look
for--well, almost anything's better than this old cyclone!"

"Tornado, lad," swiftly corrected the man of precision, leaning far
forward, and gazing enthralled upon the vision which fairly thrilled
his heart to its very centre. "Never again may we have such another
opportunity for making--"

They were now directly in the rear of the storm, and as the air-ship
headed across that track of destruction, it gave a drunken stagger,
casting down its inmates, from whose parching lips burst cries of
varying import.

"Air! I'm choking!" gasped Bruno, tearing open his shirt-collar with a
spasmodic motion.

"Hold me fast!" echoed Waldo, clinging desperately to the life-line.
"It's drawing me--into the--ah!"

Even the professor gave certain symptoms of alarm for that moment,
but then the danger seemed past as the ship darted fairly across the
storm-trail, hovering to the east of that aerial phantom.

There was no difficulty in filling their lungs now, and once more
Professor Featherwit headed the flying-machine directly for the
balloon-shaped cloud, modulating its pace so as to maintain their
relative position fairly well.

"Take note how it progresses,--by fits and starts, as it were," observed
Featherwit, now in his glory, eyes asparkle and muscles aquiver, hair
bristling as though full of electricity, face glowing with almost
painful interest, as those shifting scenes were for ever imprinted upon
his brain.

"Sort of a hop, step, and jump, and that's a fact," agreed Waldo, now a
bit more at his ease since that awful sense of suffocation was lacking.
"I thought all cyclones--"

"Tornado, my DEAR boy!" expostulated the professor.

"I thought they all went in holy hurry, like they were sent for and
had mighty little time in which to get there. But this one,--see how it
stops to dance a jig and bore holes in the earth!"

"Another exception to the general rule, which is as you say," admitted
the professor. "Different tornadoes have been timed as moving from
twelve to seventy miles an hour, one passing a given point in half a
score of seconds, at another time being registered as fully half an hour
in clearing a single section.

"Take the destructive storm at Mount Carmel, Illinois, in June of '77.
That made progress at the rate of thirty-four miles an hour, yet its
force was so mighty that it tore away the spire, vane, and heavy gilded
ball of the Methodist church, and kept it in air over a distance of
fifteen mi