long to fill up and finish the space below the
bottom shelf.
--Contributed by H. E. Mangold, Compton, Cal.
** A Battery Rheostat [80]
In a board 7 in. long and 5 in. wide bore holes about 1/4 in.
apart, in a semicircle 2 in. from the bottom, and cut notches in
top end to correspond with the holes. From a piece of brass a
switch, C, is cut with a knob soldered on at the end. Nails for
stops are placed at DD. Two binding-posts are placed in board at A
and B. With about 9 ft. of fine iron wire attach one end to the
bottom of post A and run through first hole and over in first
notch to back of board and then through second hole and over
second notch and so on until E is reached, where the other end of
wire is fastened. Connect switch to post B.
--Contributed by Edmund Kuhn, Jr., East Orange, N. J.
[Illustration: Battery Rheostat]
** Automatic Time Switch [80]
This device may be used to either open or close the circuit at any
desired time. An alarm clock is firmly fastened to a wooden
bracket and provided with a small wood or metal drum, A, to which
is fastened a cord, B.
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