IMPROVEMENTS IN SUBMARINE TELEGRAPH CABLES, AND IN THE MODE OF JOINING THE SAME
Year: 1867

page_text: LETTERS PATENT to Thomas Allan, of Adelphi Terrace, in the City of
Westminster, Civil Engineer, for the Invention of "IMPROVEMENTS IN
SUBMARINE TELEGRAPH CABLES, AND IN THE MODE OF JOINING THE SAME,"
Sealed the 31st January 1868, and dated the 2nd August 1867.
PROVISIONAL SPECIFICATION left by the said Thomas Allan at the
Office of the Commissioners of Patents, with his Petition, on the
2nd August 1867.
I, THOMAS ALLAN, of Adelphi Terrace, in the City of Westminster, Civil
Engineer, do hereby declare the nature of the said Invention for "IMPROVE.
MENTS IN SUBMARINE TELEGRAPH CABLES, AND IN THE MODE OF JOINING THE SAME,"
to be as follows:-
In the Specification of a former Patent, dated 13th August 1853, No. 1889,
I described a plan of constructing submarine telegraph cables or electric
conductors-to-obviate-the-then-engineering-and-electrical difficulties to the
making and working of submarine telegraphs of extra great lengths, and I
described a mode of forming the conductor of iron wire or strand of iron
wires in lieu of copper as then and now used, and so making the conductor
[Price 8d.1

page_text: not only the conducting medium, but also the rope itself (that is, the strength
of the cable), and in some cases I proposed to use strands of wires of two
different metals, that is, six iron wires with a centre core or wire of copper, so
as to obtain a better conductor than could be obtained by the use of iron alone.
My present improvements consist in combining the copper and iron or steel
and insulating material in such relative proportions as by so lightening the
specific gravity of the combined cable I am enabled to obtain the maximum
of conductibility for the sectional area of the conductor with the minimum
amount of the baser conducting metal consistent with the desired breaking
strain, that is to say, that instead of the proportions of the metals being as 6 of
iron to 1 of copper, 1 form or combine them in the proportions of two of iron to
1 of copper, or one of iron to one, two, or three of copper, as the requirements
of the case may be. For this purpose, as an example (of the proportions of 1
of iron to 2 of copper), I take one copper wire, No. 12 guage, and surround it
with 18 fine steel wires. No.24,slightly spiralled; or, depending on the depths
I may use a smaller guage of steel wire to surround the copper wire, and in
some cases I alternate the small steel wires with small copper wires so as to
increase the conductability of the core without increasing its sectional area.
Combined conductors constructed as above described when insulated and
completed in mile lengths, as is the usual practice, cannot be joined or spliced
into a cable so as to maintain the fullest conductability and tensile strength by
any of the modes of splicing or joining at present in use. To effect this I
take a steel tube, say 2 to 3 inches long, and previously prepared for the
purpose by having its interior surface sufficiently coated with the proper kind
of solder; this tube is then first slipped over the end. of one length of
cable, the copper wires of the two ends of the cable to be joined are bevilled
and soldered, and the space, if any, filled up to the thickness of the steel wire
covering the steel tube is then slipped over the joining in equal parts each
way; the whole is next heated till the solder has run well through and
amongst the steel wires for that space. The steel tube may or may not have
a longitudinal slit throughout its length to admit of closer compression
during the process of soldering. In laying up the steel wires around the
solid copper conductor I prefer to run them through a liquid solution of
insulating material so as to prevent and exclude any air spaces or interstices
in the combined conductor.
;

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed'
by 'the said Thomas Allan in the Great Seal Patent Office on the
1st February 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
ALLAN, of Adelphi Terrace, in the City of Westminster, Civil Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of August, in the year of our Lord One
thousand eight hundred and sixty-seven, in the thirty-first year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Thomas Allan, Her special license that I, the said Thomas Allan, my
executors, administrators, and assigns, or such others as I, the said Thomas
Allan, iny executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during
the terin therein expressed, should and lawfully might make, ise, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "'IMPROVEMENTS IN SUB-
MARINE TELEGRAPH CABLES, AND IN THE MODE OF JOINING THE SAME," upon the
condition (amongst others) that I, the said Thomas Allan, 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 caнse
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 Thomas Allan, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say :-
In the Specification of a former Patent, dated Twelfth August, One thou-
sand eight hundred and fifty-three, No. 1889, I described a plan of constructing
submarine telegraph cables or electric conductors to obviate the then cugi-
neering and electrical difficulties to the making and working of submarine
telegraphs of extra great lengths, and I described a mode of forming the con-
ductor-of-iron-wire or-strand of iron wires in lieu of copper, as then and now
-used-and-so-making the conductor not only the conducting medium, but also
the rope itself (that is to say, the strength of the cable), and in some cases I
proposed to use strands of wires of two different metals, that is to say, six iron

page_text: wires with a centre core or wire of copper, so as to obtain a better conductor
than could be obtained by the use of iron alone.
My present improvements consist in combining the copper and iron or
steel and insulating material in such relative proportions as by so lightening
the specific gravity of the cable so composed I am enabled to obtain the maxi-
mum of conductibility for the sectional area of the conductor with the minimum
amount of the baser conducting metal consistent with the desired breaking
strain; that is to say, that instead of the proportions of the metals being as 6
of iron or steel to one of copper, I form or combine them in the proportions of
two of iron to one of copper, or one of iron to one, two, or three of copper, as
the requirements of the case may be. For this purpose, as an example (of
the proportions of one of iron to two of copper), I take one copper wire, No. 12
gauge, and surround itwith eighteen fine steel wires, No.24,slightlyspiralled;
or, depending on the depths, I may use a smaller gauge of steel wire to
surround the copper wire, and in some cases I alternate the small steel
wires with small copper wires, so as to increase the conductibility of the
core without increasing its sectional area.
Combined conductors constructed as above described when insulated and
completed in mile lengths, as is the usual practice, cannot be joined or spliced
into a cable so as to maintain the fullest conductibility and tensile strength
by any of the modes of splicing or joining as present in use. To effect this I
take a steel tube, say, 2 to 3 inches long, and previously prepared for the
purpose by having its interior surface sufficiently coated with the proper
kind of solder; this tube is then first slipped over the end of one length
of cable; the copper wires of the two ends of the cable to be joined are
bevelled and soldered, and the space, if any, filled up to the thickness of
the steel wire covering; the steel tube is then slipped over the joining in
equal parts each way; the whole is next heated till the solder has run well
through and amongst the steel wires for that space. The steel tube may
or may not have a longitudinal slit throughout its length to admit of closer
compression during the process of soldering. In laying up the steel wires
around the solid copper conductor I prefer to run them through a liquid
solution of insulating material so as to prevent and exclude any air spaces
or interstices in the combined conductor.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I claim,-
First. The combining of iron or steel and copper wires in submarine
telegraph cables in such relative proportions as herein-before described as

page_text: to obtain the maximum of conductibility (for the sectional area of the con-
ductor) with the minimum amount of iron or steel consistent with the
desired breaking strain, that is to say, that the ratio of the iron or steel to
the copper shall not be more than two to one, and it may be as one to one,
as one to two, or as one to three.
Second. The joining of submarine telegraph cables substantially by the
means and in the manner herein-before described.
In witness whereof, I, the said Thomas Allan, have hereunto set my
hand and seal, this Twenty-ninth day of January, One thousand
eight hundred and sixty-eight.
THOMAS ALLAN. (L.S.)