of
clothesline rope and some No. 18 wire. The wooden catch, A (Fig.
1), must be about 1 in. thick
[Illustration: Electric Lock for Sliding Door]
and 8 in. long; B should be of the same wood, 10 in. long, with
the pivot 2 in. from the lower end. The wooden block C, which is
held by catch B, Can be made of a 2-in. piece of broomstick. Drill
a hole through the center of this block for the rope to pass
through, and fasten it to the rope with a little tire tape.
When all this is set up, as shown in Fig. 1, make a key and
keyhole. A 1/4 in. bolt or a large nail sharpened to a point, as
at F, Fig. 3, will serve for the key. To provide the keyhole, saw
a piece of wood, I, 1 in. thick by 3 in. square, and bore a hole
to fit the key in the center. Make a somewhat larger block (E,
Fig. 3) of thin wood with a 1/8-in. hole in its center. On one
side of this block tack a piece of tin (K, Fig. 3) directly over
the hole. Screw the two blocks together, being careful to bring
the holes opposite each other. Then, when the point of the key
touches the tin, and the larger part (F, Fig. 3) strikes the bent
wire L, a circuit is completed; the buzzer knocks catch A (Fig.
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