here, and picked out this place
because it was so quiet," suggested Ned.

"That's possible. But where would he operate from?" asked Tom.
"There are few in Shopton who would want to buy smuggled goods."

"They may only ship them here, and fix them so they can't be
recognized by the custom authorities, and then send them away
again," went on Ned. "This may be a sort of clearing-house for the
smugglers."

"That's so. Well, I don't know as we have anything to do with it.
Only if those fellows are using an airship I'd like to know what
kind it is. Well, come on out to the shop now, and we'll see how the
silent motor works."

On the way Tom passed his father, and, telling him not to work too
hard in the sun, gave his parent the piece of paper to read, telling
about the smugglers.

"Using airships! eh?" exclaimed Mr. Swift. "And they think there's a
clew here in Shopton? Well, we'll get celebrated if we keep on,
Tom," he added with a smile.

Tom and Ned spent the rest of the day working over the motor, which
was set going, and bore out all Tom claimed for it. It was as silent
as a watch.

"Next I want to get it in the airship, and give it a good test," Tom
remarked, speeding it up, as it was connected on a heavy base in the
shop.

"I'll help you," promised Ned, and for the next few days the chums
were kept busy fitting the silent motor into one of Tom's several
airships.

"Well, I think we can make a flight to-morrow," said the young
inventor, about a week later. "I need some new bolts though, Ned.
Let's take a walk into town and get them. Oh, by the way, have you
seen anything more of Andy Foger?"

"No, and I don't want to. I suppose he's gone back home after his
visit to Sam. Let's go down the street, where the Foger house is,
and see if there's anything going on."

As the two lads passed the mansion, they saw a man, in the kind of
suit usually worn by a carpenter, come out of the back door and
stand looking across the garden. In his hand he held a saw.

"Still at the repairs, I guess," remarked Ned. "I wonder what--"

"Look there! Look! Quick!" suddenly interrupted Tom, and Ned,
looking, saw someone standing behind the carpenter in the door. "If
that isn't Andy Foger, I'll eat my hat!" cried Tom.

"It sure is," agreed Ned. "What in the world is he doing there?"

But his question was not answered, for, a moment later, Andy turned,
and went inside, and the carpenter followed, closing the door behind
the