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 flying-machine maintained that gentle curve until it swung around well to the rear of the cloud, where again Professor Featherwit broke out in ecstatic praises of their marvellous good fortune. “'Tis worth a life's ransom, for never until now hath mortal being been blessed with such a magnificent opportunity for taking notes and drawing deductions which--” The professor nimbly ducked his head to dodge a ragged splinter of freshly torn wood which came whistling past, cast far away from the tornado proper by those erratic winds. And at the same instant the machine itself recoiled, shivering and creaking in all its cunning joints under a gust of wind which seemed composed of both ice and fire. “Oh, I say!” gasped Waldo, when he could rally from the sudden blow. “Turn the old thing the other way, uncle Phaeton, and let's go 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.