer’sbow.

“Look at those birds, Nat; they are the largest I have ever seen. I wonder what they can be?”

The birds referred to were flying and wheeling in great circles above a ravine some distance off, but far off as they were, it was easy to see that they were of immense size.

“They are bigger than the biggest turkey buzzard I ever saw in California,” said Nat, gazing at them. “Let’s have a look through the field glasses.”

He took the instruments out of their box near the helmsman’s wheel and applied them to his eyes.

“Why, they look like small aeroplanes!” he exclaimed in astonishment. “Their wing spread must be ten or twelve feet, judging from here.”

“How many of them are there, anyhow?” demanded Joe.

“Easily fifty, I should say. Maybe more. It would be impossible to count them accurately.”

“They are right on our course,” said Joe, glancing at the compass, “so that we shall soon have a close view of them.”

“I’ll go and rouse the professor. He’s taking a nap; but I know he’d like to see such a sight.”

And Nat hastened off on his errand.

By the time he returned with the professor, theDiscovererwas much closer to the giant birds. The man of science scrutinized them through the glasses.

“Condors,” he announced. “This is most interesting. These birds are the largest birds of prey in existence. Humboldt, the famous traveler, said that Indians told him that they had been found measuring eighteen feet from wing tip to wing tip.”

“Well, I should say theyareaeroplanes,” exclaimed Nat. “Do they ever attack men?”

“Cases of it are not unknown,” said the professor, “and almost every Andean village has a story about a condor flying off with a baby. As a matter of fact, though, I guess they confine their attentions mostly to young sheep or calves light enough for them to carry.”

As they drew closer to the soaring mass of birds, they could see that if they were interested in the birds, the birds were quite as much interested in them. One or two began making long, wheeling arcs that brought them closer to theDiscoverer.

“I guess they are wondering what sort of a bird we are, anyhow,” laughed Nat.

Indeed, it seemed so. Almost imperceptibly the birds gathered about theDiscoverer, wheeling and screaming all about the craft. It could now be seen that they had sharp, large, hooked beaks, and a ruffle of dark flesh at the bottom of a flabby neck. Their wings were of a dull gray color, with black tip feathers, and were of a sweep and size undreamed of hitherto by the boys.

“They look like the harpies we used to read about in school,” said Joe.

“They do, indeed,” said the professor. “One could readily imagine such creatures tearing unfortunate human beings to pieces.”

“They don’t seem afraid of us, anyhow,” said Nat suddenly, as one of the great condors swept by quite close to theDiscovererand uttered a wild scream that sounded like a cry of defiance.

“No, they don’t. I—— Bless my soul, they are attacking us!” cried the professor as two or three of the birds flew at the gas bag with beak and claw.

“Now, boys,” spoke the professor, “we must use our best marksmanship on these creatures.”

“Get out the rifles, quick!” cried Nat. “They’ll tear the bag open if they keep that up.”

“They will, indeed!” said the professor apprehensively. “Shoo!”

But he might as well have said “Shoo!” to a tiger as to the giant birds of prey that now surrounded theDiscovereron every side. Angry screams and the rushing noise of huge wings filled the air.

Nat returned with the rifles, and with Ding-dong Bell, who had already, from his post at the engines, observed the great birds.

“Now, boys,” spoke the professor, “we must use our best marksmanship on these creatures. They are a real menace to the ship.”

Nat took up his position at one side of the pilot house, Ding-dong Bell at the other, while the professor aimed from the centre window.

At the word “fire!” from the professor, all three rifles began to pump lead into the wheeling, circling, screaming flight of condors.

Several stopped abruptly in their soaring circles and fell to the earth, stricken to death. But others, that were only wounded, fought with more fury than ever. The attack by the adventurers appeared to enrage them. They flew furiously at theDiscoverer, and one or two even dashed themselves at the pilot house.

But after ten minutes or more of steady firing their numbers diminished. The ones that were left began to sheer off, and finally took flight away from the invaders of their realm. The noise of the firing brought Mr. Tubbs and Matco out of the cabin, and both watched with interest the effects of the fusillade.

When it was over, and theDiscovererhad left the last of the great birds behind, old Matco spoke excitedly in Spanish to the professor.

“What does he say?” asked Nat, when the old man had finished what appeared to be a tirade against something or somebody.

