The Progress. [volume] (White Earth, Minn.) 1886-1889, 1889-07-06
ELECTRICITY's SHADOW.
utilizing the Essence That Hangs About
Telegraph Wires.

ELESi hlSII y SF1ADOW.
Utilizing the Essence That Hangs About
Telegraph Wires.
An Englishman, G. Langdon Davis,
claims to have perfected an instrument,
called the phonopore. by which the
t'induction current" on electric wires
is utilized to carry messages, and the
capacity of telegraph or telephone
line thereby increased. The induction
current is the thing that makes the
buzzing and cracking noise in the tele-
phone and that sings fragments Of
what is passing on other wires into the
middle of what you are trying to tell
some one else over the line. It is a
sort OF faint essence of electricity that
hangs about every electric wire. and is
affected similarly, but in a lesser de-
gree. by every thing that affects the
current on the wires Its strength
varies with the intensity of the main
current and the condition of the
weather, but there is always enough of
it to be a nuisance on long wires and
when delicate work is desired.
The induction from a telegraph wire
is so strong that it will overcome en-
tirely the weaker current of tele-
phone wire near it on the same pole
and make it impossible to transmit in
telligible sounds over the latter when
the former is in use at the same time.
The English invention claims to har-
ness this faint current to regular in
struments and make it work indepen-
IDENTIFY of and simultaneously with the
main current on the wire. The main
feature of the invention appears to be
the use at the receiving instrument of
two wires insulated from each other,
but each attached at one end to the
main wire. The regular current can
not communicate through these wires,
because they are insulated from each
other, but the induction current exists
between them, in spite Of the insula-
ton, and any impulse communicated
to the induction current at any station
ION the line is faithfully reflected by the
induction current over these two wires
at the receiving end. By delicate adj
,justments similar to those used in du-
picking and quadruplexing ordinary
wires, the impulses of the induction
current are kept separate from those
~of the regular current, and will carry
a separate message from that passing
ION the main wire.
1t is claimed that it will be possible
by the use of the phonopore to double
the capacity of an ordinary telegraph
wire working singly, by simply attach
ing the new instrument at each end. A
duplex wire can be made quadrupleK
in moment by the same operation,
Tand quadruplex wire setuplex or &C.
1tuplex. The phonopore may be hitched
eon at way stations instead of at the end
of the line, and works as we'll, and in
perfect independence of the main cur
rent. 1t can be put on at Il place where
there is no regular instrument. Ex-
periments now being made over En-
4glish railroad lines are said to prove
conclusively that the invention is capa-
~ble of easy and profitable use in con-
nection with existing telegraph sys-
TENS.
1t does not appear, however, that
this new English invention is more
than an improvement and perfection of
the system of telegraphing from NOV
ing trains, which has been in use in
this country on the Lehigh Valley rail
road for some time, and is said to have
proved to be practicable and useful. In
both systems the induction from regu-
lar telegraph lines is used.-N. Y. Sun