ng-driven dynamo."

Jerry nodded. "I get it now. You rig this thing on the camera, which
is loaded with infrared film. The film registers whatever the infrared
searchlight illuminates. Right?"

"That's the idea," Hartson Brant agreed. "But it isn't as simple as
that, is it, Rick?"

"Far from it. I have to determine the effective range, then I have to
run a couple of tests to find out what exposure I have to use, and
then I have to find the field of vision of the telescope as compared
with the field of the lens. A lot depends on the speed of the film
emulsion. That will limit the range. The searchlight is effective at
eight hundred yards, but I'll be lucky if I can get a picture at a
quarter of that."

"Where did you get the sniperscope?" Scotty wanted to know.

"By mail. I read an ad in a magazine that advertised a lot of surplus
war equipment, including this."

"You might have said something about it," Scotty reproached.

Rick grinned. "You were too busy working on the motorboats. I knew you
couldn't have two things on your mind at once."

Since the boys returned from vacation, Scotty had been overhauling the
engines on the two motorboats which were used, along with Rick's
plane, for communication with Whiteside, the nearest town on the
mainland.

"I have a book downstairs that you'll find useful, Rick," Hartson
Brant said. "It gives the comparative data on lenses. It may save you
some figuring."

"Thanks, Dad," Rick replied. "I may have to ask your help in working
out the mathematics, too. Anyway...." He stopped as the phone rang.

In a moment Mrs. Brant called. "Jerry, it's your paper."

"Something must have popped!" Jerry ran for the door.

Rick hurried after him, Scotty and the scientist following. The
Whiteside _Morning Record_, for which Jerry worked, must have had
something important come up to phone Jerry on his night off.

In the library, Jerry picked up the phone. "Webster. Oh, hello, Duke.
Where? Well, why can't one of the other guys cover it? Okay, I'll be
on my way in a minute. How about a photographer? Hold the phone. I'll
ask him." He turned to Rick. "Duke wants to know if you can take your
camera and cover a story with me. A trawler went ashore down at
Seaford."

Rick nodded quick assent. The little daily paper had only one
photographer, who evidently wasn't available. It wouldn't be the first
time he had taken pictures for Duke Barrows, the paper's editor.

"He'll do it. We're on o