“He says,” rejoined the professor, “that what we have done is very good. That when he was a youngster he was carried off by one of these birds. His mother, who rushed out to save him, was attacked by the condor’s mate and so seriously maimed and torn that she died.”

“But how did he escape?”

“His father shot the bird that was carrying him off, with one of the poison arrow tubes,” rejoined the professor, “both the bird and the infant fell to the earth, and Matco says that is the reason his leg is so twisted and that he walks with a limp.”

The boys found this very interesting. It explained, too, something that they had noticed before, and that was that old Matco walked with a decided limp.

“Tell us something more about the condor, professor,” suggested Nat.

“As I think I said,” rejoined the professor, “it is one of the vulture family, and is found from the Isthmus of Panama clear down to the Straits of Magellan. They usually live in the mountains, but sometimes they come down to the seashore to pick the flesh of dead whales. In fact, they have a preference for dead or decaying flesh.”

“Just like turkey buzzards,” said Joe.

“They are a first cousin of that bird,” said the professor. “A friend of mine, who had been a great traveler in South America, told me once that the Indians will catch them for two dollars each, and that sometimes they do quite a lively trade.”

“I shouldn’t much care to have one for a pet,” spoke Joe; “but how do they manage to get hold of such immense birds?”

“By a very simple and ingenious method. They build a pen around the carcass of the first dead steer they can find on some cattle estancia, and then await the arrival of the condors to feast on the flesh.

“The condor, when he is gorged, cannot rise without taking a run——”

“Just like an aeroplane in that, too,” commented Nat.

“That is true,” said the professor. “Well, as I was saying, the bird cannot rise without this preliminary run, and, of course, the picket fence interferes with this. That is the condor catcher’s opportunity. He throws a lasso around the bird he has selected and lets the condor fight till he is exhausted. Then he throws another and another till Mr. Condor is tired out. That done, the bird is placed in a rough cage and conveyed to the customer.”

“That’s a lo-lo-lot of work for t-t-t-two d-d-d-dollars,” stuttered Ding-dong Bell.

“Any kind of work would be hard for you,” grinned Joe, which almost precipitated a fight. Nat checked it.

“Don’t roll overboard on this craft,” he said, “even if there aren’t any sharks about.”

“Humph! I don’t know that they are much worse than those condors,” was Joe’s comment.

As for Mr. Tubbs he heaved a sigh.

“If only I’d got a moving picture of that fight with the condors,” he said regretfully.

A SERIOUS ACCIDENT.

Shortly after the battle with the condors, the professor announced that, inasmuch as they were passing above a favorable landing place, he intended to make a landing. The spot selected was an open space beside a fairly large river, the glint of which could be plainly seen like a glittering ribbon beneath them.

Preparations for a landing were at once begun, and theDiscoverercommenced nestling down toward the earth. The professor announced that the first task of the evening would be to replenish the supply of gas in the bag from the hydrogen tanks.

The anchorage was made without a hitch, and theDiscoverermoored as securely as before; but in view of their experience of the night before,the travelers decided to have everything ready to “slip and run” in case the unpleasant experience was repeated.

As soon as the dirigible was secured, the task of adding to her depleted gas supply was begun. Two of the cylinders were dragged from their resting place and deposited on the ground, while the filling tube was made ready.

TheDiscovererwas anchored almost on the banks of the stream, a rapid one, with a rocky bottom and steep banks. While the others were working about theDiscoverer, Ding-dong Bell set himself to examining the gas cylinders.

They were about ten feet long and very slender in proportion to their length. They were heavy, too, as the tremendous pressure within them made it necessary to construct them of the thickest and strongest steel,—the very finest grade obtainable, in fact.

Ding-dong, with his natural curiosity, started lifting one, and found that to raise one end was all he could manage, and that only by dint of puffing and blowing.

Joe Hartley, looking around from his work on the filling tube at which he was assisting Nat and the professor, noticed what his chum was up to.

“Say, put that down! You’re not strong enough to lift it,” he jeered. “Those things aren’t for kids to monkey with.”

“They’re not, eh?” puffed Ding-dong valiantly, “I’ll soon show you.”

With a supreme effort he managed to raise the cylinder and move it a short distance.

“Here, stop that!” shouted the professor as he espied what the boy was doing. “Don’t you know those things are dangerous unless handled carefully? They’ll go off like a bomb under a sudden shock.”

