Instinctively the brothers drew nearer each other, as though for mutual protection, each one letting hand drop to belt where a revolver was habitually carried, but which was lacking now, thanks to the great haste with which they had taken wing at the approach of the tornado.

“What is it? What can it mean?” asked Bruno and Waldo, almost in the same breath, as those fierce echoes died away in the distance.

Professor Featherwit made no immediate reply, but by the glow of yonder camp-fire he fumbled inside the magic locker, fetching forth firearms, then speaking in hushed tones:

“Wait. Listen for—I knew it!”

From the opposite quarter came what might easily have been an echo of that first wild screech, only louder, longer, more savage, if such a thing be possible.

Prepared though they now were, neither brother could refrain from shrinking and shuddering, so hideously that cry sounded in their ears. But their uncle spoke in cool, clear tones:

“There is nothing supernatural about that, my lads. A panther or mountain lion, I dare say, scenting the fumes of our cookery, and coming to claim a share.”

“Then it isn't—Nothing spookish, uncle Phaeton?” ventured Waldo, in slightly unsteady tones.

The professor gave swift assurance upon that point, and, rallying as few youngsters would have done under like circumstances, the brothers grasped the weapons supplied their hands, waiting and watching for what was to come.

Once, twice, thrice those savage calls echoed far and wide, but with each repetition losing a portion of their terrors; and knowing now that prowling beasts surely were drawing nigh the camp-fire, the flying machine was abandoned by the trio, all drawing closer to the fire, which might prove no slight protection against attack.

Then followed a period of utter silence, during which their eyes roved restlessly around, striving to sight the four-footed enemy ere an actual attack could be made.

Professor Featherwit was first to glimpse a pair of greenish eyes in silent motion, and, giving a low hiss of warning to his nephews, that same sound serving to check further progress on the part of the wild beast, his short rifle came to a level, then emitted a peculiar sound.

Only the keenest of ears could have noted that, for only the fraction of an instant later followed a sharp explosion, the darkness beyond being briefly lit up by a yellowish glare.

“That's enough,—beware its mate!” cried the professor, keenly alert for whatever might ensue; but the words were barely across his lips when, with a vicious snarl, a furry shape came flying through the air, knocking Featherwit over as he instinctively ducked his head with arm flying up as additional guard.

Both man and beast came very near falling into the fire itself, and there ensued a wild, confused scramble, out of which the brothers singled their enemy, Waldo opening fire with a revolver, at close range, each shot causing the lion to yell and snarl most ferociously.

A cat-like recovery, then the fatal leap might have followed, for the confused professor was rising to his feet again, fairly in front of the enraged brute; but ere worse came, Waldo and Bruno were to the rescue, one firing as rapidly as possible, his brother driving a keen-bladed knife to the very hilt just back of that quivering forearm.

One mad wrestle, in which both lads were overthrown, then the gaunt and muscular brute stretched its length in a shivering throe, dead even while it strove to slay.

Just as the professor hurried to the front, beseeching his boys to keep out of peril if they loved him; at which Waldo laughed outright, although never had he felt a warmer love for the same odd-speaking, queer-acting personage than right at that moment.

“I'm all right; how's it with you, sir? And—Bruno?”

“Without a scratch to remember it by,” promptly asserted the elder brother, likewise regaining his feet and taking hasty account of stock. “No fault of his, though!” giving that carcass a kick as he spoke. “My gracious! I caught just one glimpse of them, and I was ready to make affidavit that each fang would measure a foot, while his claws—”

“Would pass through an elephant and clinch on the other side,” declared Waldo, stooping far enough to lift one of those armed paws. “But, I say, Bruno, how awfully they have shrunk, since then!”

Whether so intended or not, this characteristic break caused a mutual laugh, and, as there was neither sound nor sign of further danger from like source, one and all satisfied their curiosity by minutely inspecting the huge brute, stirring up the fire for that purpose.

“An ugly customer, indeed, if we had given him anything like a fair show,” gravely uttered the professor. “Only for your prompt assistance, my dear boys, what would have become of poor me?”

“We acted on our own account, as well, please remember, uncle. And even so, after all you have done for us since—”

“What was it you shot at, uncle Phaeton?” interrupted Waldo, who was constitutionally averse to aught which savoured of sentiment. “Another one of these—little squirrels, was it?”

Snatching up a blazing brand, the lad moved off in that direction, whirling the torch around his head until it burst into clear flame, then lowering it closer to a bloody heap of fur and powerful limbs, to give a short ejaculation of wondering awe.

It was a headless body upon which he gazed, ragged fragments of skin and a few splinters of bone alone remaining to tell that a solid skull had so recently been thereon.

Professor Phaeton gave another of his peculiar little chuckles, as he drew near, then patted the compact little rifle with which he had wrought such extraordinary work: a weapon of his own invention, as were the dynamite-filled shells to match.

“Although I am rather puny myself, boys, with this neat little contrivance I could fairly well hold my own against man or beast,” he modestly averred.

