Iл- PROVEMENTS IN SUBMARINE ELECTRIC CABLES, OR CONDUCTORS
Year: 1858

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the County
of Middlesex, Engineer & Patent Agent, for the Invention of "Iл-
PROVEMENTS IN SUBMARINE ELECTRIC CABLES, OR CONDUCTORS."-A com-
munication from Felix Marie Baudouin, of Rue des Recollets, Paris.
Sealed the 31st May 1859, and dated the 16th December 1858.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the 16th
December 1858.
I, WILLIAM CLARK, of 58, Chancery Lane, in the County of Middlesex,
Engineer & Patent Agent, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN SUBMARINE ELECTRIC TELEGRAPH CABLES OR CON-
DUCTORS," to be as follows:-
A variety of methods has been employed to prevent the rupture of the
wire or wires forming the internal conductors of submarine telegraph cables,
for instance, instead of employing a single wire as a conductor, several wires
have been twisted together in a spiral form, and forming a small wire rope,
but experience has proved that the capability to extension expected to be
obtained in this arrangement was neutralized, or nearly so, by the insulating
coating, which prevents their untwisting, & rendering them less susceptible'

page_text: to distension, and causing them to break under a less strain than wires
untwisted. Instead of arranging the conductor in a straight line in the centre
of the insulating coating, the conducting wire has also been wound in a spiral
form round a core of hemp, or other suitable substance, the conductor being
thus disposed within the insulating coating; but this disposition, besides (for the
above reason) not producing the results expected, is also attended with the
grave objection of considerably lengthening the traverse of the electricity, and
further, in this form the conducting wire is near the external surface of
the cable, which augments the effect of induction, and thus retarding the
passage of the electric current. It is by the following means that I give the
elastic conductors placed in the interior of submarine cables the necessary
power of extension and elasticity, so that they may, without breaking, permit
of any distension which the other constituent parts of the cable will bear, and
at the same time, which is a point not less important, that the capability of
this extension can be exercised without the conductors ceasing to form a
continuous metallic mass, through which electricity can traverse in a direct
line, and without having to traverse a helix, and consequently much longer
way. Round a cord of elastic material of any suitable kind, for instance, silk,
hemp, flax, cotton, gutta percha, india-rubber, or other elastic substance; and
which may be either a conductor or non-conductor, I wind a copper wire
round it, for example, in contiguous spirals, as in covered strings for musical
instruments.; over this I again wind another wire of the same diameter, or
very little less than the first, in such manner that this second helix falls in the
furrows of the first; I thus obtain a conductor composed of an electric core
placed in the centre of two spiral superposed coils, of which the spirals are
wound, so as to insure contact, whatever may be the extension they suffer, for
as soon as the elastic core stretches, the exterior pressure causes the external
spirals to bear on the spirals of the inner helix, and forces them into the
intervals of the, spirals of the inner helix; the extension should never exceed
double the original length, otherwise the desired continuity of the metallic
mass would cease; such a lengthening is, however, impossible without
breaking the core. According to this disposition of conductor, even although
the elastic core should break, the rupture would not extend to the metallic
wires which envelopes them; in effect, their spirals would only stretch, and
maintain, even after this rupture, a sufficient metallic communication between
the two broken parts of the internal conductor. It is evident that, according
to circumstances, I can vary the diameter of the extending core, & con-
sequently the metallic helices wound on it, according to the size of the wire
employed. I can also, instead of two layers of metallic spirals, apply three,

