to catch
the smugglers? I can promise you a big reward, and much fame if we
catch them. An airship is just what is needed. You are the one to do
it. Will you?"

CHAPTER VII

A SEARCHLIGHT IS NEEDED

For a few moments after the custom officer had made his appeal, Tom
Swift did not reply. His thoughts were busy with many things.
Somehow, it seemed of late, there had been many demands on him,
demands that had been hard and trying.

In the past he had not hesitated, but in those cases friendship, as
well as a desire for adventures, had urged him. Now he thought he
had had his fill of adventures.

"Well?" asked Mr. Whitford, gently. "What's your answer, Tom? Don't
you think this is a sort of duty-call to you?"

"A duty-call?" repeated the young inventor.

"Yes. Of course I realize that it isn't like a soldier's call to
battle, but Uncle Sam needs you just the same. When there is a war
the soldiers are called on to repel an enemy. Now the smugglers are
just as much an enemy of the United States, in a certain way, as an
armed invader would be."

"One strikes at the life and liberty of the people, while the
smugglers try to cheat Uncle Sam out of money that is due him. I'm
not going to enter into a discussion as to the right of the
government to impose duties. People have their own opinion as to
that. But, as long as the law says certain duties are to be
collected, it is the duty of every citizen, not only to pay those
dues, but to help collect them. That's what I'm asking you to do,
Tom."

"I don't want to get prosy, or deliver a lecture on the work of the
custom house, Tom, but, honestly, I think it is a duty you owe to
your country to help catch these smugglers. I admit I'm at the end
of my rope. This last clew has failed. The Fogers seem to be
innocent of wrong doing. We need your help, Tom."

"But I don't see how I can help you."

"Of course you can! You're an expert with airships. The smugglers
are using airships, of that I'm sure. You tell me you have just
perfected a noiseless aircraft. That will be just the thing. You can
hover on the border, near the line dividing New York State from
Canada, or near the St. Lawrence, which is the natural division for
a certain distance, and when you see an airship coming along you can
slip up in your noiseless one, overhaul it, and make them submit to
a search."

"But I won't have any authority to do that," objected Tom, who
really did not care for the comm