AN IMPROVEMENT IN INSULATING WIRE USED FOR ELECTRIC TELE- GRAPHS, WITH A VIEW TO OBVIATE THE EFFECTS OF RETURN OR INDUC- TIVE CURRENTS.
Year: 1853

page_text: LETTERS PATENT to Josiah Latimer Clark, of No. 2, Chester
Villas, Canonbury Park, South Islington, for the Invention of
"AN IMPROVEMENT IN INSULATING WIRE USED FOR ELECTRIC TELE-
GRAPHS, WITH A VIEW TO OBVIATE THE EFFECTS OF RETURN OR INDUC-
TIVE CURRENTS.
Sealed the 7th April 1854, and dated the 20th December 1853.
PROVISIONAL SPECIFICATION left by the said Josiah Latimer
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 20th December 1853.
I, JOSIAH LATIMER CLARK, of 2, Chester. Villas, Canonbury Park
South, Islington, do hereby declare the nature of my Invention for
"AN IMPROVEMENT IN INSULATING WIRE USED FOR ELECTRIC TELEGRAPHS;
WITH A VIEW TO OBVIATE THE EFFECTS OF RETURN OR INDUCTIVE CURRENTS;"
to be as follows:-
In constructing electric telegraphs, where considerable lengths of
insulated wire are laid in the earth or under water, it has been found
that return or induced currents take..place, and it is with a view to
obviate the effects of these currents that my Invention is directed. And
my Invention consists in causing. wires, which have been insulated by a

page_text: coating or coatings of gutta percha or india rubber, or compounds of
these matters, to be further coated or inclosed in a cheaper insulating
matter, for which purpose I prefer to employ resinous or bituminous
matters by which the diameter is increased, and the distance of the
water from the wire extended, and the objectionable effects of induced
currents on the telegraphic instruments prevented.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Josiah Latimer Clark in the Great Seal Patent
Office on the 20th June 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
JOSIAH LATINER CLARK, of No. 2, Chester Villas, Canonbury Park
South, Islington, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters l'atent, bearing date the Twentieth day of December, in the
year of our Lord One thousand eight hundred and fifty-three, in the
seventeenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Josiah Latimer Clark, Her special
licence that I, the said Josiah Latimer Clark, my executors, adminis-
trators, and assigns, or such others as I, the said Josiah Latimer Clark,
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 IMPROVEMENT IN INSULATING WIRE USED FOR ELECTRIC TELEGRAPHS,
WITH A VIEW TO OBVIATE THE EFFECTS OF RETURN OR INDUCTIVE CURRENTS,"
upon the condition (amongst others) that I, the said Josiah Latimer
Clark, by an instrument in writing under my hand and seal, should
particularly describo 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 Josiah Latimer Clark, do hereby
declare the nature of the 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):-
In constructing electric telegraphs, where considerable lengths of
insulated wire are laid in the earth or under water, it has been found
that return or induced currents take place, and it is with a view to
obviate the effects of these currents that my Invention is directed.
And
my Invention consists in causing wires which have been insulated
by a coating or coatings of gutta percha or india-rubber, or compounds
of these matters, to bo further coated or inclosed in a cheaper insulating
matter, for which purpose I prefer to employ resinous or bituminous
matters, by which the diameter is increased, and the distance of the
water from the wire extended, and the objectionable effects of induced
currents on the telegraphic instruments.prevented.
Having thus stated the nature of the said Invention, I will proceed
to describe the manner in which I perform the same. I would, however,
first remark, that it is found in using insulated wires for electric tele-
graphic purposes, where the insulated wires are submerged in water or
laid in damp carth, that where a considerable length of insulated wire
is used, that by reason of the contact of the water or moisture with the
ordinary insulated wire, and the inductive action consequent thereon,
that the successive currents do not pass to the further end of the wire
as fast as they are caused to pass into the wire, and if currents in oppo-
site directions be passed in quick succession into an insulated wire
under such circumstances they tend to neutralize each other. Hence,
if marking telegraph instruments be applied to insulated wires of con-
siderable length, they, under such circumstances, fail to produce the
desired effect, the currents passing out much more slowly than they are
introduced, and if needle telegraphic instruments be applied, their
pointings and indications become more or less confused, and when
currents are sent in opposite directions quickly they fail to produce the
correct movement of the needles or pointers, and it is to obviate these
interfering inductive effects to which my Invention is directed. And I
may state that I find that the inductive action of a current passing in one

page_text: of several insulated wires in. a bundle or rope docs: not act to produce
such an extent of inductive current to the other or others of the wires as to
be of material consequence in constructing an electric telegraph where
the insulated wires are to be laid in the water or in damp earth. And
my Invention consists of applying an additional coating of bitumen or
other cheap non-conductor of electricity to the bundle or strand of insu-
lated wires, which are to be used so as to keep the water or the damp
earth at a greater distance from the insulated wires; and I prefer for
this purpose to use bitumen, as I believe it to be the cheapest material,
though I do not confine myself thereto; and I have found that a coating
of about half an inch thick will be sufficient if the length of insulated
wire be not more than two hundred miles. And in order to apply such
material I cause the bundle or the strand of wires, cach insulated in tho
ordinary manner with gutta percha, to be passed into melted bitumen
till it has taken up a coating of the desired thickness, and I then bind
the same with strong canvass or other fabric, and in this state I lay the
wires in the earth; but if they are to be submerged in water I have
the strand of insulated wires after coating, as above described, and
bound to be covered by laying wires around the same, as when making
electric telegraph ropes; the difference in each case being the addi-
tional coating of bituminous or other non-conductor of electricity to keep
the contact of the water or the moist earth more distant from the wires.
In witness whereof, I, the said Josiah Latimer Clark, have here-
unto set my hand and seal, this Twentieth day of June, in the
year of our Lord One thousand eight hundred and fifty-four.
Witness,
JNO. COOK,
4, Old Square,
JOSIAH LATIMER CLARK. (L.S.)
Lincoln's Inn.