Western sentinel. [volume] (Winston [i.e. Winston-Salem], N.C.) 1856-1886, 1880-10-28
The hotophone.
Sound and Speech Transmitted 6z
a Beam Of Light.

kConesens se0 from the New York Sun.
The remarkable discovery, de-
scrihed in his paper read before the
American Aassociation tor the Ad-
vance.nent of Science at its late
meeting in Boston by Mr.. Alex.
Graham Bel, inventor of the Bell
telephone, that a ray of light may
be made to take the place of "a wire
III transmitting articnlate speech,
opens wide field of scientific re-
search and the marvellous posi-
bifitics OF future experiments. The
author of this paper aud Mr.. Snni-
ncr Tai ,tcl, IN exreI eIiu,vmt,,:-,
found that when vibratory beam
of light falls upon certain sub
stances, these emit sounds the pith
"t which depends upon the fire.
quency of the vihratory change in
the light. Some sixty years ago
BerEtlins, the chemist, obtained a
new elementary substance which he
called selenium," and which is
still considered simply n chemical
curiosity. In experimenting upon
it with the telephone Mr.. Bel
found that variations could he pro-
duccd in a parallel beam of light,
corresponding to the variations in
the air produced by the voice
After various experiments and Tie
trial Of fifty forms OF apparatus for
vary ing beam IT light Mr. Taint.
er and himself discovered that the
best and SIM lest device WIS
plane mirror of flexible material,
such as silvered mica or micro
scopic glass ; for when the Voice is
dir, cteG against the back of this
mirror he light reflected from it is
thrown into vibrations correspond
ing to those of the diphragm itself.
In their actual experiments The
discoverers concentrated a large
beam of sunlight by a lens on a
mirror, and alter it was reflected
rendered it parallel by another lens.
it was received at IL distant station
On paroholic r. fi.c'or, in the
focus of which was Il selcniuln cell,
con,.ected in local circuit with II
battery and telephone. 1t was II
moment OF triumph when, at dis
fance OF 213 meircs-upward OF
700 tect-upon placing the tele-
phone to his ear, Mr.. Bell heard
distinctly from the Illuminated re-
ceiycr the words: "Mr. Bell, it!
you hear what | say, come to the
window and wave your hat" !!
was found that ali the sonhd-pro-
eff cts of sunlight could also
be obtained from the oXhydrogen
light, and even from a Kerosene
lamp. But, more Extraordinary,
when a sheet of apparently opa iue,
hard rubber was interposed, even
then faint but perccptlble musical
tone Was heard from the telephone.
Since then the discoverers found
that the property ot )sensItiyencss
TO light vibrations existed in gold,
silver, plnlinnni, platinum, iron,
steel, brass. copper, zinc, lead, AN
tinony, German silver, Jenkins
metal, ivory, ceilni"id, gntta-rerci'a,
bard rubber, soft vulcalcaniZed rub
Der, paper, parchment wood, mica
and silvered glass apd the Dnl.
from which they did not
results were carbon and thin
glass. Hence they
pIopound the pi ioposition that sen
sitiveness to light vibrations is IA
general property Of all matter
The theory of the "photophone,'
as Mr.. Bell calls his new invention,
is that aytculate sounds can be
transmitted as tar as beam OF
hight can be prs.jectrd and by IFS
'g"ncy !; whether III practice it shall
be actually operative Remains to be
seen. The triupphs OF the telc-
phone have prepared lis to believe
anything possible.