“That one must have got a sudden shock when it saw Ding-dong,” scoffed Joe. “Most people do.”

It was too much for Ding-dong. He set down the cylinder and made a jump toward his tormentor. In doing so, his foot struck the cylinder which, as it happened, was only just balanced on the steepish slope leading down to the precipitous river bank.

The gas container began rolling downward. The professor gave a shout.

“Stop it! Stop it! Don’t let it fall over the river bank or——”

Before he could complete the sentence, Ding-dong was valiantly off after the rolling cylinder. He grasped it, but its weight and the velocity it had attained, caused it to evade him, and while he fell sprawling in an effort to regain his balance, the cylinder bounded on toward the brink of the steep river bank.

“Down on your faces! Down on your faces! Everybody!” fairly roared the professor.

They all obeyed blindly, not sensing the utility of the order, but realizing its urgency in the tones of the professor’s voice.

The cylinder gave a leap as it struck a stone, and then bounded over the edge of the river bank.

Bo-oo-oo-oo-m!

An explosion that shook the ground followed almost instantly. From the bed of the river a geyser of mud and water and rocks spouted up, showering everything for a radius of several yards. The explosion the professor had dreaded had taken place; but, by a miracle, no one was hurt. No doubt the fact that the detonation took place below the river bank accounted for this fact.

But the lecture that Ding-dong received! And he admitted that he deserved it.

“If you ever catch me mo-mo-monkeying with that h-h-high-diddle-diddle g-g-g-gas again you can ber-ber-ber-blow me up with it,” he declared.

“That ‘high-diddle-diddle gas,’ as you call it, is much too precious for that,” said the professor with a laugh he could not restrain, “but I shall adopt other measures.”

The boys had a good opportunity then to see the destructive force stored in one of those innocent-looking cylinders. Peering over the riverbank they could see that a great hole had been blown in its bed, and rocks riven and split in every direction.

“It’s as explosive as dynamite,” exclaimed Nat.

“It is, indeed,” said the professor. “The condition of that river bed gives mute evidence of that.”

“Just think what would happen if a spark should ever enter that gas bag of ours,” said Nat, with a slight shudder.

“We wouldn’t be able to think,” said Joe succinctly.

“Come, let us get back to work,” suggested the professor, “roll that gas cylinder closer to the filler tube and we will make the connections.”

Gingerly enough, as you may imagine, the lads rolled the cylinder toward the end of the filler tube, which now lay extended on the ground. The end of the tube was fitted with a union, which, in turn, was screwed on to the nozzle of the gas cylinder. Then the professor turned on the vapor, of whose power they had just had such a striking example.

With a hiss and a roar the gas poured through the filler tube into the bag, and several small wrinkles, which had developed in its upper surface, began to fill out. Two cylinders were emptied before the professor and Mr. Tubbs announced that the bag was full enough.

The evening passed off quietly. As before, the evening meal was eaten on the ground, and the adventurers utilized the cabin of theDiscovererfor sleeping quarters. Old Matco, the Indian, shared the meal, but refused to sleep within the cabin. Instead, he rolled himself up outside, on the substructure, like an animal of some sort. He had the true aborigine’s dislike of sleeping under a roof. It savored to him of a trap possibly.

The old fellow, now that he had become used to aerial navigation, did not seem to object to it in the slightest. He rather appeared to like it, in fact, and took a childish delight in watching the various operations that went on on board. It appeared that he had no intention of detaching himselffrom the party as yet, and indeed, seemed to have the liveliest gratitude to them for rescuing him from his unpleasant position at the end of the swinging rope.

The professor was of the opinion that Mateo might prove useful to them, so no move was made to urge him to return to his tribe. Indeed, they were now in the country of another tribe of Indians altogether,—so Matco informed them,—a tribe as warlike and resentful of the intrusion of white men as his own. This was not encouraging news, but the adventurers resolved to make the best of it, and guard against surprises by keeping a good watch.

Nothing occurred during the first part of the night, and when Ding-dong and Joe came on duty at midnight the professor and Nat had nothing to report.

“Don’t forget that time you shot at the mule,” warned Nat, addressing himself to Ding-dong.

“Oh, no danger of my doing that again,” Ding-dong assured him; “b-b-b-b-besides, they d-d-don’t have mules in this p-p-part of the country.”

