or, and Tom and Mr. Damon could hear him
turning the levers and wheels, ready to start. But before the
explosions came something happened. There was a sound as of some great,
siren whistle blowing, and then, with a howl of the on rushing air, the
Red Cloud, the propellers of which hung motionless on their shafts, was
fairly sucked forward toward the fire, as the current sucks a boat over
a water fall.

"Start the motor! Start the motor, Mr. Sharp!" cried Tom.

"I'm trying to, but something seems to be the matter."

"We're being drawn right over the fire!" yelled Mr. Damon. "It's
getting hotter every minute! Can't you do something?"

"You take the wheel," called the balloonist to Mr. Damon. "Steer
around, just as if it was an auto when we start the engine. Tom, come
here and give me a hand. The motor has jammed!"

The young inventor sprang to obey. Mr. Damon, his face showing some of
the fear he felt, grasped the steering wheel. The airship was now about
a quarter of a mile high, but instead of resting motionless in the air,
sustained by the gas in the container, she was being pulled forward,
right toward the heart of the mass of black vapor, which it could now
be seen was streaked with bright tongues of flame.

"What's making us go ahead, if the motor isn't going?" asked Tom, as he
bent over the machine, at which the aeronaut was laboring.

"Suction--draught from the fire!" explained Mr. Sharp. "Heated air
rises and leaves a vacuum. The cold air rushes in. It's carrying us
with it. We'll be right in the fire in a few minutes, if we can't get
started with this motor! I don't see what ails it."

"Can't we steer to one side, as it is?"

"No. We're right in a powerful current of air, and steering won't do
any good, until we have some motion of our own. Turn the gasolene lever
on a little more, and see if you can get a spark."

Tom did so, but no explosion resulted. The twenty cylinders of the big
engine remained mute. The airship, meanwhile, was gathering speed,
sucked onward and downward as it was by the draught from the fire. The
roaring was plainer now, and the crackling of the flames could be heard
plainly. The heat, too, grew more, intense.

Frantically Tom and Mr. Sharp labored over the motor. With the
perverseness usual to gas engines, it had refused to work at a critical
moment.

"What shall I do?" cried Mr. Damon from his position in the pilot
house. "We seem to be heading right for the midst of it?"