Year: 1878

Do in the Future.


New York Post, 22d.I


The most common mistake regarding
Mr. Thomas A Edison's latest invention,
the phonograph, is that electricity has
anything to do with it, or that the ma
chine is at all costly or in any way COM
plicated in its working. A reporter of
the Erening Post paid visit yesterday to
Room No 50, in the Tribune building,
and what follows is an accurate account
of what he heard and saw. 1t is very
fortunate for the genial gentleman who
manipulated the phonograph for the
amusement and instruction fthe crowd
of persons who constantly throng the
room with a puzzled expression on their
faces, that the days when wizards got
their deserts at the stake have passed
away.


Room NoS2 is a large and pleasant
apartment, on the fourth floor of the
building. 1t is well lighted by two large
windows, and was occupied at the time
of the reporters visit yesterday by some
thirty or forty gentlemen, drawn thither
to see the most curious invention of the
age.


On table near the center of the room
was the far-famed phonograph, which can
be briefly described as follows: A hol
low cylinder of brass, about nine inches
long and five inches in diameter, is plac-
ed horizontally in very much the same
way that piece of wood or metal is
placed between the chucks of lathe to
be turned; brass rod runs through the
center 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 to which
this handle is fixed has a screw-thread
cut on its surface, so that when the CYL
inder is turned it shifts slowly TO one
side in such way that if a pencil is held
in stationary position against the cyl
inder while it is turning it would trace
line like the thread of screw, In
stead of using pencil diminutive
drum, with only one tympanum (the
lower one), is used; firmly attached to
the under side of this lower tympanum
is small steel point like the point of a
needle. When the bottom of this drum
is made to vibrate from any cause-a
touch, or even the vibration of the air
this steel point will v;brate with it, and
in this simple fact is the whole secret of
the phonograph. A thin sheet ofcom-
mon tin-foil, such as is used to wrap to
bacco in, is placed around the brass cyl
inder, which is set in motion, the little
drum is now placed so that the point Of
it just touches the tin-foil. The slightest
movement of the tympanum of the drum
will make the needle scratch the surface
of the tin sheet as the cylinder moves.
Talking into the open end of the drum
gives the tympanum this needed vibar-
ton. Suppose that sentence eight or
ten words long is spoken into the little
drum, and the line which the needle
makes on the tin sheet is examined, the
line is seen to be make up of tiny dots
which the point of the needle made /;
where the pitch of the voice was high
the vibrations of the drum skin or tym
panum were very rapid, and the dots
were very close together; where the
voice was deep, the dots were further
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.
If, now, the needle point is placed at the
beginning of this dotted line and held
on the line while the cylinder turns, ex
actly the same kind civilizations will be
impaired to the drum, by the needle
passing over the indentations as the drum
impaired to the needle when the linden
tations were made. If the indentations
are very close together the vibrations of
the drum-skin will be very rapid, and
the note heard will be correspondingly
high, and under contrary conditions the
note will be correspondingly low.


The voice of the phonograph in its
present state Of projection is that of a
person talking in loud voice in an ad
joining room with the door closed. ANY
sound, no matter what, is faithfully re-
produced, laughing, whistling, coughing,
singing, and ordinary speaking. The
invention is yet in Its infancy, and what
may be the improvements which will
speedily and probably follow, it is i'm
possible to say. Mr. Edison has already
succeeded in making the phonograph
sufficiently delicate to record and re
produce the words cf a speaker, talking
IN an ordinary way, four feet from the
instrument The power with which the
sound can be reproduced depends en-
tirely on the species of sounding board
which is used, and On this point more
decided results will no doubt soon be OBJ
tained. At present in large room full
ofpersons there is no difficulty in hear
ing the words distinctly from all parts
of the room. The amount of talking
which can be recorded on small piece
OF tin foil is marvellous Mr. Edison has
succeeded in putting forty-eight thou
sand words on sheet of tin foil about
ten inches square. So far, thin copper
sheets have been found to work most
satisfactorily, and it is probable that dia-
mond points will ultimately be used.
Mr. Edison is confident that he will soon
be able to produce the slightest whisper