led with, and has a
greater lifting power than the hot air used in the old balloons.

"By putting more gas into the silk bag above us I can rise higher. The
less gas I use the lower we go. The gas is let into or out of the bag by
means of valves which are operated from the engine room or the steering
tower. The forward motion of the ship is brought about by means of the
propeller at the stern. This propeller works by electricity. The
electricity comes from storage batteries which are kept charged from the
dynamo run by one of the gasolene engines. I also have an electric motor
that is run by either a gasolene engine or the storage battery. If one
breaks down I can use the other. The motor alone will run the propeller
if the storage batteries fail, and I have to run the electric machine
directly from the gasolene engine.

"That apparatus there," and he pointed to a complicated machine,
"is where the lifting gas is generated. A gasolene engine runs it.
Those tubes carry the gas from the machine to the bag above."

Then the professor pointed out the levers that started and stopped
The _Monarch_, those that sent it higher into the air or toward the
earth, the wheel for steering, and told the boys and men how to read
the instrument that gave the heights, the force of the wind, the
temperature, and much other information. He showed them how the entire
control of the ship could be accomplished from the conning or steering
tower by the turning of one wheel or another.

"Rattlesnakes an' mud turtles, but she sure is a bang-up affair,"
observed Andy Sudds. "But about that gun--"

"That's so. I promised you a gun in exchange for the one you lost," said
Mr. Henderson. "Wait a moment."

He was gone a little while. Presently he returned with a fine rifle, at
the sight of which the old hunter's eyes sparkled.

"That's a beauty!" he exclaimed. "It beats mine."

"It is a magazine gun," explained the professor. "It fires sixteen shots
with one loading," he explained.

"And I can kill sixteen white bears, sixteen seals or sixteen whales!"
exclaimed Andy with delight. "Well, I certainly am glad I come along,
Professor."

"I have a gun for each of us," Mr. Henderson went on, "in case we should
meet with enemies. But we may not need them. There is also the machine
gun at the stern."

Then the professor initiated his crew into the mysteries of the kitchen
and dining room. Nearly all the foods carried on the _Monarch_ were of
the