IMPROVEMENTS IN CABLES FOR THE TRANSMISSION OF ELECTRIC CURRENTS
Year: 1869

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane,
in the County of Middlesex, Patent Agent, for the Invention of
"IMPROVEMENTS IN CABLES FOR THE TRANSMISSION OF ELECTRIC CURRENTS."
- A communication from abroad by Pier Alberto Balestrini,
Engineer, of 13, Boulevart St. Martin, Paris.
Sealed the 1st January 1870, and dated the 19th July 1869.
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 19th July 1869.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN CABLES FOR THE TRANSMISSION OF
ELECTRIC CURRENTS," to be as follows:-
This Invention relates, 1st., to a mode of multiplying the conducting
wires of cables, whether submarine, subterranean, or otherwise, and.
employed for conveying messages by electricity, for taking soundings,
or for submarine lighting, or other purposes.

page_text: 2ndly. To improving the insulation of the communicating wires.
3rdly. To protecting the wires and the insulating substances enveloping
the same from any injurious action liable to break the continuity of the
wires or covering.
4thly. To a mode of imparting sufficient suppleness to submarine
cables and sounding lines, so as to enable them to be handled and laid
with as much ease as ordinary ropes, and so prevent injury to the same
at such times.
5thly. In imparting to cables composed of fibrous materials far
superior strength to those covered with iron or steel.
6thly. In cables constructed according to these improvements the
electrical conductors are never subject to any prejudicial strain whatever
may be the depth at which the cable is laid or the tension to which it is
subjected.
7thly. All twisting of the cable is rendered impossible whatever may
be the mode of laying the same.
According to these improvements, which are illustrated in the accom-
panying Drawing, I take three or other number of conducting wires
a, a, a, of copper or other metal which may be covered with an
insulating envelope of the desired thickness; I then take four or
other number of cords c, c, Figures 1 and 2, of the same diameter as the
covered wires a, which cords are previously steeped in some insulating
matter. On one of these cords forming a core I twist the three
conducting wires, and then lay the remaining three cords in the usual
manner of making a cable, as represented in Figures 3 and 4, the six
strands of which the cable is thus composed consist of a conducting
wire and a cord c in alternate order. In this manner each cord strand
will be placed between wire strands insulated, as described, and each
wire strand will be interposed between two cords of fibrous material
previously steeped in a suitable insulating compound.
Figure 3 of the Drawing shows a transverse section of an electric
cable constructed on the above principle and which possesses a con-
siderable degree of strength. The cable as above forming the telegraphic
core I cover with tow or other suitable fibrous material f, coiling it
preferably in the manner shown, said material being previously steeped
in some insulating matter of an oily nature if desired, so as to enclose
the insulated strands 6 and protect the core. The protective covering f

page_text: applied in this manner on the cable, shown in Figures 3 and 4, greatly
contributes to the preservation of the electric wires, and also improves
their insulation. On the covering f above mentioned I twist a suitable
number of strands g so disposed as to form more elongated spirals than
those of the core. These outer strands, which form the exterior sheathing
of the cable, are also impregnated with some insulating waterproof
compound, and are laid in such manner as to neutralize the effects of
the torsion imparted to the core, and in the reverse direction, as seen
in Figures 7 and 8. On this exterior sheathing I may in some cases
weave or otherwise apply a covering of yarn previously steeped in an
insulating waterproof compound, more especially when these cables are
used for taking soundings; or in lieu of this I may use a covering
strip h of india-rubber cloth or otherwise rendered insulating and
waterproof. This strip is laid in the reverse direction to the sheathing,
as seen in Figure 8, and consequently in the same direction as the core.
The number of wires may vary, thus I may make cables or lines used
for sounding and other purposes with two, three, four, five, or more
wires, arranging them in the form of a cable according to their number.
I would observe that I make no claim to either of the parts taken
separately, nor to the use of any particular material.
The Invention consists in the improved combination shown and
described.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 18th January 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Nineteenth day of July, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-third
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Alexander Melville Clark, Her special licence
that I, the said Alexander Melville Clark, my executors, administrators,
and assigns, or such others as I, the said Alexander Melville Clark,.

