s yet the sphere had not stirred nor emitted a whisper of sound, though they knew the man inside was conning the controls in a fever of haste to leave the cavern. But they hadn't long to wait. There came a sputter, a starting cough from the rocket tubes beneath the sphere. Quickly they warmed into life, and the dully glimmering ball rocked in the hole it lay in. Then a cataract of noise unleashed itself; a devastating thunder roared through the echoing cavern as the rockets burst into full force. A wave of brilliant orange-red splashed out from under the sphere, licked back up its sides, and seemed literally to shove the great ball up towards the hole in the ceiling.
Its ascent was very slow. As it gained height it looked—save for its speed—like a fantastic meteor flaming through the night, for the orange plumage that streamed from beneath lit the ball with dazzling color. A glowing sphere, it staggered midway between floor and ceiling, creeping jerkily upwards.
"He's not going to hit the hole!" shouted Guinness.
The borer had not risen in a perfectly straight line; it jarred against the rim of the hole, and wavered uncertainly. Every second the roar of its rockets, swollen by echoes, rose in a savage crescendo; the faces of the three who watched were painted orange in the glow.
The sphere was blind. The man inside could judge his course only by the feel. As the three who were deserted watched, hoping ardently that Quade would not be able to find the opening, the left side-rockets spouted lances of fire, and they knew he had discovered the way to maneuver the borer laterally. The new flames welded with the exhaust of the main tubes into a great fan-shaped tail, so brilliant and shot through with other colors that their eyes could not stand the sight, except in winks. The borer jerked to the right, but still it could not find the hole. Then the flames lessened for a moment, and the borer sank down, to rise again a moment later. Its ascent was so labored that Phil shouted to Professor Guinness:
"Why so slow?"
And the inventor told him that which he had not seen for the intolerable light.
"Only half his rockets are on!"
