October, 1880.
THE WEST SHORE.
271
THE PHOTOPHONE SOUND REPRO
DUCED BY LICIIT.
"There ii nothing new under the eun," said
the wiie man. The time have changed. Now
everything ii new, and novelty follow novelty.
The growth of natural knowledge ha broad
ened the Held of investigation, and increased the
number of trained specialists, and an anawer to
any apeoial inquiry i almost certain to come
from some part of the soientifio domain. The
latest thing it is simply a marvel in applied
science is the discovery that "sound can be
produced by the action of a variable light from
substances of all kiudi when in the form of their
diaphragm." In other word, the ray of light
i substituted for the connecting wire, and
sounds produced at one station are reproduced
at another. It i well known that the action
of the telephone is due to variation in an eleo
trio current, caused by a diaphragm set in vibra
tion by the voioe, the ourreut thus nindilled re
producing it vibration on a sensitive diaphragm
at the other end of the circuit. In the photo
phone, a the new instrument is called, the
changes in the eleotrio current are made during
it passage through the metal selenium. This
curious metal was discovered by Brrzoliu in 1817,
and by him named selenium. It is not known
to oocur native, although several native com
pounds of it are known. In its modification it
u both a oonductor and a non-conductor of elec
tricity. A steady light allow a ourrent to pan
through an even resistance) a varying light va
ries the resistance; so that the current is
tronger or weaker after passing through the
elenium, and in a telephone it vibration are
easily turned into vibration of sound. The in
ventor have already oonversed between point
about BOO ft. apart, and they believe that a
similar result can be obtained as far as a beam
of light oan be Hashed. The simplest apparatus
yet devuea consist 01 a piane mirror 01 nexi
ble material such as tilvered microscope glaai
or mica which will quiver with the vibration
of sound. On this surface is oolleoted through
a len a beam of light from any source, good
suocess having been obtained from a kerosene
or candle name. The parallel Deam renectcd
from the plane mirror is thrown to a distant
concave mirror and fooussed on a piece of sele
nium, eleotrioally oonnectod with a telephone.
The voioe throw the plane mirror into vibra-
; i v. i j .. i I . : . .. . i. . .... f 1: ,.L .
lions, wnicn mouny in lubouaiby mv ry ui ugiib,
whioh rapidly change the resistance of the dis
tant (elenium, this varying the eleotrio ourrent
in the telephone a the voioe now doe directly.
Another mean of affecting the beam of light is
by a dials, perforated with Hit, which u rap
idly turned, producing in the selenium a ooutin
uous musical tone, whose pitch variea with the
rapidity pf the disk' rotation, a silent motion
thus producing a (ound. A strange thing is
that some suhttanoe placed in the beam of light
do not out off the sound. A sheet of hard rub
ber, for instance, made the beam invisible, but
the musical note was still heard. Other exper
intent suggest the possibility of doing entirely
without the electric ourrent in the telephone at
the reoeiving station. Many other ubataooe
were substituted for (elenium, th affected ray
of light focnued upon them, and th musical
note waa heard without the aid of a telephon
or battery. Only carbon and thin glass failed to
give a sound.
Bom minor detail of th diflloultie enooun
tered and overoome in using (elenium in th
apparatus for (peaking from a distanoe, are of
Inter. A small oar oi eetenium na a resist
anoe to electricity equivalent to that offered by
telegraph win long enough to reach from th
earth to th son. Kven the eold light of the
moon lessen thu resistance, and inch a bnl
liant light as that of burning magnesium win
naive it Bat Bell and Sumner bad to work
long to reduce this resistance within managea
ble limit. Mo (elenium crystal wm ever known
to meamu lee than 200,000 ohrnn of resujtano
in the dark. . They hav made cell msaauring
ouly 300 uhuie iu the dark aud lojuliuioaiu til
light, by melting selenium to bras conductors,
a chemical union being formed which leasens
tne resistance at the point of contact of th two
substance. Their 50 form of apparatus are
based on one of two principle either to
oontrol the sou roe of light, or to modify the
noun itseu, we seooud ocing tn most practical
The inventor of the nhotonhone are Prof.
Alexander Graham Bell, the acknowledged in
ventor of the telephone, and Mr, Sumner
Taintor, of Watortown, Mas. The paper de
scribing this invention was read by l'rof. Bell
before the American Association for th Ad
vancement of Science, and wa illustrated bv
diagram projeoted on a screen, and by working
apparatus, in interesting paper 1 desonlied
a a model of preoise statement and icientitlo
aoouracy.
Thi Fawebt Trotting ok IUcord. The
flying trotter ar (till whittling down the
second which remain above two minute, as
the time for trotting a mile. The rnoord is
now reduced to 2 : 109, made September 18th
at Chicago, by "Maud 8." Thi is. of oonrse.
a great event in equine history, and we give
the brie! description of the feat which baa been
transmitted by telegraph. It will be under
stood that the mare trotted against time and
so had the track to henelf. It wa nearly sir
o'clock and growing dark when "Maud 8." wa
brought on the track. Th sky wa cloudy
and a strong touth wind wa blowing. At th
firat lend off "Maud" soon left her feet Her
driver, barm, turned her baok for a fresh start.
She then trotted to the starting point sqiiara
and level, and a her driver nodded for th
word, quickly lengthened out her stride and
got to the quarter in 34 seconds. It wa then
believed impoaaibl for hsr to do better than
2:18 or 2:18, but when ah got down to th
scoond quarter at a Z:U3 gait, the fastest record,
there wa a breathless interest aud xpectancy.
