"A most pronounced seismic disturbance—I should say earthquake."

"I should say it was pronounced!" grunted Phineas Roebach. Being a fat man, he had fallen heavily. He was now rubbing himself tenderly where he had been bruised upon the hard ground. "This shock beats the one we had the other day."

"Not a shock, my dear sir," said Professor Henderson, quickly. "An earthquake is not, strictly speaking, a shock at all. Within the past twenty years science has learned to measure and to study earthquakes. If we have learned nothing else, we have learned that an earthquake is not a shock."

"It tumbled us about a whole lot, then, Professor," said Jack Darrow. "What would you call it, if not a shock?"

The phenomena being over for the time—as all could see—they returned to the cabin to complete their meal. Roebach had said something soothing to his Indians, but they, like Washington White, preferred remaining in the open. Wash sat down beside the cage of his pet rooster, and declared to the boys when they urged him to come in again:

"No, sah! I ain't hongry, nohow. An' w'edder de professor am right dat dese yer earthquakes ain't shockin', I kin tell yo' right now dat it shocked me! Nor I ain't gwine ter gib it no secon' chance ter tumble dat ruff down on ma haid—no, sah!"

Once more at the breakfast table, with the affrighted Indian squaw waiting upon them, the professor took up the topic of earthquakes again, in answer to Jack's observation.

"From the time of the ancients to the middle of the last century the phenomena of earthquakes were observed and described upon countless occasions," he said. "Yet even Humboldt's 'Cosmos', published as late as 1844, which summarized the then existing knowledge on the subject, did not suggest that earthquakes should be studied like other mechanical motions.

"The effects of the great Neapolitan earthquake of 1857 were so studied by Mr. Robert Mallet," continued the professor. "He disabused his mind of all superstition, threw away all the past mysteries, and attacked the problem from its mechanical side only. He believed that an earthquake was a series of shocks, or blows; but what he learned led other and later students to the discovery that an earthquake is not made up of blows at all."

"That's all very well to say," grumbled Mr. Roebach. "I'm pretty solid on my feet; but what was it but a shock that threw me down? Tell me that, sir!"

"Very easily explained," said the scientist, smiling. "Which will the quicker take you off your feet—a blow from, say, Jack's fist, or your stepping inadvertently upon a piece of glare ice? The ice, because it affords you so insecure a footing, is likely to throw you easier than a pretty solid blow; eh?"

"True enough," admitted the oil hunter, smiling at Jack. "Although Darrow looks to be a pretty husky youngster." "My point is this," pursued the professor. "An earthquake is a continuous series of intricate twistings and oscillations in all possible directions, up and down, east and west, north and south, of the greatest irregularity both in intensity and direction. This writhing of the earth—of the very foundations of the ground we walk on—caused our recent overthrow," concluded Mr. Henderson.

But the two boys were much more interested in the possibility of there being an active volcano in the neighborhood. The volcanic ash which covered the leaves and grass like road-dust assured them all that some huge "blow-hole" of the earth was near.

"I wasn't looking for no such things as volcanoes," said Andy Sudds, seriously, "when I shipped for this voyage. I reckoned volcanoes blowed mostly in the tropics."

"Alaska is a mighty field of active volcanoes," declared Professor Henderson. "But they have been mostly active on the Pacific coast, and among the islands which form a barrier between that ocean and Bering Sea. Islands have been thrown up, while others have sunk there because of volcanic disturbances, within the last few years."

"And I presume the earthquake and the volcanic eruption are closely connected?" suggested Mark.

"We may safely believe that," agreed the professor. "I am sorry my instruments are not at hand. I sincerely hope none was damaged when the Snowbird made such a bad landing."

"And I'd like to give the machine an overhauling at once to see just how badly she's damaged," Jack Darrow said, hastily. "What do you say, Mark?"

"I'm with you," returned his chum. "Can't we take Andy and Wash, Mr. Henderson, and go right up to that hollow and see what needs to be done to the flying machine? Perhaps we can get off for Aleukan by to-morrow if we hustle."

"If you boys think you can repair the damage done the machine in so short a time," agreed the professor, doubtfully. "But you know we must at least arrive at Aleukan in time to meet the train from Coldfoot. If the Snowbird cannot be launched again, we will have to see if our good friend here, Mr. Roebach, can fit us out with dogs and men."

"That I'll do to the best of my ability," said the oil man, rising. "But I'd better get out now and set my men to work. I am boring in a new place this week, and it looks promising. We are down a hundred and twenty feet already." They put on their outer garments and left the cabin. Although this was summer weather, there was a sting of frost in the air even as it neared mid-forenoon. But the sun was strangely overcast, and that might account for the drop in temperature.

"Disher day fo'git ter grow," complained Washington, rolling his eyes until, as Jack suggested, they could see only the whites of them in the dark, and the gleam of his teeth. "'Nstead o' bein' as sunshiny as it doughter be arter dat storm, it's suah growin' night fast! 'Taint a full-grown day, nohow!"

"Sort of stunted; is it, Wash?" chuckled Jack.

Andy Sudds here spoke decisively:

"I been tryin' to make out what it was, like feathers, a-touchin' my face. But it ain't snow. It's ashes!"

"Volcanic dust!" cried Mark.

"That volcano must be active again. That's what brought about the earthquake," said Jack. "And the darkness. What we thought was a fog over the sun must be a cloud of ashes."

"This ain't no place for us," declared Andy. "I wish we were back at that man's house."

"Or could find the Snowbird pretty soon," added Mark.

"We're going right for it—I'm sure of that," said Jack, cheerfully. And scarcely had he spoken when the four suddenly clung to each other, rocking on their feet! Washington White shrieked aloud, fell upon his knees, and it took but little to drag the boys and Andy Sudds with him.

"The whole world is done rockin' ergain!" wailed the darkey. "Dis is de end ob de finish!"

The vibrations of the ground grew in strength. The air about them seemed to shake. The darkness was so intense that Jack, holding a shaking hand before his face, could not distinguish its outline. And all the time the volcanic ash drifted down through the writhing tree-tops, while the boys and their companions were unable to stand erect.



CHAPTER XI

THE WONDERFUL LEAP

Unlike the former trembling of the earth, this experience gave no immediate promise of cessation. The world rocked on in awful throes—as though it really was, as the black man feared, the end of all material things. Jack and Mark rolled upon the ground in the grove of huge trees, clinging to each other's hands, but unable to rise, or to find their two comrades.

A rising thunder of sound accompanied this manifestation, too. And, after some stricken minutes, the boys realized that it was thunder.

With the earthquake and the storm of volcanic ashes, came an electric disturbance of the atmosphere, the like of which neither of the boys had ever dreamed. They had felt the "itch" of the electric current just before the 'quake. Now the hair on their heads rose stiffly like that on the back of an angry cat, and when Jack and Mark chanced to separate for a moment, and each put out their hands to seize the other, the darkness under the trees was vividly shot through for an instant with the sparks which flew from their fingers.

Washington White began to bawl terrifically at this display of "fireworks," as he called it.

His lamentations were well nigh drowned by the rolling thunder. This latter did not sound in ordinary explosions, or "claps," but traveled in rapidly repeated echoes across the skies. The thick cloud of ashes which obscured the sun and the whole sky was cut through occasionally by a sword of lightning; but mostly the electricity showed itself in a recurrent, throbbing glow upon the northern horizon, not unlike some manifestations of the Aurora Borealis.

But even this uncertain—almost terrifying—light was of aid to the boys; Jack, at least, remembered very clearly the way to the wrecked flying machine, and of course the old hunter was not likely to lose his way in as black a night as ever was made.

They struggled on between the intervals of pitch darkness, for the trembling of the earth had again ceased. The visitation had been much heavier than they had previously suffered.

"The best thing we can do," muttered Mark in Jack's ear, "is to fix up the Snowbird and beat it away from here just as fast as we can. This is altogether too strenuous a place for us, believe me!" "If we only can!" responded Jack, secretly as worried as his chum. "This is a pretty fierce proposition, Mark. Just think of our bonny Snowbird wrecked on her first voyage! It's mighty hard; eh, chum?"

But the duty before the two boys just then was to find the wrecked 'plane and see what could be done with it. The thunder continued to mutter and the intermittent flashes of electricity helped them somewhat in finding the way to the spot where the Snowbird had made her final landing. But the fall of volcanic ash continued and the darkness, between the lightning flashes, remained as smothering as before.

They reached the spot, however—seemingly a small plateau on which the huge trees did not encroach, giving them plenty of space for a flight if they were fortunate enough to get the Snowbird in condition for such an attempt.

There were both electric lamps and lanterns in the machine and Mark sent Washington White to light every one while he and Jack went over the wrenched mechanism. Andy Sudds stood guard with his rifle, or ready to lend a hand should the boys need him.

The storm in the clutch of which the flying machine had traveled so many hundred miles had wrenched her not a little. And the two landings she had made on the mountainside had done her no particular good. There was a broken plane, any number of wires to splice, and bent rods innumerable.

These were the more apparent injuries. But the more delicate machinery of the Snowbird required a thorough overhauling. It was absolutely necessary for them to have the use of a forge, and Jack had already learned that such an article was among the oil hunter's possessions at his camp.

They were a solid three hours putting to rights the machine and correcting the damage done to her smaller parts. Then, with several rods to be straightened and the light framework of the broken plane, that must be put in the fire for a bit, the party started down the mountain to Phineas Roebach's camp.

