suggested:

"Looks like the blame thing was sick at the stomach!"

No doubt this was meant for a feeble attempt at joking, but
Professor Featherwit took it for earnest, and made quick reply:

"That is precisely the case, my dear lad, and I am greatly joyed
to find that you are not so badly frightened but that you can
assist me in taking notes of this wondrous happening. To think
that we are the ones selected for--"

"I say, uncle Phaeton."

"Well, my lad?"

"If this thing is really sick at the stomach, when 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."