AN IMPROVED MODE OF INSULATING ELECTRICAL CONDUCTING WIRES
Year: 1859

page_text: LETTERS PATENT to David Edward Hughes, of New York, but now
residing at Northampton Square, in the County of Middlesex, Telegraphic
Engineer, for the Invention of "AN IMPROVED MODE OF INSULATING
ELECTRICAL CONDUCTING WIRES."
Sealed the 8th July 1859, and dated the 11th January 1859.
PROVISIONAL SPECIFICATION left by the said David Edward Hughes
at the Office of the Commissioners of Patents, with his Petition, on
the 11th January 1859.
I, DAVID EDWARD HUGHES, of New York, but now, residing at Northampton
Square, in the County of Middlesex, Telegraphic Engineer, do hereby declare
the nature of the said Invention for "AN IMPROVED MODE OF INSULATING
ELECTRICAL CONDUCTING WIRES," to be as follows:-
The chief object of this Invention is to maintain the insulation of submarine
telegraphic wires even after the gutta percha covering has become injured and
no longer able to protect the wires from contact with the water. One.mode
by which I attain this end is to insert in the gutta percha tube.that encloses
the conducting wires a semi-fluid substance which, when the gutta percha
coating is pierced or.cut, will ooze.out and fill.up the fissure, and thus restore
or maintain the insulation. Various semi-fluid substances may be used, the
preference being given to india-rubber combined with .oil, rosin dissolved.in
[Price 8d1

page_text: oil or turpentine, or such spirit or other varnish as is not readily affected by
changes of temperature. Or in place of the semi-fluid substance, I use a
rosin soap or its equivalent, which when brought into contact with water by
the rupture of the gutta percha or other outer covering, will be decomposed
or dissolved by the water, and deposit a varnish or cement which will
close the fissure, and restore or maintain the insulation.
Instead of bringing this restorative medium in direct contact with the
enclosed wires, I may first cover the wires with a non-conducting material,
as gutta percha, and then apply a coating of the semi-fluid or other
restorative medium between this first and a second covering of gutta
percha. It will be understood that this Invention applies to all wires that
receive au insulating coating.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said David Edward Hughes in the Great Seal Patent Office on
the 11th July 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
EDWARD HUGHES, of New York, but now residing at Northampton Square,
in the County of Middlesex, Telegraphic Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of January, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said David Edward Hughes, Her special license that I, the said David
Edward Hughes, my executors, administrators, and assigns, or such others as
I, the said David Edward Hughes, 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 "AN
IMPROVED MODE OF INSULATING ELECTRICAL CONDUCTING WIRES," upon the con-
dition (amongst others) that I, the said David Edward Hughes, by an
instrument in writing, under my hand and seal, 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.

page_text: .
NOW KNOW YE, that I, the said David Edward Hughes, 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 (that is to say):-
The principal object of this Invention of "An Improved Mode of Insulating
Electrical Conducting Wires," is to maintain the insulation of submarine
telegraph wires even after the gutta percha or other covering of the electric
conductor has become impaired, and no longer able to protect the wires from
contact with the water, and prevent the electric current from escaping
laterally. With some trifling modifications, the Invention may be also applied
for insulating electrical conducting wires employed ou land or underground.
It is well known that when a fissure, hole, opening, or defect of any kind
occurs in the gutta percha or other covering of the electrical conducting wires
of telegraphic apparatus the insulation of the wire is impaired, and its power
of conducting the electric current is seriously affected, if not absolutely
destroyed. It is also well known that sometimes only slight, and at first
apparently trivial defects occur, but owing to the inconvenience or impossibility
of getting at the defective part of the conductor that is sunk to a considerable
depth in the ocean, it is difficult, if not impossible to repair this defect, which
consequently goes on increasing until the conducting power of the wire is
entirely destroyed, and the cable becomes perfectly useless for telegraphic
purposes. It will be evident, therefore, that any means that can be devised
for repairing such defects as may accidentally occur in the telegraph cable
after it has been laid, must present considerable advantages. This object is
attained by the present Invention, whereby should the electrical conductor
become exposed by a hole or fissure being made in the outer tube or
covering, such hole, fissure, or defect will be repaired from the interior of
the electric cable itself without any external assistance.
One mode by which I attain the desired end, is to insert in the gutta percha
tube that encloses the conducting wires a semi-fluid or soft non-conducting
substance, which when the gutta percha coating is pierced or cut, will ooze
out and fill up the fissure, and thus restore or maintain the insulation of the
electrical conductor. Various non-conducting substances may be used for
surrounding or enclosing the electrical conductor in this manner, but for most
ordinary purposes I prefer to use rosin dissolved in oil or turpentine; or I
employ some spirit or other varnish which is not readily affected by changes
of temperature, or india-rubber combined with or dissolved or softened by
some hydrocarbon may be employed. Or, in place of the semi-fluid sub-
stances, above mentioned, I use a rosin soap or some resinous or bituminous

