IMPROVEMENTS IN ELECTRIC TELEGRAPHS
Year: 1868

page_text: LETTERS PATENT to Cromwell Fleetwood Varley, of Beckenham,
in the County of Kent, for the Invention of "IMPROVEMENTS IN
ELECTRIC TELEGRAPHS."
Sealed the 5th January 1869, and dated the 29th August 1868.
PROVISIONAL SPECIFICATION left by the said Cromwell Fleetwood
Varley at the Office of the Commissioners of Patents, with his
Petition, on the 29th August 1868.
I, CROMWELL FLEETWOOD VARLEY, of Beckenham, in the County
of Kent, do hereby declare the nature of the said Invention for "IM-
PROVEMENTS IN ELECTRIC TELEGRAPHS," to be as follows:-
This Invention has for its object improvements in electric telegraphs.
For deep sea cables the insulated conductor is laid side by side and
parallel, with a cord or cords and lashed at intervals thereto. The cords
or ropes are made of hemp, jute, or other suitable fibre combining great
strength with little or no weight in water. The effect of water upon
hemp is to cause it to contract, and as cables have hitherto been

page_text: constructed this contraction compels the core to contract also, and
hence destruction of insulation by the protrusion of the conducting
wires through the dielectric or insulator, in this cable any contraction
of the strength giving ropes after submursion only causes the core to
form festoons and does not therefore injure it. The core should be
previously covered with a slight serving to protect it against abrasion.
The cord or rope may be composed partly of hemp and partly of iron or
steel. The core (or insulated conductor) should be lashed to the cord,
rope, or ropes at intervals of about one foot (more or less according to
circumstances) unless they are twisted together in a slow spiral, in
which case the lashings may be dispensed with. In this way cables of
great strength and very low specific gravity are formed at a very
moderate cost, capable of being laid and recovered from the deepest
known ocean. To preserve the hemp or other vegetable fibre used in
these and other telegraphic cables or ropes it is first saturated with
strong brine or chloride of sodium and dried (wholly or partially) it is
then covered with a mixture of pitch and chloride of sodium well
mixed. To guard against the teredo or other boring insects of the
warm oceans, the outer covering of the insulator is mixed with fine
glass powder or other hard material detrimental to the teeth of the
marine animals. The pitch and chloride of sodium may be also mixed
with the same hard powder. By the term pitch is included wood or
mineral tar, wood or mineral pitch or resin; other chlorides, such as
chloride of calcium, may be substituted for chloride of sodium in some
cases with advantage, especially where the cable is to be laid under
ground. In the case of cables buried in the ground the chlorides also
serve to prevent injury to the dielectric from vegetable growths.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Cromwell Fleetwood Varley in the Great Seal
Patent Office on the 27th February 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CRожWELL
FLEETWOOD VARLEY, of Beckenham, in the County of Kent, send
greeting.
3
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of August, in the 3

page_text: year of our Lord One thousand eight hundred and sixty-eight, in the
thirty-second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Cromwell Fleetwood Varley, Her
special licence that I, the said Cromwell Fleetwood Varley, my
executors, administrators, and assigns, or such others as I, the said
Cromwell Fleetwood Varley, 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, usc, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "IMPROVEMENTS IN ELECTRIC TELEGRAPHS,"
upon the condition (amongst others) that I, the said Cromwell
Fleetwood Varley, 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 Cromwell Fleetwood Varley, 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 :-
This Invention relates to the cables of electric telegraphs. Hemp,
jute, and similar substances have been used for deep sea telegraphic
cables, but as they have been hitherto constructed the contraction of
these materials compels the insulated conductor to knuckle out and the
conducting wire to protrude through the insulating material, and thus
the insulation is destroyed. This defect may be remedied, as stated in
my Provisional Specification, either by lashing the insulated conductor
to the rope or ropes or twisting them together in a slow spiral. In
practice I have not found the lashing process a good one, so I do not
claim it, but adhere to the second alternative, namely, that of twisting
the insulated conductor with the strands of the cable, so that the
insulated conductor occupies the place of one of the spiral strands in an
ordinary cable. Such a cable can be passed over the wheel of the
paying-out and pulling-up machinery without injuring the insulated
conductor, and any contraction of the comparatively elastic strands does
not cause the conductor to knuckle out and endanger the insulation.
The strands which, combined with the insulated conductor, constitute

page_text: the cable are made of hemp or other similar fibre combining strength
with little or no weight in water. The insulated conductor should be
covered with a slight serving or with tape to protect it against abrasion.
The other part of my Invention relates to a method of preserving the
hemp or similar vegetable fibre of telegraphic cables. To preserve
the
hemp or similar vegetable fibre used in telegraphic cables or ropes it is
first saturated with strong solution of either chloride of sodium or
chloride of calcium, or a mixture of the two, and dried; it is then
saturated with a mixture of pitch and chloride of sodium or calcium
well mixed. In this term pitch are included wood or mineral tar
and wood or mineral pitch or resin.
And in order that my said Invention may be fully understood and
readily carried into effect I will proceed to describe more in detail
the manner in which I prefer to construct telegraphic cables.
The conductor which I prefer to employ is as usual a strand of copper
wires of a section adapted to the work which is required of it. It is
insulated with a suitable thickness of gutta percha or caoutchouc as is
well understood. In order to protect the insulator from abrasion I
serve the insulated conductor with common serving or with tape. I
next take two hempen cords or ropes; they may conveniently be of
rather larger diameter than the served insulated conductor. I lay
together the two cords and the insulated conductor in a very slow spiral,
say with one turn of the lay in a length equal to thirty diameters of one
of the cords, as shown in the Drawing hereunto annexed. Before laying
them together I usually submit the cords to the preservative process
which constitutes the second part of my Invention. It is not absolutely
essential that they be submitted to this process which is principally used
for the purpose of retarding decay. For preserving the vegetable fibre
in telegraphic cables I soak the cords in brine until they are thoroughly
saturated, and I then dry them at a gentle heat. I then saturate them
with a mixture of pitch, as above defined, and pulverized chloride of
sodium in such proportions that the compound will neither run nor
become hard at any temperature to which the cable will be exposed.
It is difficult to state any fixed proportions, as the pitch and tar of
commerce vary in quality, but a compound of about forty-five parts of
pitch, thirty-five parts of tar, twenty parts of chloride of sodium or
calcium, will usually be sufficient.
What I claim is the constructing electric telegraphic cables by twisting

page_text: an insulated conductor with a cord or cords of hemp or other similar
fibrous material, as herein-before described.
I also claim the use in the manufacture of telegraphic cables of
cords, yarns, or tape impregnated by chloride of sodium or calcium,
and then coated with pitch and chloride of sodium or calcium, as herein
described.
In witness whereof, I, the said Cromwell Fleetwood Varley, have
hereunto set my hand and seal, this Twenty-fifth day of
February, in the year of our Lord One thousand eight hundred
and sixty-nine.
CROMWELL F. VARLEY. (L.S.)