“That’s good logic, at all events,” laughed the professor, who had heard the story of how Ding-dong shot at a mule in mistake for an Indian the night the Motor Rangers camped in the petrified forest in the Sierras.

Ding-dong and Joe marched up and down for some time, without anything occurring to mar the quiet of the night. But on what was, perhaps, the stuttering lad’s twentieth parade around the dirigible, he heard a queer, inexplicable sort of noise coming from the river.

“Indians,” was his first thought. But then:

“That sounds like somebody snoring, and Indians who were coming to attack us wouldn’t announce their presence like that,” thought Ding-dong.

The snoring noise continued. Joe was on the other side of the dirigible, while Ding-dong was on the river end of it.

“It’s a good chance to distinguish myself,” thought the lad, “after the mess I made of that gas cylinder this afternoon. I’ll just creep down there and see what on earth that racket is.”

He began tiptoeing softly toward the river bank, while the grunting, snoring sound still continued.

“I do believe it’s some one asleep down there,” exclaimed the lad to himself. “Maybe I’ll make a prisoner and get even on Joe for laughing at me.”

His mind full of these visions of glory, Ding-dong at last reached the river bank. Behind him he could hear Joe softly calling, but he made no answer.

“I’m going to investigate this thing alone,” he said to himself.

Lying flat on his stomach Ding-dong peered cautiously over the bank. He could see the gleam of the water about ten feet below him and—what was that? Two dark figures, that appeared to have bulk of considerable size, moving about in the water? One was larger than the other, andit didn’t take the boy long to make out that whatever the mysterious objects were, they were not human beings.

“Wonder if they’re panthers?” thought the boy with a sudden chill. But then he recollected that panthers are not in the habit of prowling about in the river bottom.

“And I never heard of a panther grunting,” considered Ding-dong, “I guess I’ll just——”

But what Ding-dong had “just” made up his mind to do was never revealed. The bank at the point where he had been leaning over, was cut out beneath by the action of the river, and in scrutinizing the dark objects he had leaned rather far over.

Suddenly the bank caved in, and amidst a shower of gravel, rocks and small bushes, Ding-dong went rolling down into the river.

Splash!

He landed in a deep pool, which, luckily for him, was of sufficient depth for him to avoid injuring himself. Still clutching his rifle he rose to the surface, puffing and blowing, and scrambled out.

“Well, here’s a fix,” thought Ding-dong, “just like my luck. I’m always getting in bad.”

All this time he had quite forgotten about the two dark, moving objects, to whom he owed his present predicament. But their existence was rudely recalled to him as, out of the darkness, something rushed at him, snorting loudly and angrily, and advancing like an express locomotive.

OVERBOARD!—1950 FEET UP!

The adventure might have had a serious termination for the lad if Joe, who had heard the collapse of the bank and the subsequent roar of the avalanche, of which the luckless Ding-dong was the centre, had not rushed to the river bank. Ding-dong, far too much astonished to raise his rifle, was standing stupidly gazing at the animal that was rushing toward him when Joe fired.

The creature gave a leap into the air, a queer kind of squeal, “like a stuck pig,” Ding-dong said afterward, and fell dead.

The shot aroused every one on theDiscoverer, and they came crowding down to the river, to find Joe and Ding-dong examining, by their electric pocket lights, the carcass of a large animal with a peculiarly shaped snout. Explanations ensued, and the professor announced that it was a tapir, a species of water animal common in South America.

Matco assured them that the meat of the creature was very good eating, and much esteemed by his people, and he was permitted to cut some steaks from Joe’s prize.

“If I hadn’t ter-ter-tumbled into that pool, though, he’d have been mer-mer-mine,” declared Ding-dong positively.

“I guess you’d have been his,” laughed Joe, “that is, if you didn’t move any quicker than you were when I saw you.”

“You watch me. I’ll do something great yet,” declared Ding-dong, with a positiveness that deprived him of his stammer.

“It must have been great the way you went over that bank,” laughed Joe unfeelingly.

The professor made Ding-Dong put on dry clothes, and then the interrupted rest of the travelers was resumed. The remainder of the night passed without incident, and a breakfast that tookplace soon after dawn was eaten amidst much rallying of Ding-dong on his adventure of the night before.

“I’d like to have seen any of the re-re-rest of you ber-ber-brave enough to have gone near that snor-snor-snoring,” sputtered the lad, valiantly helping himself to some more tapir steak, which was found to be as good as the old Indian had declared was the case.

