IM- PROVEMENTS IN SUBMARINE TELEGRAPH CABLES
Year: 1858

page_text: LETTERS PATENT to Jonathan Nash Hearder, of Plymouth, in the County
of Devon, Philosophical Apparatus Maker, for the Invention of "IM-
PROVEMENTS IN SUBMARINE TELEGRAPH CABLES."
Sealed the 28th May 1858, and dated the 5th March 1858.
PROVISIONAL SPECIFICATION left by the said Jonathan Nash Hearder
at the Office of the Commissioners of Patents, with his Petition, on
the 5th March 1858.
I, JONATHAN NASH HEARDER, of Plymouth, in the County of Devon,
Philosophical Apparatus Maker, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN SUBMARINE TELEGRAPH CABLES," to be as
follows:-
My Invention consists of an improved mode of insulating telegraphic wires
for submarine purposes, so as to lessen the inductive action usually known as
a statical charge of the surfaces of the insulating sheath or covering, after the
manner of a Leyden jar, which action now interferes with the operation of the
simple dynamic electric current. I effect this by covering the conductor with
cotton, silk, wool, hair, flax, or other fibrous or porous substances in any of
their forms in one or more layers, previously to coating it with the plastic
insulating medium, and if necessary by putting on subsequent alternate layers
of fibrous covering and insulating coating, which latter may be gutta percha,
india-rubber, or any plastic insulating composition.

page_text: The porous, fibrous, or textile material with which the conductor is covered,
or which is inserted between the layers of the insulating medium, should have
its porosity preserved as much as possible, that is to say, the insulating com-
position should not be allowed to penetrate through it, consequently only plastic
insulating substances should be employed, fluid solutions of any kind being
unfit for the purpose, insomuch as they would be likely to penetrate into the
porous material and interfere with its intended action...
As telegraph cables are usually constructed, the gutta percha or other
insulating substance which encloses the conductor acts the part of a Leyden
jar, the internal conductor serving as the inner coating, and the water as the
outer coating, and my object is to interpose a fibrous or porous substance
between the wire and the insulating coating, in order to prevent the contact
of the metal with the homogeneous surface of the insulating medium; as a
further precaution, I also cover, if necessary, the insulating substance with
fibrous, porous, or textile material, and this again with another coat of plastic
insulating substance, so as to prevent. the water from coming in contact with
the outer surface of the inner, insulating sheath. I thus on the one hand
prevent the wire from forming an inner coating to the insulating compound
after the manner of a Leyden jar, and the water on the other band from
forming an outer coating to the same sheath after the same manner. Where
two or more conductors are to be embodied in the same cable, I take the
requisite number of conductors prepared in either of the ways aforesaid, and
either bind them together with the porous material and then cover them with
insulating medium, or I cover them with insulating medium at once, or I
apply the porous, fibrous, or textile material, and the insulating medium over
the whole in alternate layers as before described. I am aware that patents
have been taken out and contrivances have been adopted for employing fibrous
or textile substances in conjunction with insulating materials, but they have
been applied in a different way and with a different object, viz., wires have
been covered with fibrous material, in order to form a surface into which
insulating and waterproofing solutions would penetrate, and thereby attach
themselves when they could be made not to adhere sufficiently well to the wire
without such fibrous coating; fibrous substances have also been used to give
strength, solidity, and durability to the insulating material employed, by being
impregnated and incorporated with it, or to give tenacity to insulating substances,
such as bituminous matters, &c. which could not be employed' without the
intervention of some fibrous material with which they could be incorporated;
and which would serve to bind them together, and form with them a compact
insulating mass. Fibrous substances have also been used for giving buoyancy

