--that is, only their images will be caught on the film.

"Oh, I see," exclaimed Ned, and then he helped Tom fix the machine for
the test.

CHAPTER VII

WHAT THE CAMERA CAUGHT

"Well, is she working, Tom?" asked our hero's chum, a little later,
when they had set the camera up on a box in the garden. It pointed
toward the main shop door, and from the machine came a clicking sound.
The electric light was glowing.

"Yes, it's all ready," replied Tom. "Now just act as if it wasn't
there. You walk toward the shop. Do anything you please. Pretend you
are coming in to see me on business. Act as if it was daytime. I'll
stand here and receive you. Later, I'll get dad out here, Koku and
Eradicate. I wish Mr. Period was here to see the test, but perhaps it's
just as well for me to make sure it works before he sees it."

"All right, Tom, here I come."

Ned advanced toward the shop. He tried to act as though the camera was
not taking pictures of him, at the rate of several a second, but he
forgot himself, and turned to look at the staring lens. Then Tom, with
a laugh, advanced to meet him, shaking hands with him. Then the lads
indulged in a little skylarking. They threw snowballs at each other,
taking care, however to keep within range of the lens. Of course when
Tom worked the camera himself, he could point it wherever he wanted to,
but it was now automatic.

Then the lads went to the shop, and came out again. They did several
other things. Later Koku, and Eradicate did some "stunts," as Tom
called them. Mr. Swift, too, was snapped, but Mrs. Baggert refused to
come out.

"Well, I guess that will do for now," said Tom, as he stopped the
mechanism. "I've just thought of something," he added. "If I leave the
light burning, it will scare away, before they got in front of the
lens, any one who might come along. I'll have to change that part of
it."

"How can you fix it?" asked Ned.

"Easily. I'll rig up some flash lights, just ordinary photographing
flashlights, you know. I'll time them to go off one after the other,
and connect them with an electric wire to the door of my shop."

"Then your idea is--" began Ned.

"That some rascals may try to enter my shop at night. Not this
particular night, but any night. If they come to-night we'll be ready
for them."

"An' can't yo'-all take a picture ob de chicken coop?" asked Eradicate.
"Dat feller may come back t' rob mah hens."

"With the lens pointing toward the s