Produced by Mary Wampler, Juliet Sutherland, Charles

Aldarondo, Charles Franks and the Online Distributed
Proofreading Team.

ON A TORN-AWAY WORLD

Or

The Captives of the Great Earthquake

BY ROY ROCKWOOD

Other titles by ROY ROCKWOOD

THE GREAT MARVEL SERIES

THROUGH THE AIR TO THE NORTH POLE

UNDER THE OCEAN TO THE SOUTH POLE

FIVE THOUSAND MILES UNDERGROUND

THROUGH SPACE TO MARS

LOST ON THE MOON

ON A TORN-AWAY WORLD

DAVE DASHAWAY, THE YOUNG AVIATOR

DAVE DASHAWAY AND HIS HYDROPLANE

DAVE DASHAWAY AND HIS GIANT AIRSHIP

DAVE DASHAWAY AROUND THE WORLD

THE SPEEDWELL BOYS ON MOTOR CYCLES

THE SPEEDWELL BOYS AND THEIR RACING AUTO

THE SPEEDWELL BOYS AND THEIR POWER LAUNCH

THE SPEEDWELL BOYS IN A SUBMARINE

CONTENTS

I. SHOT INTO THE AIR!

II. MARK HANGS ON

III. THIS FLIGHT OF THE "SNOWBIRD" IV. "WHO GOES THERE?"

V. BETWEEN TWO PERILS

VI. ON THE WINGS OF THE WIND

VII. DROPPED FROM THE SKY

VIII. PHINEAS ROEBACH, OIL HUNTER

IX. THE EARTHQUAKE

X. THE BLACK DAY

XI. THE WONDERFUL LEAP

XII. THE GEYSER

XIII. NATURE GONE MAD

XIV. ON THE WING AGAIN

XV. A PLUNGE TO THE ICE

XVI. PROFESSOR HENDERSON REVEALS THE TRUTH

XVII. ON AN ISLAND IN THE AIR

XVIII. IMPRISONED IN THE ICE

XIX. A NIGHT ATTACK

XX. THE HEROISM OF THE SHANGHAI ROOSTER

XXI. MARK ON GUARD

XXII. THE WOLF TRAIL

XXIII. THE FIGHT AT ALEUKAN

XXIV. THE FLIGHT TOWARD THE COAST

XXV. THE HERD of KADIAKS

XXVI. THE ABANDONED CITY

XXVII. THE WHALE HUNT ASHORE

XXVIII. ON THE WHALING BARK

XXIX. WHEN THE SEA ROLLED BACK

XXX. AN ENDURING MONUMENT—CONCLUSION

CHAPTER I

SHOT INTO THE AIR

"Hurrah!" shouted Jack Darrow, flicking the final drops of lacquer from the paintbrush he had been using. "That's the last stroke. She's finished!"

"I guess we've done all we can to her before her trial trip," admitted his chum, Mark Sampson, but in a less confident tone.

"You don't see anything wrong with her, old croaker; do you?" demanded
Jack, laughing as usual.

"'The proof of the pudding is in the eating thereof; not in chewing the pudding bag string'," quoted Mark, still with a serious countenance.

But like Jack he stood off from the great body of the wonderful airship, and looked the completed task over with some satisfaction. Having emergency wings, she was also a plane. She was white all over and her name was the Snowbird. Jack and Mark had spent most of their time during this vacation from their college in building this flying machine, which was veritably an up-to-the-minute aerial vehicle, built for both speed and carrying capacity.

The hangar in which the machine had been built was connected with Professor Amos Henderson's laboratory and workshop, hidden away on a lonely point on the seacoast, about ten miles from the town of Easton, Maine. At this spot had been built many wonderful things—mainly the inventions of the boys' friend and protector, Professor Henderson; but the Snowbird, upon which Jack and Mark now gazed so proudly, was altogether the boys' own work.

The sliding door of the hangar opened just behind the two boys and a black face appeared.

"Is eeder ob you boys seen ma Shanghai rooster?" queried the black man, plaintively. "I suah can't fin' him nowhars."

"What did you let him out of his coop for?" demanded Mark. "You're always bothering us about that rooster, Washington. He is as elusive as the Fourth Dimension."

"I dunno wot dat fourth condension is, Massa Mark; but dat rooster is suah some conclusive. When I lets him out fo' an airin' he hikes right straight fo' some farmer's hen-yard, an' den I haster hunt fo' him."

"When you see him starting on his rambles, Wash, why don't you call him back?" demanded Jack Darrow, chuckling. "If I did, Massa Jack, I'spect he wouldn't know I was a-hollerin' fo' him."

"How's that? Doesn't he know his name?"

"I don't fo' suah know wedder he does or not," returned the darkey, scratching his head "Ye see, it's a suah 'nuff longitudinous name, an' I dunno wedder he remembers it all, or not."

"He's got a bad memory; has he?" said Mark, turning to smile at Washington White, too, for Professor Henderson's old servant usually afforded the boys much amusement.

"Dunno 'bout his memory," grunted Wash; "he's gotter good forgettery, suah 'nuff. Leastways, when he starts off on one o' dese perambulationaries ob his, he fergits ter come back."

"Let's see," said Jack, nudging his chum, "what is that longitudinous' name which has been hitched onto that wonderful bird, Wash? I know it begins with the discovery of America and wanders down through the ages to the present day; but a part of it has slipped my memory—or, perhaps I should say, 'forgettery'."

With a perfectly serious face the darkey declaimed:

"Christopher Columbus Amerigo Vespucci
George Washington Abraham Lincoln Ulysses
Grant Garibaldi Thomas Edison Guglielmo Marconi
Butts."

"For goodness sake! Will you listen to that!" gasped Mark, while Jack went off into a roar of laughter.

"Don't—don't it make your jaw ache to say it, Wash?" cried the older lad when he could speak.

"Not a-tall! not a-tall!" rejoined the darkey, shaking his woolly head.
"I has practised all ma life speakin' de berry longest words in de
English language—"

"And mispronouncing them," giggled Jack.

"Mebbe, Massa Jack, mebbe!" agreed Washington, briskly. "But de copy book say dat it is better to have tried an' failed dan nebber to have tried at all."

"And did you ever try calling the rooster back, when he starts to play truant, with all that mouthful of words?" queried the amused Mark.

"Yes, indeedy," said Washington, seriously.

"Don't he mind, then?"

"I should think he'd be struck motionless in his tracks," chuckled
Jack.

"No, sah," said Washington. "Dat's de only fault I kin fin' with dat name—it don't 'pear to stop him. An' befo' I kin git it all out he's ginerally out ob sight!"

That sent both boys off into another paroxysm of laughter. Meanwhile the darkey had come into the great shed and was slowly walking around the flying machine. "What do you think of her, Wash, now that she's finished?" asked Mark.

"Is she done done?" queried the darkey, wonderingly.

"She certainly is," agreed Jack.

"De chile is bawn and done named Nebbercudsneezer, heh? Well! well!"

"No; it's named the Snowbird," Mark retorted. "And to-morrow morning, bright and early, we shall sail on its trial trip. The professor is going with us, Washington. Of course, you will come, too?"

"Lawsy me! don't see how I kin!" stammered Washington White, who always wished to be considered very brave, but who was really as timid as a hare. "Yo' see, Massa Mark, I'spect I shall be right busy."

"What will you be busy at?" demanded Jack.

"Well—well, sah," said Wash, "if dat Shanghai don't come back befo', I shall hab ter go snoopin' aroun' de kentry a-huntin' fo' him. He'll be crowin' 'bout sun-up, an' he suah can't disguise his crow."

"If Andy was here, he would surely want to go with us," declared Jack to Mark. "Andy Sudds isn't afraid of anything."

"My! my!" cried Washington. "Yo' don't fo' one moment suppose, Massa Jack, dat I's afeared; does yo'?" "No, you're not afraid, Wash," returned Jack, chuckling. "You're only scared to death. But you go ahead and hunt your rooster. See that you keep him from flying too high, however, or we'll run him down in the Snowbird."

"Pshaw!" said Mark. "That rooster is so fat he couldn't fly high, anyway."

"And perhaps the Snowbird won't fly very high; eh?" retorted Jack, letting a little anxiety creep into his voice.

"But dat rooster suah kin fly high," said Washington White, eagerly.
"Yo' gemmens knows dat he's flowed as high as de moon—he, he!"

"And 'flowed' is a mighty good word, Wash," chuckled Jack. "Ah! here is the professor, Mark."

Professor Henderson was an aged man with snow white hair and beard. Although he was not physically as strong as he once was, his brain and energy were not in the least impaired by advancing years. He had taken the two lads, Jack Darrow and Mark Sampson, both orphans, under his care some years before, and under his tuition and by his aid they were much farther advanced in knowledge of the practical sciences than other boys of their age.

The professor welcomed them cordially and at their request gave a thorough scrutiny to the various mechanical contrivances that went to the make-up of the flying machine. He pronounced it, as far as could be known before a practical test, a perfect mechanism.

"And we will try it to-morrow morning, boys," he said, with almost as much enthusiasm as Jack and Mark themselves displayed. "You have completed the machine in excellent time, and I 'un likewise ready to make the experiment."

"What experiment, Professor?" asked the boys in chorus.

"Haven't you noticed what I was tinkering on at the other end of the shop?" queried Professor Henderson, in surprise.

"Why, I see that you have a long steel plank there, with some kind of a compressed air contrivance at one end," said Jack.

"Is that what you mean, Professor?" queried Mark.

