IMPROVEMENTS IN AND CONNECTED WITH CABLES FOR TELEPHONIC PURPOSES
Year: 1880

page_text: LETTERS PATENT to Edgar George, of Liverpool, in the County of Lancaster,
Electrician, and Joseph Bond Morgan, of the same Place, Cotton Broker, for
8
an Invention of 'IMPROVEMENTS IN AND CONNECTED WITH CABLES FOR
TELEPHONIC PURPOSES."
PROVISIONAL SPECIFICATION left by the said Edgar George and Joseph
Bond Morgan at the Office of the Commissioners of Patents on the 3rd
November 1880.
EDGAR GEORGE, of Liverpool, in the County of Lancaster, Electrician, and
JOSEPH BOND MORGAN, of the same Place, Cotton Broker. "IMPROVEMENTS IN
AND CONNECTED WITH CABLES FOR TELEPHONIC PURPOSES."
In electric telegraphy induced currents affect to a small extent only the working
of the apparatus now in use on account of the want of sensitiveness in such
apparatus. In telephony however the instruments used act with extreme delicacy
and sensibility, and are easily affected by induced currents; hence when telephonic
instruments are attached to wires laid parallel or nearly so to wires connected to
ordinary telegraph apparatus, where currents of comparatively great power are used,
the noise arising from induced currents is often sufficient to drown the tones
produced by the smaller power used in telephony.
So delicate are telephonic instruments that on open wires in dry weather the
disturbances are so injurious as to induce the belief that they are due to metallic
contact; but to the more observant nind it will be obvious that the effects are
occasioned by currents induced in the dry atmosphere surrounding the wires. In a
moist atmosphere the effects of induction are less noticeable, as the particles of
moisture assist in carrying off a considerable portion of the static electricity. A
dry atmosphere greatly increases the effects of induction; it sometimes happens, in
the United States, for instance, that owing to the extreme dryness of the atmo-
sphere the effects of induced currents are very marked; in illustration, voice
vibrations passing over an open wire have been communicated to and heard
in connection with a wire parallel thereto and six feet distant therefrom.
Our Invention has for its principal object to obviate to a great extent the above
mentioned obstacle to the perfect and practical working of telephonic apparatus.

