ached his sending plate, and he also substituted
for the ordinary incandescent light, a powerful tungsten one, that
would give illumination enough to cause the likeness to be
transmitted over the wire.

The same thing was done to a number of the public telephones in
that vicinity, each one being fitted up so that the picture of
whoever talked would be transmitted over the wire when Tom turned
the switch. To help the plan further the telephone manager marked
a number of other 'phones, "Out of Order," for the time being.

"Now, I think we're done!" exclaimed the young inventor, with a
sigh, late that night. He and Ned and the line manager had worked
hard.

"Yes," answered the young banker, "the traps are set. The question
is: Will our rat be caught?"

CHAPTER XXI

THE PHOTO TELEPHONE

Tom Swift was taking, as he afterward confessed, "a mighty big
chance." But it seemed the only way. He was working against
cunning men, and had to be as cunning as they.

True, the man he hoped to capture, through the combination of his
photo telephone and the phonograph, might go to some other
instrument than one of those Tom had adjusted. But this could not
be helped. In all he had put his new attachment on eight 'phones
in the vicinity of the sawmill. So he had eight chances in his
favor, and as many against him as there were other telephones in
use.

"It's a mighty small margin in our favor," sighed Tom.

"It sure is," agreed Ned. They were at Mrs. Damon's house,
waiting for the call to come in.

"But we couldn't do anything else," went on Tom.

"No," spoke Ned, "and I have a great deal of hope in the
proverbial Swift luck, Tom."

"Well, I only hope it holds good this time!" laughed the young
inventor.

"There are a good many things that can go wrong," observed Ned.
"The least little slip-up may spoil your traps, Tom."

"I know it, Ned. But I've got to take the chance. We've just got
to do something for Mrs. Damon. She's wearing herself out by
worrying," he added in a low voice, for indeed the wife of his
friend felt the absence of her husband greatly. She had lost
flesh, she ate scarcely anything, and her nights were wakeful ones
of terror.

"What if this fails?" asked Ned.

"Then I'm going to work that button clue to the limit," replied
Tom. "I'll go to Boylan and see what he and Peters have to say."

"If you'd done as I suggested you'd have gone to them first,"
spoke Ned. "You'll find they're mixed