"That, boys," said the scientist, with some pride, "is a modern catapult—an up-to-the-minute catapult which, had it been known to the ancients, would have enabled the hosts of Joshua, for instance, to batter down the walls of Jericho without the trouble of marching so many times around the city."

"And what has a compressed air catapult got to do with the Snowbird?" queried Jack. "You propose launching your flying machine in the usual way," said the professor. "I see you have wheel trucks all ready to slip under her. We will not use those wheels, boys. I have a better plan. We will launch the Snowbird into the air from my catapult."

"Great goodness, Professor!" cried Mark. "Is that practicable?"

"We'll know after we have tried it," retorted Professor Henderson, drily.

"How did you happen to start working on this catapult idea?" asked
Jack.

"Well, I can't tell you everything," replied the inventor, "for it is partly a secret."

"Huh," laughed Mark. "You're mysterious. You haven't joined forces with some department of our government, or with another country?"

The professor smiled, thinking how keen this young man always proved himself to be.

"You've guessed it," he replied. "And I'm sorry I can't explain more to you."

"We understand," said Jack. "And no doubt this machine is a super-catapult."

"True," was the answer. "Of untold use to the scientific world. For the present I shall confine testing its efficiency right in this place. Now is my chance."

"But of what advantage will it be to our flying machine to start it in this way?" "Stop and think, my boy," said the professor. "Just as an aeroplane can literally be shot into the air within a very short space, so can your airship. Of course, this is not necessary, but we will be able to start the ship much faster that way than we could withjust the motors."

"You'll make history, Professor," added Jack. "Exciting headlines for the papers."

"Sure enough," said Mark enthusiastically.

"The publicity doesn't interest me," replied the scientist. "Moreover, my super-catapult must remain a secret, as I told you a while ago."

"So you really propose to launch the Snowbird in this way?" asked
Jack.

"We will be shot into the air. If you are sure of your machine, I am sure of my catapult, and we will try the two contrivances together."

In the morning all rose bright and early and prepared the Snowbird for her trial flight. Washington White had indeed disappeared—possibly in search of his Shanghai rooster—and Andy Sudds was off on a hunt. Therefore the professor and his two young comrades essayed the trip alone.

Jack and Mark tossed a coin to see who should first guide the great air machine, and Mark won the preference. He, as well as his chum and the professor, had already donned their aeronautic uniforms, and he now strapped himself into the pilot's seat. The steering apparatus, the levers that controlled the planes, and the motor switch were all under his hand. While in flight the Snowbird need be under the control of but one person at a time.

The professor had rigged his catapult so that he could release the trigger from the flying machine. Mark said he was ready; the professor reached for the cord which would release the trigger.

"Start your motor, Mark, a fraction of a second before I release the compressed air," commanded Mr. Henderson. "Now!"

The motor of the flying machine buzzed faintly. Jack's eyes were on the speed indicator. He suddenly felt the great, quivering flying machine, which had been run out of the hangar on to the steel plank of the catapult, lurch forward. The feeling affected him just as the sudden dropping of an elevator from a great height affects its passengers.

The finger of the speed indicator whirled and marked forty miles an hour ere the flying machine left the steel plank, and shot into the air with the fearful force of the compressed air behind it.

Both Mark and Jack were well used to guiding aeroplanes and other air machines. But this start from the ground was much different from the easy, swooping flight of an airship as usually begun. Like an arrow the Snowbird was shot upward on a long slant. It was a moment ere Mark got the controls to working. The propellers were, of course, started with the first stroke of the motor.

But Mark Sampson was nervous; there was no denying that. At the instant when the nose of the airship should have been raised, so as to clear the tops of the forest trees and every building on the Henderson place, Mark instead guided the rapidly flying Snowbird far to the left.

It skimmed the corner of the stable by a fraction of a foot, and Jack yelled:

"Look out!"

His cry made Mark even more nervous. The tall water-tank and windmill were right in line. Before the young aviator could swerve the flying machine to escape the vane upon the roof of the tower, and the long arms of the mill, they were right upon these things!

The fast-shooting Snowbird was jarred through all her members; but she tore loose. And then, in erratic leaps and bounds, she kept on across the fields and woods towards Easton, never rising very high, but occasionally sinking so that she trailed across the treetops, threatening the whole party with death and the flying machine itself with destruction, at every jump.

CHAPTER II

MARK HANGS ON

Professor Henderson and his adopted sons—Jack Darrow and Mark Sampson—had been in many perilous situations together. Neither one nor the other was likely to display panic at the present juncture, although the flying Snowbird was playing a gigantic game of "leap-frog" through the air.

The professor had himself constructed many wonderful machines for transportation through the air, under the ground, and both on and beneath the sea; and in them he and his young comrades had voyaged afar.

Narrated in the first volume of this series, entitled, "Through the Air to the North Pole," was the bringing together of the two boys and the professor,—how the scientist and Washington White rescued Jack and Mark after a train wreck, took them to the professor's workshop, and made the lads his special care. In that workshop was built the Electric Monarch, in which flying ship the party actually passed over that point far beyond the Arctic Circle where the needle of the compass indicates the North Pole.

Later, in the submarine boat, the Porpoise, the professor, with his young assistants and others, voyaged under the sea to the South Pole, the details of which voyage are related in the second volume of the series, entitled "Under the Ocean to the South Pole."

In the third volume, "Five Thousand Miles Underground," is related the building of that strange craft, the Flying Mermaid, and how the voyagers journeyed to the center of the earth. The perils connected with this experience satisfied all of them, as far as adventure went, for some time. Jack and Mark prepared for, and entered, the Universal Electrical and Chemical College.

Before the first year of their college course was completed, however, Professor Henderson, in partnership with a brother scientist, Professor Santell Roumann, projected and carried through a marvelous campaign with the aid of Jack and Mark, which is narrated in our fourth volume, entitled, "Through Space to Mars." In this book is told how the projectile, Annihilator, was built and, the projectile being driven by the Etherium motor, the party was transported to the planet Mars.

Later, because of some knowledge obtained from a Martian newspaper by Jack, they all made a trip to the moon in search of a field of diamonds, and their adventures as related in "Lost on the Moon" were of the most thrilling kind. The projectile brought them safely home again and they had now, for some months, been quietly pursuing their usual avocations.

The knowledge Jack Darrow and Mark Sampson had gained from textbooks, and much from observation and the teachings of Professor Henderson, had aided the lads in the building of the Snowbird. It was the first mechanism of importance that Jack and Mark had ever completed, and they had been quite confident, before the flying machine was shot from Mr. Henderson's catapult, that it was as near perfect as an untried aeroplane could be.

"Hang on, Mark!" yelled Jack, as the great machine soared and pitched over the forest.

Her leaps were huge, and the shock each time she descended and rose again threatened to shake the 'plane to bits. Mark swayed in his seat, clutching first one lever and then another, while Professor Henderson and Jack could only cling with both hands to the guys and stay-wires.

The sensation of being so high above the earth, and in imminent danger of being dashed headlong to it, gripped Mark Sampson like a giant hand. He felt difficulty in breathing, although it was not the height that gave him that choking sensation. There was a mist before his eyes, still the sun was shining brightly. The startling gyrations of the flying machine for some time shook the lad to the core.

But Jack's cheerful cry of "Hang on!" spurred Mark to a new activity—an activity of hand as well as brain. He knew that something had fouled and that this accident was the cause of the machine making such sickening bounds in the air. She was overbalanced in some way.

With Jack's encouraging shout ringing in his ears, Mark came to himself. He would hang on! His friends depended upon him to control the machine and to save them from destruction, and he would not be found wanting.

One lever after another he gripped and tried. It was one controlling the rising power that was fouled. He learned this in a moment. He sought to move it to and fro in its socket and could not do so. He had overlooked this lever before.

Again the Snowbird dashed herself from a height of five hundred feet toward the earth.

They still flew over the forest. The tops of the trees intervened, and Mark managed to counteract the plunge before the prow of the machine burst through the treetops. She rose again, and using both hands, Mark jerked the wheel stick into place.

At once the flying machine responded to the change. She rode straight on, slightly rising as he had pointed her, and Mark dared touch the motor switch again. Instantly the machine speeded ahead.

"Hurrah for Mark!" shrieked Jack. "He's pulled us through."

"He has indeed," agreed the professor, and they settled into their seats and gave attention to the working of the apparatus. Mark now had the Snowbird well under control.

Jack changed places with his chum and managed the Snowbird equally well. At his touch she darted upward at a long slant until the altimeter registered two thousand feet above the sea. And the sea was actually below them, for Jack had guided the flying machine away out from the land.

"Boys," said Professor Henderson, quietly, "you have done well—remarkably well. I am certainly proud of you. Some day the people of the United States will be proud of you. I am sure that the inventor's instinct and the scientist's indefatigable energy are characteristics you both possess."

"That's praise indeed!" exclaimed Jack, smiling at his chum. "When the professor says we've won out, I don't care what anybody else says."

"Do you think the Snowbird is fit for long-distance travel?" asked
Mark of Professor Henderson, now displaying more eagerness than before.

"I do indeed. I think you have a most excellent flying machine. I would not hesitate to start for San Francisco in her."

"Or farther?" asked Jack.

"Certainly."

"Across the ocean?" queried Mark, quickly.

"I do not see why any one could not take a trip to the other side of the Atlantic in your 'plane," replied the professor. "With proper precautions, of course."

They reached the land and came safely to rest before the hangar without further accident. The professor was delighted with the working of his catapult and at once made ready to call the attention of the Navy Department to his improvement in the means of launching an airship from the deck of a vessel. Ere he had written to the Department, however, he and his young friends were suddenly made interested in a scheme that was broached by letter to Professor Henderson from a fellow-savant, Dr. Artemus Todd, of the West Baden University.