page_text: or even more. I can equally, instead of composing each layer of metallic
spirals of a single wire, form a helix of a cord formed of two, or three, or more
wires, but in multiplying the number of wires thus wound in spirals round the
elastic core, the power of distension of the metallic envelope is diminished,
but, on the other hand, this disposition of metallic wires enables it to resist
greater tension than when the spirals are longer. If it were necessary that
the metallic conductor which is produced by the superposition of wires thus
arranged in spirals should take a quarter or less share in the resistance to
the tension, I combine such condition with the amount of distension, which is
the principal object in view, as follows:-Around a small core of elastic
material I wind, say, only one helix, or it may be two helices, of metallic wires
in contiguous spirals. In this combination I form the inner core of a
metallic cord, which I obtain by winding in spiráls, more or less stretched,
a sufficient number of wires of a suitable diameter.
By reason of the property of extension of this core on which the wires.
forming the external surface of the conductor rest, it will have in itself
sufficient elasticity, for when the distending core (a single or double helix)
stretches by reason of its distensibility, it will deminish in diameter, and the
exterior spirals will be displaced and stretch themselves, and will approach
each other in a rectilinear direction. Again, in this case when a rupture
takes place of the wires placed at the surface, the interior helix (which, in
unwinding, should easily stretch or lengthen considerably) would maintain a
metallic communication between the two broken parts of the cable. I would
observe that this system of enveloping any kind of core with a wire disposed
in the manner of a spiral spring in one or more layers, can be applied to a
metallic core; this core may, however, be composed of a single wire, or,
better, of several wires, arranged parallel and in contact or twisted together;
in this case the elasticity will be less, but the advantage would result, that in
case of rupture of the metallic core conductor, the spiral wire or wires
which envelope it in being stretched, would maintain its metallic communica-
tion between the broken parts of the said conductor.
I would remark also that the improvements which I have mentioned are
independent of the nature of wires employed, and that I can vary the nature
of the metal employed, aluminium, iron, copper, &c., may be used; for
example, in cases where the metallic conductor should be constructed in such
manner that in a part of its length it should possess great extensibility, and
that in the remainder it should present great resistence to tension. I can
employ for the extensible part metallic springs of copper wire, while, for the
external spirals of a larger size, I employ a certain number of iron wires, in

page_text: which the resistance to rupture would be much more, and would aid the copper
in resisting strain. I can also reverse it, that is to say, superpose the copper
on the iron.
The improvements which I have mentioned are independent of the mode of
insulating, and the method necessary to adopt to form a protecting covering
for submarine cables. I would remark also, that for a protecting covering of
iron wire for the cable itself, in which, in order to augment the flexibility and
elasticity of the cables, cords or strands composed of a certain number of iron
wires are twisted together, I can considerably augment this elasticity and
flexibility, in applying for the improvements of these strands one of the
improvements before mentioned. I have remarked, in effect, that if, for
example, for the iron wire placed as a core in the middle of six other wires,
which with it compose each of the strands of the iron covering of submarine
cables, be substituted a wire or core of extensible matter, this substitute
suffices to give to each of these strands an elasticity which otherwise they
would not have, this elastic core being compressed by tension, to which the
wire cords of the exterior covering are subjected, which permits of their.
stretching and recoil. In conclusion, I claim the different points, namely, the
substitution for the conductors hitherto employed in the manufacture of sub-
marine electric cables, of conductors of considerable flexibility and extensibility,
without which the electric way would cease to be direct and continuous; the
said conductors present the following peculiarities, either separate or in
combination :-
1st. The use of a flexible and extensible core.
2ndly. The winding of a wire round the extensible core in contiguous
spirals, forming a sort of spiral spring or helix.
F
3rdly. The superposing of second and third layers of similar helices entering
into the furrows of the first helix, this disposition having for its object to
maintain the direct continuity of this metallic conductor, even when the
extension is great.
4thly. In cases where it has been seen that the metallic conductor thus
formed round the extensible core has not, of itself, an excess of extensibility,
but, on the contrary, presents a certain resistance to tension, I employ an
analogous arrangements to the foregoing, but obtained by the aid of a certain
number of wires wound round the extensible core, in such a way as to form a
combined wire helix, more or less lengthened.
j
5thly. The combination of this arrangement with the preceding by varying
the form of the helix, and also in varying, according to the case, the kind of
wire used.
.:

page_text: 6thly. The employment of the extensible core to form the centre of the iron
wire strands intended to protect the exterior of submarine electric cables, and
to give them the elasticity required.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the 13th
June 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM.
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of December, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-second year of
Her reign, did,- for Herself, Her heirs and successors, give and grant unto
me, the said. William Clark, Her special licence that I, the said William.
Clark, my executors, administrators, and assigns, or such others as I, the
said William Clark, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all. times there-
after 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 "Im-
PROVEMENTS IN SUBMARINE ELECTRIC CABLES OR CONDUCTORS," a communication
from Felix Marie Baudouin, of Rue des Recollets, Paris, upon the condition
(amongst others) that I, the said William 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 William 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 follow-
ing statement (that is to say):
A variety of methods have been employed to prevent the rupture in the wire
or wires forming the internal conductor of submarine telegraph cables. For
instance, instead of employing a single wire as a conductor, several wires have.
been twisted together in a spiral form, thereby forming a small wire rope; but

page_text: experience has proved to me that the capability of extension expected to be
obtained in this arrangement, is neutralized, or nearly so, by the insulating
coating which prevents their untwisting, and renders them less susceptible to
distension, besides being liable to break under a less strain than wires untwisted.
Instead of arranging the conductor in a straight line in the centre of the insu-
lating coating, it has been usual to wind it in a spiral form round a core of
hemp or other suitable substance, & in this form disposed in the insulating
coating; this disposition, for the above reason, does not produce the results
expected, and is further attended with the grave objection of considerably
lengthening the traverse of the electricity; moreover, in this form the conducting
wire is near the external surface of the cable, whereby the effect of induction
is augmented, and consequently the passage of the electric currents is retarded.
It is by the following means that I give to the electric conductors placed in
the interior of submarine cables, the necessary power of extension and elasticity
so that they may without breaking permit of any distension, which the other
constituent parts of the cable will bear, and at the same time this capability of
extension can be exercised without interrupting the direct and continuous
metallic mass through which electricity can traverse in a direct line.
Round a cord of elastic material of any suitable kind, for instance, silk, flax,
hemp, cotton, gutta percha, india-rubber, or other elastic substance, which may
be either a conductor or a non-conductor, I wind a copper wire, for example,
in contiguous spirals, as in covered strings for musical Instruments, &c.; over
this I again wind another wire of the same diameter or very little less than
the first, in such manner that this second helix falls in the furrows of the first.
I obtain thus a conductor composed of an elastic core placed in the centre
of two spiral superposed coils in which the spirals are wound so as to insure
contact, whatever may be the extension they suffer, for in proportion as the
elastic core stretches, the exterior pressure causes the external spirals to bear
on the spirals of the inner helix, and forces them in the intervals of the spirals
of the inner helix; the distension should never exceed double the original length,
such
otherwise the desired direct continuity of the metallic mass would cease;
a lengthening is, however, impossible. According to this disposition of the
conductor, even although the elastic core should break, the rupture could not
extend to the metallic wires which envelope them; in fact, their spirals would
only stretch and maintain, even after this rupture, a sufficient metallic com-
munication between the two broken parts of the core and internal conductor.
It is evident that according to circumstances I can vary the diameter of the
extending core, and consequently the metallic helices wound on it. I can also
vary the size of the wire employed, and also instead of two layers of metallic