The four had left the plateau where the Snowbird lay and were just descending into the forest, carrying two storage battery lamps with which the easier to find their way.

There was no preliminary trembling of the earth or the air. There was an unheralded clap of sound—a sharp detonation that almost burst their ear-drums.

They did not fall to the ground; the earth, instead, seemed actually to rise and smite them!

A cataract of sound followed, that completely overwhelmed them. They realized that the huge trees were swaying and writhing as though a sudden storm-breath had blown upon them. Had a tornado swept through this wood no greater danger could have menaced them. Trees about them were uprooted; many bent to the earth; some snapped off short at the ground—great boles two and three feet through!

Jack and Mark, with Andy Sudds and the terrified Wash, would have been destroyed within the first few seconds of this awful upheaval had it not been for a single fortunate circumstance. When the cataclysm was inaugurated the first shock drove the four into a sort of hollow walled about with solid rock. Upon this hollow fell the first huge tree trunk of the flying forest—and it sheltered them instead of crushing them to death.

The four had but small appreciation of this—of either their temporary safety, or the perils that menaced them. Suddenly the thick air seemed to stifle them. They could neither breathe nor see. The lamps had been lost when they were flung—like dice in a box—into the rock-sheltered hollow.

As the huge tree fell across their harbor of refuge, they all lost consciousness.

What happened during the next few minutes—perhaps it was a quarter of an hour—none of the little party of adventurers ever knew. It was Jack who first aroused.

The whole world seemed still shrouded in pitch darkness. But he could breathe without difficulty and he sprang to his feet with a peculiar feeling of lightness as he did so.

But then he stumbled over Mark, and his chum came up, too, ejaculating:

"What is it, Jack? What is the matter now?"

"You can search me!" responded the other boy. "If this sort of business keeps on I shall wish, with Wash, that we'd never come to Alaska."

"You can wish it with me!" grumbled Mark. "Washington doesn't want to get back to Maine any more than I do right now, Jack."

"We must complete the repairing of the Snowbird," gasped Jack.

"And where are the rods—and the plane frame? And where are the lights?"

They held on to each other in the darkness of this over-shadowed hollow and neither boy was willing to speak for a moment. Then Andy Sudds staggered to them.

"I've lost my gun!" he ejaculated, with a quaver in his voice that was quite surprising.

"And we've lost our lamps; but we'll find 'em, Andy," said Jack Darrow, curiously enough becoming leader of the expedition right then, instead of the man. It wasn't that the old hunter was frightened; merely, he did not know what to do in this emergency.

"Do you notice—?" began Jack, seriously, and then stopped.

"Do I notice what, son?" responded Andy.

"I don't see how you can notice anything without a light," interrupted Mark querulously.

This statement seemed to arouse Jack's faculties completely. He did not continue his remark, but said:

"That's our first job; isn't it?"

"What's our first job?" asked the hunter.

"To get a light. We can't find the flying machine, nor get back to Roebach's camp, without light. Why, it can't be more than mid-afternoon, yet it's as dark as a stack of black cats in a coal-chute."

"And that's where I feel as though I'd been," declared Mark.

"Where?"

"Fighting the cats in the coal-hole. Ouch! I'm lame and sore all over."

"We're sure up against it," repeated Andy. "But there must be some way out, boys."

"Light is the first requisite," agreed Jack, more cheerfully. "Got any matches, Andy?"

"Plenty of 'em in a corked flask. I don't ever travel without matches, son," returned the old hunter.

"But matches won't show us the way to Roebach's camp," complained Mark.

"Don't croak, old boy," advised Jack. "Let's have that bottle of cosmolene I saw you tuck in your pocket there at the Snowbird."

"I was taking that to the professor. He said he would want it," said Mark. "What's it good for?"

"You'll come pretty near seeing in a minute, Mark," returned the quick-thinking Jack. "Here, Andy! let me have that woolen scarf you wear. You'll have to say good-bye to it—bid it a fond farewell."

"I'm sort of friendly to that scarf, youngster," said the hunter. "What's to be done to it?"

"It's going to become a lamp wick right here and now," declared young Darrow, promptly. "So! I've got the cosmolene smeared on it already. There! that's the last of it. Now a match, Andy."

"Joshua!" grumbled the hunter. "It is good-bye, I guess!" The match flared up. Jack touched it to the greasy woolen cloth. It began to burn brightly and steadily at once.

"Now, you all hunt around for the things we dropped. If we can find them we'll push out right away for the camp and the professor. You know he'll be worried about us, just as we are worried about him!"

With the light of the improvised torch flaring about them they saw what manner of place they were in. The huge trunk of the fallen tree had not entirely shut them in the hole. Mark got in position to climb out beside the tree-trunk.

There was a small, tough root sticking out of the bank above his head. He leaped to catch it with one hand, intending to scramble out by its aid.

And then the very queerest thing happened to him that could be imagined. The spring he took shot him up through the hole like an arrow taking flight.

He never touched the root, but over-shot the mark and disappeared with a loud scream of amazement and alarm into the outer world.



CHAPTER XII

THE GEYSER

"Somebody grabbed him!" shouted Andy Sudds.

"Oh, lawsy-massy-gollyation!" yelped the frightened darkey. "Massa Mark done been kerried up, suah 'nuff! I tole youse disher was de end ob de worl'."

But Jack, followed by the old hunter, sprang to the opening. How light they were upon their feet! The experience of moving shot this surprising thought through Jack Darrow's mind:

"I'm as light as a feather. I have lost half my weight, I declare I How can that be possible?"

Andy Sudds was evidently disturbed by the same thought. He cried:

"Somebody holt onto me! I'm going up!"

He did actually bump his head upon the tree trunk above them. But the next moment Jack scrambled through the opening, light and all, and came out upon the open ground.

"I'm here, Jack! I'm here!" cried Mark. "But what's happened to me?" "Whatever it is, it has happened to us all," returned his chum. "I seem to have overcome a good bit of the law of gravitation. Never felt so light in my heels in all my life before."

"What can it mean?" whispered Mark in his chum's ear. "It's magic!"

"You've got me," admitted Jack. "I'm not trying to explain it. But I know that the air pressure on me isn't as great as it was. I feel like we did when we were on the moon."

"Something awful has happened," suggested Mark, his tone still worried.

"We can be sure of that," Andy Sudds said. "What shall we do?"

"Find that stuff we were carrying and get back to the professor with it," said Jack, briefly. "Here! I see the storage battery lamp—or, one of them at least."

Mark at the same time stooped to pick up two of the lost rods. Jack found the lamp to be in good order and gave it to Andy. The torch was rapidly becoming exhausted.

"Come, Washington," urged Jack, "you hunt around, too. We must find the parts of the airship we dropped. If we don't find them we'll never get away from this place."

"And is we gotter go in de Snowbird, Massa Jack?" queried the darkey. "Has we jest gotter go in dat flyin' contraption? Gollyation! dis chile hoped de walkin' would be good out oh Alaska. He an' Buttsy jest erbout made up deir minds dat dey wouldn't fly no mo'. Fac' is, I had some idea ob clippin' Buttsy's wings so dat he couldn't fly no mo'!"

"You can walk if you want to," said Mark, crossly; "but I want to get away from this part of the country just as soon as ever I can. If the flying machine was ready I'd only wait long enough to get the professor and then we'd start."

"Guess we're with you there, Mark," agreed his chum, emphatically.

Meanwhile they were all scrambling about for the parts of the machine that had escaped them when the awful blast had knocked them into the hole and deprived them of consciousness. Fortunately none of the missing parts was very small and in twenty minutes of close scrutiny every piece was assembled. They did not find the second hand lamp, however.

"Now we must hurry back to the professor," Jack urged. "I know he will be dreadfully worried."

"Do you notice that it's getting lighter, boys?" remarked Andy Sudds.

"I believe you!" cried Mark. "The ash has stopped falling, too."

"I know that the air is a whole lot clearer," rejoined his chum. "And it's colder—or is it rare? Doesn't it seem like mountain air, Mark?"

"We've been half-stifled for so long I reckon the change to purer air is what makes it seem so peculiar," returned his friend.

Yet Mark was puzzled—indeed they all were more or less disturbed by the strange feeling that possessed them. Unless Washington White was an exception. The darkey went along blithely despite his expressed distaste for their surroundings, and as they came to the lower end of the grove of big trees, he began to run.

It had grown lighter all the time as they advanced. The cloud that had hidden the sun seemed to be rolled away like a scroll. The party could see all about them. The ashes lay from two to eight inches deep on the ground. Plants and shrubs were covered with the volcanic dust, and it was shaken from the trees as they passed.

Washington White bounded along like a rubber ball. He came to the plateau that overlooked the sheltered camp of the oil hunter. As the darkness retreated across the valley, the derrick and the shanties belonging to Phineas Roebach's outfit appeared.

Suddenly several gunshots rang out in succession, and the sounds startled the boys and Andy. Wild cries likewise arose from the valley. The commotion was at the camp.

"The professor is in danger!" cried Andy Sudds, and began to run.

His first leap carried him twenty feet; his second took him over a fallen tree-trunk six feet through.

"By Joshua!" ejaculated the startled hunter. "I've got springs in my shoes; ain't I?"

"What can it mean, Jack?" panted Mark, as the boys hurried on, side by side.

Jack Darrow had no answer to make. He was as amazed as his companions, and perhaps a little frightened as well.

