, as he would have
done if we had come in any other machine."

"That's so!" exclaimed Tom. "I'm going to give him a sensation. I'll
fly right over his head, and he won't know it until he sees us. I'll
come up from behind."

A moment later he put this little trick into execution. Along swept
the airship, until, with a rush, it passed right over Mr. Damon's
head. He never heard it, and was not aware of what was happening
until he saw the shadow it cast. Then, jumping aside, as if he
thought something was about to fall on him, he cried:

"Bless my mosquito netting! What in the world--"

Then he saw Tom and Ned in the airship, which came gently to earth a
few yards further on.

"Well of all things!" cried Mr. Damon. "What are you up to now, Tom
Swift?"

"It's my noiseless airship," explained our hero. "She doesn't make a
sound. Get aboard, and have a ride."

Mr. Damon looked toward the house.

"I guess my wife won't see me," he said with a chuckle. "She's more
than ever opposed to airships, Tom, since we went on that trip
taking moving pictures. But I'll take a chance." And in he sprang,
when the two lads started up again. They made quite a flight, and
Tom found that his new motor exceeded his expectations. True, it
needed some adjustments, but these could easily be made.

"Well, what are you going to do with it, now that you have it?"
asked Mr. Damon, as Tom once more brought the machine around to the
odd man's house, and stopped it. "What's it for?"

"Oh, I think I'll find a use for it," replied the young inventor.
"Will you come back to Shopton with us?"

"No, I must stay here. I have some letters to write. But I'll run
over in a few days, and see you. Then I'll go on another trip, if
you've got one planned."

"I may have," answered Tom with a laugh. "Good-bye."

He and Ned made a quick flight home, and Tom at once started on
making some changes in the motor. He was engaged at this work the
next day, when he noticed a shadow pass across an open window. He
looked up to see Ned.

"Hello, Tom!" cried his chum. "Have you heard the news?"

"No, what news? Has Andy Foger fallen out of his airship?"

"No, but there are a whole lot of Custom House detectives in town,
looking for clews to the smugglers."

"Still at it, eh? Shopton can't seem to keep out of the limelight.
Has anything new turned up?"

"Yes. I just met Mr. Whitford. He's back on the case and he has
several men with him. They received word t