“A modern David,” gravely added Bruno, while Waldo chimed in with:

“What a dandy Jack the Giant-killer you would have been, uncle Phaeton, if you had only lived in the good old days! I wish—and yet I don't, either! Of course, it might have been jolly old sport right then, but now,—where'd I be, to-day?”

“A day on which has happened a miracle far more marvellous than all that has been set down in fairyland romance, my dear son,” earnestly spoke the professor. “And when the astounding truth shall have been published, broadcast, throughout all Christendom, what praises—”

“How thoroughly we shall be branded liars, and falsificationers from 'way up the crick'!” exploded the youngster, making a wry grimace and moving on to view the headless lion from a different standpoint.

“He means well, uncle Phaeton,” assured Bruno, in lowered tones. “He would not knowingly hurt your feelings, sir, but—may I speak out?”

“Why not?” quickly. “Surely I am not one to stand in awe of, lad?”

“One to be loved and reverenced, rather,” with poorly hidden emotion; then rallying, to add, “But when one finds it impossible to realise all that has happened this afternoon, when one feels afraid to even make an effort at such belief, how can the boy be blamed for feeling that all others would pronounce us mad or—wilful liars?”

Professor Phaeton saw the point, and made a wry grimace while roughing up his pompadour and brushing his closely trimmed beard with doubtful hand. After all, was the whole truth to be ever spoken?

“Well, well, we can determine more clearly after fully weighing the subject,” he said, turning back towards the flying-machine. “And, after all, what has happened to us thus far may not seem so utterly incredible after our explorations are completed.”

“Of this region, do you mean, sir?”

“Of the Olympic mountains, and all their mountainous chain may encompass,—yes,” curtly spoke the man of hopes, stepping inside the aerostat to perfect his arrangements for the night.

Waldo took greater pleasure in viewing the mountain lion towards whose destruction he had so liberally contributed, but when he spoke of removing the skin, Bruno objected.

“Why take so much trouble for nothing, Waldo? Even if we could stow the pelts away on board, they would make a far from agreeable burden. And if what I fancy lies before us is to come true, the more lightly we are weighted, the more likely we are to come safely to—well, call it civilisation, just for a change.”

“Then you believe that uncle Phaeton is really in earnest about exploring this region, Bruno?”

“He most assuredly is. Did you ever know him to speak idly, or to be otherwise than in earnest, Waldo?”

“Well, of course uncle is all right, but—sometimes—”

A friendly palm slipped over those lips, cutting short the speech which might perchance have left a sting behind. And yet the worthy professor had no more enthusiastic acolyte than this same reckless speaking youngster, when the truth was all told.

Leaving the animals where they had fallen, for the time being, the brothers passed over to where rested the aeromotor, finding the professor busily engaged in rigging up a series of fine wires, completely surrounding the flying-machine, save for one narrow, gate-like arrangement.

“Beginning to feel as though you could turn in for all night, eh, my boys?” came his cheery greeting.

“Well, somehow I do feel as though 'the sandman' had been making his rounds rather earlier than customary,” dryly said Waldo, winking rapidly. “I believe there must have been a bit more wind astir to-day than common, although neither of you may have noticed the fact.”

Professor Featherwit chuckled softly while at work, but neither he nor Bruno made reply in words. And then, his arrangements perfected save for closing the circuit, which could only be done after all hands had entered the air-ship, he spoke to the point:

“Come, boys. You've had a rough bit of experience this day, and there may be still further trouble in store, here in this unknown land. Better make sure of a full night's rest, and thus have a reserve fund to draw upon in case of need.”

There was plenty of sound common sense in this adjuration, and, only taking time to procure a can of fresh water from yonder stream, the two youngsters stepped within that charmed circle, permitting their uncle to close the circuit, and then test the queer contrivance to make sure all was working nicely.

A confused sound broke forth, resembling the faraway tooting of tin horns, which blended inharmoniously with the ringing of nearer bells, all producing a noise which was warranted to arouse the heaviest sleeper from his soundest slumber.

“That will give fair warning in case any intruder drifts this way,” declared the professor, chucklingly, then sinking down and wrapping himself up in a close-woven blanket, similar to those employed by the boys.

“Even a ghost, or a goblin, do you reckon, uncle Phaeton?”

“Should such attempt to intrude, yes. Go to sleep, you young rascal!”

But that proved to be far more readily spoken than lived up to. Not but that the brothers were weary, jaded, and sore of muscle enough to make even the thought of slumber agreeable; but their recent experience had been so thrilling, so nerve-straining, so far apart from the ordinary routine of life, that hours passed ere either lad could fairly lose himself in sleep.

Still, when unconsciousness did steal over their weary brains, it proved to be all the more complete, and after that neither Bruno nor Waldo stirred hand or foot until, well after the dawn of a new day, Professor Featherwit shook first one and then the other, crying shrilly:

“Turn out, youngsters! A new day, and plenty of work to be done!”