They hurried after Andy and Wash; but the latter was far ahead. There was a second volley of gunshots and at that moment Wash came to the verge of the steep descent to the camp.

He beheld some half dozen Indians—all swart, lank, fierce-looking bucks—just at the point of rushing the oil borer's hut.

It was no time for explanations, nor for hesitancy. Wash, like the others behind him, believed that the Indians were making an attack upon their master, and the first thought of all was that Professor Henderson was with the oil man, and in peril.

"Gollyation! Git erway from dat dar door!" bawled Washington. The black man was as timid as a fawn as a usual thing; but he was devoted to the old professor and he had that feeling of gratitude for Mr. Henderson that overcame his natural cowardice. When the Indians, without giving him a glance, rushed at the door, and a single shot from the half-opened window missed them by ten feet, Wash uttered another yell and sprang to reach the descending path.

But this strange lightness of body that had overtaken them all during the past hour, played Wash a strange trick. Instead of landing a few feet down the steep way, he cast himself fairly into the air, twenty feet out from the hillside, and sailed down upon the startled Indians like some huge black buzzard.

The red men glanced up over their shoulders and beheld the flying man. The sight seemed to terrify them. With loud cries they started to run; but two of them could not escape the flying black man.

Wash landed sprawling upon their shoulders bearing both Aleuts to the ground. The door of the cabin was dashed open and Phineas Roebach ran out and seized the two red men before they could scramble up. The others were streaking it for the woods as fast as they could travel.

"Gollyation!" quoth Washington White. "Has dem rapscallawags done harmed de ole perfesser?"

"I am perfectly safe, Washington," said Professor Henderson, appearing at the door of the cabin. "And here are the boys and Andy. I am relieved to see you all alive again—I really am."

"Ain't this been a gee-whizzer of a storm?" queried the oil man, holding the two Aleuts at arm's length.

Already the boys and Andy were tearing down the steep path. They traveled like goats—as surefooted and as light upon their feet. Professor Henderson watched their career in evident interest. Then, gingerly, trying the feat curiously, the old gentleman sprang for a small boulder beside the cabin. He leaped entirely over it.

"Light! Light as air!" he murmured. "This is a most puzzling circumstance."

"Now, you fellows," growled Phineas, urging the two Indians along to the boring machine. "You'll get to work. I don't care if your friends have run off and left you to do it all alone. I tell you we've near struck oil. I know the signs." Then he gabbled at them a bit in their own language and the Aleuts took hold of the heavy bar by which the earth-auger was turned. "They left the job—the whole of them—when that last clap came," he explained to the boys.

But Jack and Mark were not much interested in the oil hunter's affairs. Only Jack remarked that he thought the fat man had been foolish to arm the Aleuts, or allow them to be armed. The Indians had evidently quite gone off their heads.

"They believe that we are spirits of the air," Professor Henderson told his friends. "That we are evil spirits. And I guess that Washington flying down upon them as he did will clinch that belief in their minds."

"Did you ever hear of anything like it before in all your days, Professor?" cried Jack. "Why, we can all jump like deer. I never saw anything like it."

Before the professor could reply there came a shout from the direction of the oil man's derrick. The two Aleuts, with their driver, had been working only a few moments at the auger. But perhaps the tool, so far down in the earth, had been ready to bite into the gas-chamber. There was a rumble from beneath that suggested to all that another 'quake was at hand. Then the Indians and the fat man started away from the derrick on the run.

The auger and piping shot out of the hole like stones driven by a catapult. Following the broken tools was a column of gas, gravel, water and mud that rose two hundred feet in the air. The earth trembled, and squawking like frightened geese, the Aleuts took to the tall timber, following the trail of their more fortunate comrades who had gotten away before. And they were not alone in their fright. The white men were likewise amazed and troubled by the marvelous geyser. It was as though the oil man had bored down to the regions infernal.



CHAPTER XIII

NATURE GONE MAD

The fat man came panting to the group surrounding Professor Henderson, just as fast as he could move his feet. And never before had the boys, or the professor, or Andy, or the black man beheld such an apparently heavy man get over the ground at such speed.

"A very mysterious thing," the professor was saying again—and he did not mean the roaring, spouting geyser that was shooting gas and debris a couple of hundred feet into the air.

Nor did he have time then to explain what seemed so mysterious to him. The descending debris threatened them all, and although they retired in a more dignified way than had the Indians from the vicinity of the spouting monster, they were all more or less disturbed by this new phenomenon.

Stones weighing from ten to twenty pounds were projected into the air, some of them crashing through the roof of the cabin when they descended. The mud and water grew into a pool, then a lake, completely surrounding the spot where the derrick had stood and where the geyser continued to spout.

"We surely must move out," the oil man said, in much perturbation. "My shop yonder seems to be a target for those rocks. There goes another!"

"And we have got to use a forge to weld and straighten these damaged rods!" Mark cried, worriedly.

"Sorry, boy. I don't believe any of us will be able to get at my forge till this shower of missiles stops," said Phineas Roebach.

"What needs to be done to the flying machine?" asked the professor, briskly. "Are you sure it can be repaired, Mark?"

"Very sure, sir," replied the boy.

"And you, Jack?" repeated Professor Henderson.

"We could fix it up all right before midnight," declared the other. "But we must have a forge."

"This geyser will stop playing after a bit, we will hope," said the professor, encouragingly. "If the flying machine is not past repair we need not worry. Nor need you, Mr. Roebach. We can all get away from this region if it becomes necessary."

"Ma goodness!" gasped Washington White, who had listened to this speech with his mouth ajar. "Don't you consider, Perfesser, dat dere has erbout 'nuff happened yere fo' ter make it seem quite necessarious dat we evacuate de premises sorter promscuous an' soon like? Why, I done was sure de end ob He finish was at hand when dat las' big eart'quake hit us—I suah did!"

"I must say I don't care to linger around here myself," muttered Andy.

"We must not lose our courage," said the professor. "Never before have I been in a position to study seismic disturbances so closely. I only regret I have not with me here the instruments I brought in the Snowbird. And we must somehow learn the location of that volcano which is in eruption."

"It's all right to learn the location of it," whispered Mark to Jack. "But if we learn that we'll be pretty sure to fly in the opposite direction—what do you think?"

"Believe me," said Jack, "I've got enough. The old professor is all right, but he doesn't think about danger when his interest in any natural phenomena is aroused."

The roaring of the geyser was a most unpleasant sound and the upheaval of the stones was more than unpleasant—it threatened danger to them. The vicinity of the oil-boring had been exceptionally free from small stones; but in half an hour one might have picked up a two-horse cartload weighing from ten to twenty pounds each.

Washington had run in and saved Buttsy in his cage, and they had all retired now to the little plateau from the verge of which Washington had made his famous leap to the backs of the two Indians. Phineas Roebach had released the dogs from the shed where they had been confined. There were twenty of the animals—three or four teams—fierce and intractable brutes as a usual thing, unless under the sharp control of their Indian drivers. But now they came whining and crouching to the feet of the human beings grouped together on the plateau.

The evening was growing clear; but the geyser continued to roar like the exhaust of some mighty engine and to throw off filth and evil-smelling gas. Professor Henderson stood there, wrapped in his furs, and penciled notes in his book with a grave enjoyment of the scene that made his companions wonder.

But Andy Sudds read signs other than those of which the professor made notes. Jack saw the old hunter watching the sledge dogs with a puzzled frown wrinkling his brow.

"What's the matter with you, Andy?" queried the youth.

"Them dogs," declaimed the hunter.

"What about them?" "They're plumb scart. All this disturbance and mystery has got in on them. They act just like they were seeing spooks."

"Spooks!" repeated Jack in surprise. "Do you mean to say dogs can see ghosts?"

"All dogs can smell out when things is going to happen," declared Andy Sudds. "They're better prophets than old women, you bet you! And these dogs act to me as though we hadn't come by the worst of our trouble yet."

Oddly enough it was Professor Henderson himself who took up the suggestion that more trouble was in the offing.

"It is my opinion, Mr. Roebach," he said, to the oil man, "that you had better remove such possessions as you can from this valley at once. And put your dogs somewhere so that they cannot run away like your Indians. If we are balked in attempting to repair the flying machine, these dogs and sleds are what we must depend upon."

"To escape from this country, you mean, sir?" asked Mark.

"To reach Aleukan and the valley where the Chrysothele-Byzantium is to be found," replied the professor, promptly.

But it was to run the chance of a rain of death to go down into the basin where the shop and cabin were situated. Further up the hillside the dogs' quarters had been built, and the sleds were there, too. The oil man and Andy Sudds looked at one another.

"All the stores are in the far end of the cabin," grunted Roebach. "And you can see what that geyser is doing to the shed where the tools are. There goes another stone through the roof!"

"If we could only get hold of that portable forge," said Mark.

"And that is what we must get," exclaimed Jack. "Is the door of that shanty locked, Mr. Roebach?"

"It's nothing but a skin door," replied the oil man. "But it's at the far side—fronting that old mud-slinger. Did you ever see the beat of that? That stone must have weighed fifty pounds."

But Jack Darrow noticed a certain fact. That was that the debris from the spouter was not shot so high as at first. Therefore, it was not being spread abroad so far.

Only small stones, now, were dropping around the tool shed. And the rear wall of the shanty was made of the most flimsy material.

Suddenly he slipped down to one side and got upon the level of the valley. Nobody but Mark noticed his movements for a minute, and to him Jack had given a warning glance.

The boy had crossed to the back of the tool-shed before the men of the party noticed his absence from the knoll.

