Take two hardwood boards, marble, or slate plates, about 8
or 10 in. long, place them together, as in Fig. 1, and mark and
drill about 500 holes. These two pieces should be separated about
8 in. and fastened with boards across the ends, as shown in Fig.
2.
Take soft copper wire, not smaller than No. 18 gauge, and cut in
lengths to pass through the holes in the two boards, leaving
sufficient end to make a tie. It will require about 70 ft. of wire
to fill one-half the number of holes. Also, cut the same number of
lengths from the same gauge galvanized-iron wire to fill the
remaining holes. The wires are put through the holes in the boards
alternately, that is: begin with copper, the next hole with iron,
the next copper, the next iron, and so on, twisting the ends
together as shown in Fig. 3. The connections, when complete,
should be copper for the first and iron for the last wire.
When the whole apparatus is thus strung, the connections, which
must be twisted, can be soldered. Connect one copper wire to the
bell and the other terminal, which must be an iron wire, to the
other post of the bell.
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