"Wonderful! Marvellous! Incredible! That rara avis, an
exception to all exceptions!" declared the professor, more deeply
stirred than either of his nephews had ever seen him before. "A
genuine tornado which has no eastern drift; which heads as
directly as possible towards the northwest, and at the same
time--incredible!"

Only ears of his own caught these sentences in their entirety,
for now the storm was fairly bellowing in its might, formed of a
variety of sounds which baffles all description, but which, in
itself, was more than sufficient to chill the blood of even a
brave man. Yet, almost as though magnetised by that frightful
force, the professor was holding his air-ship steady, loitering
there in its direct path, rather than fleeing from what surely
would prove utter destruction to man and machine alike.

For a few moments Bruno withstood the temptation, but then leaned
far enough to grasp both hand and tiller, forcing them in the
requisite direction, causing the aeromotor to swing easily around
and dart away almost at right angles to the track of the tornado.

That roar was now as of a thousand heavily laden trains rumbling
over hollow bridges, and the professor could only nod his
approval when thus aroused from the dangerous fascination.
Another minute, and the air-ship was floating towards the rear of
the balloon-shaped cloud itself, each second granting the
passengers a varying view of the wonder.

True to the firm hand which set its machinery in motion, the