The true northerner. [volume] (Paw Paw, Mich.) 1855-1920, 1879-07-04

A Practical Test Of His Loud-speshins
Telephone.

Telephone.
[From the Philadelphia Times.l
Edison's latest invention, the electro
chemical or loud-speaking telephone,
was exhibited last evening for the first
time in this country at the closing
spring meeting of the Franklin Insti-
tute. Its operation had never been
shown in public before except once,
within the last few weeks, by Prof.
Tyndall, at the Royal Institute, in Lon
don.
A paper treating upon the principle
involved in the construction of the in
strument vas read by Henry NJ. Bent
ley, President of the Philadelphia Local
Telegraph Company, who then con-
Quoted experiments with the improved
telephones. The instrument, he said,
was simply an attachment of the electro
photograph receiver to the Edison car
bon transmitter. He would use for this
occasion the rude box which Mr. Edison
had used in experimenting. If neces-
sary, a coil to counteract induction
could also be attached. The operation
about to be exhibited, he said, would
not be SO satisfactory as what would be
shown in the early future when an open
and perfected instrument would take
the place of the rude box which he had
brought from Mr.. Edison's establish
ment on the previous evening. Mr..
Bentley slipped wheel of chalk upon
an axle inside the little box, and, as the
transmissions were received from the
office OF the telephone company, he
continually turned a small crank pro-
jecting from the box. This caused the
transmissions, which, under other cir
cumstances, could not be heard at dis
lance of more than two or three feet
from the receiver, to be audible in all
parts of the hall.
The speaking was as distinct as if the
speaker were just at the other side of a
board partition. with wide interstices
between the boards, and the sound had
all the characteristics of his voice. To
show a comparison of voices, Mr.. Bent
ley several times called O different
speaker to the transmitter. Whistling
of such airs as Yankee Doodle"
Sweet By-and-By," and Poor Little
Buttercup" was particularly distinct
and accurately transmitted. The sound
heard by the audience, Mr.. Bentley
said, was two or three times as loud as
that sent into the transmitter. The
playing of cornet came rather harshly
and irregularly at first, but, when Mr..
Bentley had requested the performer
not to hold the horn so close to the
transmitter, the music was almost as
satisfactory as if the player, instead of
being nearly five squares away, were on
the spot where Mr.. Bentley stood. AS
in the case of the speaking, whistling,
and other transmissions, it would seem
that only partition full of holes or
wide cracks interviewed between the
performers and the listeners. Mr..
Bentley saw no reason why people, in
the near future, could not enjoy a
lecture or concert going on at the
Academy of Music by staying at home
with their electro-chemical" tele-
phones. Being asked how far such per-
formances could be satisfactorily trans
mitted, he replied that the question
could not vet be definitely answered,
but he believed that they could be
heard at distance of 100 miles as well
as they were heard now. As a finale, a
cornet performance of some of pima
fore's" iveliest airs came with astonish-
ing distinctness and accuracy, sounding
almost as well as if the performer was
on the platform, and putting the
audience In the best of humor.