Professor Henderson and Dr. Todd had often exchanged courtesies; but the university doctor was mainly interested in medical subjects, while Mr. Henderson delved more in the mysteries of astronomy and practical mechanics.

The doctor's letter to Professor Henderson read as follows:

"Dear Professor:

"I am urged to write to you again because of something that has recently come to my knowledge regarding a subject we once discussed. As you know, for some years past I have been investigating not the cause of aphasia and kindred mental troubles (for we know the condition is brought about by a clot of blood upon the brain), but the means of quickly and surely overcoming the condition and bringing the unfortunate victim of this disorder back to his normal state. In our age, when mental and nervous diseases are so rapidly increasing, aphasia victims are becoming more common. Scarcely a hospital in the land that does not have its quota of such patients under treatment—patients who, in many cases, have completely forgotten who and what they are and have assumed a totally different identity from that they began life with."

"We know that, in some cases, hypnotism has benefited the aphasia and amnesia victim. His condition is not like that of the mentally feeble; he has merely lost his memory of what and who he previously was. Believing that all disease, of whatsoever nature, can be safely treated only through the blood, this ill to which human flesh is heir particularly must be treated in that way, for we know that a stagnant state of the blood in one spot, at least, is the cause of the patient's malady. Therefore I have been experimenting botanically to discover a remedium for the state in question—something that will act swiftly upon the blood, and directly dissipate such a clot as is spoken of above."

"My dear Professor! I can announce with joy that this remedium is discovered. I obtained a specimen of a very rare plant brought back from Alaska by a miner who wandered into the fastnesses of the Endicott Range, far beyond the usual route of gold miners and in a district which, I understand, is scarcely ever crossed by whites and which is, indeed, almost impassable, even in the summer months. With the aid of this herb—Chrysothele-Byzantium (it was known to the ancients, but very rare)—I have brewed a remedium which, in one case at lest, instantly cleared the blood vessels of the patient and brought him back to a knowledge of his real self."

"But my supply of the herb is gone. It reached me in its dry state, or I should have first tried to propagate it. It seeds but once in seven years and therefore is rare and hard to grow. But I must have a supply of the Chrysothele-Byzantium seeds, plants, and all. I look to you, my dear Professor Henderson, for help. To you space and the flight of time are merely words. You can overcome both if you try. I need somebody to go to the northern part of Alaska—that is, beyond the Endicott Range—to obtain this rare plant for me. You have already flown over the North Pole and a trip which carries one only three or four degrees beyond the Arctic Circle is a mere bagatelle to you."

"Yes! it is in you I place my hope, Professor. The hopes of many, many afflicted people may be placed in you, too. I ask you to fly to this distant place and obtain for me the herb that will do humanity such great good. Under another enclosure I send you drawings of the plant in its several states and a full and complete description of how it was found. You can make no mistake in the Chrysothele-Byzantium. You know that I am a cripple, or I would offer to join with you in this search. But at least I am prepared to pay for any expense you may be under. Draw upon me for ten thousand dollars to-morrow if you so desire, and more if you need before the start. The Massachusetts Bay Trust Company, of Boston, will honor the draft. Make up the expedition as you see fit. Take as many men with you as you think necessary. Make all preparations which seem to you fit and needful. I limit you in nothing—only bring back the herb."

"Remember I shall impatiently await your return and look for your success—I expect nothing but unqualified success from your attempt. You who have achieved so much in the past surely cannot fail me in this event. I await your agreement to attempt this voyage with confidence. I must have the herb and you are the only person who can obtain it for me."

"Your friend and co-worker for the betterment of humanity,
ARTEMUS TODD, M.D., Ph.D."

Professor Henderson read this strange letter aloud in the evening as he and his friends were sitting before the small, clear fire of hickory logs in the big living room of the bungalow in the woods, built beside the great workshops and laboratory. With the scientist and the two boys was Andy Sudds, the old hunter, who sat cleaning his rifle, and Washington White was busy in and out of the room as he cleared away the supper and set the place in order.

"Well! what do you know about that!" exclaimed Jack Darrow, always ready with a comment upon any subject. "Dr. Todd is certainly some in earnest; isn't he?" "But what a cheek he has to ask you to go on such a journey!" cried Mark. "He talks as though he expected you to start immediately for the Arctic Circle."

"There would be good hunting up there in the mountains," said Andy
Sudds, succinctly. "I wouldn't mind that."

"An'disher chrysomela-bypunktater plant he wants," grunted Washington. "Hi, yi! ain't dat de beatenest thing? Who ebber heard of sech a plant befo'?"

"Nobody but you, I guess, Washington," said the professor, quietly. "That seems to be a plant of your own invention."

"But, sir!" cried Mark, "you have no idea of taking this trip he suggests; have you?"

"Dr. Todd has done me many a favor in the past," said Professor
Henderson, thoughtfully.

"Well, if you're going, count me in," said Jack, quickly. "I don't mind a summer trip to the Arctic. Say! it can't be much cooler up there than it is here right now. This fire doesn't feel bad at all."

"Humph!" muttered Mark, who never was as sanguine as his chum. "This cool spell will only last a day or two here; but I understand the tops of the Endicott Range are always white."

"B-r-r!" shivered Washington, at this statement. "Dis chile don't t'ink much ob such a surreptitious pedestrianation as dat, den. Don't like no cold wedder, nohow! And Buttsy don' like it, needer."

"Who's Buttsy?" demanded Jack, grinning.

"Why, fo' suah," said the darkey, gravely, "you knows Christopher
Columbus Amerigo Vespucci George Washington Abraham Lin——"

"But you wouldn't expect to take Christopher Columbus And-so-forth to
Alaska with us; would you?" asked Andy Suggs.

"Why not?" demanded the darkey. "He flowed to de moon in de perjectilator; didn't he? Huh! In co'se if de perfessor goes after disher chrysomela-bypunktater, I gotter go, too; and in co'se if I go, Buttsy done gotter go. Dat's as plain as de nose on yo' face, Andy."

The hunter rubbed his rather prominent nasal organ and was silenced. Jack and Mark had turned more eagerly to the professor as the latter began to speak:

"Yes, Dr. Todd is my good friend. He turns to me for help quite properly; who else should he turn to?"

"But, Professor!" ejaculated Mark, warmly. "Are you to be driven off to Alaska at your age to hunt for this herb—which is perhaps only the hallucination of a madman?" "Mark's hit the nail on the head, Professor!" declared Jack. "I believe this Todd must certainly be 'touched' in his upper story."

"Am I touched, as you call it, Jack?" demanded Professor Henderson, in some indignation.

"But you don't believe Todd is on the trail of any great discovery?" cried Mark.

"Why not? Mind may yield to herbal treatment. Todd is an advanced botanical adherent. He believes almost anything can be accomplished by herbs. And he says he has successfully treated one case."

"One swallow doesn't make a summer," remarked Mark, doubtfully.

"But it is enough that he wants us to find the herb," said the professor, more vigorously.

"'Us'!" repeated Jack.

"And he will pay us any reasonable price for our work," added their mentor.

"He really means to go!" cried Mark.

"I certainly do. I think you and Jack will accompany me," said the professor, quietly. "I know that Washington will, and of course Andy will not be left behind."

"Not if there'll be a chance at big game," declared the hunter. "I'm with you, Professor Henderson."

"Yo' suah can't git erlong widout me, I s'pose?" queried the darkey, in some uncertainty. "I'se mighty busy right yere jes' now."

"And you'll be busy if we go to Alaska, Wash!" cried Jack. "Hurrah!
I am willing to start to-morrow, Professor."

"And you, Mark?" queried the old gentleman of his other adopted son.

"How will we go, sir? We shall be until fall traveling to the Arctic
Circle by any usual means."

"True," said the professor. "And haste is imperative. I cannot spend much time in this matter. We must take unusual means of getting to the Endicott Range."

"What do you mean?" asked the boys in chorus.

"Your Snowbird is ready for flight. It can be provisioned and will take us all quicker than by any other means. Therefore in the Snowbird we will make the journey."

CHAPTER III

THE FLIGHT OF THE SNOWBIRD

Jack Darrow and Mark Sampson were glad enough to be of the party aiming to reach northern Alaska and the Endicott Range, if Professor Henderson really intended going to find the strange herb for which Dr. Todd was willing to pay so generously.

Of discussion, pro and con, there was much. Indeed, they sat up until after midnight after the reading of Dr. Todd's letter, talking over the contemplated journey, and gradually the details of the trip, including all preparations for it, were worked out.

Jack and Mark put into the affair, once they were determined to aid the professor, their characteristic energy. Professor Henderson wired his brother scientist that he would undertake the journey to Alaska, and accepted the ten thousand dollars to defray expenses. Andy Sudds made characteristic preparations for hunting the big game of the Alaskan mountains. Washington White built a traveling coop of very light but strong material for his pet Shanghai, and then announced himself as ready to depart for the Arctic Circle.

The instructions and map furnished by Dr. Todd, locating the very spot beyond the Endicott Range where the rare herb had been plucked by the miner, showed it to be in a very wild region indeed. There was a native settlement named Aleukan within a hundred miles of the valley where the herb was supposed to grow in abundance. Professor Henderson determined to lay their course for this place.

But the nearest white man's town was Coldfoot, on the other side of the mountains. There was a trail, however, passable in summer for a dogtrain from Coldfoot to Aleukan; and a dogtrain could likewise pass from the native village to the valley where the miner had found the herb.

