Juniata sentinel and Republican. [volume] (Mifflintown, Juniata County, Pa.) 1873-1955, 1877-03-28
SCIENTIFIC.

SCIENTIFIC.
The Speaking Teleqrgph.-We have
heretofore given accounts of the Won
derful success of Professor Bell In
transmitting the vibrations of the hu-
man voice by electrical means over a
telegraph wire. He has lately made
improvements in his method of trans
mission, by which he dispenses with
the use of the battery, and substitutes
the magnetic electric plan of producing
the current. The Boston Transcript
describes recent experiment with tue
new apparatus, by which conversation
and singing was successfully carried
on between Boston and Maiden. a dis
tance of six miles. The telephone, In
its present form, consists OF powerful
compound permanent magnet, 20 the
poles of which are attached ordinary
telegraph coils of insulated wire. In
front of the poles, surrounded y these
coils of wire, is placed diaphragm of
iron. A mouthpiece to converge the
sound upon this diaphragm substan-
tally completes the arrangements. As
is we'll known, the motion of steel or
iron in front of the poles of magnet
creates a current of electricity in coils
surrounding the poles of the magnet,
and the duration of this current of cleo
tricity comedies with the duration of
the motion of the steel or iron moved
or vibrated in the proximity of the
magnet. When the human voice causes
the diaphragm to vlbrate, electrical
undulations are induced in the coils
envirOning the magnets, precisely an
alogOus to the undulafiors of the air
produced by that voice. These coils
are connected with the line wire, which
may be of any length, provided tine in
sulation be good. The undulations
which are induced in these coils travel
through the line wire, and, passing
through the coils of an instrument of
precisely similar construction at the
distant station, are again resolved into
air undulations by the diaphragm of
this instrument.
The experiments were as follows:
Telephones having been connected with
the private telegraphic line of the Bos-
ton Rubber Shoe Company, conversa-
ton was at once commenced. Sta
toned at the Boston end of the wire,
Professor Bell requested Mr.. Watson,
who was at the Maiden end, to speak
in loud tones, with view of enabling
the entire company at once to dlstln-
guish the sounds.
This was so successful that smile
of mingled pleasure and surpriseplaye
on the features of those present. That
il, however, might not be supposed that
loud speaking was essential to lntelll-
gibility, Mr.. Bell explained that soft
tones could be heard across the wires
even more distinctly than loud utter
ances, even a whisper being audible.
In confirmation of this statement, Mr..
Watson commenced speaking in turn
with each member of the company;
and after the efficiency of this method
had been proved 10 the satisfaction of
all he took up a newspaper and IN
formed the assemblage that gold had
closed the previous evening at New
York at 1863. As there were quite a
number of business men present, the
effect that this practical demonstration
of the value of the telephone produced
can scarcely be exaggerated. Other
passages from the daily journal were
then given, and by this time the desire
for conversation having become gen
eral, Mr.. Watson was piled with ques-
tions such as: ''ls it thawing or freez-
ing at Maldenf Who will be the next
President n etc. 1t was remarkable
that Mr.. Watson was able TO distinguish
between the voices at the Boston end,
he calling at least one gentleman by
name as soon as the latter commenced
speaking.
This went on for some time, until a
lady at the Maiden end sent the COM
pany an invitation to lunch per tele-
phone, and an appropriate response
was made by the same medium. AT
length the Boston company were re-
quested to remain quiet while lady at
the other end conveyed to them the
sweet strains of music. The assem-
blage thereupOn listened with rapt at
tention while a young lady commenced
singing. "The Last Rose of Summer"
The effect was simply charming. The
sound of the voice penetrated into the
Boston end of the telephone with
distinctness equal to that attainable in
the more distant parts of large con-
cert room, and a unanimous vote of
thanks was sent by the handy little
instrument which had procured for the
assemblage SO agreeable an hour.