"Look at that reckless fellow!" ejaculated the professor. "Come back here, Jack!"

But Master Jack was already at the shed. He tore away a part of the rear wall in a moment. The mud rained down upon him, but fortunately no rock came his way.

There was light enough yet for him to see inside the hut. Andy Sudds had already started after Jack, and when the latter dragged the small forge out of the shelter, the old hunter picked it up, flung it upon his shoulder, and trotted back to the highland.

"Come away! Come away, Jack!" cried the professor again.

But the youth stopped long enough to obtain a sledge hammer and other tools that he knew they should need. As he ran from the hut two stones shot out by the geyser crashed through the roof; but he escaped all injury.

He was plastered with mud from head to foot, however, when he regained the high land.

"It was worth it," Jack declared, laughing, when he was safe. "I want to get away from this neighborhood just as quick as we can. And if we can fix the Snowbird let us do it this very night and take our flight for other climes. We don't know when another earthquake or volcanic eruption will occur."

"Very true, my boy," admitted the professor, with a sigh. "At least, we will endeavor to repair the damage done to your flying machine at once. But there is much going on here that interests me."

Andy and Jack set up the forge and in a few minutes they had a glowing fire in it. Then the boys set to work welding the broken rods and straightening those that had become bent.

Meanwhile Mr. Roebach hauled out his sled and whipped the dogs into line so that he could gear them up. The canines acted badly because they were more used to their Indian masters. When the boys had done their work, however, the oil man was ready to transport them all up the mountainside to the plateau where the Snowbird lay.

His cabin was by this time riddled by the flying stones and everything in and about it was plastered with mud. It would have been foolhardy indeed to attempt to get at the provisions.

"You see," Mark said, "we are forced to get away in the Snowbird at once, or to escape to some town where we can get food. There isn't much left of our stores on the flying machine." "And what will Mr. Roebach do about his dogs? They must be fed," said Jack.

"He'll have to abandon them if he goes with us on the Snowbird," returned his chum.

It was now the long twilight of the Arctic evening. None of the party had eaten since breakfast and they felt the need of sustenance. If nothing else, this need of food would have hurried the party on to their destination farther up the mountainside.

As they advanced the roaring of the mud geyser diminished. The professor continued to be much interested in the condition of Nature about them as they climbed the hill. The uprooted trees, and the huge trunks broken off by the final upheaval of the earth, made the old gentleman look very serious indeed.

"There has been a mighty change in the face of Nature," he said thoughtfully. "You boys were saved from death by a miracle, I have no doubt."

"We were all knocked senseless for a time," Mark told him.

"Indeed? And so were we at the camp. All of us lost consciousness. Dear, dear! what happened during those minutes that we were all unconscious? Something of the greatest importance—some great change took place that now we can scarcely understand." "And what do you make of that over yonder?" queried Jack, suddenly pointing toward the northern horizon.

A deepening glow had appeared in that direction. Rapidly it increased until there appeared above the horizon the edge of a huge disk. Its light was mellow like the moon's; but whoever heard of the moon rising in the North?

"What can that possibly be, Professor?" cried Mark as they all gazed in wonder at the rapidly increasing body rising into complete view.

Professor Henderson shook his head slowly. For once he was surely at a loss to explain a scientific phenomenon. The huge globe, evidently reflecting palely the sun's light, mounted upward more rapidly than the moon ever crossed the heavens.

"All nature has gone mad!" gasped Professor Henderson at length. "Have we discovered a new celestial body? I never heard of such a thing—so near to us, too! Come, hurry on, boys. Let me get and mount the telescope. This new mystery must be solved."



CHAPTER XIV

ON THE WING AGAIN

There was no member of the party who was not amazed and disturbed by the strange happenings of the last few hours. The earthquake and volcanic disturbances, followed by the outburst of the geyser, and now capped by the appearance of a new and wondrous planet on the northern horizon, were happenings calculated to make more than Washington White shake with terror.

What Professor Amos Henderson really thought about this new celestial body it would be hard to tell. While the others chattered in their amazement—after his first statement—he remained strangely quiet.

But the moment the party reached the spot where the flying machine rested he went at once to the locker where he had stowed the very powerful telescope that he had insisted upon bringing with them from home. With Washington's help he was an hour in setting up the telescope and properly adjusting it, while the boys and Andy worked steadily upon the repairing of the flying machine. Roebach had loosed his dogs again and threw them the last bits of fish he had for them, and they were fighting over the putrid flesh at one side. The oil man watched the repairs with interest. He had agreed to travel as far as Aleukan with the party and there hire fresh Indians and sleds, hoping to find these dogs on his return. He had to have assistants and provisions before he could go on with his work for the Universal Oil Company.

"Merely that yonder oil-shoot turned into a mud-bath doesn't feaze him," chuckled Jack to Mark. "Earthquakes and volcanoes don't seem to bother that chap any more than they do the professor."

"Just watch him now," suggested Mark, suddenly.

"Watch who—Roebach?"

"The professor," explained Mark.

The old gentleman was certainly deeply interested at that moment in his study of the great pale globe that was rising toward the zenith so much more quickly than any moon that the boys had previously seen. The professor was crouched at the mirror of the telescope gazing into it through the powerful lens. Suddenly he threw up his hands and staggered back from the instrument, turning a pallid face upon his companions. "What done happened yo', Perfesser?" cried Washington White. "What done skeer yo' now? Dis suah am de startlin'est place dat we ebber got into. Gollyation! Ain't dat moon risin', dough?"

"It is no moon!" declared the professor.

"A most mysterious thing," Mark said. "Is it some great planet out of its orbit, sir?"

"It is a planet—of course it is a planet," admitted the professor, going back to his telescope with eagerness.

"And how light it is getting—almost like day," said Jack. "No moonlight was ever like this."

"Why, we're not as far away from that planet as the moon is from the earth," said Mark. "Suppose it bumps us?"

"All the more reason for our getting the Snowbird into flying shape," responded Jack. "Maybe we'll be able to escape the bump!"

"You can laugh," grumbled Mark. "But I don't like the look of that thing."

"Evidently the professor does not like it, either," agreed Jack. "See him now."

Professor Henderson was gazing first into the telescope and then drawing upon a paper before him. For several minutes he was thus engaged. Finally he beckoned the boys to him.

"What do your eyes tell you that looks like?" he demanded of Jack and Mark, pointing to the outline he had drawn upon the paper.

The boys gazed on his drawing in surprise. It was Jack who exclaimed:

"Why, Professor, that looks a whole lot like an outline map of the Hudson Bay Territory, Canada, and Newfoundland. There's the mouth of the St. Lawrence, sure! What are you doing?"

"I have been drawing," said the gentleman, solemnly, "an outline of what I see upon that luminous body floating there in space," and he pointed a trembling finger at the strange planet.

"Impossible!" cried Mark.

"I do not think I am losing my mind," said the professor, testily. "It remains, however, that the outline of certain bodies of water and of land upon that luminous globe seem to be the exact counterpart of land-bodies and water-bodies on the Earth."

"But what does it mean?" questioned Jack.

"If I knew that," grumbled the professor, returning to his instrument, "I should feel better satisfied."

That some strange—some really wonderful—change had taken place in their physical surroundings, too, there could be no doubt. But what it was the boys could not imagine. Of one thing they were sure, however: The law of gravitation had been partly overcome. And a second fact was discernible: There was a surprising rarity to the air they breathed, and had been since the fall of volcanic ashes had ceased.

In lifting the heavier tools they handled it was noticeable that they seemed lighter. And Andy Sudds surprised them all, when it became necessary to roll a log out of the way of the flying machine, by seizing the heavy timber and lifting it with the ease with which one might lift a small sapling.

"We've all become strong men—professional strong men," gasped Jack. "Wash is the champion jumper and Andy beats old Samson, I declare! What do you make of it, Mark?"

"If the professor cannot explain it, don't expect me to do so," returned his chum.

"It am de seriousest question dat has ebber come befo' us," declared Washington, looking wondrous wise. "Disher jumpin' has always been in ma fambly, howebber. We had some great jumpers down Souf befo' de War."

The boys hurried to finish the repairs. It was some time after midnight when they pronounced the Snowbird again ready for flight.

The professor had to be urged more than once to leave his telescope, however; and then he insisted upon setting it up on the deck of the flying machine. He would not discuss the situation at all; but his serious visage and his anxious manner betrayed to them all that he was disturbed indeed by the strange, pale planet he had so closely examined.

Mr. Roebach turned loose his dogs again and climbed gingerly aboard the flying machine.

"I've never been up in the air," he said, "and I must admit that I am somewhat more afraid of a flying machine than I am of an earthquake."

"No more earthquakes in mine, thank you!" cried Jack. "I'd rather sail on a kite than go through what we did yesterday."

They had studied the chart and laid the course for Aleukan without any difficulty. Now Jack strapped himself into the operator's seat and the others took their places, Washington White stowing his rooster carefully amidships as he had before.

Jack started the motor and the Snowbird began to quiver throughout her frame. He touched the lever by which the propellers were started. With a whir and a bound the flying machine left the earth.

Never had it sprung into the air so quickly before. It shot up at a sharp incline and was over the tree-tops in a breath. The indicator registered eighty miles an hour before the plateau was behind them. Then the pointer whirled to ninety—to a hundred—to a hundred fifteen miles an hour, and both Jack, in the pilot's seat, and the others gasped for breath.