These facts the professor and his young associates discovered as soon as Dr. Todd's instructions arrived. They made their plans accordingly.

By telegraph the professor ordered a trainload of supplies to be started at once from Fort Yukon. First, these supplies would go by boat down the Yukon Flats and up the Chandler River, past Chandler and Caro, beyond which latter town there was a good road over a small range of hills to Coldfoot. This trail was open at all seasons and there was a regular system of transportation into Coldfoot.

From that town dogs and men would be hired to take the supplies on to Aleukan. These arrangements were made through an express company, and in three days the professor received word that the supplies were already aboard a small steam vessel which had left the Fort Yukon dock for the trip to Caro.

The trip by boat and overland for the supply train would consume about a week or two, providing nothing untoward happened to delay it. And the season was favorable to a quick journey.

But the professor and his young comrades figured that the Snowbird, following the shortest air-line to the far side of the Endicott Range, could make the trip in much shorter time. The distance "as the crow flies" was from 3,700 to 3,800 miles from their point of departure. Under favorable conditions the great flying machine should travel ninety miles an hour on the average. Unless there was a breakdown, or they ran into a heavy storm, which would necessitate their descending to the earth, they could count upon the Snowbird being in the vicinity of Aleukan within three or four days' time at the longest.

In the flying machine itself they could carry a supply of concentrated foods, medicines, necessities of many kinds, and their arms. It was probable that meat could be had for the killing in the valley to which they were bound, and the Indians at Aleukan could be hired to supply necessary food for a time. But the professor did not propose to take his friends into the wilderness without completely warding off disaster.

Considerable space in the Snowbird was occupied by Professor Henderson's scientific instruments. He was amply supplied with powerful field glasses, a wonderful telescope, partly of his own invention; instruments for the measuring of mountains heights, the recording of seismic disturbances, and many other scientific paraphernalia of which Jack and Mark did not know even the uses.

The boys were as well supplied with firearms as Andy Sudds himself. They knew that they would probably see and be obliged to kill dangerous beasts; and although the several tribes of Indians inhabiting Alaska are all supposed to be semi-civilized and at peace with the whites, they had had experience enough in wild countries before to warn them that the temper of aboriginal man is never to be trusted too far.

Their own readiness for departure in the Snowbird had been gauged by the telegraph dispatches from Fort Yukon. When the final message came that the boat bearing the supplies had started, Professor Henderson asked: "And now, boys, when can we leave by the air route?"

Jack and Mark glanced at each other and nodded. Jack said:

"All you have to do, Professor, is to put your bag aboard the ship and step in. We are ready to start the Snowbird at any moment. Andy has his guns aboard, and plenty of ammunition. Mark and I are all ready. At your word we will leave."

"It is already dark," said the professor, slowly. "Shall we wait until morning?"

"The moon will be up in an hour—and it is almost at its full," Mark said, quickly. "The quicker we are off the better, it seems to me."

"Very well," agreed Professor Henderson. "If you boys say the word, we will start. Is Andy here?"

"He is already aboard—asleep in his bunk," said Jack, "with his best rifle cuddled in the hollow of his arm. He does not propose to be left behind," and the young fellow chuckled.

"And where is Washington White?"

"He's done yere," answered the darkey for himself, and he appeared bearing the traveling coop of Christopher Columbus And-so-forth in his arms.

"Here, Wash!" ejaculated Jack. "Surely you are not going to clutter up the flying machine with that thing?"

"An' why fo' not?" sputtered the darkey. "Whatebber has Buttsy done ter yo', Massa Jack, dat yo' should be obfendicated at his 'pearance in de present state ob de obsequies?"

"Then the rooster accompanies the expedition," chuckled Jack. "Only remember, if we have to throw out anything to lighten ship, Buttsy goes first—even before we are obliged to dispense with your services, Wash!"

"Den we are ready to start," declared the darkey, solemnly. "Nottin' will now disturb de continuity ob de ebenin's enj'yment. Forward, march, is our motter!"

And he marched away to the flying machine and got aboard with the coop and Buttsy in his arms.

The professor had found the last of his possessions he wished to take with him. He followed the negro aboard. The Snowbird was already outside the hangar and on its wheels, ready for the start. This time they dispensed with the professor's catapult, for it would be necessary to have the trucks attached to the aeroplane to enable her to start properly from any point on which they might land. The workshop and plant in general were left in charge of a watchman and caretaker, and only this man was present when Jack took his place in the controller's seat and Mark started the powerful motor and clambered aboard.

The craft ran across the field, at first slowly and then more rapidly as Jack increased the speed. The flying machine began to lift almost immediately.

"Hurrah!" shouted the irrepressible Jack. "We're off!"

"About nor-norwest is the course, Jack," cried Mark Sampson, likewise inspired by the flight of the Snowbird.

As for Washington White, he gazed down to the dusky earth below them and his eyes rolled.

"Gollyation!" he muttered. "If Buttsy should fall down dere, he'd suah jounce himself some; wouldn't he?"

CHAPTER IV

"WHO GOES THERE?"

With the moonlight lying like a benediction over the fields and forests of Maine, the Snowbird, her motor humming like a huge bumble-bee, and her propellers and controls working in perfect order, swept on her course into the northwest. The lights of Easton, ten miles from their home, melted into the earth-shadow behind the sky-voyagers within the first hour of the sure-to-be eventful journey.

Jack Darrow did not force the pace of the flying machine. They had a long and trying flight before them. The machine as a whole had been tried out only two or three times during the few days that had elapsed since she was completed and this present expedition had been planned. These short flights had served merely to put the parts in good working trim; but the lad knew better than to make the pace that of top-speed from the start.

He wanted her to "warm up." He knew that the Snowbird could make one hundred twenty-five miles an hour. But such speed was likely to shake something loose and cripple the mechanism.

A flight of seventy or eighty miles an hour would bring them well into Canada by noon of the next day. They would have to there descend at, or near, some town, and report themselves and the nature of their flight to the authorities. This was to be done as a precaution in case they had a breakdown somewhere in crossing British possessions. A passport would then aid them if they were obliged to call upon the authorities in the heart of Canada for aid.

But at present none of these things bothered the party much. Sudds and the professor slept as though they were in their beds at home. The old hunter could sleep anywhere, and awake instantly with all his faculties about him. And the scientist slept profoundly because his body was exhausted.

Under the brilliant moon the Snowbird swung along the air-way like a veritable bird. Jack increased the revolutions of the propellers a trifle and the ship responded like a spirited horse to the spur. She darted ahead at a ninety mile speed and Washington White emitted a mournful groan.

"What's the matter with you now, Wash?" shouted Mark, for they all wore ear-tabs and had to shout to make one another hear.

"Oh, lawsy-massy on us!" groaned Wash. "I'se got sech a misery, Massa
Mark, I dunno but ma time has camed."

"What time has come?" demanded Mark, without much sympathy. "It'll be time for you to hustle and get us something to eat before long."

"For de goodness gracious Agnes' sake!" gasped the negro, "yo' suahly ain't a-gwine ter dribe me ter wo'k up in disher flyin' contraption? Dat would suah be cruelty ter animiles, boy—it suah would!"

"We've got to eat, Wash," said Jack, chuckling, "and you are steward and cook of this craft."

"Gollyation! did I ship fo' sech wo'k? I nebber knowed it. It does seem to me dat de consanguinity ob de 'casion done call fo' notting but de quietest kind o' verisimilitude. De qualmishness dat arises in de interiorness of ma diaphragm ev'ry time I circumnavigates erbout in disher flyin' ship makes me wanter express mahself in de mos' scatterin' kin' ob er way—I hopes you gits ma meanin' clear?"

Jack was laughing so that he could not speak, but Mark managed to say:

"You mean that the motion of the aeroplane gives you a feeling of mal de mer?"

"Dat's wot I done said," Wash replied, seriously. "I nebber in ma life felt so mal-der-merry as I do at dis present onauspicious 'casion; an' if dat mal don't stop merryin' purty quick, I suah shall be—ugh!—sick ter ma stummick!"

This wail fairly convulsed Jack Darrow and Mark Sampson; but they knew that if Wash paid more attention to his duties and thought less about his own situation he would be better off. Mark insisted on his going at once into the tiny, covered "galley," as the boys called it, hung amidships, in which were the means of heating water, making coffee, and cooking certain simple viands in their stores.

Wash went to his duties grumblingly; but he was an ingenious and skillful cook and when he got to work he forgot his "feeling of mal-de-merry."

It was now approaching midnight and the flying machine had been steadily traveling northward for some hours. Both Andy Sudds and the professor awoke and offered to relieve the boys in their work. But Mark had taken Jack's place in the controller's seat and neither he nor his chum felt that he wished to give over the guidance of the Snowbird to anybody else.

Now, some distance ahead, the peak of Mt. Katahdin, gloriously mantled in moonlight, rose before them. Their direct course lay over the summit of this eminence, and Mark decided that it would be better to rise to a higher strata and cross the mountain than to swing around it. Therefore Mark raised the bow of the flying machine and she darted upward on a long slant, drawing ever nearer to the shining peak of the great mountain. The night air was chill—it had been cool when they left the earth—and as they rose to the rarer ether it was evident that they would find a degree of temperature far lower than the usual summer heat.

Mark kept the Snowbird scaling swiftly upward, mile after mile; but the long tangent at which he had started to clear the summit of Katahdin did not prove sufficient, and by and by they found themselves within a very few yards of the rocky side of the peak.