page_text: 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 CABLES FOR THE TRANSMISSION OF ELECTRIC CURRENTS," a
communication to me from abroad by Pier Alberto Balestrini, Engineer,
of .13, Boulevart St. Martin, Paris, upon the condition (amongst others)
that I, the said Alexander Melville Clark, my executors or adminis-
trators, 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 Alexander Melville 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, reference being had to the Sheet of Drawings
hereunto annexed and to the letters and figures marked thereon (that is
to say)-
This Invention relates, first, to a mode of multiplying the conducting
wires of cables, whether submarine, subterranean, or otherwise employed
for conveying messages by electricity, for taking soundings, or for
submarine lighting, or other electrical purposes.
Secondly. To improving the insulation of the said conducting wires.
Thirdly. To protecting the wires and the insulating substances
enveloping the same from any injurious action liable to break the
continuity of the wires or covering.
Fourthly. To a mode of imparting sufficient suppleness to submarine :
cables and sounding lines, so as to enable them to be handled and laid
with as much ease as ordinary ropes, and so prevent injury to the same
at such times.
Fifthly. In imparting to cables constructed of fibrous materials far
superior strength to those covered with iron or steel.
Sixthly. In cables constructed according to these improvements the
electrical conductors are never subject to any prejudicial strain whatever
3

page_text: may be me depen at which the cable is laid of the tension to which it is
subjected.
Seventhly. All kinking or untwisting of the cable is rendered im-
possible whatever may be the mode of laying the same.
According to these improvements, which are illustrated in the
accompanying Drawing, I take three or other number of conducting
wires a, a, a, of copper or other metal which may be covered with an
insulating envelope 6 of the desired thickness; I then take four or
other number of cords c, c, Figures 1 and 2, of the same diameter as
the covered wires a, which cords have been previously steeped in some
insulating matter. On one of these cords forming a core I twist the
three conducting wires, and then lay the remaining three cords in the
usual manner of making a cable, as represented in Figures 3 and 4,
the six strands of which the cable is composed thus consisting of a
conducting wire and a cord c in alternate order. In this manner each
cord or strand will be placed between wire strands insulated, as des-
cribed, and each wire strand will be interposed between two cords of
fibrous material previously steeped in a suitable insulating compound.
Figure 3 of the Drawings shows a transverse section of an electric
cable constructed on the above principle and which possesses a consi-
derable degree of strength. The cable as above forming the telegraphic
core I cover with tow or other suitable fibrous material f, coiling it.
preferably in the manner shown, said material being previously steeped
in some insulating matter of an oily nature if desired, so as to enclose
the insulated strands 6 and protect the core. The protecting covering f
applied in this manner on the cable, shown in Figures 3 and 4, greatly
contributes to the preservation of the electric wires, and also improves
their insulation. On the covering f above-mentioned I twist a suitable
number of strands 9 so disposed as to form more elongated spirals than
those of the core. These outer strands which form the exterior sheathing
of the cable are also impregnated with some insulating waterproof
compound, and are laid in such manner as to neutralize the effects of
the torsion imparted to the core, and in the reverse direction, as seen in
Figures 7 and 8. On this exterior sheathing I may in some cases weave
or otherwise apply a covering of yarn previously steeped in an insulating
waterproof compound, more especially when the cable is used for taking
soundings; or in lieu of this I may use a covering strip h of india-
rubber cloth or cloth otherwise rendered insulating and waterproof.

page_text: This strip is laid in the reverse direction to the sheathing, as seen in
Figure 8, and consequently in the same direction as the core. The
number of wires may vary, thus I may make cables or lines used for
sounding and other purposes with two, three, four, five, or more wires,
arranging them in the form of a cable according to their number.
Having described the nature of this Invention, and the manner of
performing the same, I would observe that I make no claim to either
of the parts taken separately, nor to the use of any particular material;
but what I claim as the Invention to be protected by the herein-before
in part recited Letters Patent is, constructing electric cables in the
manner herein-before described and illustrated in the Drawing annexed,
it being understood that I .reserve the right of varying the number of
the conducting wires and the nature of the insulating substances
employed; I also reserve the right to apply the cable for the trans-
mission of electric currents generally.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Eighteenth day of January,
in the year of our Lord One thousand eight hundred and seventy.
Witness,
JAMES DAISH,
53, Chancery Lane,
London.
A. M. CLARK. (L.S.)