IMPROVEMENTS IN TELEGRAPH CABLES
Year: 1858

page_text: LETTERS PATENT to Josiah Latimer Clark, of Adelaide Road, in the
County of Middlesex, Civil Engineer. Frederick Braithwaite, of Bridge
Street, in the City of Westminster, Civil Engineer, and George Edward
Preece, of Bernard Street, in the County of Middlesex, Electrician, for
the Invention of "IMPROVEMENTS IN TELEGRAPH CABLES."
Sealed the 25th February 1859, and dated the 30th August 1858.
PROVISIONAL SPECIFICATION left by the said Josiah Latimer Clark,
Frederick Braithwaite, and George Edward Preece at the Office of the
Commissioners of Patents, with their Petition, on the 30th August
1858.
We, JOSIAH LATIMER CLARK, of Adelaide Road, in the County of Middlesex,
Civil Engineer, FREDERICK BRAITHWAITE, of Bridge Street, in the City of
Westminster, Civil Engineer, and GEORGE EDWARD PREECE, of Bernard Street,
in the County of Middlesex, Electrician, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN TELEGRAPH CABLES," to be as follows:-
Our Invention refers, first, to improvements upon an Invention for which
Letters Patent for Great Britain were granted to Josiah Latimer Clark, the
20th December 1853, for the use of asphalte and other similar dielectric
substances placed around the insulated wires of submarine and subterranean
telegraph cables, in order to lessen the induction and consequent retardation
of electric currents. Now, these improvements consist in the means of more
[Price 8d.]

page_text: effectually applying and supporting the said non-inductive coating,and for this
purpose the wire or wires already insulated with gutta percha or other
ordinary insulating material are covered with a coating of hemp, or other
fibrous material, which has been highly desiccated and deprived of all
moisture, and then saturated with a hot mixture of turpentine, rosin, pitch,
tar, asphalte, oil, or other similar well-known substances, such saturation
being completed by passing the said materials through or placing them in
air-tight vessels, from which the air is exhausted before the admission of
the non-conducting mixture, and into which the air or the mixture can
afterwards be injected under pressure. The insulated wires are surrounded
with this perfectly saturated mixture of fibrous and non-conducting material,
which may either be laid on in a mass, or preferably in the form of strands
coiled around the wires, either with or without an admixture of iron wires;
aud the cable thus formed is again saturated with the mixture, by placing
it in or passing it through an air-tight vessel, and submitting it as before
to the influence of a vacuum and subsequent pressure. The wires thus
become surrounded with a perfectly non-inductive material, and are at the
same time preserved from decay and injury.
Our Invention consists, secondly, in a method of preserving submarine or
other iron telegraph cables from decay, by surrounding the iron wires with
a compound of pitch, tar, asphalte, or other similar well-known preservative
materials, retained upon and around the cable by strands or flat bands of
hemp or other fibrous materials, saturated with the preservative substance
or mixture, and coiled around the cable in such manner as either to envelop
it completely, or to form a worming in the interstices between the wires.
Thirdly, in a method of preserving iron cables from decay by intermingling
among them one or more wires of zinc in place of iron, whereby the iron is
kept in an electro-negative condition, and thereby preserved from oxidation
or decay.
Fourthly, in means of joining the iron wires and the interior conducting
wires of submarine and other cables.
Where the wires are sufficiently large to admit of it, we form a light-
hand thread on the end of one wire, and a left-hand thread, on the end of
the other wire to be united to it; we then screw over the two ends a collar,
cut with corresponding right and left threais, and thus form a good and
secure joint. Where the wires are not sufficiently thick, we introduce the
two ends to be joined into a ferrule or collar, and by pressure or otherwise
flatten the wires and the collar about the centre, whereby the whole wil
be securely held together, and continuity will be ensured.

page_text: And, lastly, in forming the interior metallic conducting wires of telegraph
cables or wires in a round or polygonal form, by combining two or more
peculiarly formed wires together, such wires being so shaped that when
combined together they may form a solid cylindrical or nearly cylindrical
wire, that is to say, a wire having a circular section; the wires after being
drawn or rolled into their proper form, are combined or laid together with
a slight twist, so as to keep them together, and in this form are drawn
through a template or between rollers, to close up the interstices and give
the compound wire solidity and correct form.
The forms most preferred are those in which the circular section of the wire
is divided or bisected into two equal and similar half circles, by a section
across the diameter, or into three equal and similar segments, by three radii
diverging at angles of 120 degrees. In some cases a solid central wire is
surrounded by flat spiral bands or wires, the section of each band being similar
to the voussoirs or segments of an arch; or a single wire or band is wound
round the central wire like a harp string, and united to it by solder or tin.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Josiah Latimer Clark, Frederick Braithwaite, and George
Edward Preece in the Great Seal Patent Office on the 28th February
1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME we, JOSIAII
LATIMER CLARK, of Adelaide Road, in the County of Middlesex, Civil
Engineer, FREDERICK BRAITHWAITE, of Bridge Street, in the City of West-
minster, Civil Engineer, and GEORGE EDWARD PREECE, of Bernard Street, in
the County of Middlesex, Electrician, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of August, 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 us,
the said Josiah Latimer Clark, Frederick Braithwaite, and George Edward
Preece, Her special licence that we, the said Josiah Latimer Clark,
Frederick Braithwaite, and George Edward Precce, our executors, adminis-
trators, and assigns, or such others as we, the said Josiah Latimer Clark,
Frederick Braithwaite, and George Edward Preece, our 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