Out of a dark glen a spark of light suddenly shot—almost like a rocket in swiftness. Jack saw it first and cried:

"See that! What is it? What do you make of it?"

"A shootin' star, I declare!" said Andy Sudds.

"Nothing of the kind," exclaimed Jack, quickly. "A star could not shoot up from the earth."

"Wot's dat says somebody's a-shootin' at us?" gasped Washington White.
"If dey punctuates our tire, we'll suah go down wid a big ker-smash!"

The professor, however, watched the "shooting star" for some moments without speaking, and then rapidly made his way to Mark's side.

"Send your 'plane up in spirals, boy!" he commanded. "Don't let that light rise over us. Be quick, now!"

"What is it, Professor?" asked young Sampson, as he obeyed the scientist's injunction.

"I am sure it is a light in the bow of another airship—but what manner of ship she is, or who drives her, I cannot guess," declared Professor Henderson, gravely.

"Another airship!" cried Jack, who overheard him. "What do you know about that?"

Mark handled the Snowbird with great skill, and the powerful craft mounted much more swiftly than the distant spark of light. The spiral course the 'plane now followed carried it at times much farther from the mountain side than it had been when first the strange light was noticed. That light followed the Snowbird up and up in similar spirals, and the boys were soon convinced that Professor Henderson's discovery was a fact. The lamp was in the bow of another air craft.

"But why should we keep over them?" asked Jack. "There is no danger; is there?"

"We do not know who they are," said the professor, shortly. "The craft came right out of a fastness in the mountain-side—a place difficult to reach, and which would not seem to attract aviators of the ordinary class." "I know what he is thinking of," cried Mark, suddenly. "I read in the paper that the Department of Justice officers are after some big smugglers and that it is believed the criminals, in going back and forth into Canada, use some kind of an aerial craft. Isn't that so, Professor Henderson?"

"I had the fact in mind. The flying machine is being put already to uses that are not commendable, to say the least. The Maine and Canadian border has for years been used by bands of smugglers, and if one of these gangs have purchased and can use a flying craft, they may make the revenue men a deal of trouble."

"You're right, sir. And I read likewise that the government officers proposed using an aeroplane themselves to track the smugglers. Perhaps the villains, if that is their ship below us, may take us for secret service men."

As he spoke the lamp so far below them darted up at a sudden and sharp angle, there sounded the sharp crack of some weapon, and Washington White jumped and screamed.

"Gollyation!" he bawled. "Dem fellers is suah tryin' ter punctuate us!"

Through the blackness of the night a distant voice hailed the pilot of the Snowbird.

"Ahoy! ahoy! Who goes there?" was the cry, and it was repeated twice.

CHAPTER V

BETWEEN TWO PERILS

Mark Sampson, having all the mechanism of the flying machine under his immediate control, had it in his power to increase speed and seek to escape the second airship. And Jack wondered why his chum did not immediately send the Snowbird flying at increased speed over the top of Mt. Katahdin and so seek to escape the menace below.

But the young fellow at the controls of the Snowbird had an advantage over his companions that Jack had forgotten. He could hear sounds at a much greater distance than they, and much clearer.

This was because of an invention of Professor Henderson—a small instrument similar to part of the ordinary telephone. The sensitive disk was a form of radio receiver which could be attached to any aviator's helmet, and was being put into general use by pilots. The two boys always adjusted this whenever they were strapped upon the pilot's seat.

Thus, although the report of the gun had sounded but faintly to the other members of the party, to Mark it seemed as though the explosion was within a hundred yards. The voice hailing them likewise seemed to ring in his ears very plainly; and beyond the words somewhat distinguished by his companions the young operator of the Snowbird could make out a further phrase spoken by the person who hailed from the other air-craft.

"Halt in the name of the law!"

Those were the sharp words Mark had caught, and for that reason he hesitated to increase the Snowbird's speed.

In a strap hung near his left hand was a transmitter. Without taking the advice of any of his companions in the flying machine, Mark seized it, put it to his lips, and replied to the hail:

"Ahoy! what do you want?"

Instantly the voice rose from the black abyss below them:

"Heave to! Stop in the name of the law!"

That time the professor and Jack heard the words spoken by their pursuer.

"What do you know about that?" demanded Jack. "'In the name of the law', no less!"

Professor Henderson jumped to the same conclusion that Mark had, and that instantly. "It may be the Secret Service men themselves," he said. "Ah, Andrew! it is just as well to withhold your fire until we know for sure."

For Andy Sudds had seized his rifle and stood ready to withstand an attack, should such an act become necessary.

Up from the depths came the cry again:

"Hold your ship. I propose to come aboard and search her. In the name of the United States Government!"

Mr. Henderson took the radio telephone out of Mark's hand and replied:

"We wish to know who and what you really are. We will not put ourselves in your power without knowing. We are amply armed."

"Don't you dare to fire upon a United States officer in the discharge of his duty," cried the voice from below, and now the strange airship was much nearer to them. "Who do you claim to be?"

"This is the Snowbird, from Easton, Maine, She is manned by her builders, Darrow and Sampson. She carries as passengers Washington White, Andrew Sudds and Amos Henderson," declared the professor, in reply. "And she is bound for Alaska."

"Well, well!" exclaimed the voice of their pursuer. "That may all be so. But I have my suspicions. I am Ford, special agent of the Department of Justice. Stand by. Now I am coming aboard."

At a nod from the professor, Mark had already brought the Snowbird to a halt. She lay floating, with all planes extended and without motion of propellers, poised over the summit of Mt. Katahdin.

The descending moon threw its beams over the height and revealed to the vaguely anxious occupants of the Snowbird, the other machine darting up from below.

This was a craft of much different aspect from their own. It was a great deal smaller and apparently without half the power possessed by the one built by Jack and Mark.

She shot into the air above their heads at a swift pace, however, and immediately poised over them. In this attitude Ford, as he called himself, had the occupants of the Snowbird completely at his mercy. A bomb dropped upon the huge flying machine would have blown her to pieces. Or, with a gun, he could have picked off one after another of the five people below.

"Stand out of the way, there!" commanded Ford.

Instantly those upon the larger air-craft saw a figure swing down from the framework of the airship above their heads. A light rope ladder unrolled and fell upon the upper deck, or platform of the Snowbird, and the man came down this ladder, hand under hand, and in half a minute stood in their midst.

He was a small, gray man—gray suit, gray hair and close-cropped mustache, and gray face, colorless and deeply lined. His age would be hard to judge.

"The Snowbird; eh?" he observed, looking sharply from one to the other of the five passengers of the huge flying machine. "You are Amos Henderson, sir?" he pursued, nodding to the professor. "I believe I have heard your name before. Professor Henderson, whose scientific discoveries have made us all marvel of late?"

"I am Professor Henderson," said the old gentleman, quietly. "And I can vouch for my companions. These boys, my adopted sons, have built this flying machine, and we are bound for Alaska."

"Indeed! Then I fear I have caused you some slight trouble, not to say delay," said Mr. Ford. "We revenue agents are extremely anxious to overhaul and interview all aviators along the border. You understand?"

"I believe that you have cause to suspect certain flying machines operating between the Canadian towns and Maine settlements," admitted Professor Henderson. "Quite right. And if our suspicions are based on fact, innocent flying men like yourselves may well beware of the fellows we are after. To be frank with you," pursued Mr. Ford, "a band of desperate smugglers are operating by aid of one or more aeroplanes. And piracy in the air may soon became as frequent—and as grave a peril to innocent aviators—as was ever piracy on the Spanish Main."

"It seems impossible!" said the professor. "Who are these desperate criminals?"

"A man named Bainbridge is at their head. He was originally a diamond dealer and finally was caught smuggling gems into the port of New York. He had to pay a huge fine and served a term at Atlanta for that crime and since then has sworn to be revenged upon the Government that punished him.

"We learned of late that he was operating on the Mexican border—bringing into the States diamonds that had paid no duty—by aid of a flying machine. But the uprising in Chihuahua and along the border made his work exceedingly dangerous, and he was driven away from that part of the country.

"Now we believe he has joined forces hereabout with ancient enemies of the Federal officers. At least, there is a strange aeroplane reported from both sides of the border, and some fine gems have appeared in the hands of certain suspected dealers in Maine, and as far south as Boston and Providence.

"Bainbridge is known to be a desperate man. Look out for him, Professor. If you are hailed by another machine, better keep away from it," and the secret service agent laughed. "Had I been in your place I would not have halted on this occasion. You certainly can outsail any airship I have ever seen operated."

Mr. Ford seemed quite satisfied that our friends were law-abiding and he ascended to his waiting craft in a few moments; and the Snowbird started onward again through the starlight.

But the warning of the special agent had impressed the boys as well as the professor. Andy Sudds refused to lie down again, although Jack and Mark continued to operate the flying machine. The old hunter sat with a rifle in his hand for the rest of the night. But the professor went to bed.

An hour after midnight a cloud from the west completely masked the moon and the whole heavens became misty. This cloud brought both wind and rain, and low upon its edge the lightning played fitfully.

"There will be a heavy tempest about dawn," Andy promised the boys. "I have seen a thunderstorm gather like this before." "But not while you were in a flying machine," chuckled Jack.

"No, sir. But on a mountain top a tempest looks much the same."

Mark, while at the controls, had scaled the machine down the air-ways until they were not more than fifteen hundred feet from the earth. But the boys decided to let the storm gather beneath them, and so shot the Snowbird up again until the indicator registered three thousand feet.