page_text: substance dissolved in some suitable hydrocarbon or other oil or solvent of
such substances. It is preferable, under some circumstances, that the sub-
stance or compound employed for the above purpose should be of such a
nature that when brought into contact with water by the rupture of the
gutta percha or other outer covering, some part of the protecting substance,
which I denominate the restorative medium, will be decomposed or dis-
solved by the water, and will deposit a varnish or cement which will close
the fissure, and restore or maintain the insulation.
The substances or compounds above referred to have the property of
hardening under water, and thus closing the fissure or defect in the gutta
percha with a substance which is not liable to be washed away or removed
by the action of a current of water; such compositions will, therefore, be
found applicable where the cable is likely to be exposed to currents, as
when laid down along the beds of rivers, or across straits or arms of the
sea. The substances I prefer to use for such purposes are, first, rosin soap
made by dissolving rosin in spirits of turpentine or other hydrocarbon, and
adding a sufficient quantity of alkali thereto to saponify the mass; or,
second, I take the crude turpentine of commerce or Venice turpentine, and
dissolve the same in alcohol, so as to bring it to a semi-fluid mass.
In constructing cables for deep sea telegraphs, it is not necessary that a
liardening substance, such as the compounds above named, should be employed,
as at the bottom of the ocean the cable will not be exposed to currents. For
cables of this kind, therefore, I propose and prefer to use rosin oil rendered
sufficiently thick or viscid for the purpose by the addition of rosin or the
solid residuum obtained from the distillation of palm oil or Rangoon tar,
or other hydrocarbon or bituminous or resinous substances; or I take any
liquid hydrocarbon freed from naphtha or other solvent of gutta percha,
and I thicken it in like manner with any suitable resinous or bituminous
substance, such as rosin or Trinidad pitch, or any analogous substance.
Either of the above soft semi-fluid compounds will be cheap and easy of
application, but india-rubber dissolved in some suitable hydrocarbon, and
brought to a proper consistence may also be employed, and will effect the
desired object, but at an increased cost.
Instead of bringing the soft or semi-fluid restorative medium in direct
contact with the enclosed wires, I sometimes first coat the wires with a non-
conducting material such as gutta percha or india-rubber, and if preferred the
wire may be previously covered with some fibrous material. The insulated
electrical conductor, thus coated or covered, is then to be placed in a gutta
percha or other tube, which forms the outer covering of the electrical.con-

page_text: ductor; and I introduce between the first coating or covering of the
electrical conductor and the second or outer covering of gutta percha one
of the soft or semi-fluid restorative mediums above-mentioned.
My Invention applies to all wires that receive an insulating coating, and
may be employed as well for land telegraphic communication as for sub.
marine telegraphs; and the Invention is as applicable when two or more
electrical conductors are placed in one common tube or outer covering as
when only one conductor is employed. It will of course be understood that
when two or more conductors are to be employed in the same tube or outer
covering, each conductor must be separately coated or insulated by some
suitable substance or substances, and then any required number of such
coated, covered, or insulated conductors may be placed in the gutta percha
or other outer covering, and surrounded with any of the soft or semi-fluid
restorative mediums above referred to by filling up the interstices between
the separate wires and the vacant space in the gutta percha or other tube with
the said soft or semi-fluid substance.
Having now described my Invention of An Improved Mode of Insulating
Electrical Conducting Wires," and having explained the means and manner of
carrying the same into effect, I would observe, that although I have mentioned
the substances which I prefer to use as the restorative medium or insulating
compound to be employed for the purposes of my Invention, yet I do not
mean or intend to confine myself thereto, as other substances may doubiless
be found which will have the same effect, and may, perhaps, be advantageously
employed, without departing from the nature and object of my Invention.
In conclusion: I claim, as the Invention secured to me by Letters Patent as
aforesaid, the mode herein-before described of insulating electric conductors.
In witness whereof, I, the said David Edward Hughes, have hereunto
set my hand and seal, the Eleventh day of July, in the year of our
Lord One thousand eight hundred and fifty-nine.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
DAVID E. HUGHES. (L.S.)