en will it erupt? I'd
give a dollar and a half to just get out o' this, science or no science,
notes or no notes at all!"

"Patience, my dear boy," gravely spoke the little man of science, busily
studying those eddying currents like one seeking a fairly safe method of
extrication from peril. "It may come far sooner than you think, and
with results more disastrous than feeble words can tell. We surely are
a burden such as a tornado must be wholly unaccustomed to, and I really
believe these alternations are spasmodic efforts of the cloud itself to
vomit us forth; hence you were nearer right than you thought in making
use of that expression."

Just then came a rush of icy air, and Bruno pantingly cried:

"I'm swelling up--like Aesop's--bullfrog!"

CHAPTER IV. THE PROFESSOR'S LITTLE EXPERIMENT.

Again those involuntary riders of the tornado were tossed violently to
and fro in their seemingly frail ship, while the balloon itself appeared
threatened with instant dissolution, those eddying currents growing
broken and far less regular in action, while the fierce tumult grew in
sound and volume a thousandfold.

All around the air-ship now showed ugly debris, limbs and boughs and
even whole trunks of giant trees being whirled upward and outward, each
moment menacing the vessel with total destruction, yet as frequently
vanishing without infringing seriously upon their curious prison.

Sand and dirt and fragments of shattered rock whistled by in an
apparently unending shower, only with reversed motion, flying upward in
place of shooting downward to earth itself.

Speech was utterly impossible under the circumstances, and the
fate-tossed voyagers could only cling fast to the hand-rail, and hold
those precious air-tubes in readiness for the worst.

Never before had either of the trio heard such a deafening crash and
uproar, and little wonder if they thought this surely must herald the
crack of doom!

The tornado seemed to reel backward, as though repulsed by an immovable
obstacle, and then, while the din was a bit less deafening, Professor
Featherwit contrived to make himself heard, through screaming at the top
of his voice:

"The mountain range, I fancy! It's a battle to the--"

That sentence was perforce left incomplete, since the storm-demon gave
another mad plunge to renew the battle, bringing on a repetition of that
drunken swaying so upsetting to both mind and body.

A few seconds thus, then the tornado conq