Near the earth it must have been very warm and sultry; but up here it was down to freezing, and the party were all warmly dressed. The clouds soon hid the whole earth from them and the great flying machine traveled in space, with the star-lit heavens above and the rolling mass of vapor, streaked now and then with lightning flashes, beneath.

The deafening roll of the thunder awoke Washington White from a short nap, and the darkey was not at all sure that he was safe from the lightning bolts.

"How d'I know dem bolts won't fly disher way?" he demanded of the boys when they tried to reassure him.

"Why, the earth attracts the electric bolt, and that attraction is much stronger than any the Snowbird may have for the electricity in the clouds," Mark told him. "I don't know erbout dat," grumbled Wash. "An' if jest one o' dem crazy lightning bolts should take it into its haid ter segastuate eround disher flying merchine—biff! bang! dat would be erbout all. Dere would be a big bunch o' crape hung on Wash White's do', suah as you is bawn, boy!"

But although the roar of the thunder and whining of the wind nearly drowned other sounds in and about the flying machine, save for a freshening of the gale the Snowbird was at first but little disturbed by the tempest which raged with such fury a thousand feet below.

Suddenly Mark caught sight of something moving across the red streak in the eastern sky—the light that warned them of the approach of the sun.

"What is that—a huge bird?" he demanded of Andy Sudds, pointing this moving figure out to the hunter.

Andy's eyes were very keen, for he was used to sighting along a rifle and gazing over long distances in search of game. But he, too, thought the object must be a bird.

"I declare, I didn't know birds flew so high," said Mark. "It must be an eagle. No other fowl could fly so high."

"'Nless it were Buttsy," remarked Washington, sotto voce. The professor was still asleep and the boys paid little attention to the flying object for some time. It was coming up behind the Snowbird, and they had no occasion to look behind.

The sun arose, angry and red, while the thunder continued to roll below them, and the crackling of the electric flashes was like minute guns. The Snowbird was winging its way along at about seventy-five miles per hour. Wash had gone into the covered galley to prepare breakfast. Jack was still in the operator's seat.

Suddenly Andy Sudds uttered a loud shout. A huge shadow was thrown athwart the flying Snowbird. Some object was hovering over them and they cast their eyes upward, at Andy's cry, to see another aeroplane swooping down directly upon them.

It was not the machine manned by Secret Service Agent Ford and his companion, but a much heavier and more rapid vehicle. And until its shadow fell across the Snowbird, the boys had had no warning of its approach.

At first glance it was apparent that the strange aircraft intended mischief. It was shooting down from a higher level, its sharp bow aimed directly for the Snowbird. Jack pushed over the switch and raised the bow of their own ship. She leaped forward and began to slant upward, too.

But instantly the course of the stranger was deflected to meet this change in the movement of the Snowbird. She had the advantage of the boys' craft, too. She evidently proposed to retain her overhead position, and as she shot in closer, Jack was constrained to descend again to escape collision with her.

"Keep away!" he shouted through the transmitter, and at his cry, and the bustle about him, the professor was awakened.

But no reply came from the strange aeroplane, although they could see several figures moving upon her. It swooped down upon them, and Jack had to deflect his planes again and slant downward toward the storm-cloud.

And then he saw the other peril. He was between two great dangers. If the reckless aviator tried to ram him from above, his only escape was by plunging through the tempest which raged just below them.

Down came the stranger upon the Snowbird again. She surely meant them ill—she was bent on their destruction. And meanwhile the thunder roared below and the crackling of the lightning was almost incessant.

Jack Darrow had to decide quickly—and he must determine which of the two risks to take.

CHAPTER VI

ON THE WINGS OF THE WIND

Speedy as the Snowbird was, she could not get out from under the shadow of the strange aeroplane. That was driven at a sharp angle down upon the boys' flying machine, and it seemed to all those in the lower 'plane that a collision was imminent.

The thunder fairly deafened them all. Around them rolled the mists and the wind shrieked through the stays of the aeroplane and shook the structure like a dog worrying a bone.

Down they fell, and in an instant the rushing rain, emptied in a torrent from the clouds, swept about them, saturating their garments and beating the flying machine itself toward the distant earth.

During the next few moments Jack Darrow, Mark Sampson, and their companions were in as grave peril as had ever threatened them in their eventful lives.

The torrents of water all but beat the flying machine to the earth—and to be dashed down from such a height spelled death to all and destruction to the aeroplane.

Jack, however, had been taught to keep cool in moments of danger, and he realized that their lives depended entirely upon his handling of the great machine. They had descended below the level of the storm-cloud at a most inopportune moment. They were caught in the midst of a veritable cloudburst.

Shaken desperately by the wind, and beaten upon by tons upon tons of water, it was a wonder that the great planes, or wings, of the flying machine were not torn away. All Jack could do was to guide her the best he could, and all his companions could do was to cling to a slender hope and endure the lashing of the gale.

But Jack Darrow did not propose to be cast to the ground—and the flying machine and his friends with him—without some further attempt to avert such a catastrophe.

After the first breath-taking rush of the storm he diverted the course of the machine again upward. He could scarcely see, the driving rain was so blinding; nor could he observe the indicators before him with any clearness. But he was quite sure that the enemy that had driven him down into the storm-cloud could see the Snowbird no better than he could see that strange aeroplane that had threatened to collide with them.

So he shot the Snowbird upward again at a long slant, and put on all the power of the engine to drive her onward. The flying machine shook and throbbed in every part. The power of the engines would have driven her, under other and more favorable conditions, at more than one hundred miles an hour—possibly a hundred and twenty-five.

Jack himself was almost blinded and deafened. He was strapped to his seat, so could give both hands to the work of manipulating the levers. He brought the Snowbird through the cloud and—with startling suddenness—they shot out of the mass of rolling moisture and into the sunlight of the dawn. But they were far off their course.

The change from the chaos of the storm-cloud to the almost perfect calm of the upper ether was so great that it was almost stunning. For a minute none of the five spoke a word.

Then it was Mark who shouted:

"There's that 'plane again, Jack I Look out for her!"

The enemy had missed them. She was some miles away, and although still on a level above, at the pace the Snowbird was now traveling it would take a fast flying machine indeed to overtake her.

The pursuit of the enemy (which they all believed to be the smuggler, manned by Bainbridge and his friends) was not kept up for long. By eight o'clock the Snowbird had dropped the other machine below the horizon, and the swift pace at which they had driven the Snowbird was rapidly bringing them once more toward Canada.

The storm had broken, but the clouds still hovered below them. They descended about noon, passing harmlessly through the vapor which had so long hidden the earth from them, and so came to within a thousand feet of the ground, where they swung along at fair speed for some hours.

They crossed the line, but did not descend until near St. Thomas. They went out of their way a good bit to land near this town on the shore of the St. Lawrence, for the flying machine had been so shaken in its struggle with the thunderstorm that some repairs were needed.

They descended in a field on the edge of the town, gave the farmer who owned the place a five-dollar bill to allow the machine to stand on his land, and then engaged him to drive Professor Henderson and the boys into town.

While the professor saw the authorities and obtained a legal document recommending the exploring party to the good offices of all British-Canadian officers whom they might meet, the boys went to a machine shop to have a rod repaired. The party took supper with the farmer, and an hour later the flying machine being pronounced by both Mark and Jack in perfect order, they got off amid the cheers of the onlookers, whose numbers were by that time swelled to almost five hundred persons.

It was long after dark and the moon had not risen. It was a cloudless night, however, and as the flying machine soared heavenward the voyagers could look deep into the seeming black-velvet of the skies, picked out by the innumerable sparkling stars, and thought they had never seen so wonderful or beautiful a sight.

As they cast their gaze downward, too, they beheld the torches at the Canadian farm rapidly receding, and then, in a few minutes, they were flying over St. Thomas, where the lights twinkled, too. Then they shot over the broad, island-dotted bosom of the St. Lawrence River, and so on across country and town toward the vast Canadian wilderness.

The professor and Andy had the watch and Jack and Mark went to bed. The excitement of the previous twenty-four hours had kept the boys up; but once they closed their eyes, they slept like logs all night. Andy Sudds relieved the professor now and then in the operator's seat, and they did not call the boys until Washington White made breakfast at daybreak. By that time the Snowbird had passed Lake St. John, far to the north and east, and was heading for Hudson Bay. The earth below them was a checker-board of forest and field, with here and there a ribbon of river, and occasionally a group of farmsteads, or a small town. Suddenly they were forced down, and had to remain many hours for repair work before ascending again.

The ranges of hills—some of them dignified enough to be termed "mountains"—which they crossed necessitated their flying high. They were generally at an altitude of two thousand feet and the rarefied atmosphere so far above the earth was cool, anyway. Since leaving St. Thomas, on the bank of the St. Lawrence, they had averaged eighty miles an hour, and before moonrise they were cognizant of the fact that they were approaching a great sheet of water.

"St. James Bay, the lower part of Hudson Bay," Professor Henderson explained.

Soon the moonlight shimmered upon the waves beneath them. Jack, who was guiding the craft, deflected the wings and they slid down the airways toward the water. They traveled all night over this great inland sea, at times so close to the surface that the leaping waves sprinkled them with their spray—for there was a stiff breeze.

A gale broke in earnest over the Hudson Bay territory that day, and despite the efforts of the voyagers they could not rise in the Snowbird above the tempest. Had there been solid ground beneath them they could easily have descended and remained upon terra firma until the storm was past.

This gale was favorable to their course, but it gripped them in its giant grasp and hurled them on into the northwest at a speed that imperiled the safety of the flying machine each moment. There was no sleep for any of the party now, and Washington White came pretty near (as Jack said) "making good his name in his face"—for if ever a darkey of Wash's ebony complexion turned pale, the professor's servant did so at this juncture.

