IMPROVEMENTS IN THE MANUFACTURE OF MARINE TELEGRAPH CABLES
Year: 1870

page_text: LETTERS PATENT to Matthew Gray, of Highbury Hill, in the County
of Middlesex, Engineer, and Frederick Hawkins, of Silvertown, in
the County of Essex, Electrician, for the Invention of "IMPROVE-
PROVISIONAL SPECIFICATION left by the said Matthew Gray and
Frederick Hawkins at the Office of the Commissioners of Patents,
with their Petition, on the 29th August 1870.
We, MATTHEW GRAY, of Highbury Hill, in the County of Middlesex,
Engineer, and FREDERICK HAWKINS, of Silvertown, in the County of
Essex, Electrician, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE MANUFACTURE OF MARINE TELEGRAPH CABLES," to be
as follows:-

page_text: telegraph cables. These wires have commonly been overlaid with a
thread or threads of hemp coiled around the several wires, but it has
been found that on exposing to sea water a cable protected with wires so
covered oxidation is quickly induced, the water entering between the
coils of the thread and attacking the metal, and a rapid destruction of
the hempen covering ensues. Thus not only is the strength of the
"armour" deteriorated but it becomes loose around the core, thereby
providing facilities for the injury of the core itself and the destruction of
the cable. To remedy these inconveniences we propose to lap around
each protecting wire (before applying them to the cable) strips of woven
cloth saturated with a waterproof composition, consisting-by-preference_
of vegetable bitumen, tar, rosin, and india-rubber. The cloth may be
made of cotton, flax, or other yarn, and it may be prepared in the piece
and cut up (while in the form of a roll) into strips of the desired width
in a lathe by means of an ordinary turning or cutting tool. The wires
will have at least two coatings of the cloth, which strips are to be laid
helically around the wires alternately in opposite directions, and with a
sufficient lap to ensure the complete and effectual covering of the wires.
An incidental advantage of using wires thus covered is that where a small
diameter of armoured cable is desired a material diminution of bulk of
the cable is obtained without reducing its breaking strain. The wires
thus prepared are laid around the core in the usual manner of applying
external strengthening wires.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Matthew Gray and Frederick Hawkins in the
Great Seal Patent Office on the 28th February 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, MATTHEW
GRAY, of Highbury Hill, in the County of Middlesex, Engineer, and
FREDERICK HAWKINS, of Silvertown, in the County of Essex, Electrician,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of August, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-fourth
year of Her reign, did, for Herself, Her heirs and successors, give and

page_text: grant unto us, the said Matthew Gray and Frederick Hawkins, Her
special licence that we, the said Matthew Gray and Frederick Hawkins,
our executors, administrators, and assigns, or such others as we, the
said Matthew Gray and Frederick Hawkins, our 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 THE MANUFACTURE OF
MARINE TELEGRAPH CABLES," upon the condition (amongst others) that we,
the said Matthew Gray and Frederick Hawkins, our executors or
administrators, by an instrument in writing under our, 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 Frederick Hawkins, on behalf of
myself and of the said Matthew Gray, 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,
reference being had to the Drawing hereunto annexed, and to the letters
and figures marked thereon (that is to say) :-
The object of our Invention is to protect from oxydation (more
effectually than heretofore) the external strengthening wires or "armour"
of marine telegraph cables. These wires have commonly been overlaid
with a thread or threads of hemp coiled around the several wires, but it
has been found that on exposing to sea water a cable protected with wire
so covered oxydation is quickly induced, the water entering between the
coils of the thread and attacking the metal, and a rapid destruction of
the hempen covering ensues. Thus not only is the strength of the
armour deteriorated but it becomes loose around the core, thereby
providing facilities for the injury of the core itself and the destruction of
the cable. To remedy these inconveniences we propose to lap around
each protecting wire (before applying the same) to the cable strips of
woven cloth saturated with any approved waterproof composition, and in
most telegraph cable manufactories that which we prefer to use is a
و,

page_text: compound of vegetable pitch, tar, rosin, and india-rubber, which possesses
the consistency when hot of melted marine glue. In applying the
composition to the woven cloth we pass the cloth through a bath of the
composition kept heated by the circulation of steam through a steam
jacket surrounding the vessel containing the composition. The cloth t
passes under a guide roller mounted in the vessel, and it is led up to a
pair of hollow nipping rollers heated by steam. The action of these
rollers will be to press the composition well into the pores of the cloth
and keep back any superfluity. The cloth may be made either of cotton
or flax yarn, and it may be prepared in the piece and cut up (while in 1
the form of a roll)-into-strips-of-the-desired-width in a lathe by means of
an ordinary turning or cutting tool. The wires will have at least two
coatings of cloth, the inner coating being by preference of cotton, and
the outer one of Hessian canvass, which is a very cheap material. The
strips are laid helically around the wires, the coatings being laid
alternately in opposite directions, and with a sufficient lap at the
edges of the strip to ensure the complete and effectual covering of the
wires.
In the accompanying Drawing Fig. 1 shews a portion of one of the
protecting wires partially stripped to illustrate the mode of covering the
same with the waterproof strips; Fig. 2 is a cross section of a cable
clothed with protecting wires prepared according to our Invention; and
Fig. 3 is an external view of a portion of the same cable.
An incidental advantage of using wires thus covered is that a material
diminution of bulk of the cable is obtained without reducing its breaking
strain, and this is the more apparent when a comparatively small diameter
of armoured cable is manufactured with the coated wires.
The Drawing illustrates the pattern of the Wexford cable, and by the
adoption of the Invention thereto the diameter is reduced about one-
tenth. The wires prepared with the saturated cloth strips are laid
around the core in the usual manner of applying external strengthening
wires.
Having now set forth the nature of the Invention of "
Improvements
in the Manufacture of Marine Telegraph Cables," and explained the
manner of carrying the same into effect, we wish it to be understood that
under the above in part recited Letters Patent we claim, preparing the

page_text: <<
external strengthening wires or armour
manner and for the purpose above set forth.
5,
of marine cables in the
In witness whereof, I, the said Frederick Hawkins, have hereunto
set my hand and seal, the Twenty-fifth day of February, in the
year of our Lord One thousand eight hundred and seventy-one.
FREDERICK HAWKINS. (L.S.)