t beams. Then when Mr. Moth comes
flying down the path of light and gets over the top of the
sucker--_zing_, in he goes. Get my idea? Wait, I'll draw a plan of
the thing for you," and, rushing over to the writing table in the corner,
Nipper began to draw hastily while the scouts all crowded around him and
watched.

"There you are. There's the whole plan of the thing. Easy to make and
easy to operate and I guess it's original all right."

The drawings traveled from hand to hand, each lad scrutinizing them
carefully for some fault in the mechanical detail.

"Jiminy, I think you've struck it," exclaimed Gordon.

"Struck it? Why, man, he's got the first prize in his pocket right now,"
insisted Romper as he looked over the plans.

"Well, if it meets with your approval, fellows, let's get busy right now
and build our moth trap."

"Right-o. No more procras--something-or-other, as Bruce said the other
day. We'll get busy immediately," said Bud Weir.

"Well, first of all I think we should talk it over with Mr. Ford. He
will be able to see flaws in our plans where we can't, you know," said
Nipper.

"That was exactly my idea. And, by the way, did you notice that the
pamphlet from the Mayor's office named Mr. Ford among the members of the
judging committee in this contest?" said Bruce.

"Yes, I did," said Bud, "and for that reason I think he would like to see
us boys try for the prize even though we don't win anything. Come on,
we'll go over and talk with him."

Bud was quite right. When Mr. Ford learned that the boys had become
interested in the fight against the Brown Tail moth he was delighted.

"That's the stuff, scouts. Take an interest in everything in the nature
of a public improvement. If you grow up with that idea in mind you will
make useful citizens," he said, when the boys informed him that they had
been studying the Brown Tail moth campaign and intended to try for one of
the town's prizes.

"Well, I'm afraid that it was more of a selfish motive that led us to
take an interest. The troop needs one of those prizes to swell its
treasury," said Bruce.

"Never mind, many of the noblest works in this world resulted from the
selfish desire on the part of some one who wanted to win some kind of a
prize. But I won't sermonize. Let me see what you have in mind as a
moth exterminator," said the Assistant Scoutmaster.

The electrical engineer spent nearly half an hour in silent contemplation
of