On and on they were driven hour after hour. Scarcely a word was spoken the entire time. There was no cessation of the gale. The great body of water was passed and they knew that there was land beneath them again. But each time they tried to descend they found the storm near the earth-crust far heavier than at the upper levels.

To descend through the belt of the storm might partially wreck their flying machine and the professor knew, by the study of his recording instruments, that they were passing over an utter wilderness in which no help could be obtained and from which, should they be wrecked, they could not escape before the rigorous Arctic winter set in.

Hour after hour they drove on. The speed of the Snowbird at times, when driven by the full force of the gale, had mounted to one hundred thirty miles an hour.

Great Slave Lake was far south of their route; yet the professor told them that, had it been clear, at the altitude they traveled, they could have seen and marked this great body of water.

They actually crossed the Great Bear Lake and the Mackenzie River, however, and saw the ragged peaks of the Rocky Mountains, which here almost touch the shores of the Arctic Sea. Blown on and on, with little diminution of speed, it was not many hours before the Snowbird was flying over Alaskan wilds. The flying machine had kept closely to the course the professor had laid out for her when they left Maine. They were still headed for the slopes of the Endicott Range and the native town of Aleukan.

The question paramount in all their minds, however, was this: Would they reach their destination in safety?

CHAPTER VII

DROPPED FROM THE SKY

A thick mantle of fog masked the heavens; but beneath this the wind—traveling at great velocity—drove the ragged clouds like frightened sheep across the pastures of the firmament.

The moon and stars gave so little light that the earth seemed but a vague and shadowy mass—nothing more. The wind shrieked in many voices, as though a troop of goblins raced through the air, or rode the strangely formed and hurrying clouds.

Driven on with the tumbling banks of vapor, as vaguely outlined in the gloom as the clouds themselves, was the great flying machine, which the wind buffeted and harried about as though against it Old Boreas had some special spite.

Jack was in the operator's seat; but there was little to do but hang on to the steering wheel. The wind blew them as it listed.

"I don't well see how anybody can sleep in this horrid storm," complained Mark Sampson. "And the machine rocks so—ugh! I'm as sick as though we were at sea." "And we are pretty completely 'at sea,'" chuckled the more volatile Jack. "I hope the professor knows where we are. I don't!"

"And I don't see how he can tell," grumbled his chum.

"Pluck up your spirits, old man!" returned the older lad, but Mark interrupted him, still crossly:

"I hope I am as courageous as the next. We've done some funny stunts together, Jack Darrow—you and I and the old professor. But this caps them all, I declare. It's a mystery to me how Mr. Henderson and Andy Sudds can remain asleep."

"Well, they are both tired out, I reckon. They had a long watch—and we slept, you know."

"That was a long time ago," grunted Mark,

"It's pretty tough, I admit," said Jack, when Washington White broke in with:

"Hi, yi! Whuffo' you boys be sech cowards? Is I skeert? Huh!"

"You bet you're scared," returned Jack, emphatically. "When we got caught in that flaw yesterday afternoon he wanted to jump out; didn't he, Mark?"

"Wash certainly tried to climb out," rejoined Mark. "Well, den! dat showed I warn't no coward," crowed the black man, though in a very shaky voice. "If I'd been scart', would I really have wanted ter jump? It was a might long way to de groun' right den, I guess."

Suddenly the Shanghai crowed loudly. "Tell yo' what!" cried the black man, scratching his head. "Dat rooster done crow fo' company."

"Company!" gasped Mark. "What does he think he hears up here—angels' wings? We're about as near being in the company of the celestial hosts as we'll ever be and remain alive, I reckon."

"No, sah!" retorted Washington. "Dat Shanghai done know dat we is near some oder fow-el——"

"Up here in the air, Wash?" cried Jack.

"Dunno whar dey is," said the darkey, doggedly. "Dar he crows ergin!
Dar is suttenly critters ob his kind nearby—yes—sah!"

It may have been the Shanghai's raucous tone that aroused Andy. The old hunter suddenly appeared on the platform behind the operator's seat, where the boys and Wash were clinging, and Andy brought his rifle with him.

"Hullo!" he said. "Is the watch called?"

"I'm sorry if we awoke you, Andy," Jack said. "There is nothing for you to do."

"Nothing to shoot at; eh?" said the old hunter. "I reckon I ain't of much use in a flying machine, anyway. Sort of 'up in the air'; ain't I?"

"That's where we all are," complained Mark. "And I, for one, wish we were down again."

"Guess we're all with you in that wish, old man," agreed Jack.

As he spoke, the wind-blown figure of the professor hove into view from the small, sheltered cabin. He glanced at the various indicators and the compass in front of Jack.

"We are all in safety yet; are we, boys?" he queried.

"If you can call being driven helplessly before such a gale and about a mile above the earth safe," retorted Mark.

"Surely not as high as that," exclaimed Professor Henderson. He examined the instruments again, and said, quickly: "We are descending! How is that, Jack?"

"Not with my knowledge, sir," returned the boy aviator. "I think we have remained on the thousand-foot level since crossing the Rocky Mountains."

"I believe you have been faithful, my boy," returned the professor, quickly. "But the earth is certainly less than three hundred feet below us—ah! see that? The indicator registers 250 feet. Now 240!" "We are falling!" cried Mark.

"No!" said the professor. "The earth is rising. We are being blown against the mountainside. We must be within a few hundred miles, at least, of our destination. Those are the Endicott Mountains yonder," and he waved a hand at the darkness to the south of them.

"Hark!" cried Andy Sudds, suddenly.

There was a momentary lull in the wind. From below came the broken crowing of a cock in answer to the Shanghai's challenge. Then a dog barked.

"There's a farmhouse down there," said the hunter.

"What did I tell yo'?" cried Washington White. "Dat Buttsy knows his business, all right!"

"We must descend," commanded the professor. "Deflect the planes, Jack. Watch the indicator. Reduce the speed. Let us float down as easily as possible."

But, wrestling as the flying machine was with the wind, she could not descend easily. She scaled earthward with fearful velocity. The irrepressible Jack yelled:

"Go-ing down! We're going to bump hard in a minute!"

The aged professor and Andy Sudds showed no perturbation. Jack and
Mark had been through so many wonderful experiences with the professor,
Andy, and the negro, that they were not likely to be panic-stricken. Yet
all realized that death was imminent.

The finger on the dial showed a hundred feet from earth, and still they descended. Fifty feet!

"Hold hard!" commanded the professor. "We'll be down in a minute."

There seemed to be a break in the hurrying clouds. There was light in the sky—the twilight of the Long Day, for they were far beyond the Arctic Circle.

Looking down they could dimly see objects on the earth—trees, a house of some kind—several houses, in fact.

And then suddenly there was added to their perils an unlooked-for danger. Out of the murk which covered the earth below the flying machine sprang a point of light and the explosion of a gun echoed in the aviators' ears.

A rifle bullet tore right through to the inside and passed between the professor and Andy Sudds. There were men with firearms below, and they were firing point blank at the flying machine.

CHAPTER VIII

PHINEAS ROEBACH, OIL HUNTER

As has been said, the boys and their older companions had been in many perilous situations; but no adventure promised to end more tragically than this flight of the huge airship. The descent of the Snowbird, punctuated by the rifle shot below, seemed likely to be fatal to them all.

"What kind of people can they be?" gasped Mark. "They are trying to shoot us."

"Give me my rifle! I'll show 'em!" exclaimed the old hunter.

"You'll do nothing of the kind, Andy," commanded Professor Henderson.
"Do not make a bad matter worse by yielding to your passions."

A second shot was fired by those upon the ground; but the bullet went wide of the mark. Jack shouted:

"We are drawing away from them. Look out! we all but hit that tree!"

"Steady, Jack," admonished the professor. "We'll be down in a minute, my lads. Cling to anything handy. She will bounce some, but I believe we shall not be injured." The calmness of the aged scientist would have shamed the others into some semblance of order, were it needed; but both the boys were courageous, Andy Sudds did not know fear, and if Washington White was in a panic of terror, he did not get in the way of the others to hamper their movements.

The Snowbird was fluttering over the ground like a wounded bird, while so black were their surroundings that none of the party could distinguish anything of nearby objects. The clouds had broken but little, and only for a moment.

"She's down!" suddenly shouted Mark Sampson, and the flying machine jounced on its rubber-tired wheels, and then struck the ground again almost immediately.

Mark leaped down on one side and Andy Sudds on the other. Instantly, relieved of their weight, the flying machine was carried on again and Mark and Andy were thrown to the ground.

Perhaps that was well, for several rifles were again fired behind them and they heard the bullets whistle above their heads.

"Low bridge, Mark!" cried the old hunter, meaning for the boy to keep close to the earth. "I've got my gun."

"Don't fire on them, Andy," responded young Sampson, remembering the professor's warning. "We don't know who they are or what they mean by their actions."

"We don't want to be shot down without making any fight; do we?" cried
Andy.

"Let us escape without a fight if possible," urged the cautious youth, feeling sure that Professor Henderson would approve of this advice.

But the pounding of many feet approaching over the rising ground—evidently, as Mr. Henderson had said, the foothills of the mountain range—warned Mark and the hunter to keep still. In the partial light they saw a group of tall men, all armed, running past them in the direction the wounded Snowbird had been blown.

"Hush!" whispered Andy. "Indians!"

