!"

"Cheerful," remarked Tom in a low voice, with an apprehensive look
at Ned.

"Is there any danger?" asked his chum.

"Danger? Plenty of it," replied the young inventor. "The frozen
particles may rip open the gas bag." He stopped suddenly and looked
at a gage on the wall of the steering-tower--a gage that showed the
gas pressure.

"One compartment of the bag has been ripped open!" cried Tom. "The
vapor is escaping! The whole bag may soon be torn apart!"

The noise of the pelting hailstones increased. The roar of the
storm, the bombardment of the icy globules, and the moaning of the
wind struck terror to the hearts of the gold-seekers.

"What's to be done?" yelled Ned.

"We must go up, to get above the storm, or else descend and find
some shelter!" answered Tom. "I'll first see if I can send the ship
up above the clouds!"

He increased the speed of the motor so that the propellers would aid
in taking the ship higher up, while the gas-generating machine was
set in operation to pour the lifting vapor into the big bag.

CHAPTER XIII

A FRIGHTENED INDIAN

The violence of the hail storm, the clatter of the frozen pellets as
they bombarded the airship, the rolling, swaying motion of the craft
as Tom endeavored to send it aloft, all combined to throw the
passengers of the RED CLOUD into a state of panic.

"Bless my very existence!" cried Mr. Damon, "this is almost as bad
as when we were caught in the hurricane at Earthquake Island!"

"I am sure that this storm is but the forerunner of some dire
calamity!" declared Mr. Parker.

"I'm afraid it's all up with us," came from Abe Abercrombie, as he
looked about for some way of escape.

"Do you think you can pull us through, Tom?" asked Ned Newton, who,
not having had much experience in airships had yet to learn Tom's
skill in manipulating them.

The young inventor alone seemed to keep his nerve. Coolly and calmly
he stood at his post of duty, shifting the wing planes from moment
to moment, managing the elevation rudder, and, at the same time,
keeping his eye on the registering dial of the gas-generating
machine.

"It's all right," said Tom, more easily than he felt. "We are going
up slowly. You might see if you can induce the gas machine to do any
better, Mr. Damon. We are wasting some of the vapor because of the
leak in the bag, but we can manufacture it faster than it escapes,
so I guess we'll be all right."

"Mr. Parker, may I ask you to oil the