Make the saw cut along the line of the
crack. The opening caused by the saw will allow the free vibration
of the metal.
--Contributed by F. W. Bently, Jr., Huron, S. Dak.
** How to Make a Paper Phonograph Horn [71]
Secure a piece of tubing about 1-3/4 in. long that will fit the
connection to the reproducer, and wrap a quantity of heavy thread
around one end as shown in the enlarged sketch A, Fig. 1. Form a
cone of heavy paper, 9 in. long and 3 in. in diameter, at the
larger end with the smaller end to fit the diameter of the tube A,
making it three-ply thick and gluing the layers together. Attach
this cone on the tube A where the thread has been wrapped with
glue, as shown in Fig. 2. Fig. 2 is also an enlarged sketch. Make
ten pieces about 1 ft. 10 in. in length and 3 in. wide from the
thin boards of a biscuit or cracker box. Cut an arc of a circle in
them on a radius of 2 ft. (Fig. 3). Make a 10-sided stick, 12 in.
long, that will fit loosely in the tube A, to which nail the 10
pieces as shown in Fig. 4, connecting the bottom by cross pieces,
using care to keep them at equal distances apart and in a circle
whose diameter is about 2 ft.
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