It wa feared, however, that the itrong head
wind, when ahe turned, would slacken her
speed materially and render it still impossible
to win. She kept straight forward, however,
without a break or a (kip, and marked the
three quarter mile pole in 1:3(1. Darin urged
her gently with voice and whip aud ahe re
sponded qulokly, and the multitude wa breath
leu a she went the Dual quarter and thundered
down th bom itrotch in 2;10J. The tim by
Suarter was, first, 0:34) second, 0:30) third,
:.HJ; fourth, 0:34. Loud oheen greeted the
mare, her driver and manager a they went to
her stable.
Invkhtoe or tiii Tii inioxi Prof. Alex,
Graham Bell baa received the VolU prise of th
French Academy of 110,000 for the Invention of
the telephone, as "the best application of eleo
trioity." Frof. Bell is also the inventor of the
photophone, whloh be la said to regard at pres
ent a a scientific toy, as th telephone wa re
garded at tint Th future us of th photo
phone will be, he think, between ship at sea,
wreck and the shore, and for military commu
nication. Prof, Bell annonnoed the possibility
of producing sound by interrupting th action
of light on (elenium to the Royal Institute of
Great Britain in May, 1878) and shortly after
ward he beard Willoughby Smith announce to
the Society of Tslegraphio Kngineer that h
had heard th action of a ray ol light on a crys
tal of (elenium by a telephone in eooneatioo
with it . Prof. Bell we born in Scotland, and
wa etlaoaUd at the University of Kdinburg.
II arrived in Canada in 1870, and wa called
to a chair in Boston University in 1872. He is
aid to be a man of remarkably fin presence.
Thi boas (till stand in Salem, built about
1032 by Roger William, in which i a low
room, with (olid oak beam and timber, where
th witch trial war beld, and whence many
victim wer ltd oat to die.
OUTBURSTS OP HEAT IN THE SUN.
Lately many soientifio Journals hav con
tained account of the observation of new and
luspeoted variable atari. Th more carefully
we study the (tar th mora evidont It benome
to us, that a large proportion of them undergo
and exhibit ohange of light with a certain de
gree of regularity. Very few atari ohange their
brilliancy o quiokly a Algol, th "winking
demon," in Medusa' Huad, but there are many
that wax and wane in a remarkable manner,
Thi subject become especially interesting,
remarks a writer In th New York Sun, when
we consider the fact that reason hav been
shown why our own sun may be regarded as a
variable star. Prof. Proctor in hi essay on th
' End of Many Worlds," suggests that period!
oal outburst of heat in th sun may account
for the curious traditions running alik through
the Indian, Egyptian, Chinese and Greek myth
ologies, that th aaith at certain epoch
undergoes destruction and renovation by fire.
On such a supposition the story of Phaeton be
come the tradition of an actual event in the
earth' history. According to th myth, Phae
ton persuaded hi father Apollo to let him drive
the oar ol the suu (or a day, lost the road, and,
approaching too near th earth, let Olympus on
lire, consumed oitio and whol nation with
flams, and turned th northern end of Africa
into a waterles desert
Th oause of any sudden sooess of heat In th
un, or in a star, is believed to b th dowufall
upon it surface of a vast quantity of meteoric
matter whirling in the track of some comet.
W hav record of a sudden brlgh tiling of th
un in modern time, A remarkable phenome
non of thi kind occurred on September 1, I8A0,
and although it wa of very brief duration, It
produoed startling effect lu various part of th
world.
If ther I a mas of meteor rushing In an
orbit that th sun orosse at certain epochs, and
which then oause hi lire to bunt nut with th
e (loots doscribed in th ancleiit traditions, they
hav thu far cd th ken of the astronom
er. Observation ha shown, however, that if
uoh meteor xit they are to be looked for in
the wak of a comet and w oan depend upon
th astronomers to giv du notlo of th oomet'l
appearanoe.
How Railway Tim is Kirr. There are in
use between thi city and New York 13 slectrlo
clock, two of th number being placed in th
waiting-room and on in th dispatcher's ofTlo
at th Grand Central depot, New York. The
time on the clock in the depot at Kan Albany
correspond exactly with th tim In New York,
Each on of th docks I oonnscUd with th
General Superintendent' ollloe in New York,
in which the railroad tim I kept on what I
called th "big clock." Conductor, train men
and other ar compelled to keep their watch
in strict oonformity with th Superintendent'
clock. It i act by standard time, and con
nected with the time service department of th
gold and stock telegraph, Th tim 1 distrib
uted over th line each week day a follow ;
At 10 o'clock 68 minute and S seconds A. M.
th word "time" I sent by th main ofllo to
th telegraph stations between New York and
Albany. Thi word is repeated for 28 sec
onds, daring which tim operator must see
that their Instrument are adjusted. At 10
o'clock and 00 second, ooniloommne best
ing, and eontinu for 60 teoond. The word
"switch" is then nt over th wire, and opera,
tors having eleotrio clocks connect them imme
diately with th circuit known a number 0
wire. Ten seoond are allowed la which to
mak th connection. At II A. ., with on
touch of the New York key, the hand na th
different clock are eet to II o'clock. If they
are fast or alow, thy chug all at one to tn
J boar named. A Ibany Aryttt,