d you'll soon
get over it. Are you casting off those ropes, Tom? Is all clear?"

"All but the bow and stern lines."

"You attend to the bow line, and I'll go to the stern," and, going over
to the gas generator, Mr. Sharp started it so as to force more vapor
into the red aluminum container. This had the effect of rendering the
airship more buoyant, and it tugged and strained harder than ever at
the ropes.

"Good-by, Tom," called Mr. Swift, reaching up to shake hands with his
son. "Drop me a line when you get a chance."

"Oh, Tom, do be careful," implored Mrs. Baggert, her kind face showing
her anxiety. "May I kiss you good-by?"

"Of course," answered the young inventor, though the motherly
housekeeper had not done this since he was a little chap. She had to
stand on a soap box, which Eradicate brought in order to reach Tom's
face, and, when she had kissed him she said:

"Oh, I'm so worried! I just know you'll be killed, risking your lives
in that terrible airship!"

"Ha! Not a very cheerful view to take, madam," observed Mr. Damon.
"Don't hold that view, I beg of you. Bless my eyelashes, but you'll see
us coming home, covered with glory and star dust."

"I'm sure I hope so," answered Mrs. Baggert, laughing a little in spite
of herself.

The last ropes were cast off. Good-bys were shouted as the airship shot
into the air, and Mr. Sharp started the motor, to warm it up before the
propellers were thrown into gear. The twenty cylinders began exploding
with a terrific racket, as the muffler was open, and Tom, looking down,
saw Boomerang awaken with a jump. The mule was so frightened that he
started off on a dead run, swinging the rickety, old wagon along behind
him.

Eradicate Sampson, who had been feeling his muscle since he discovered
what he thought was his marvelous strength, saw what was happening.

"Whoa, dar, Boomerang!" he shouted. Then, as the tailboard of the wagon
swung past him, he reached out and grabbed it. Perhaps he thought he
could bring the runaway mule up standing, but, if he did, he was
grievously disappointed. Boomerang pulled his master along the gravel
walk, and kept running in spite of Eradicate's command to "whoa, dar!"

It might have gone hard with him, had not Garret Jackson, the engineer,
running in front of Boomerang, caught the animal. Eradicate picked
himself up, and gazed sadly at his arms. The navigators of the air
could not hear what he said, but what he thought was evident to