Faster than when shot out of Professor Henderson's catapult the Snowbird winged her way into the northwest. Jack managed to keep her on an even keel. But he had the same feeling that he would have had, had he been hanging to the bit of a runaway horse.

Indeed, the Snowbird was practically out of his control.



CHAPTER XV

A PLUNGE TO THE ICE

Jack Darrow was a youth less likely to be panic-stricken than his chum; but just as Mark Sampson had lost his head for a few minutes on the occasion when the Snowbird was tried out, so Jack was flustered now.

The flying machine shot up at such a tangent, and so swiftly, that he was both amazed and frightened. The speed indicator showed a terrific pace within a few seconds, and when Jack first tried to reduce the speed he learned that the mechanism acted in a manner entirely different than ever before.

The motor made more revolutions a minute than she was supposed to make when pressed to the very highest speed. When he had raised the bow of the flying machine at the start she had shot up almost perpendicularly into the air. He was afraid she was going to turn a back somersault.

As he depressed the planes he found that it took much more depression to bring the Snowbird down to even keel. And the rapidity with which they left the ground and soared upward was in itself enough to shake Jack's coolness. Suddenly (being furnished with the professor's patented ear-tabs) he heard that gentleman calling to him from below:

"Get back to the five-hundred-foot level—quick!"

Light as his head had become, and confused as he was, Jack realized what these words meant, and he knew enough to obey without question. He brought the Snowbird down the air-ways on a long slant and at a swift pace. He realized that, as they descended, he was able to breathe more easily and his head stopped ringing. For some moments he had felt like an intoxicated person in the vastly rarified plane of the upper ether.

The professor staggered to the young operator's side.

"Danger! Danger above, boy!" he gasped. "We cannot cross these mountains while—while the air is so thin."

"But we need not cross them to reach Aleukan?" suggested Jack, speaking with some difficulty himself. There was a pain in the region of his lungs and he saw that Professor Henderson was very pale.

"That is a fact," panted the professor. "Descend, Jack. Make it two hundred feet. Be careful!"

For as the youth depressed the planes again the ground beneath seemed to fairly leap up to meet them.

"What do you know about that?" gasped the young aviator. "She—she doesn't work at all like she used to."

"Less attraction," declared the scientist.

"What do you mean, sir?" cried Jack. "Has the law of gravitation lost its power over us—and over the flying machine?"

"There is a difference—a great difference," proclaimed Professor Henderson. "The power of attraction is lessened mightily."

"What does it mean? What can it mean?" murmured the disturbed youth.

"I suspect—I fear—"

What the professor would have said was not spoken then. Mark interrupted by shouting:

"Look ahead! Look ahead! What is that—a river?"

"There is no river of size in this locality," declared the professor, quickly, training his glasses on the white streak that appeared on the ground ahead.

Phineas Roebach struggled forward to the operator's bench. He gasped:

"This is worse than I ever thought flying could be. Do you have to go so fast? I cannot get my breath. Hullo! That's the glacier ahead. The dog trail to Aleukan follows the ice for more than fifty miles."

"A glacier it is," agreed Professor Henderson. "It seems pretty smooth, Jack. You can descend still farther."

That they were all suffering from the rarity of the atmosphere was plain. It seemed as though the envelope of breathable air surrounding the earth had suddenly become vastly rarified. If the. atmosphere had been so changed all over the globe it would be a catastrophe unspeakable.

"We certainly can't cross these mountains—nor the Rockies," groaned Jack. "How are we ever going to get home again?"

"If the air remains as it is now?" asked Mark. "You're right! We're imprisoned in this part of Alaska just as fast as though we were caged behind iron bars."

"If we only had some of those torches we used on the moon," said Jack.

"What will we do, Professor?" begged Mark.

"Let us not lose hope," responded the old scientist. "First we will get to Aleukan and see if our provisions have been brought over from Coldfoot."

"I'll bet they haven't been brought across the range," said the pessimistic Mark. "If the air everywhere is so rarified the men would die crossing the mountains." "Think of the people living on Mt. Washington—and other heights!" cried Jack, suddenly. "Why, they will be snuffed out like candles. It is an awful thought."

"We will hope, at least, that this fearful catastrophe is local," said the professor, seriously. "Have a care, Jack! Don't dip like that. We do not want to descend here."

It was extremely difficult to manage the Snowbird, for she answered to the levers so much more quickly than before. The air pressure on the craft was so slight that at the least touch she mounted upward like a scared quail! The speed of the aeroplane had to be reduced, too; they traveled scarcely forty miles an hour.

On either hand as they winged their way over the great river of ice (it was quite four miles broad) sharp cliffs arose, guarding the glacier. These cliffs ranged from two hundred to a thousand feet high.

The professor, at once interested in such a marvel of nature, begged Jack to reduce the speed even more. They merely floated above the cracked expanse of whitish-green ice for some minutes.

"That's what the earthquakes did for it," said Phineas Roebach. "You see those crevasses—and some of 'em mighty deep? Well, they weren't here the last time I came this way." "She is in motion again, perhaps," suggested Professor Henderson.

"It ain't been in motion for ages—or, so the Aleuts say," responded the oil hunter.

"But there looks now to be some sagging forward. There is a crevasse splitting the glacier from wall to wall," proclaimed the scientist.

"We'd never be able to sled over this trail in the world!" cried Mark. "How would you pass such a yawning gulf as that?"

"It beats me what's happened here since I was across last," muttered Roebach, scratching his head in bewilderment.

The yawning ice was right beneath the flying machine. It was a hundred yards across at the surface. They seemed to be looking down for five hundred feet, or more, into its greenish depths.

Jack had turned the Snowbird's prow and they were drifting toward the western cliffs which guarded the glacier. Here the rocky heights were at least seven hundred feet above the ice.

Out of a crack in the high wall—from its eyrie without doubt—a huge female eagle suddenly shot down toward the drifting aeroplane. The flying machine seemed not to startle the great bird at all; it only angered her. Perhaps she had young up there in the cliff and she feared her hereditary enemy, Man, was coming on wings to deprive her of them.

With a scream of rage the eagle dashed herself directly into the face of Jack, strapped to the operator's seat. For once Andy Sudds had not his rifle at hand; and, the attack was so unexpected, it is doubtful if he could have come to the rescue in season.

With beak and claws the bird endeavored to tear at the youth's face. Jack jerked loose the transmitter and beat it to pieces over the bird, but without making her desist.

Again and again the feathered creature darted in, claws expanded and beak snapping. With one talon she raked Jack's right arm and shredded the heavy coatsleeve, the sleeve beneath, and scratched his arm. The next instant her iron beak snapped upon his left hand.

Jack Darrow was plucky, but the pain of the wound brought a scream to his lips. It was answered by the wild shrieks of the eagle.

And then, ere any of his friends could reach him (for the professor had gone back to the cabin), the boy, fighting for his sight—indeed, for his very life—by some unfortunate movement depressed the planes. Like an arrow from the bow the Snowbird shot downward into the yawning crevasse which split the glacier from wall to wall. With a yell of terror Mark Sampson sprang forward to the operator's bench. But he was too late—if he could have done any good at all.

The Snowbird swung to one side. Her right forward plane crashed against the wall of ice, shattering some of the hard crystal. But on the rebound the fluttering flying machine sank lower. Jack tried to make her rise. She refused to obey the lever.

And then, with a suddenness that made them all catch their breath, the Snowbird plunged down into the ice-gulf and ended her dive with a terrific crash on a narrow shelf at least two hundred feet below the surface of the glacier.



CHAPTER XVI

PROFESSOR HENDERSON REVEALS THE TRUTH

The force with which the flying machine had plunged into the chasm in the ice was sufficient to smash her keel-fin to bits. There was other damage done, too—how great this damage was the boys and the professor could not immediately discover.

They were all alive—that was one thing to be thankful for. And Washington White's Shanghai, aroused from sleep by the disturbance, began to crow vociferously.

The Snowbird was wedged into a very small space upon the ledge of ice. At first view it was quite certain that she could not be launched again from this position by any ordinary means. And the steering gear was practically a wreck, so that she positively must be repaired before attempting another flight.

Jack's wounds were dressed by Andy first of all. Mark and the professor made some attempt to look over the wreckage. The disaster was so great that Mark gave up hope.

"We're done for now!" he cried. "The poor Snowbird is a wreck. And how are we ever going to get out of this hole?"

"Hush, my boy!" admonished the professor. "Don't lose your grip. This is truly a serious predicament; but we have been in tight places before."

"Nothing worse than this," grumbled Mark. "Nor half so bad. How are we going to get out of this chasm? Why, just as Washington says, we've been swallowed up like a duck gobbling a June bug."

"This is certainly a bad situation," Phineas Roebach remarked. "But, as the professor says, it isn't the worst that might happen."

"What worse could happen?" demanded Mark.

"Hold on! Don't you step too near the edge of this shelf," warned the oil man. "If you step off and fall clear to the bottom of this crevasse you'll probably find that a good deal worse than our present position. B-r-r! Isn't it cold?"

Two hundred feet below the surface of the ice river was indeed a cold spot. Washington produced all the warm clothing there was aboard the flying machine and all hands were glad to bundle up. Then the professor suggested that the black man prepare some hot drink and a ration of their food, while all gathered in the cabin for a discussion as to their future course. "Our perilous situation is apparent," said Professor Henderson, quietly. "But there is always more than one way out of a serious predicament—sometimes there are a dozen ways."