page_text: 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 TELEGRAPH CABLES," upon the condition
(amongst others) that we, the said Josiah Latimer Clark, Frederick Braith-
waite, and George Edward Preece, or one of us, our executors or adminis-
trators, by an instrument in writing under our, or their, or one of our or 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 we, the said Josiah Latimer Clark, Frederick
Braithwaite, and George Edward Preece, do hereby declare the nature of
our 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, reference being had to the Drawings hereunto annexed (that is
to say):-
Our Invention refers, first, to improvements upon an Invention for which
Letters Patent for Great Britain were granted to Josiah Latimer Clark, the
Twentieth December, One thousand eight hundred and fifty-three, for the use
of asphalte and other similar dielectric substances placed around the insulated
wires of submarine and subterranean telegraph cables, in order to lessen
the induction and consequent retardation of electric currents. Now, these
improvements consist in the means of more effectually applying and
supporting the said non-inductive coating, and for this purpose the wire
or wires already insulated with gutta percha or other ordinary insulating
material are covered with a coating of hemp or other fibrous material which
has been highly desiccated and deprived of all moisture, and then saturated
with a hot mixture of turpentine, rosin, pitch, tar, asphalte, oil, or other
similarwell-known substances, such saturation being completed by passing the
said materials through or placing them in air-tight vessels, from which the air
is exhausted before the admission of the non-conducting mixture, and into
which the air or the mixture can afterwards be injected under pressure.
The insulated wires are surrounded with this perfectly saturated mixture of
fibrous and non-conducting material, which may either be laid on in a mass,
or preferably in the form of strands coiled around the wires, either with or
without an admixture of iron wires, and the cable thus formed is again
saturated with the mixture by placing it in or passing it through an air-tight
vessel, and submitting it as before to the influence of a vacuum and subsequent

page_text: pressure. The wires thus become surrounded with a perfectly non-inductive
material, and are at the same time preserved from decay and injury.
The manner in which we carry this part of our Invention into effect is as
follows:-We take a single wire or a suitable number of conducting wires,
which we prefer to have insulated with caoutchouc on account of its capability
of withstanding an elevated temperature. We lay or twist them into a
bundle, and pass them through a vessel of melted pitch,asphalte, marine glue,
gutta percha, or othersimilar and well-known insulating materials or mixtures,
and as they emerge from the melted mixture we cover them with a suitable
number of strands of rope yarn or other fibrous material which have been
thoroughly saturated with the mixture by previous immersion, and which
pass through the hot melted mixture in the same manner as the conducting
wires, and at the same time as soon as they emerge from the pitch, they
are slightly twisted together by an ordinary rope-making machine, or
plaited or braided, and they are then covered by a set of clean yarns, or by
flat bands wound in the opposite direction, so as to enable them to be
handled. The substances which we prefer to use for these purposes are
common pitch or pitch and gutta percha.
When we employ gutta percha covered wire, which will not admit of the
application of so high a temperature as caoutchouc covered wire, we use the
pitch in a nearly cold state, and having laid up the conducting wires and the
saturated hemp yarns together, we place the whole into or pass it through an
air-tight vessel, from which we exhaust the air and then admit the semi-
fluid pitch or mixture. We then apply pressure to drive the pitch into
every cavity, and then withdraw the rope and cover it with hemp strands,
as before described. Such ropes or cables as we have described may be
cither laid or drawn into underground tubes in the usual manner, or may
be covered with iron wires to form submarine cables.
We do not claim generally the use or manufacture of gutta percha covered
or other electric telegraph wire surrounded with yarn saturated with pitch,
tar, &c., laid together in a cold state, but we claim under this first head of
our Invention, the method of saturating the yarns, filling up all the interstices
between the yarns and the wires with pitch or other protecting material, by
passing the wires and the yarns through these melted materials at the time
of manufacture, and laying up the cable in a hot state. We also claim
injecting these hot inelted materials under pressure in such manner as to
obtain a compound of fibrous and insulating material, forming an impervious
water-tight and non-inducting coating.