page_text: For that purpose we, under the first part of our Invention, coat wires for
conveying telephonic messages with an insulating substance or material of any
ordinary or desired kind, and by preference imbed or combine with the said
insulating substance or material wires or metal, substantially as set forth under the
following second head. The said wires or metal or the outside surface of the said
insulating substance or material is connected to earth by conductors of electricity
at intervals more or less distant as may be found necessary.
Under the second part, the non-induction insulated or open wires or metal above
mentioned may be laid around parallel to or otherwise in connection with each
insulated conductor, so that when placed together such conductors form a cable
which is by preference strengthened by a central metallic core. The cable as a
whole may be surrounded by a network or riband of metal or by bands or clips of
metal at intervals of, say, about three feet. Cables constructed as above set forth
are carried on or by suitable supports, standards, or carriers, and the strengthening
or carrying core and outside coating of the cable are connected to earth through
electrical conductors at each support, carrier, or standard, or at greater or less
distances if desired.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, and of
an Order of the Lord Chancellor, filed by the said Edgar George and Joseph
Bond Morgan in the Great Seal Patent Office on the 27th May 1881.
EDGAR GEORGE, of Liverpool, in the County of Lancaster, Electrician, and
JOSEPH BOND MORGAN, of the same Place, Cotton Broker. "IMPROVEMENTS IN
AND CONNECTED WITH CABLES FOR TELEPHONIC PURPOSES."
In electric telegraphy induced currents affect to a small extent only the working
of the apparatus now in use on account of the want of sensitiveness in such
apparatus. In telephony however the instruments used act with extreme delicacy
and sensibility, and are easily affected by induced currents; hence, when telephonic
instruments are attached to wires laid parallel or nearly so to wires connected to
ordinary telegraph apparatus, where currents of comparatively great power are used,
the noise arising from induced currents is often sufficient to drown the tones
produced by the smaller power used in telephony.
So delicate are telephonic instruments that on open wires in dry weather the
disturbances are so injurious as to induce the belief that they are due to metallic
contact, but to the more observant mind it will be obvious that the effects are
occasioned by currents induced in the dry atmosphere surrounding the wires. In a
moist atmosphere the effects of induction are less noticeable, as the particles of
moisture assist in carrying off a considerable portion of the static electricity. A dry
atmosphere greatly increases the effects of induction; it sometimes happens in the
United States, for instance, that owing to the extreme dryness of the atmosphere,
the effects of induced currents are very marked; in illustration, voice vibrations
passing over an open wire have been communicated to and heard in connection with
a wire parallel thereto and six feet distant therefrom.
Our Invention has for its principal object to obviate to a great extent the
above mentioned obstacle to the perfect and practical working of telephonic
apparatus.
For that purpose we, under the first part of our Invention, coat wires for con-
veying telephonic messages with an insulating substance or material of any ordinary
or desired kind, and by preference imbed or combine with the said insulating
substance or material wires or metals, substantially as setforth under the following
second head. The said wires or metal or the outside surface of the said insulating
substance or material is connected to earth by conductors of electricity at intervals
more or less distant as may be found necessary.
Under the second part, the non induction insulated or open wires or metal above
mentioned may be laid around parallel to or otherwise in connection with each
insulated conductor, so that when placed together such conductors form a cable,
which is by preference strengthened by a central metallic core. The cable as a
whole may be surrounded by a network or riband of metal or by bands or clips of
metal at intervals of, say, about three feet. Cables constructed as above setforth
are carried on or by suitable supports, standards, or carriers, and the strengthening
or carrying core and outside coating of the cable are connected to earth through
electrical conductors at each support, carrier, or standard, or at greater or less
distances if desired

page_text: Fig. 1. a, metallic wire core; b, wires insulated in any ordinary or desired
manner for conveying telephonic messages. The said wires are twisted round the
case a so as to form a rope, and are held in position by the spirally wrapped
covering c. In use the core of the said cable and the outside surface thereof are
connected to earth at convenient distances. Fig. 6 shews the method of suspending
the said cables from overhead supports. &, standards or telegraph poles;
e, suspension wires stretched from standard to standard or from pole to pole. The
cables are suspended from the said wires by metallic cross strands for hangers g.
h are metallic connections between the wires e and earth. It will be seen that the
outside surfaces of the cables are connected to earth at short intervals by means of
the cross strands f, hangers g, wires e, and earth connections f. The cores a are
connected to earth through the wires h.
Fig. 2. The insulated wires b are laid longitudinally around the core a;
metallic wires are twisted in opposite directions around the said cable, and the
whole is encased in a braided cover k; here the wires j and the core a are connected
to earth at intervals.
Fig. 3. In this cable the metal wires j are twisted round each insulated wire b.
Fig. 4. In this cable the insulated wires b are braided together, and wires are
interwoven in the braided covering k. The wires in k and the core are connected
to earth as above setforth.
Fig. 5. Here a metallic tube serves the purpose of the wires j, and is connected
to earth in the manner herein setforth.
Having now described and illustrated the said Invention in such manner that
others will be enabled to carry our improvements into effect, we would have it
understood that we do not confine ourselves to the details herein described and
illustrated. What we do claim is,-
The improvements in and connected with cables for telephonic purposes,
substantially as herein setforth.
In witness whereof, I, the said Edgar George, have hereunto set my hand
and seal, this Twenty fifth day of May, in the year of our Lord One
thousand eight hundred and eighty one.
DAD ARADAN
JAMES JOHNSON,
Patent Office,
4, Clayton Sqr.,
L'pool.
Witness.
EDGAR GEORGE. (S.)