page_text: to
a cable by the amount of air enclosed in their interstices, or they have beeni
used for giving strength, in which latter case they are laid on in such a manner
as to bear a portion of the strain to which the cable might be subjected.
My object is totally different from all these, and I use my fibrous materials.
solely for the sake of keeping the surfaces of the insulating medium from con-.
tact either with the internal conductor on the one hand, or the water on the
other; and the Invention is founded upon the following principle:-
The effect of the discharge of a Leyden jar or coated glass plate of given size,
will depend, first, upon the thinness of the glass and the consequent proximity
of the opposed coatings to each other; and, secondly, upon the complete and
perfect contact of these coatings with the glass surface. If paper, cloth, 'silk,
or any other fibrous substance be inserted between the glass and its tin foil
jar or plate are
coatings, the electrical defects of the discharge from such a
trifling when compared with those produced by one not so prepared.. This.
effect is not simply due to the increased distance of the coatings from each
other, but to the interference of the interposed fibrous substances with the
electrical conditions of the jar, for a jar or plate whose thickness of glass shall:
be equivalent to the united thickness of the glass and fibrous coatings of
another jar or plate of similar size, and whose coatings are consequently at as
great a distance from each other, will produce a greater effect in discharge than
one having fibrous substances between the tinfoil coatings and the glass. As.
an ordinary submarine telegraph then represents an extended Leyden jar of.
enormous dimensions, a very minute charge over the surfaces of which produces:
great disturbing influences, it is of the highest importance to adopt means.
both to reduce the amount of this charge, and prevent the mischievous effects..
of the discharge.
By surrounding the internal conductor of the cable with the fibrous
substances before described, which, may be wound spirally or transversely
round it. previously to coating it with the insulating medium, I prevent that
0 close contact of the conductor with the insulating medium, which is absolutely.
necessary to favor the conditions of the statical charge or discharge., I also by
interposing a layer of fibrous substance between the outer surface of the non-
conductor and the water, and protecting this again by a waterproof sheath,
further prevent the water from acting as an external coating to the outside of
5 the sheath, which may be in any way induced upon or charged inductively by
the current of the internal conducting wire, thereby breaking up to a very
great extent the conditions of the Leyden arrangement, and thus lessening the
tendency of the insulating sheath to become charged; and also preventing the
disturbing influences of any small portions of charge which may possibly be

page_text: taken up by it. It is also evident that the efficiency of the arrangement may
be still further increased by a second or third alternation of fibrous material
and insulating coating. Any cable constructed upon this principle may be
subsequently covered with wire in the ordinary manner, but this is no part of
my Invention.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Jonathan Nash Hearder in the Great Seal Patent Office on
the 4th September 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JONATHAN
NASH HEARDER, of Plymouth, in the County of Devon, Philosophical Apparatus
Maker, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of March, in the year of our Lord One
thousand eight hundred and fifty-eight, in the twenty-first year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Jonathan. Nash Hearder, Her special licence that I, the said Jonathan
Nash Hearder, my executors, administrators, and assigns, or such others
as I, the said Jonathan Nash Hearder, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United Kingdom
of Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN SUBMARINE TELEGRAPH CABLES," upon the
condition (amongst others) that I, the said Jonathan Nash Hearder, my
executors or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Jonathan Nash Hearder, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
My Invention consists of an improved mode of insulating telegraphic wires,
for submarine purposes, so as to lessen the inductive action usually known as

page_text: a statical charge of the surfaces of the insulating sheath or covering; after the
manner of a Leyden jar, which action now interferes with the operation of the
simple dynamic electric current. I effect this in the following manner:-
Firstly, I cover the conductor with cotton, silk, wool, hair, flax; or other fibrous
or porous substance or substances, in any of their forms, in one or more layers,
previously to coating it with the insulating material, which material may be
india-rubber, gutta percha, or any of their compounds, or any other insulating
composition; or, secondly, I coat the wire with the insulating material, and
then apply any of the before mentioned porous or fibrous substances over the
insulating coat, and I cover the whole again with the insulating material, and,
if necessary, put on additional alternate layers of fibrous and insulating material;
or, thirdly, I coat the conductor with the fibrous, porous, or textile materials,
in the manner described in the first process, and then apply the alternations of
insulating and fibrous materials in the manner described in the second process.
The porous, fibrous, or textile material with which the conductor is covered,
or which is inserted between the layers of the insulating medium, is better for
having its porosity preserved as much as possible consistently with the required.
strength of the cable. The precise mode of laying on the fibrous materials may.
vary according to circumstances, but I prefer to lay them on, when used in the
form of threads or strands, in a long spiral direction, and when more than
one layer is used, each layer is better for being put on in the direction opposito
to the former one, or where economy is not a great object, they may be
braided on. When in the form of tapes or strips, they may either be wrapped.
spirally round or laid longitudinally along the insulated or uninsulated-wire,
and folded round it, the latter mode being preferable, as it gives greater
strength. In all cases I recommend the employment of a soft adhesive
insulating medium which shall adhere to the fibrous material as well as to the
surface of the more solid insulating substance used for the several coatings,
in order to prevent the layers from sliding over each other. I do not, however,
confine myself to any of these plans, but merely recommend them as among
the best modes of combining the porous or fibrous substances with the
insulating material.
As telegraph cables are usually constructed, the gutta percha or other
insulating substance which encloses the conductor acts the part of a Leyden jar,
the internal conductor serving as the inner coating, and the water as the
outer coating, and my object is to interpose a fibrous or porous substance
between the wire and the insulating coating in order to prevent the contact of
the metal with the homogeneous surface of the insulating medium, and for a
similar reason I.also put on the outer layer or layers of porous and insulating

