The record-union., 1896-04-28

making the e1dOphOne, for a paSteDoard
mouthpiece foot long and wide
enough in the open end to accommodate
the mouth will do as we'll If the rubber
sheet is not to. be had take piece of
thin, smooth, crinkly paper and paste
it across the top of the can, wetting it
first so that it will draw tight when it
dries.
WONDERS OF VOICE FIGURES.
With this simple instrument and fine
sand, lycopodium powder, which can be
bought at any drug store. and some col
ored glycerine anyone who sings can
make voice figures and experiment in
visible sound.
Sprinkle some sand, which must be
fine and dry, lightly over the rubber
disk. Hold the eidophone so that the
surface of the rubber is horizontal and
sing one note-n0t too strong-into the
mouthpiece or tube. The note must be
sustained steadily, keeping an UNMARRIED
Pitch. When the first sound vibrations
lombard the under side of the rubber
disk the sand will begin moving, com
ing together in places and separating in
others Here and there little whirlpools
cf sand will spin around without NOV
ing away from the center of agitation
and in other spots sand rings, like the
smoke rings puffed from locomotive
stacks, will whirl and circle. Sing on
with increased force and the sand will
form geometrical figures and keep the
shape until the pitch is changed.
EXPERIMENTS WITH LYCOPO-
DIUM POWDER.
The same results will follow with
lycopodium powder, but care must be
taken not to sing with too much force
for the light powder viii jet up in lit
tie fountains, and even fly from the
rubber Spread the colored glycerine in
a thin sheet over the rubber and sing
The surface will form in intersecting
corrugations, serpentine scrolls and
spirals and conch-sheu figures. Ferns
and flower shapes will flash into view,
and sometimes tree shapes with spread
ing branches will appear, depending on
the pitch of the note Thin down water
colors to a watery paste, just thick
enough not to flow, and spread it over
the center of the rubber disk. Start
with low note and observe the result
Take the next higher note, and thus
ascend the scale. It will be found that
each note viii make q new voice figure.
One of them will form a daisy, another
pansy, another a sunfower shape
and other flowers with six, nine twelve
and up to thirty petals will appear.
The number and variety of figures
that can be made with the eidophone is
apparently without limit, and combina-
tions of sand and lycopodium powder,
the powder and colored glycerine
water and OIL and other materials will
give beautiful evidences of the power
and versatility of sound waves.
THE FLYING TOOTHPICKS
Place half a dozen wooden tooth
picks on the rubber and sing low note
softly and steadily. If the right note is
sung those toothpicks viii fly up in
the air as though they had been
snapped by the finger. A square of or
dinary writing paper laid on the rubber
win take up the vibrations, and sand
powder or glycerine, laid on the paper,
will act as they do on the rubber.
An evening at home spent in expert
menting with the ediophone, will dis
close many Of the possibilities that are
latent in the instrument. 1t shows, as
nothing else can, the action of sound
waves or sound vibrations. for it makes
the waves visible. If it were possible
to keep the rubber diaphragm at the
same degree of tension any particular
sound figure could be made by singing
that note which will make the figure.
but the rubber loosens, and in conse-
quence its vibratory condition is
changed.
VIBRATIONS OF VOCAL CHORDS.
To those who have not studied physics
| the generally accepted theory that
every molecule of matter in the universe
is in state of perpetual vibration is
beyond comprehension. They believe it
because wise men say it is so. but they
do not understand it. But the demon
stration Of the effects of sound waves
and sound is vibrations which are ap-
preciated by the ear, and sound waves
are vibrations-by the eidophone will do
much toward giving a tangible body to
the theory. The vibrations of the vocal
chords in singing throws the air into
exactly similar vibrations. The vibra-
tions enter the tube and the air in the
can becomes sympathetic, the can itself
| responds and the rubber disk vibrates
| in unison with vocal chords. The vi
brations are carried to the sand or
| powder, or whatever is on the rubber
| disk, and, according TO the intensity of