[Illustration: Detail of Phonograph Horn]
The cone is placed over the stick as shown by the dotted lines in
Fig. 4 and temporarily fastened in position. Cut out paper
sections (Fig. 5) that will cover each space between the 10
pieces, allowing 1 in. on one side and the top, in which to cut
slits that will form pieces to overlap the next section and to
attach with glue. Fasten the sections all around in like manner.
The next course is put on in strips overlapping as shown at B,
Fig. 6. Finish by putting on sections in the same way as the first
course, making it three-ply thick. Remove the form, trim to suit
and glue a piece of paper over the edge. When the glue is
thoroughly hardened, put on two coats of white and one of blue
paint, shading it to suit and striping it with gold bronze.
** How to Make a Hygrometer [71]
A homemade hygrometer, for determining the degree of moisture in
the atmosphere, is shown in the accompanying sketch and consists
of a board, A, with a nail at each end to hold the silk thread B.
A second piece of silk thread, C, is tied to the center of B and
connects with an indicating hand or pointer supported by the
bracket D.
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