, Mr. Swift. Well, that party didn't call up from here."

"I know, Larsen. It was from another station. We're after him.
Much obliged to you. Come on back."

Tom was sure his theory was right. The man had called up the Damon
house from some telephone near a sawmill. And a little later Tom's
theory was proved to be true. He got a report from the second
detective. Unfortunately the man had not been able to reach the
telephone station before the unknown speaker had departed.

"Was the place near a sawmill?" asked Tom, eagerly.

"It was," answered the detective over the wire. "The telephone is
right next door to one. It's an automatic pay station and no one
seems to have noticed who the man was who telephoned. I couldn't
get a single clue. I'm sorry."

"Never mind," said Tom, as cheerfully as he could. "I think I'm on
the right track now. I'm going to lay a trap for this fellow."

CHAPTER XX

SETTING THE TRAP

Troublesome problems seemed to be multiplying for Tom Swift. He
admitted as much himself after the failure to capture the man who
had telephoned to Mrs. Damon. He had hoped that his plan of
sending detectives to the location of the telephones would
succeed. Since it had not the youth must try other means.

"Now, Ned," he said to his chum, when they were on their way from
Mrs. Damon's, it being impossible to do anything further there.
"Now, Ned, we've got to think this thing out together."

"I'm willing, Tom. I'll do what I can."

"I know you will. Now the thing to do is to go at this thing
systematically. Otherwise we'll be working around in a circle, and
won't get anywhere. In the first place, let's set down what we do
know. Then we'll put down what we don't know, and go after that."

"Put down what you don't know?" exclaimed Ned. "How are you going
to put down a thing when you don't know it?"

"I mean we can put a question mark after it, so to speak. For
instance we don't know where Mr. Damon is, but we want to find
out."

"Oh, I see. Well, let's start off with the things we do know."

The two friends were at Tom's house by now, having come from
Waterford in Tom's airship. After thinking over all the exciting
happenings of the past few days, Tom remarked: "Now, Ned, for the
things we do know. In the first place Mr. Damon is missing, and
his fortune is about gone. There is considerable left to Mrs.
Damon, however, but those scoundrels may get that away from her,
if we don't watch out. Se