Barbour County index. [volume] (Medicine Lodge, Kan.) 1880-current, 1889-05-29
ELECTRICAL SCIENCE.

GAGO1 IC4OAA OOlUNOus
Latest Achievements Of the Lang.
don-Davies Phonopore.
An Instrument by Means of Which Elec.
trical Effects Are Produced Under Con-
ditiOns Which Had Been Thought
to Make Them Impossible.
In order to render description of the ex
perlments and their results clear, it will be
necessary at the outset to describe briefly
the nature of the invention. And here says
the London Times, we must first refer to the
well-known fact that, if telephone be
inserted in wire situated near to line of
telegraph wires, every passing current will
produce noises in the telephone, notwith-
standing that the telephone wire is perfect
ly insulated from the telegraph wires
These noises are known as induction noises,
and 1t was while investigating the phenom-
ena of induction with the view of devisihg
means to obviate its effects in telephones
that Mr.. Langdon Davies made the discov-
cry which has led to the important results
under consideration. HIS investigations
led him to the conclusion that induction was
caused by some form of electrical force,
which might be separated from currents
and which would pass freely through insu-
lations, impossible by currents. He further
concluded that, if this were So new series
Of instruments might be constructed for the
utilization of this force, and capable of be-
ing put in operation in company with cur
rent instruments on the same wire His con-
ciuslons have been proved TO be perfectly cor
rect by what has since resulted from the de-
velopnent of the principle. Instruments
have been made which represent a system
of communication of the highest practical
utility, and by means of which Mr., Langdon-
Davies has added a distinct and independent
chapter to the history of electrical develop
ment. The only form of electrical force
which finds free passage through these in
struments appears to be always capable of
being associated with sound. The inventor
has therefore denominated the force ''pho-
noporic impulse and the instrument the
''phonopore."
1t is certainly very remarkable, and to
some 1t may appear almost incredible, that
phonoporlc messages can be transmitted
and received through an ordinary line wire
by the phonopore, while at the same time
Geographic messages are being transmitted
and received through the same wire by the
ordinary telegraphic apparatus. No less re-
markable is it, but it is no less a fact, that
the phonoporic instruments have no con-
Quoting circuit through them. The phono-
pore gives uninterrupted passage to cleo
trical effects capable of being associated
with sound, although it does not permit the
passage of electric currents. Externally
the phonoporic transmitter resembles an
ordinary Morse key, mounted upon base
about four inches high, containing an instru-
meat somewhat similar to an induction coil
The Impulses are generated in a specially
constructed primary circuit, over which is
wound, in place of a secondary circuit,
phonopore, consisting of two wires insu-
lated from each other throughout their
whole length and at both ends. Each of
these wires, however, is connected at one
end to the line The number of phonoporic
impulses generated per second in the trans
mitter is regulated by the vibrations of an
organ-reed placed in the primary circuit.
Another reed tuned to the same rate of vibra-
tion IS placed as a receiver at the distant sta
ton. in front of an electromagnetic, and the
phonoporic impulses from the transmitter
cause 1t TO vibrate. A special form of con-
tact breaker, operated by the receiver
reed, completes local relay circuit when
the reed is still, but breaks it whenever the
reed vibrates at it's proper rate, thereby
setting in action any required instrument
in connection with any battery. Divested
OF its technical surroundings, the phonopore
presents itself as 4 small and simple ap-
paratus, consisting only Of d pair of insulated
copper wires.
We now turn to its practical application,
and to make this clear we will suppose that
an ordinary telegraph line from one town
TO another is provided at each end with the
usual telegraph instruments and that, owing
to increase of business. 1T becomes necessary
to provide some additional means of com
munication. All that is now necessary is
to attach to the line at each end a phonopore,
without IN any way altering the existing
instruments, batteries or line. The pho
nopore can be worked at the same time
as the ordinary telegraph instruments, and
one line is thus made to do the work of
two. If the line is already duplexed by or
dinary duplex telegra Instruments, the
addition Of the phonopore will qnadruplex
it. II the line is-as few trunk lines are
-quadruplexed, the phouoporic instruments
viii ''sextuplex" or 'octuplexp it Indeed,
it would seem difficult at present to
carrying capacity of the new system
Upon the artificial line which Mr. Langdon-
Davies has set up in his laboratory messages
were transmitted at the recent demonstra-
ton, first by the ordinary telegraph instru-
f1ents alone, and secondly by phonoporic
instrument alone. In the next place the or
binary telegraph instrument and the phono-
pore were worked together In opposite di-
rections duplex, after which the ordinary
Instruments and the phonopore were worked
together in the same direction duplex. The
final experiment consisted in the ordinary
telegraph and both the phonopore telegraphs
being worked together simultaneously
through the single line The three mes
sages were perfectly Transmitted. although
some of the operators had not previously
used the phonopori, Instruments. These
experiments proved not only the complete
possibility Of Simultaneous working. bit
that the phonopore can be arranged to work
ordinary telegraph Instruments, and that
when used IN duplex or quadruplex work it
requires ne special regulating or balancing
Iney also proved that any wire already pro-
vided with an ordinary service can instant
~ be dnDlexed By merely attaching the
E,honcpore instruments. On a second arti-
hcial Inc there We're installed two harmon
10 pEores::Jre seunder telegraphs. eonsti-
Suy;Eg duplex service without any ar
rangement whatever to balance the lines,
and working through resistance equiva-
lent % that Of about G 900 miles Of telegraph
wire Messages were perfectly transmit
ted through this line in both directions al
the same time