"I'd like to hear of a dozen ways of getting out of this hole," murmured Mark Sampson.

"Mr. Roebach," said the professor, ignoring the youth, "what do you say? What is your advice?"

"The sun will be up in an hour, or thereabout. It's pretty dim down here. Let us wait and see what daylight shows us," was the oil man's reply.

"The moon—the other moon—is just appearing," Jack said. "We'll have light enough in a few minutes."

"Two moons! what do you think of that?" cried Mark.

"Are you sure, Jack?" queried the professor, eagerly.

"I just saw it peeking over the eastern cliffs while Andy was patching me up." He carried one arm in a sling, and his other hand was bandaged.

"Then I must take an observation," ejaculated the professor, and seizing some instruments he had arranged on the table he went out to where the powerful telescope was adjusted.

"He's forgotten all about gittin' out of this hole in the ice," said Andy. "I, for one, think we'd ought to take axes and begin to cut steps up the wall. How else will we escape from the place?"

"The poor old Snowbird cannot be repaired in a hurry, that is sure," muttered Mark.

"And this is no place to remain for fun," agreed Jack. "Suppose the walls of the crack should shut together—where would we be?"

"Just about here, for fair!" said Phineas Roebach, grimly, while Washington uttered a most mournful wail.

"Gollyation! Is we gotter be squeeged ter deaf in disher awful cavernarious hole? Dis is suah a time ob trouble an' tribbilation."

They heard an exclamation from the professor and Jack led the way to the open deck of the crippled flying machine. By chance the Snowbird in landing had remained upright, her decks on a level. They found the professor bending over some further calculations on a great sheet of paper. Here, two hundred feet below the surface of the ice, the heavenly bodies all looked brighter and more distinct than they had while the aeroplane was in flight above the ground.

The strange new planet had not yet gone out of sight. From the east the old moon was soaring steadily. There could be no mistaking the two orbs, now that both were visible in the sky at once. The new planet or moon was much larger than the real moon.

"What do you suppose that great planet is?" queried Jack.

The professor looked up from his calculations. His face was very pale; his eyes glowed with excitement. The boys had seldom seen the old gentleman so moved.

"You are right, my boy. A planet it surely is," he said to Jack.

"But why have we never seen it before?" demanded Mark.

"For a very good reason," returned the professor, solemnly. "We were never in a position before to behold that planet, save on two occasions."

"Then we have seen it twice before?" asked the puzzled Jack.

"On two occasions we have been enabled to stand off, as it were, and look at that planet as though we were inhabitants of another world—when we went to the moon, and when we went to Mars."

"What do you mean, Professor?" cried Mark.

"It's the earth!" exclaimed Jack Darrow. "It's the earth! We have left the earth—is that it, Professor?"

The old scientist nodded. Phineas Roebach snorted his disbelief, while Washington White gave vent to his trouble of mind most characteristically:

"Goodness gracious gollyation! De fat am suah in de fiah now! We'se done los' de earf an' Buttsy an' me will nebber see our happy home no mo'."

"Oh, Professor! how could we have left the earth?" demanded Mark. "See! we are standing upon it now; at least, this glacier is an ice-river of Alaska, and Alaska has not been wiped off the map!"

"But that is exactly what has happened to it," said the professor, earnestly. "At least, a part of Alaska—we do not know how much of that territory, or how much other territory with it—is no longer a part of the sphere called the earth."

Phineas Roebach looked at the old scientist as though he thought the latter had taken leave of his senses. But Jack Darrow leaped to the right conclusion.

"You mean, sir, that the earthquake and the volcanic eruption have torn away some great fragment of the world, and we are on it?"

"That is what I mean."

"We are floating in space, then—an entirely new world? And that is the old world shining there in the sky?"

"That is what has happened, Jack," declared Professor Henderson, with solemnity. "I suspected it when we first felt the lightness of the atmosphere. I was convinced when I found the ether envelope of this new world—this island in the air, as it were—was so thin. My calculations regarding the rising of the moon, and the outlines of objects upon the great globe hanging yonder, prove to my mind conclusively that the awful cataclysm we endured, when we all completely lost consciousness, was the time when the eruption occurred, and we, with this great fragment of the earth, were blown out into space."

"It can't be! it can't be!" shouted Phineas Roebach. "We've lost our heads, perhaps; but we haven't lost our hold on the earth. It's nonsense!"

"I sincerely wish I could feel that same confidence, Mr. Roebach," said Professor Henderson, drily. "These instruments of mine, however, cannot lie. It is a simple calculation to figure that the moon, now just risen, is thousands of miles out of her course, if we are still on the earth. No, Mr. Roebach, I am stating the exact truth when I say that we have been blown off the earth by that awful volcanic eruption, and that we are now floating on a torn-away world, or a new planet, in space, doubtless hanging between the earth and the sun. We are as unsafe as though we were on a wandering star, or meteor—only this island is not afire. But in time we shall fall into one or the other greater bodies of our system—of that end there can be no possible doubt."



CHAPTER XVII

ON AN ISLAND IN THE AIR

The stern and uncompromising statement of Professor Henderson relating to the awful fate that had overtaken his friends and Phineas Roebach was so uncompromising—almost brutal—that not a word was spoken for several minutes.

Even Washington White was dumb. The fact that the fragment of the earth on which they were imprisoned was floating miles above the globe, in the rarified atmosphere of the outer universe, and that they were at that moment able to look up and see the great, calm, palely glowing sphere which had been their home, rolling across the arch above them—all this was too awful a mystery to be grasped immediately by the professor's companions.

Jack Darrow, whose mind was the keenest of any, was the first to break the depressing silence. And he spoke in an awed tone that showed how fully he realized the horror of their situation, if nothing more.

"Then, Professor, we are at the mercy of Chance—at any moment this fragment of the earth may fall again—or be propelled into the sun?"

"We are in the hands of Providence, my boy," replied Professor Henderson, reverently.

"The fact remains that we are totally unable to help ourselves," said Jack, firmly. "Even could we repair the Snowbird, and get her out of this crack in the ice, we could not fly to the earth. Between us and the earth lies a portion of the universe that has no atmosphere—no breathable air—like that envelope which surrounds the moon. Am I right?"

"Practically correct, I believe, Jack," responded the aged scientist.

"But," cried Mark, at last getting his speech, "how can such a thing be possible? Blown off the earth! Why, we'd simply go up in the air and come down again."

"Now you're talking sense, young fellow," muttered Roebach, still rubbing his head as though stunned.

"Not if we were blown far enough to get beyond the earth's attraction—or to get so far away from that body that the sun's attraction counterbalances that of the earth," replied the professor, calmly.

"And why do we not fall off?" asked Mark.

"We do come pretty near falling off," returned Professor Henderson, grimly. "I should think you could see that, Mark."

"Our lightness!" Jack cried. "Washington's jumping and the lightness of all objects! I see. This fragment of the earth—this island in the air, as you call it, Professor—is large enough to possess some powers of attraction of its own; but not as much as the earth. I wonder how large it really is?"

"That is a matter for future discovery," returned the scientist, with some eagerness.

"My goodness me!" groaned Mark. "He really enjoys the situation."

"No man has ever been in such a position before—I am convinced of that," declared the professor. "Were it not that you are all in as perilous a situation as myself, I would not worry about this condition. It is marvelous, and the situation affords me opportunity to learn many things that science has only guessed at before."

"Don't talk that way!" wailed the oil man, suddenly. "You'll make me believe in this island in the air business, and I know it's craziness!"

Nor could anything the professor say convince the oil man that there was any common sense in the plain statement of their situation. It was beyond Phineas Roebach's powers of imagination.

As for Washington White, he could not understand the affair anyway. But he always accepted the professor's words as Bible truth and he had no doubt of the surprising fact.

"We was bound ter git inter trouble, Buttsy an' me, w'en we agreed ter start on any sech foolish journey. And de consanguinuity ob dis 'casion assuages me ob de fac' dat we'se only got our come-upance fo' bein' so reckless. Now we is nebber gwine ter see de State o' Maine again, 'ceptin' it is froo de perfesser's telescope."

His complaint received little attention from Jack Darrow or Mark Sampson; they were too deeply interested in the explanation of the catastrophe that had overtaken them.

"How big a slice of Alaska do you suppose has been blown off the earth, Professor?" asked Jack.

"It may be much more than a part of Alaska," replied Mr. Henderson. "Until we have a chance to explore the region more thoroughly I cannot even guess the answer to your question."

"And how can we explore it?" demanded Mark, quickly. "If there is no atmosphere on these mountain tops which we see—or, which we saw before we fell into this crevasse—we cannot get off this plane. We are imprisoned on the low ground. The lack of air will keep us from climbing the mountains."

"Or from flying over them if we can get the Snowbird into commission again," added Jack. "Every necessity brings its own invention," said the professor. "Let us not despair. We may yet find some means of traveling all about this floating island."

"And what will you do if you get to the edge—fall off?" exclaimed Andy.

He likewise accepted the professor's words at their face value. He never thought of doubting either the aged scientist's honesty or his learning.

"If the attraction of this fragment holds good here, it will hold good all over its surface," proclaimed the professor. "We have no means yet of weighing this torn-away world we are on—this new planet. But it must be of considerable size. Otherwise it would not hang here in space as it does."

"And without movement?" cried Jack.

"I believe it is circling the earth as the earth circles the sun. We are practically on a second moon—only the fires in the heart of our young planet are not dead."

