Out of stout pasteboard cut twenty circles, five inches wide, and cut
them all from the edge to the centre, as marked.
[Illustration: Fig. 110.]
Bore a hole through them an inch wide. Join them together by glueing the
cut side C of circle A to the cut side D of circle B, and so on, till
all the circles form but one piece, which, being thus lengthened, has
the shape of a screw. Let them dry. Through the hole run a wooden rod to
thread them, and set them three or four inches apart; glue them in that
position. Cover them along their outer edge, and at one end with
parchment-paper, wet, so as to dry tight, like a drum-head. When dry,
put in about a pound of fine shot, more or less, according to the size
of the instrument, and close the open end with strong paper.
The lead being at one end of this case, horizontally, if you lift it up
gently by the end with the shot, they will run slowly to the other end
in the road formed between the circles, and their strokes against the
paper cover will closely imitate the patter of rain. If the case is
tilted up suddenly, the much louder sounds will resemble hail. By
alternately depressing and elevating the case, to keep the shot in
motion, the effect can be made continuous.
[Illustration]