"Let go!" cried the youthful inventor, and the man gave the little craft a shove. Across the rather uneven ground of the doctor's yard it ran, straight for a big iron barrier.
"Look out! We'll be into the fence!" shouted the surgeon. "We'll be killed!" He seemed about to leap off.
"Sit still!" cried Tom, and at that instant he tilted the elevation planes, and the craft shot upward, going over the fence like a circus horse taking a seven-barred gate.
"Oh!" exclaimed the physician in a curious voice. They were off on their trip to save the life of Mr. Swift.
What the sensations of the celebrated specialist were, Tom never learned. If he was afraid, his fright quickly gave place to wonder, and the wonder soon changed to delight as the machine rose higher and higher, acquired more speed, and soared in the air over the country that spread out in all directions from Kirkville.
"Magnificent! Magnificent!" murmured the doctor, and then Tom knew that the surgeon was in the grip of the air, and was one of the "bird-men."
Every moment the Humming-Bird increased her speed. They passed over the river near where men were working on the broken bridge. It was now no barrier to them. Tom, noting the barograph, and seeing that they were twenty-two hundred feet high, decided to keep at about that distance from the earth.
"How fast are we going?" cried Dr. Hendrix, into the ear of the young inventor.
"Just a little short of a hundred an hour!" Tom shouted back. "We'll hit a hundred and five before long."
His prediction proved true, and when about forty miles from Shopton that terrific speed had been attained. It seemed as if they were going to have a trip devoid of incident, and Tom was congratulating himself on the quick time made, when he ran into a contrary strata of air. Almost before he knew it the Humming-Bird gave a dangerous and sickening dive, and tilted at a terrifying angle.