f us still napping.

THE CLUB PIN.

[Illustration: Fig. 187. The Club Pin.]

The only other charm our secret club afforded was the wearing of a
mysterious club pin. It was a silver beetle, with the letter G engraved
on the head and the letter B on the body, while down the center of the
back was the letter I (see Fig. 187). In public we called ourselves the
G. I. B.'s, but it was only the initiated members who knew that these
letters were to be read backward, and, with the beetle on which they
were engraved, signified the "Big Bugs." Of course, we had some secret
signs and signals, a secret hand grasp, a peculiar whistle as a warning
to run, another meaning "lie still," and a third signifying "all is
well."

THE COMBINATION LOCK.

[Illustration: Fig. 188 The Notched Washers.]

[Illustration: Fig. 189. Washers Fastened on Spools.]

[Illustration: Fig. 190. The Combination Lock.]

We found it necessary to close the entrance of our cave with a door
fastened with a padlock, so as to keep meddlers out. The entire school
had watched us build the cave house, and, of course, knew just where our
entrance lay. Then, in addition to the outer door, we put in another
one, half-way down the dark passageway. On this Bill rigged up a simple
combination lock which would baffle any one who managed to pick the
padlock. This inner door opened outward. It was hinged to the floor of
the passageway, and swung up against a frame set in the passageway. At
the top was a board whose lower edge lay flush with the edge of the door
when it was closed. For the combination lock we used a couple of spools,
each with one head cut off and the central hole plugged up with a stick
of wood. In the floor and the top board of the frame, holes were drilled
just large enough for the shanks of the spools to fit snugly in them.
Next we made a trip to a hardware store for a file and a couple of large
copper washers, about 1-1/4 inches in diameter. The washers were
fastened to the inner ends of the spools after they had been pushed
through the hole. The washer on the door came just to the edge of the
door, while the other extended below the door frame and lapped under the
door washer. Then in the edge of the washer on the frame a notch was
filed, while in the other washer two notches were filed, so as to leave
a tooth which fitted snugly into the notch of the first washer (see
Figs. 188, 189). The door was locked by turning both the washers until
the n