of notion of how it works, for a change."

"How you talk!" Henry was suddenly cocky. He sneered. "I always know how
my inventions work--"

His gaunt friend glowered.

"I was afraid of this," he grunted. "Give you half a compliment and
there's no living with you." Then: "However, I won't waste time and
energy bringing you down to earth right now. The main thing is, get your
notes together. I want you to show them to Major Coggleston tonight; I
think maybe the army can use this invention of yours."

And, as Henry again raised the glasses in the direction of the nudist
camp:

"But get rid of those glasses for now. I don't want to catch you ogling
blonde beauties, or any other kind. Those people in that camp put up
that fence because they wanted privacy. So put those binoculars away
right now. Do you understand?"

"Oh, all right," fretted Henry. "I'll get rid of them."

Dinner was a thing of the past, and Major Coggleston, Professor Paulsen
and Henry were settled comfortably on the front porch, enjoying the
quiet of the summer evening.

"If these glasses of yours work as well as you say they do, the Army
certainly can use them," commented the major thoughtfully. "Such an
invention would completely revolutionize espionage and its
counter-measures. Nothing would be safe! Why, a spy could stand
half-a-mile from the laboratory I'm supposed to be protecting, look
through the walls to the records room, and steal the formulae for our
latest explosives right from under our noses, with none of us the
wiser."

"Yes." The professor nodded. "I can see how much it would mean. That's
why I had you over tonight--wanted you to have a chance to investigate."
A pause. "By the way, how's the work coming at the laboratory?"

"Better than we'd hoped for, Joe. We've got a young fellow in charge
who's a genius on explosives." The major hesitated for a moment, then
continued: "Confidentially, I understand he's just developed a new
powder that makes TNT look like something to use for loading
firecrackers. It's the greatest thing in years. The Nazis and Japs would
give their eye-teeth for it. It's simpler to make than gunpowder,
even--"

_Brrrnng!_

"I'll answer," said Henry. He skittered inside to the telephone.

A minute later he was back.

"It's for you, Major Coggleston."

* * * * *

The officer hurried to answer. When he returned, his face was tense with
worry.

"Something's wrong!" he rap