"I should say they were not dead, if that geyser Mr. Roebach opened up is any sign of life," remarked Mark.

"You are quite right, my boy," said the professor, cheerfully. "The volcanic disturbance brought about great earthquakes. These, however, were merely warning symptoms. We did not know it, however. Finally the great mass of gas formed beneath the earth's crust somewhere about the Alaskan coast of the Arctic Ocean, we will say, exploded and forced an enormous portion of the crust into the air.

"No wonder we lost consciousness," he continued, with enthusiasm. "We were probably traveling faster than human beings ever traveled before. The entire nature of the portion of the earth we stood upon was changing. Our atmosphere was changing. We were shot into the sky and in a flash were beyond the common influence of what we call the law of gravitation."

"But what a hole we must have left in that part of the world!" gasped Jack. "Think of it! The seas must have run right into the chasm and made the bottoms of the old seas dry land."

"Not at all! Not at all!" returned the professor. "Think what a mighty globe the earth is. Remember that there are valleys miles deep—mountains miles high! There are holes in the ocean which have remained unfathomed to this day! The surface of the earth is very, very rough. What keeps the oceans from overflowing the land and filling all those sinks and valleys that are deeper than the ocean bed? Merely the power of attraction which the earth exercises.

"Suppose explorers hurry to the scene of the great earthquake—to the edge of the vast crater which the blowing-out of this portion of the earth has left. What will they find—a hole filled with the waters of the Arctic Ocean?"

"And why not?" demanded Jack, stoutly.

"Because the evidence of our own eyes assures us that such is not the case," declared the professor, pointing again to the rolling planet they had so strangely left. "The earth is not overbalanced. She still rolls on her proper course, I have no doubt. The breaking away of this island is not a serious matter to the earth as a whole. The contour of the hemispheres is not changed. I showed you how I had traced the outlines of the continent before, even, that I was confident we had been blown off the earth.

"No. Those who explore the region which we have left will find hills and valleys as before—awful crevasses, perhaps, and steaming cauldrons of water and mud. No vegetation, of course, but snow has perhaps fallen on some parts of the raw scar, and those explorers may be able to travel through a region that was—a week ago—the bowels of the earth!

"The foundation rocks of the earth are left raw and exposed, as they may be after some terrific land-slip. But nothing more. We sail here high above the earth——"

"Looks like we were below it now," muttered Mark.

"But if we have been observed from the earth—and of course those great telescopes at the Lick Observatory have found us out ere this—we will appear above her," said the professor. "Many things about this strange happening we may only guess at. Of one thing we are sure—we have air to breathe, water to drink, there are wild animals to kill for food, vegetation exists; we are, in fact, upon a miniature world which is not much different from that we have left—as yet, at least."

"All that sounds mighty fine," interrupted Phineas Roebach. "And I expect you believe it all, Professor Henderson. But there's just one thing that I believe: We're down here, two hundred feet or more from the top of this ice wall, and the game, or the vegetation, or anything else, isn't going to help us much while we're here. What I want to know is: How are we going to get out of this crevasse?"



CHAPTER XVIII

IMPRISONED IN THE ICE

The oil hunter's demand was like a bomb thrown in their midst. The boys had been so deeply interested in the professor's relation of facts, and in the scientific phase of their situation, that the more practical questions of their mere existence on this island in the air had not before held their attention for long.

"We've got to find some way of climbing out, I reckon," Mark said, slowly.

"Well, find it!" snapped Phineas Roebach. "Let's talk of something practical. We'll freeze to death down here very soon, if we don't starve first."

"Very true," said the professor. "Mr. Roebach is eminently practical. We must give our attention to the immediate peril that menaces us."

At this moment Andy came forward with two hatchets and an axe.

"These are the things we want, I guess," he said, quietly. "We've got to chop steps in the wall, and climb up in that way." "And abandon all our instruments—and the telescope?" exclaimed Professor Henderson.

"And the Snowbird?" added Mark.

"We can hoist all the small things up to the top of this wall—if we can get up there ourselves," said the old hunter.

"Right you are, Mr. Sudds," declared Phineas Roebach, with vigor.

"But the flying machine?" queried Jack. "It seems too bad to let it go."

"We won't let it go, Jack," declared Mark.

"Andy is right, boys," said the professor. "Let us first make our own escape sure. Then, if it be possible, we will hoist the flying machine as well as the instruments and our remaining provisions out of this chasm."

"I'm afraid we'll never be able to hoist the Snowbird," said Jack, sadly. "I reckon we'll have to say good-bye to it."

"Don't lose heart," repeated Professor Henderson. "Lead the way, Andy. Let us try chipping the ice away."

Cold it indeed was down there in the maw of the ice-field; but Wash made some more hot drink and the hunter and the oil man went at the ice-wall with vigor. They chipped out good, wide steps, two feet apart, two working together, and mounting upward steadily. The lightness of their bodies aided not a little in the speed at which they worked. Before an hour had passed they were forty feet above the shelf on which the crippled flying machine rested.

By that time the earth had rolled out of sight and the moon itself had paled into insignificance. There was a bright glow in the sky and the party knew that the sun had risen into view. Deep down as they were in the cavity, they soon felt the difference in the temperature. For several days it had been cold on the earth; but now the sun's heat seemed to strike more directly upon the island in the air.

The wall of ice on the other side of the crevasse began to glisten, and soon streams of water were trickling down it, falling with a gentle murmur into the abyss. The workers threw off some of their heavy clothing. The sun's rays began to creep down the other wall, and the ice melted rapidly.

Jack and Mark took the places of Andy Sudds and Mr. Roebach with the hatchets. The ice on this side of the chasm was still cold and brittle, but the sun was mounting very rapidly toward the zenith and the trickling rills upon the opposite wall of the crevasse became torrents.

"We are in serious danger," Professor Henderson warned them. "Since being shot off the world, we have begun a course around our parent planet which brings this portion of the island, at least, in much closer juxtaposition to the sun than Alaska ever was before. I fear that the heat will become tropical in due season."

"And this whole glacier will melt?" cried Mark, jumping to that conclusion instantly.

"Not all at once, we will hope," said the professor. "If the length of the day on this island in the air was as long as the earth's day, the sun might melt the ice so rapidly that we would be washed off this wall and drowned in the abyss."

"Gollyation! We's done for den, fo' suah!" groaned Washington White.

"But the island will doubtless circle the world in such a way that the sun will only strike upon us directly for a few hours at a time—the entire circuit we make around the world may be of considerable duration; but the sun will shine directly upon us—at the rate those rays are traveling down that opposite wall—for only a short time. Do you see?"

The boys had resigned their turn at the chopping and returned to the shelf by now. Again Andy and Mr. Roebach were high above their heads, clinging to the slippery wall.

For the ice on this side, while it was in the shade still, was becoming moist. The heat of the day was intense. Down the opposite wall of the crevasse tumbled a sheet of water which fairly hid the ice itself. Occasionally huge blocks of the melting crystal were broken off by the action of the water and fell into the chasm with thunderous crashes. There was good reason for the party being worried over their situation.

The heat increased and over the edge of the wall they sought to climb the water began to pour. Andy Sudds and the oil man were driven down from their perch. The sun appeared, blazing directly down into the crevasse and the melted ice rained in torrents about them, falling upon the Snowbird as though a heavy rainstorm was in progress.

They fled to the roofed cabin to escape this downpour. But they were fearful that at any moment the flying machine, resting so insecurely upon the shelf of ice, would be washed into the depths.

A terrible hour followed. The heat became torrid. The splashing of the water and thunder of huge pieces of ice falling into the crack almost deafened them.

Just as the sun had crossed the narrow arc above the crevasse there came a thunderous roar. Used as they had been for some hours to explosions of sound, this one made all tremble. The ice-wall seemed to crack and stagger from base to summit. The flying machine shook as though it were about to take flight. But they all knew that the only flight it could take was to the bottom of the abyss.

The thunder of falling ice continued for some minutes. A mighty avalanche had fallen into the depths. But whether it had fallen from their side of the crevasse or from the other, they could not at the moment tell.

The sun was out of sight. Its rays, however, still played upon the wall above their heads, while from the lower part of the gulf there rose a steam, or fog, which wrapped the flying machine around and smothered all in its embrace.

The light disappeared from above. The heat of the torrid sun departed. The chill of the fog bit in like a knife. They were glad in an hour to get into their furs, and there remained shivering in the damp, cold fog, while the streams of water which had poured down the ice-wall congealed again into the hardest of crystal.

Roebach and Andy possessed themselves of two storage battery lamps and went cautiously to examine the wall up which they had climbed for more than a hundred feet.

It was now as smooth as glass!

The wash of the falling water had worn away the ice so that the steps of their ladder had disappeared. The work they had done toward escape had gone for naught.

They were just as much prisoners of the ice now as they had been when first the Snowbird had settled upon this ledge in the crevasse. And now they lost hope. There seemed no possibility of their escaping from the gulf by cutting their way out.



CHAPTER XIX

A NIGHT ATTACK

It was the aged scientist who again put heart in the party when Andy Sudds and Phineas Roebach brought back the report of this catastrophe.

"We must not give up hope," declared Professor Henderson, cheerfully. "We have lost what work has been done on the ice-wall, it is true. But we can begin again."

"And of what use will that be?" demanded Mark Sampson. "The sun will melt away the ladder again."

"We have many more hours of night here than we have of daylight—you can all see that, eh?" said the professor.