Mark had seen their long hair and beardless faces, and believed the hunter was right. The enemy were dressed in clothing of skins and were without hats. Yet Mark knew that the Indians of Alaska were much different from the savages of the western territories of the United States. He did not believe these Alaskan aborigines would attack white men.

It was growing lighter about them every moment. The lad and the tall hunter arose and stood listening for a further alarm—or for some cry from their comrades in the flying machine.

As the light increased they saw that they were in a grove of huge trees. Somehow the Snowbird had fluttered away through these forest monarchs and was now out of sight.

"I wonder what's happened to them?" gasped Mark.

"Them Indians haven't attacked yet," growled Andy Sudds. "If they begin to shoot we'll know which way to go, and we'll foller them."

But the first sound they heard came from behind them. There was the crash of heavy footsteps and a big man suddenly came panting up the slope. Cold as it was, his shirt was open at the neck, he was bare-headed, and he had not stopped to pull on his boots when he arose from his bed. In his right hand he carried a battered "fish-horn," and without seeing Mark and Andy he stopped and put this instrument to his lips, blowing a blast that made his eyes bulge and his cheeks turn purple.

"Hold on, Mister!" ejaculated the hunter. "What you got to sell? Or be you callin' the cows?"

"Mercy on me!" cried the fat man, and in a high, squeaky voice that seemed to be a misfit for his huge body. "I am sure I'm glad to meet you. You must have just arrived," and he squinted at the strangely clad hunter and his boy companion, for Mark wore a helmet with ear-tabs.

"We just landed, that's sure," admitted Andy. "From an airship, I fancy," exclaimed the other. "That is what is the matter with my Aleuts, then. They never have seen such a thing as an airship, I'll be bound. Have they hurt any of your party?"

"I don't know," Mark said, hastily. "If you are in command of those Indians, call them off, please. There are three of our party somewhere with the flying machine, and the Indians have been shooting at them."

"I'll try it," declared the man, instantly. "I can usually call them together with this horn," and he raised it to his lips again and blew another mighty blast.

"I have had this bunch of Aleuts six months," he explained, when he got his breath again. "They are good workers, but as superstitious as you can imagine. They are particularly shaky just now, for a number of queer things have happened lately in these parts. There is a volcano somewhere in action—we had a storm of ashes a week ago. And night before last there was a positive earth-shock."

"You seem like a pretty intelligent man," grunted Andy Sudds, in his blunt way. "What are you doing up here in this heaven-forsaken country?"

"Why, I am an oil hunter," said the fat man, simply. "A what?" repeated Andy and Mark together.

"Oil hunter. My name is Phineas Roebach, and I am in the employ of the Universal Oil Company. I am here—as I have been in many lands—boring for petroleum. You understand that my mission is semi-secret. If we find oil here we shall obtain a grant from the Government, or something like that."

Just at that moment Mark Sampson was not particularly interested in the odd-looking Mr. Roebach or his business.

"Blow your horn again, sir," he begged. "Call off your Indians. They may shoot our friends."

"If your party is all dressed as peculiarly as yourself, young sir," said Phineas Roebach, "my Aleuts could scarcely be blamed for taking a pot shot at them."

Then he blew the horn mightily for the third time.

CHAPTER IX

THE EARTHQUAKE

The long twilight which preceded full day had now grown so strong as to reveal matters more plainly about the spot where Mark and Andy Sudds had disembarked from the flying machine. They soon saw several objects running through the grove toward them, and these objects proved to be the returning Indians.

There were half a dozen of them, and they were all armed with rifles.
The moment they beheld the old hunter and the youth, with Phineas
Roebach, they gave every indication of shooting, for they stopped and
raised their rifles, pointing them at Mark and Andy.

Mr. Roebach sprang between his Aleuts and his visitors and began to harangue them angrily in their own harsh dialect. However, his huge body so entirely sheltered Mark and Andy that neither was much terrified by the Indians. Besides, the Maine hunter advanced his own rifle and calculated he could do considerable execution with it while the red men were hesitating.

"They believed you all spirits of the air," said the oil man, turning finally to speak to his new friends. "They were much frightened."

"Ask them for news of Professor Henderson and the others," begged the anxious Mark.

"They chased the crippled flying machine for some distance, but did not find it. My horn bade them return," replied Mr. Roebach.

Even as they started to walk with the oil man and his sullen Indians toward various shacks which they saw through the trees, and lower on the mountain side, they heard a hail and looked up to see Professor Henderson, Jack Darrow, and the negro, Washington White, descending the mountain in their rear.

"This is your party; is it?" demanded Mr. Roebach.

"Yes, sir," said Mark.

"Bring them directly to my cabin. The Aleuts will not hurt you, now that they know we are friends."

He hurried away, but Andy handled his rifle very suggestively and kept both eyes on the red men. The latter, however, kept to themselves and only stared at the crew of the Snowbird with great curiosity.

"Hurrah!" quoth Jack, when in earshot. "Here they are, safe and sound,
Professor!"

"We have been just as afraid that something bad was happening to you," Mark said, quickly. "Where's the machine?" "Your beautiful 'plane is badly wrecked, Mark, my boy," said Professor Henderson. "But I believe we shall be able to repair it in time. We are not, however, I feel sure, far from Aleukan. Do those men speak English?"

"Not much of it, I reckon, Professor," said Andy Sudds. "But they have got mighty nasty dispositions. If it wasn't for the fat man I reckon they would jump on us."

"He told us to follow along to his cabin," Mark proposed. "I do not think these Indians will touch us."

"They'd better think twice about it," said the belligerent Andy, pushing in between the professor and the Aleuts, as the whole party descended the mountain side toward the place where the oil man had pitched his camp.

As they proceeded the light grew and the newcomers to Alaska identified objects about them more clearly. Near at hand was the framework of a boring machine, or derrick. The professor began to notice a deposit of ash that lay thickly on the ground in sheltered places.

"How remarkable—how very remarkable!" he ejaculated. "One would think there was a volcano in action very near here."

Mark repeated what Phineas Roebach had said about the 'quake and the storm of ashes. The professor began to rub his hands together and his eyes twinkled. "I declare! I declare!" he repeated. "A seismic disturbance in this locality? Ah! our visit to Alaska for Dr. Todd may repay us nobly indeed."

Washington White's eyes opened very wide and he demanded:

"What's disher t'ing yo' calls 'sezmik', Professor Henderson? I suah don't understand no sech langwidge."

"He means an earthquake, Wash," said Jack, as the professor paid no attention to the darkey's question.

"Gollyation! is we goin' ter collek a nearthquake along wid dat chrisomela-bypunktater plant? And what good's a nearthquake w'en you got him?"

This unanswerable question of the darkey's fell flat, for the party just then reached the huge, two-roomed log cabin in which Phineas Roebach made his headquarters. The "oil hunter," as he called himself, appeared in a costume more fitted to the rigor of the weather.

"Come right in, gentlemen," was his cordial cry. "I have an Indian woman here who can cook almost as well as white folks. At any rate, she can make coffee and fry bacon. This is Professor Henderson? Glad to meet you, sir," and so went on, being introduced to the whole party.

The professor immediately began to question the oil hunter regarding the exact situation of his camp and learned that they were but a hundred and fifty miles from Aleukan. Phineas Roebach had a plentiful supply of dogs and sleds, too, with a goodly store of provisions. If worse came to worst and the flying machine could not be at once prepared, Mr. Roebach could supply the party with transportation to the Indian settlement where Professor Henderson would meet his own supplies from Coldfoot and there could obtain other dogs and sleds to go on to the valley where the Chrysothele-Byzantium was supposed to flourish.

"And the road from here to Aleukan is a good one at this season of the year. More than half the way you travel over a glacier, and as the icefield has not been in motion for ages, it makes a fine highroad," the oil hunter declared.

They were discussing these matters during breakfast, and everybody was feeling particularly thankful over the safe descent of the aeroplane, when they were startled by a sudden, jarring shock. The cabin rocked and the boys, at least, felt a qualmishness in the pit of the stomach that forbade further eating.

"What's that?" demanded Andy Sudds.

Washington White dropped the plate he was carrying to the table and ran to the door. Before he could open it, the door was broken in by the Indians, who came pouring in, loudly jabbering in their native tongue.

"A 'quake, sure enough!" ejaculated Phineas Roebach, getting quickly on his feet.

As he spoke, there was a repetition of the shock, only greatly increased. The oil hunter was thrown to the floor, as was everybody else in the house who was not seated. The roof of the cabin creaked and threatened to descend upon their heads.

The Indians, uttering cries of alarm, scrambled out of the cabin faster than they came in. But they had nothing on Washington White there. He was the first person to get through the door.

The white people followed the others in quick time. Jack and Mark felt that if the cabin was going to fall, the open air was the safer place. Here, however, it seemed that they could not keep their feet. They reeled about like drunken men, and the forest trees bent and writhed as though an invisible wind tore at them, whereas the fact was that the wind had fallen and it was a dead calm.

The air about them seemed to rock with the shock, there was a dull roaring sound which hummed continually in their ears, and the vibrations of the earth continued. They were indeed experiencing a most serious earthquake.

CHAPTER X

THE BLACK DAY

The 'quake was over in a very few moments; the Indians and Washington
White, however, cowered upon the ground for some time, crying out their
fear of what they considered supernatural phenomena. Jack Darrow and
Mark Sampson were not frightened in the same way as the darkey and the
Aleuts; nevertheless they were much shaken.

Professor Henderson, however, displayed naught but the keenest interest in the scientific side of the happening. He clambered to his feet the moment he could stand, and observed:

"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.