sty but satisfying supper at the farmhouse, the son drove Tom and
Jackson several miles to a railroad station, where they could catch a
train for Shopton.

In due season Tom's home was reached. He intended to stop but a minute,
to assure his father that everything was all right, and then get out
his speedy runabout to go to see Mary, to tell her the news.

But when Tom sought his father in the library, he was told that there
was a visitor in the house.

"Tom," said his father, "this gentleman is from Washington. He wants to
arrange for a government test of your silent airship. I told him I
thought you were about ready for it."

"A government test!" cried Tom. "Why, I didn't think the government
even knew I was working on such an idea!" Tom was greatly surprised.

CHAPTER XXIV

IN THE MOONLIGHT

With a reassuring smile the visitor from Washington looked at Tom Swift.

"The government officials," he said, "know more than some people give
them credit for--especially in these war times. Our intelligence bureau
and secret service has been much enlarged of late. But don't be
alarmed, Mr. Swift," went on the caller, whose name was Mr. Blair
Terrill. "Your secret is safe with the government, but I think the time
is ripe to use it now--that is, if you have perfected it to a point
where we can use it."

"Yes," answered Tom slowly, "the invention is practically finished and
it is a success, except for a few minor matters that will not take long
to complete.

"Our accident this afternoon had nothing to do with the efficiency of
the silencer," Tom went on. "It was deliberately damaged by some spy.
I'll take that up later. That I am interested to know how you heard of
my Air Scout, as I call it."

"Well, we have agents, you know, watching all the inventors who have
helped us in times past, and we haven't forgotten your giant cannon or
big searchlight. I might say, to end your curiosity and lull your
suspicions, that your friend, Ned Newton, who has been doing such good
Liberty Bond work, informed us of your progress on the silent motor."

"Oh, so it was Ned!" exclaimed Tom.

"Yes. He told us the time was about ripe for us to make you an offer
for your machine. I think we can use it to great advantage in scout
work on the western front," went on the agent, and he soon convinced
Tom that when it came to a knowledge of airships, he had some very
pertinent facts at his disposal.

"When can you give me a test?" M