At eight o’clock theDiscovererwas ready to resume her flight. She took the air without any accident, and under her replenished supply of gas rose with tremendous buoyancy. In fact, the descending plane had to be adjusted to keep her from shooting up too rapidly. No one on board had any desire to repeat that flight to the chilly regions of the upper air. As Ding-dong put it, “N-n-n-no more on my per-per-plate, thank you.”

“Do you think we shall sight the city to-day?” inquired Nat, as he and the professor stood on deck, just below, and in front of, the pilot house.

“Impossible to say, my lad,” was the rejoinder. “As I told you, the directions to reach it are vague in the extreme. We may have to cruise about for several days before we satisfy ourselves of its existence or non-existence.”

Nat looked disappointed. The boys, at a consultation among themselves, had about decided that that day ought to find them at their long-sought goal. Their expectation had been keyed up to such a height that delay was exasperating.

At noon the professor took his observations, and declared that, if the city existed in that part of the country, they ought to be within striking distance of it.

Excitement ran at fever heat. The boys could hardly leave the deck to eat a hasty meal. The field glasses were in constant demand. The professor announced that he would donate a handsome rifle to the first lad to spy a sign of the mystery of which they were in search.

If the boys had been eager before, this offer doubled their alertness. Ding-dong even climbed into the rigging till he was sternly ordered down by the professor.

“I thought if I got higher that I c-c-c-c-could see it s-s-s-sooner,” he explained.

“As we are now at a height of two thousand feet,” observed the professor, “I don’t think that a foot or two more of elevation would give you a very much extended view.”

It was about one-thirty when Mr. Tubbs, who was at the wheel, called the professor’s attention to something odd on the horizon. “It’s glittering,” he said, “and may be a ledge of quartz or something.”

“Can you still see it?” asked the professor.

“No,” was the rejoinder. “It just flashed up for an instant,—like a mirror in the sunlight,—and then vanished.”

“Keep a sharp lookout for its reappearance,” said the professor, with a hint of suppressed excitement in his voice.

“Shall I steer in the direction in which I last saw it?” asked the navigator of theDiscoverer.

“Yes. If the old documents are correct we are so near to the location of the lost city now that any clue is worth following.”

“Then you think that the glitter may have come from the city?” asked Nat.

“I cannot say,” rejoined the professor. “It may have been that, or it may have been the sunlight flashing, for an instant, on a hidden lake.”

“But wouldn’t a lake up here come pretty near to proving the existence of the city we are in search of?” asked Nat.

“How do you draw such a conclusion?” inquired the professor, with scientific exactitude.

“I thought you said the old documents said that the lost city was on an island in a lake.”

“Ah, yes; but there may be many lakes of the kind described in these regions,” was the reply. “Any more unusual signs yet, Mr. Tubbs?” he asked presently.

“No,” was the rejoinder; but the moving picture man’s keen eyes scanned the distance like those of a hawk.

It was an hour later that Nat, who had the glasses, set them down with an excited face.

“I can see a lake!” he cried. “At least, I’m almost certain it is one.”

“Where?”

The professor’s voice had caught the infection of the boy’s excitement.

“Off there—in the same direction that Mr. Tubbs saw a glitter. I only caught a glimpse of it, but it looked as if there was the glint of water in among those queer, sharp-pointed peaks off there.”

“Speed up the engine if you can, Master Bell,” said the professor, with an expression in his voice that the boys had never heard there before.

“We must investigate this at once and lose no time,” he went on. “The old documents say that the lost city is on an island in a lake set in the midst of mountains, over which there is no way of climbing but by the lost and secret roads of the Incas.”

“I guess you get the rifle, Nat,” said Joe, without a trace of envy in his voice, though.

“I w-w-w-wish I’d s-s-seen it f-f-first,” sputtered Ding-dong, who was leaning far out over the rail.

“You’d have shot a tapir with the rifle, I suppose,” scoffed Joe.

“No; I’d have shot a-a——”

“Good heavens!” cried the professor, as both Nat and Joe sprang forward.

The abrupt conclusion of the stuttering boy’s speech had been caused by the fact that, as he made it, he half turned, and losing his balance plunged over the rail.

TheDiscovererwas then nineteen hundred and fifty feet above the surface of the earth!

Back to Index Next