page_text: materials, viz, to prevent the water or other external conductor from coming
in contact with and forming an external coating to the insulating sheath which
immediately includes the conductor.
Where two or more conductors are to be embodied in the same cable, I
take the requisite number of conductors prepared in any of the ways aforesaid,
and either bind them together with the porous materials before described, and
then cover them with insulating medium; or I unite and cover them with
insulating medium at once; or I apply the porous, fibrous, or textile material,
and the insulating medium over the whole, when thus united in alternate
layers as before described.
I am aware that patents have been taken out and contrivances have been
adopted for employing fibrous or textile substances in. conjunction with
insulating materials, but they have been applied for different purposes, viz*.,
wires have been coated with fibrous substances in order to effect the adhesion
of insulating materials, which would not adhere sufficiently to the wire without
them; or, fibrous substances have been incorporated with insulating materials
so as to bind them together, and, to give solidity, strength, and tenacity to
substances which could not be used without them..
Now, although the introduction of my fibrous layers may add to the strength
of the cable, yet my object is different, for I use them as before mentioned for
the purpose of keeping: the surfaces of the insulating medium from contact
either with the internal conductor on the one hand, or the water on the other;
and the Invention is founded upon the following principle:-
The effect of the discharge of a Leyden jar or coated glass plate of given size
will depend, first, upon the thinness of the glass and the consequent proximity
of the opposed coatings to each other, and secondly, upon the complete contact
of these coatings with the glass surface. If paper, cloth, silk, or any other.
porous substance be inserted between the glass, and either or both of its tinfoil.
coatings, the electrical effects of the discharge from such a jar or plate are
trifling when compared with those produced by one not so prepared. This
effect is not simply due to the increased distance of the coatings from each
other, but to the interference of the interposed fibrous substances with the
electrical conditions of the jar; for a jar or plate whose thickness of glass shall
be equivalent to the united thickness of the glass and fibrous coatings of
another jar or plate of similar size, and whose coatings are consequently at as
great a distance from each other, will produce a greater effect in discharge
than one having fibrous substances between the tinfoil coatings and the glass.
As an ordinary submarine telegraph then represents an extended Leyden jar
of enormous dimensions, a very minute charge over the surfaces of which

page_text: produces great disturbing influences, it is of the highest importance to adopt
means to reduce these mischievous actions as much as possible.
By inserting a fibrous material between the surface of the conductor and
the inner surface of the insulating sheath, I prevent that perfect contact
of the two surfaces which is absolutely necessary for the full effect of the
statical charge or discharge; so also by interposing
a layer of fibrous
substance between the outer surface of the nonconductor and the water, and
protecting this again by a waterproof sheath, I further prevent the water
from acting as a coating to the outside of the sheath, which may be in any
induced upon, or charged inductively by the current of the internal con-
ducting wire, thereby breaking up to a very great extent the conditions of the
Leyden arrangement as before described, and thus diminishing the effects of
any residual charge which may be taken up by the insulating sheath.
way
The efficiency of the arrangement may be still further increased by a
second or third alternation of fibrous material and insulating coating.
As, however, the effect of the external fibrous coating is greater than that
resulting from the internal one, the latter may be occasionally dispensed with,
especially where more than one external alternation is employed. Any cable
constructed upon. this principle may, for the sake of additional protection
from injury, be covered with yarn, wire, or any other protecting substance, if
required.
And having now described the nature of the said Invention, and in what
manner the same is to be performed, I declare that I claim,-
First, the coating of the conductors of submarine telegraph cables with
cotton, silk, wool, hair, flax, or other suitable fibrous or porous substance or
substances previously to coating them with the insulating material, in the
manner and for the purposes herein-before described.
Secondly, the coating of such conductors with any suitable insulating
material, then applying any suitable fibrous or porous substance or substances
over the insulating coat, and again applying a coating of insulating material,
repeating the application of alternate layers of fibrous or porous and insulating
material as often as may be required, in the manner and for the purposes
herein-before described.
Thirdly, the interposing of a layer or layers of fibrous or porous substance or
substances between the inner surface of the insulating material and the wire,
and between the outer surface of the insulating material and the water, and
the protecting of such layer or layers by a waterproof sheath, and the putting
on of additional alternate layers of fibrous and insulating materials, in the
manner and for the purposes herein-before described.

page_text: Fourthly, the method of combining two or more conductors in the same
cable, as herein-before described.
In witness whereof, I, the said Jonathan Nash Hearder, have hereunto
set my hand and seal, this Thirtieth day of August, One thousand
eight hundred and fifty-eight.
JONATHAN NASH HEARDER. (L.S.)