page_text: Our Invention consists, secondly, in a method of preserving submarine or
other iron telegraph cables from decay, by surrounding the iron or steel
wires with a compound of pitch, tar, asphalte, or other similar well-known
preservative materials retained upon and around the cable by strands or
flat bands of hemp or other fibrous material, saturated with the preservative
substance or mixture, and plaited or braided round the cable, or coiled
around the cable in such manner as either to envelope it completely, or to
form a worming in the interstices between the wires.
The manner in which we carry this second part of our Invention into effect
is as follows: To preserve the iron or steel wires of telegraph cables from
oxydation, we cover them with a mixture of hemp or other fibre saturated
with pitch or asphalte, marine glue, gutta percha, and apply the preserving
coating on the cable in a hot state. By preference we employ pitch, and we
prefer to apply the coating at the time of the manufacture of the cable.
The cable, as fast as it leaves the covering machine, is caused to pass
through a vessel of common tar, and is led up vertically through a pipe in
the centre of a cauldron or tank, and passing through is carried up from the
bottom thereof. The cauldron is kept revolving at a convenient speed, and
contains a quantity of the pitch or preserving material or mixture in a melted
state, kept hot by heat applied in any convenient manner. The cauldron also
contains several reels of spun yarn well saturated with the pitch. The reels
revolve loosely on horizontal axes, and are wholly are partially immersed in the
melted pitch; the yarns as they are unwound off these bobbins pass up over
suitable guides, and are wound spirally, or are plaited or braided in a hot
state around the cable. Sometimes we lay up the wires and the saturated
fibrous materials together and with the same machine; in such cases the iron
or steel wires are led through the closing nozzle of the covering machine at
the same time, the iron wires a little in advance of the hempen yarns, so that
they may close round the core first, and then become completely enveloped
by the outer protecting yarns. We claim under this head of our Invention,
the preserving telegraph cables from decay in the manner described under
this second head of our Specification.
Thirdly, our Invention consists in a method of preserving iron cables from
decay, and which we claim as new, by intermingling among them one or more
wires of zinc in place of iron, whereby the iron is kept in an electro-
negative condition, and thereby preserved from oxydation or decay.
The fourth part of our Invention consists in new methods of joining the
iron wires and the conducting wires of submarine and other telegraphs. We

page_text: form a right-handed thread or screw on the end of one of the wires, and a
left-handed thread on the end of the other wire to be united to it; we then
insert the two ends in a screwed ferrule or collar cut with corresponding right
and left threads, and by screwing it up draw the two ends into contact, and
form a secure joint. Sometimes, and especially with small wires, the ends are
not screwed, but are simply introduced into a plain ferrule or collar, when
by pressure or by the blows of a hammer we flatten both the ferrule and the
ends of the wires about the centre, so that the ends of the wires cannot be
drawn out of the collar. We claim the use of the last-mentioned joint both
for submarine and suspended telegraphs, but we only claim the use of the
screwed joint when employed to join the wires of submarine telegraphs.
And, lastly, our Invention consists in forming the conducting wires of sub-
marine cables in the manner hereafter set forth. It has been heretofore
customary to lay up several small copper wires together into one spiral strand,
so that any faulty place in a wire might not by its fracture destroy the con-
tinuity of the whole cable, and render it useless. But such compound strands
have the disadvantage that their sectional area is not so great in proportion to
the surface exposed to induction as in solid wires, and also their effective
length,measured along the spiral,is commonly greater byabout twelve or fifteen
per cent. than the actual length of the cable itself. Both these causes
combined tend very seriously to retard the transmission of the current, and to
increase the amount of induction, and thereby to render their use objectionable.
Now, our improvement consists in building up a solid conducting wire in
segments, so that any defect or breakage in a single segment will not endanger
the continuity of the whole cable, and for this object we divide the circular
section of the wire (by preference) into five segments, by five divisions, in the
form of radii, and we draw wires through templates, of such a form as to give
each wire a similar section to that of one of the segments. We then lay five
of these wires together, so as to form a single round wire equal in conductive
power to a solid wire. The shape may be further improved by passing the
whole through a template, or between small grooved rollers, to close the
segments tightly together. In joining such wires together we carefully break
joint with each segment, and unite the ends of the two segments to each
other and to the neighboring segments by a blow pipe and fine or silver
solder. The joint may be further secured, if thought necessary, by wrapping
a small wire round it spirally in the usual manner, and soldering the ends.
In some cases we extend the spiral wrapping along the whole length of a
conducting wire, so as to insure continuity in case of fracture.

page_text: Figure 1 represents on an enlarged scale the section of a wire formed of
five segments, and Figure 2 one composed of three segments; Figure 3
represents a solid central core surrounded by five segmental outer cones.
We claim forming the interior conducting wires of telegraph cables sub-
stantially in the manner herein described.
In witness whereof, I, the said Josiah Latimer Clark, have hercunto
set my hand and seal, this Twenty-eighth day of February, Oue
thousand eight hundred and fifty-nine.
JOSIAH LATIMER CLARK. (L.S.)