page_text: spirals apply three or even more. Further, instead of composing each layer of
metallic spirals of a single wire, I can form a helix of a cord formed of two,
three, or more wires, but by multiplying the number of wires thus wound in.
spirals round the elastic core, the power of distension of the metallic envelope
is diminished, but on the other hand this disposition of metallic wires enables
it to resist greater extension than when the spirals are more lengthened.
If it be necessary that the metallic conductor produced by the superposition
of wires in this arrangement in spirals should take a greater or less share in.
the resistance to tension, I involve such condition with the capability of dis-
tension, which is the principal object in view, as follows:-Around a small core
of elastic matter I wind, say, only one helix, or it may be two helices of metallic
wires in contiguous spirals. In this combination I form the inner core of a
metallic cord, which I obtain by winding a sufficient number of wires of
suitable diameter in spirals more or less lengthened. By reason of the property
of extension of this core on which the wires forming the external surface of
this conductor rest, it will have in itself sufficient elasticity, for when the dis-
tending core of a single or double helix is extended, it will diminish in
diameter, while the exterior spirals will be displaced and stretch themselves,.
and approach at the same time each other in a rectilinear direction.
Again, under these conditions, if a rupture takes place of the wires placed on
the exterior, the interior helix in unwinding would easily stretch or lengthen
considerably, and would maintain a metallic communication between the broken
parts of the cable. I would observe that this system of enveloping a core
with a wire disposed in the manner of a spiral spring in one or more layers,
can be applied to a metallic core; this core may either be composed of a single
wire, or better, of several wires placed in contact, and arranged parallel or
twisted together. In this case the elasticity will be less, but an advantage will
result, that in case of rupture of the metallic core conductor, the spiral wire or
wires which envelope it become stretched, and still continue to maintain the
metallic communication between the broken parts of the said conductor; I
would remark also, that the improvements which I have just mentioned are.
independent of the nature of the metallic wires employed, and I can vary the
nature of the metals employed; iron, aluminium, copper, &c., may be used, for
example, in cases where the metallic conductor is required to be constructed
in such manner that in one part of its length it possesses great extensibility,
and that in the remainder it presents sufficient resistance to tension. I employ
for the extensible. part metallic spirals of copper wire, while for the external
spirals which are more lengthened, I employ a certain number of iron wires, in

page_text: which case the resistance to rupture would be much more considerable, and
would relieve the copper. I can also reverse the arrangement, that is to say,
superpose the copper on the iron.
The improvements which I have mentioned are independent of the mode of
insulating, and the methods necessary to adopt to form a protecting covering
for submarine cables. I would remark also, that for a protecting covering of
iron wire of the cable itself, which in order to augment the flexibility and
elasticity of the cables, consists of cords or strands composed of a certain number
of iron wires twisted together, I can considerably augment this elasticity &
flexibility by applying for the improvements of these strands one of the improve-
ments before-mentioned. In effect I have remarked that if, for example,
instead of the iron wire placed as a core in the middle of six other iron wires,
which with it compose each of the strands of the iron covering of submarine.
cables, be substituted a wire or core of extensible material, this substitute.
suffices to give to each of these strands an elasticity which they otherwise would
not have; this elastic core being compressable by the tension to which the wire
cords of the exterior covering are subjected, thus permits of their extension
and recoil.
Having described the nature of the Invention and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent, is,―
The use of electric cables or conductors, having considerable flexibility and
extensibility, in which the direct continuity of the electric conductor is not
interrupted by flexure or distension, by reason of the following peculiarities
which may be either used separately or in combination.
First, the use of a core formed of a flexible and extensible material.
Secondly, the winding of a wire round the extensible core in contiguous
spirals, forming a sort of spiral spring or helix.
Thirdly, the superposing of second and third layers of similar helices entering
in the furrows of the first and second belices, this disposition having for its
object to maintain the direct continuity of the metallic conductor, even when
the extension is great.
Fourthly, in cases where the metallic conductor thus formed round the
extensible core is not of itself required to possess any great extensibility, but,
on the contrary, presents a certain resistance to tension, I employ an analogous
arrangement, but produced by a certain number of wires. wound on the.
extensible core in such way as to form a combined wire helix, more or less.
lengthened.

page_text: Fifthly, the combination of this arrangement with the preceding, by varying
the form of the helix, and also varying according to circumstances the kind of
wires used.
Sixthly, the employment of the extensible core to form the centre of the
iron wire strands intended to protect the interior of submarine electric cables,
and to give them the elasticity required.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Thirteenth day of June, in the year of our
Lord One thousand eight hundred and fifty-nine.
Witness,
W. G. E. SWINNOCK,
53, Chancery Lane, London.
W. CLARK. (L.S.)