The New Orleans daily Democrat. [volume] (New Orleans, La.) 1877-1880, 1878-04-11
TIE PHONOGRAPH.
THE PRESENT STATS or TEE INvEN-
TgON.

New York Evening PoHt.l

New York Evening PoHtl
The most common mistake regarding Mr..
Thos, A. Edison's latest invention, the phono-
grapb. is that electricity has anything to do
wifi ID. or that the machine is Mt all costly or
In apv way complicated in its working. A re-
porter of the Epe',ing Post paid a visit y,ester-
day to room No. 49, In the Tribune building,
and what follows is an accurate account on
what he heard and saw. 1t is very fortunate
for the genial gentleman who manipulated
the photograph for the amusement ana III
strlcton Of Che crowd of persons who con,
expression on their faoes, that the days when
wizards got their deserts al the stake have
passed away.
On table near the centre of the room was
the far famed phon3graph, which can cant, DE
Of brass. about nine inches long ana hye
inches In diameter, Ia placed horizontally in
very. much the. same way that piece on
wood or metal Is placed between the chtlcks
OF q lathe to be turned; brass roo runs
through the centre Of the cylinder, and at the
end OF this rod is little crank which enables
one to turn the cylinder around at any rate
Of speed desired the rod 10 which this handle
In fixed has d screw thread cut on Its surface,
80 that when the cylinder is turned 1t shifts
slowly to ono side In such way that II
pencil s held In stationary position against
the cylinder while 1t is turning 1t would trace
line like the thread of screw. Instead
OF using pencil diminutive drum with
firmly attached TO the under side of this
lower tympanum is small steel point like
The point Of needle. When the bottom OF
this drum is made to vibrate from any cause
"a touch, or even the vibration of the cir. =
this steel point will yibrate with 1t, and In
this simple acti Ia the whole secret OF the phOnO-
graph A thin sheet Of common tin-foi, such
as is used to wrap tobacco In, Is placed around
little drum is now placed 80 that the point of
the needle Just touches the tin-fofl. The
slightest movement Of The tympan,lm of the
drum will make the needle scratch the sur
face of the tin sheet as the cylinder moves.
Talking into the opcn end Of the drum
gives the tympanum this needed vibration.
Suppose that a sentence eight or ton words
long s spoken into this little drum, and the
line which the needle makes on the tin sheet
Is examined, the line ie seen TO be made up of
tiny dots which the point of the needle made
where the pitch Of Che voice was high the vi
brations Of the drum skin or tympanum was
very rapid, and the dots were very close to-
gether: where the voice was deep the dots
were farther apart; where the sound was
very loud the vibrations OF the tympanum were
very energetic, and the point was pushed far
In and made very deep indentations. Ii, now,
th s Soted ne and held On a. the line whe the
OF vibration will be impaired to the
drum by the needle passing oyer the indenta-
tions as the drum impaired to the needle
dentations are very close together the vibra-
tions of the drum skin will be very rapid, and
the note heard will be correspOndingly high,
and under contrary motions the note will be
correspondingly low.
The voice OF the monograph In Its present
state Of perfection Is that of person talking
In loud voice In an adjoining room with the
door closed. Any sound, no matter what, is
faithfully reproduced laughing, whistling,
coughing. singing and ordinary speaking.
The invention Is yet in its infancy, and what
may be the improvements which will speed
lily and probably follow 1t Ia impossible to
say. Mr.. Edison has already succeeded In
making the photograph sufficiently delicate
to record and reproduce The words of a speak
or, talking In an ordinary way, four feet from
the instrument. The power with which the
sound can be reproduced depends on the
species Of sounding board which is used, and
on this point mort, decided results will nc
doubt soon be obtained. AT present In O large
room full Of persons there is no difficulty In
hearing the words distinctly from all parts Of
the room. The amount Of talking which car
be recorded on a small piece of tin-foi is mar
velous Mr.. Edison has succeeded In putting
$4,000 words on sheet of tin-foil about tor
inches square. So far. thin copper sheets have
been found to work most satisfactorily, ant
1t is probable that diamond points will ult
mately be used. Mr.. Edison is confident that
he win soon be able to reproduce the slightest
whisper as well as the 'screech of a steam
y whiStlp