AN IMPROVEMENT IN ELECTRIC TELEGRAPHS WHEN INSULATED WIRES ARE LAID UNDER WATER OR IN THE EARTH
Year: 1855

page_text: LETTERS PATENT to Lewis Dunbar Brodie Gordon, of Abingdon Street,
Westminster, Civil Engineer, for the Invention of "AN IMPROVEMENT IN
ELECTRIC TELEGRAPHS WHEN INSULATED WIRES ARE LAID UNDER WATER OR
IN THE EARTH." -A communication from Werner Seimens, of Berlin.
Sealed the 8th January 1856, and dated the 15th September 1855.
PROVISIONAL SPECIFICATION left by the said Lewis Dunbar Brodie
Gordon at the Office of the Commissioners of Patents, with his Petition,
on the 15th September 1855.
I, LEWIS DUNBAR BRODIE GORDON, of Abingdon Street, Westminster, Civil
Engineer, do hereby declare the nature of the Invention for "AN IMPROVEMENT
IN ELECTRIC TELEGRAPHS WHEN INSULATED WIRES ARE LAID UNDER WATER OR IN
THE EARTH to be as follows:-
In electric telegraphs, where insulated wires are laid in water or in the moist
earth, difficulties have arisen from the effects of the static charge (depending
upon lateral induction), in retarding the electric current, as well as from the
residual magnetism of the Leyden arrangement, which the insulated wires
alluded to present. Heretofore it has been usual, in constructing electric
telegraphs with wires in the earth or in the water, to employ the earth as part
of the circuit, the insulated metallic wire being the other part, and it has been
by such a state of circumstances that the effects of static charge and residual
magnetism have been found to prevail.

page_text: Now, the improvement consists in placing two wires or sets of wires,
insulated from each other in the same insulating mass, and making the current
conveyed by the one return by the other, thus completing the metallic circuit
by the two conductors placed in one insulating mass.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Lewis Dunbar Brodie Gordon in the Great Seal Patent Office
on the 15th March 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, LEWIS
DUNBAR BRODIE GORDON, of Abingdon Street, Westminster, Civil Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of September, in the year of our Lord
One thousand eight hundred and fifty-five, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Lewis Dunbar Brodie Gordon, Her special licence that I, the said Lewis
Dunbar Brodie Gordon, my executors, administrators, and assigns, or such
others as I, the said Lewis Dunbar Brodie Gordon, my executors, adminis-
trators, 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 ELECTRIC TELEGRAPHS WHEN INSULATED
WIRES ARE LAID UNDER WATER OR IN THE EARTH," (a communication from
Werner Seimens, of Berlin,) upon the condition (amongst others) that I, the
said Lewis Dunbar Brodie Gordon, 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 Lewis Dunbar Brodie Gordon, 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 sending telegraph messages through long submarine or underground
conductors, considerable practical inconvenience has been experienced in

page_text: consequence of the time which elapses in the passage of cach current of
electricity from the battery to the receiving instrument at the extremity of the
metallic conductor. In removing the battery from the electric circuit, the
current subsides gradually at the opposite end of the submerged conductor, and
consequently currents that follow each other with rapidity merge into one
continuous stream and cease to work the receiving instrument; and when
several insulated wires have been combined into one cable, hinderance has
been experienced in working through these several conductors simultaneously
in consequence of the volta induction produced by the one upon the others.
The object of the Invention is materially to reduce or entirely to obviate
the charge and volta induction, and to provide means of transmitting telegraph
messages through greater lengths of submarine cables and under-ground
conducting wire than could hitherto be effected with a sufficient degree of
certainty and rapidity.
The Invention consists chiefly in using a set of two insulated
wires, placed in close proximity to each other, and imbedded in the middle of
one mass of gutta percha or other insulating material as one electric circuit, in
which the battery and receiving instrument are inserted, without using the
earth as part of the circuit. The two conducting wires will be charged
equally at any given point, the one with positive and the other with negative
electricity; and since. both of them are in equal proximity to the surrounding
water or earth, it follows that no electric charge can take place between the
wires and the earth; nor will any induced current be produced in additional
conducting wires that are imbedded in the same conducting mass, provided
they are placed equidistant from two wires forming the electric circuit.
The same cable may
therefore contain one or more sets of insulated
wires, as a, a, and b, b, in close proximity to each other, which may be used
simultaneously as circuits without the interference of one with the other.
But in order to render the electric waves succeeding each other still more
separate and distinct, I arrange the communicating instrument in such manner
that each positive wave is followed immediately by a negative wave; that may
be produced by reversing for an instant the poles of the battery employed
before breaking the circuit.
If an electric cable is to contain only a single pair of conductors to form

page_text: a circuit, I sometimes prefer to insulate one copper wire by a covering
of fibrous material; and 1 then cover it with iron or copper wires
close to each other (and of a conducting capacity equal to the central
wire), which in their turn are covered first with fibrous material, and
then with gutta percha, or other plastic insulating substance. I employ the
copper wire to convey the current in one direction and the iron wires for the
return current, and so complete the circuit without making use of the earth,
as at present practised.
What I claim as the Invention is, first, the manufacture of electrical con-
ductors by placing two wires or sets of wires insulated from each other by
fibrous materials in the middle of one mass of gutta percha.
Second, the using two insulated wires, placed in close proximity to each
other and imbedded in the middle of one insulating mass, as one electric
current, as described.
Third, the sending reverse currents through the circuit of two wires
arranged as described.
Fourth, the manufacture of double metallic conductor cables, as described.
Fifth, in using a cable formed of one copper wire insulated and covered
with iron or copper wires, which are surrounded by fibrous material, and then
with gutta percha, or other insulating substance, as one electric circuit, as
described.
In witness whereof, I, the said Lewis Dunbar Brodie Gordon, have here-
into set my hand and seal, this Fifteenth day of March, in the year
of our Lord One thousand eight hundred and fifty-six.
Witness,
FRED HARRIS.
LEWIS D. B. GORDON. (L.S.)