"The sun seemed to shine on us not more than six hours," admitted Jack.

"Less than that, I believe. The rays were not hot more than four and a half hours. If we begin our work of cutting steps the moment the heat of the short day departs, we will be able, I am convinced, to get to the top of the ice cliff."

"You're wrong, Professor," said Roebach. "This ice is spongy even now—at least, a good deal of it is. We can't make secure footholds in that wall. We're beaten, I tell you—beaten!"

"No. Only balked in one way. There are other means of escape," declared Professor Henderson.

"I'd be glad to have you tell us what those means are," cried the oil man. "I've racked my brains to think of some other way of getting out. I'm beaten, I tell you!"

"We will not give up so easily," insisted Professor Henderson. "There is no sense in that. We must struggle on. Wait until this fog is dissipated. It will soon rise, for the air is becoming extremely cold and the fog cannot long endure the frost."

They were indeed suffering much from the increasing cold. The change—and so sudden a change—from the tropical heat of the short day to the bitter cold of this ice-gulf was hard to bear.

The fog thinned perceptibly three hours after the sun had set. Meanwhile all but Jack and Washington White had piled up in the cabin for some much-needed sleep. Jack's wounded hand would not let him rest, so he offered to keep watch, while the black man had been reposing most of the time in which Andy and the oil man had dug so strenuously at the cliff.

"Disher proves, Massa Jack, how contrariwise disher world do go," Wash grunted. "Here we starts out ter hunt fo' dat Dr. Todd's chrysomela bypunktater plant, an' we don't find it, but nothin' but trouble—lashin's ob trouble! I'se nigh erbout descouraged ober de perfesser. He suah do lead us all inter sech tribbilations. I done lose heart 'bout him."

"Oh, I wouldn't," said Jack. "The professor can't help it if an old volcano comes along and blows us off the earth. You can't really blame him for that, Wash."

"Well, now," said the darkey, "if he hadn't taken us so far away from home, it wouldn't have happened. We don't nebber have no earfquakes, nor no volcanoes in Maine. It's against de law, I reckon—like sellin' gin. No, sah I disher awful catastriferous conglomeration ob fortituitous happenings dat's put us where we is right now would nebber hab got at us if we'd minded our own business an' stayed to home. No, sah!"

"There may be some truth in what you say—barring your use of the big words, Wash," admitted Jack Darrow. "But we certainly can't blame the old professor for any freaks of Nature that may happen."

"No. But I hasn't gotter encourage him in disher foolishness ob runnin' up an' down de world, huntin' fo' new t'ings. I don't like new t'ings," declared Wash. "Looked disher now! Whoeber said Washington White wanted ter transmogrify hissef to a new planet? Nobody, not dat I hears on."

"I reckon we none of us had much choice in the matter," returned Jack, with a sigh.

"Glory! Dar's dat moon again!" cried Wash, suddenly.

"No; it's the earth in sight," returned his youthful companion. "The mist is being dissipated, just as the professor said. Let's go out and look about."

"We done wanter be mighty careful walkin' on dis ice," admonished the darkey. "It jest as slippery as it kin be."

Which was true enough, as Jack found the moment he stepped down upon the shelf from the flying machine frame. Where the ice had melted and then its surface had congealed again, it was as smooth as a mirror. The reflected light from the huge globe that now began to traverse the small arc of their heaven gave them plenty of light. They could see down into the green depths of the crevasse, but not far along the shelf on which the Snowbird rested, in either the one direction or the other.

"Whar you goin', Massa Jack?" demanded Wash, as the boy started away from the flying machine toward the nearest wall of rock that shut in the glacier. "I want to see what lies beyond that turn," replied the youth. "Perhaps we may learn something to our advantage by exploring a bit."

Washington White followed him very cautiously. Before he came to the turn himself, Jack had rounded it. The next moment the darkey was startled by a yell from Jack.

"Fo' de goodness gracious gollyation sakes!" bawled Wash. "What done gone an' disturbed de continuity ob your sagastuations? Yo' done frighten me inter a conniption fit if yo' hollers dat way."

Here he rounded the turn himself and almost bumped into Jack. Even the darkey's volubility was stilled at the sight before them.

A great part of the wall of the crevasse—the wall which they had hoped to climb, had broken off and fallen into the gulf. A wide crack, or gully, was opened in this side of the chasm, leading in an easy slope to the surface of the glacier.

Although their attempt to reach the surface had been foiled, here was a way which the sun, melting the ice and causing a great avalanche, had made for them. It was plain that all could easily mount to the top by this sloping gulch.

Jack dashed back to announce the discovery and Wash came after him, intent upon seeing that Buttsy was carried, in his well wrapped-up coop, out of the crevasse. The youth awoke his friends instantly and in ten minutes all had taken a look at the way of escape and preparations were at once made for departure from the flying machine.

Everybody save the professor was laden with stores or instruments, or extra clothing and blankets, as they filed away from the crippled Snowbird. The two youthful inventors and builders of the flying machine bade good-bye to her with full hearts. It was not a certainty that they could recover the flying machine, and Jack and Mark felt pretty bad about it.

The first thought of all, however, was centered in standing once more upon the surface of the glacier. The fact that the upper part of the ice field might move at any time, and the crevasse be closed while they were held in it, had troubled them all.

In half an hour, however, all that danger was past. Other perils might immediately face them; but the chance of being snapped between the jaws of ice was no more to be feared.

The golden ball of the earth, around which the island in the air was following its orbit, gave them plenty of light as yet, for the sun was still in such a position that its light was reflected from the earth upon the fast-traveling island in the sky.

The party, shaking with cold now, for the night was really arctic in temperature, made for the nearest morainial deposit where trees grew, under the shelter of the cliff which rose so high above the face of the glacier. As the river of ice had pushed its way downward during the past ages, it had scraped earth and stones from the walls of its bed, and this deposit, falling on the ice, had given root to trees and shrubs, while grass had sprung up and birds had doubtless nested there.

"They are like the oases in the desert," Mark said.

"They will afford us shelter and firewood," the professor added.

And in short order they were encamped in a clump of fir trees with a huge fire of dry branches burning before them, its warmth diffused over the whole party.

This grove of sturdy trees was backed close against the base of the cliff, and the rocky wall was sheer, mounting at least eight hundred feet above their heads.

"I suppose no life could exist higher than this cliff, eh, Professor?" Jack Darrow asked, as they became comfortable in the fire's warmth and threw back their fur wraps.

"I am not sure of that, Jack," returned the scientist. "From our experience in the Snowbird, since the eruption that threw us off into space, and while on the higher levels of air, we cannot doubt that at a thousand feet above this ice, at least, animal life would become extinct."

"I reckon there isn't much animal life left in these parts now, at any rate," Andy Sudds said. "I don't see what we're going to do if something doesn't turn up for food. We're going to be on short commons."

Wash had set his "bird cage," as the oil man called the Shanghai's coop, within the warmth of the fire, and the rooster evidently felt the grateful glow of the flames. He had been picking up some corn that Wash flung him, grain by grain. Now he suddenly stopped, raised his head, and uttered a loud and apparently frightened squawk.

"What dat?" demanded the darkey, his eyes rolling. "Buttsy hear sumpin'—he suah do."

"What do you reckon he hears?" queried Jack, idly.

"I dunno dat. But he's some disturbed—yo' kin see it's so," returned Washington, nervously. "Does yo' hear anything yit?"

"You think he can smell out an enemy, do you?" chuckled Jack.

"He done gotter great head, Buttsy has," declared the black man. "If dere is anyt'ing prowlin' aroun' permiscuous like, he's de boy to hear 'em—yes, sah!" "By the same token it was a flock of geese that saved Rome," Mark said.

Wash had his back to the thick clump of firs. Jack was facing him. Suddenly the boy, raising his eyes to look across the fire at the darkey, beheld a huge black object rise out of the brush directly in Washington's rear.

One glance told Jack what the creature was. There was no mistaking the gleaming eyes, the pointed, slobbering muzzle, and the hairy, yellowish breast of the gigantic Kodiak bear as it poised its huge body over the unconscious darkey.

Like a ghost the bear had crept to the camp of the explorers and was now on the eve of an attack, totally unheralded!



CHAPTER XX

THE HEROISM OF THE SHANGHAI ROOSTER

Jack Darrow was the only person in the group around the campfire who at first saw the huge bear. And he was so startled that for a breath he did not know what it was best to do. To shriek out in alarm would neither save the darkey nor frighten off the bear.

The Shanghai rooster settled down with a half-stifled squawk in the bottom of his coop. Without doubt the bird saw the bear and realized that his life was in peril.

"What de matter wid yo'?" demanded Washington, rolling his eyes and beginning to look scared himself.

Jack's mouth was dry and he had to wet his lips before he could as much as whisper. Only a few seconds had elapsed since the bear rose into view behind the darkey; but it seemed to Jack as though an eternity had passed.

His whispered words were for the old hunter, whom he knew was always alert.

"Andy! Your rifle!"

The brown claw of the old hunter was never far from the grip of his gun when he lay before a campfire. Jack saw the hand clamp upon the weapon even before Sudds rolled over.

"What's up, Jack?" he whispered.

"Behind Wash—quick!"

No need to tell the hunter to be quick. He was on his knees and the gun was at his shoulder in the twinkling of an eye.

"Come here, Wash—quick!" ejaculated Jack, with sudden inspiration, and the darkey, used to obeying orders without question, scrambled up and started toward the boy.