MENTS IN INSULATING WIRE FOR ELECTRIC TELEGRAPHS
Year: 1859

page_text: LETTERS PATENT to Hugh Adams Silver, of Cornhill and Bishopsgate
Street Within, in the City of London, and Silver. Town, in the County
of Essex, India-rubber Manufacturer, for the Invention of "IMPROVE-
Sealed the 28th June 1859, and dated the 15th April 1859.
PROVISIONAL SPECIFICATION left by the said Hugh Adams Silver
at the Office of the Commissioners of Patents, with his Petition, on
the 15th April 1859.
I, HUGH ADAMS SILVER, of Cornhill and Bishopsgate Street Within, in the
City of London, and Silver Town, in the County of Essex, India-rubber
Manufacturer, do hereby declare the nature of the Invention for "IMPROVE-
MENTS IN INSULATING WIRE FOR ELECTRIC TELEGRAPHS," to be as follows:-
This Invention has for its object improvements in insulating wire for electric
telegraphs. For these purposes the conducting wires are wound round with
strips of india-rubber applied in one or more layers, and then subjected to the
action of steam, or heated vapour, or heated air, by which the edges of the
india-rubber become joined or cemented together, and a complete coating of
india-rubber is obtained to the conducting wire or wires. In some cases the
conducting wire or wires having been wound round with one or more layers of
india-rubber the coated wire is subjected to the action of a melted' sulphur
bath, and this process may also be resorted to after the india-rubber covering
has been subjected to the action of a bath of steam or of hot vapour or of hot

page_text: air. And in some cases the wire when coated with india-rubber by winding,
as above stated, has a further coating of india-rubber combined with sulphur
applied thereto by dies or other suitable means, and then the coated wire or
wires is subjected to the action of a melted sulphur bath.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Hugh Adams Silver in the Great Seal Patent Office on
the 15th October 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HUGH
ADAMS SILVER, of Cornbill and Bishopsgate Street Within, in the City of
London, and Silver Town, in the County of Essex, India-rubber Manu-
facturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of April, in the year of our Lord One
thousand eight hundred and fifty-nine, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Hugh Adams Silver, Her special licence that I, the said Hugh
Adams Silver, my executors, administrators, and assigns, or such others
as I, the said Hugh Adams Silver, 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, use, exercise, and vend, within the United Kingdom
of Great Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN INSULATING WIRE FOR ELECTRIC TELEGRAPHS," upon
the condition (amongst others) that I, the said Hugh Adams Silver, my exccu-
tors 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 Hugh Adams Silver, 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 has for its object improvements in insulating wire for electric
telegraphs. For these purposes the conducting wires are wound round with

page_text: strips of india-rubber applied in one or more layers, and then subjected to
the action of steam or heated vapour, or heated air, by which the edges of the
india-rubber become joined or cemented together, and a complete coating of
india-rubber is obtained to the conducting wire or wires. In some cases, the
conducting wire or wires having been wound round with one or more layers
of india-rubber, the coated wire is subjected to the action of a melted sulphur
bath, and this process may also be resorted to after the india-rubber covering
has been subjected to the action of a bath of steam, or of hot vapour, or of
hot air. And in some cases the wire when coated with india-rubber by winding,
as above stated, has a further coating of india-rubber combined with sulphur
applied thereto by dies or other suitable means, and then the coated wire or
wires is subjected to the action of a melted sulphur bath.
Having thus stated the nature of my Invention, I will proceed more fully
to describe the manner of performing the same.
The wire or other form of metal conductor is first covered with india-
rubber, which is by preference uncombined with other matters, though other
matters other than sulphur or sulphur compounds may be used, but to which
coating of india-rubber I make no claim, the same having been before prac-
tised by others. I, however, prefer to cover the conductor by wrapping a
fillet of india-rubber spirally around the conductor first in one direction and
then in the other, taking care that the edges of each spiral lapping overlap
each other, and that the next spiral lapping breaks joint with the previous
one, all which is well understood, and the peculiarity of the first part of
my Invention consists in subjecting the same to steam for a few minutes
according to the thickness of the coating of india-rubber. The temperature
of the steam may be varied, but generally I prefer a temperature of 212 to
220° Fahrenheit, when three minutes is sufficient for a moderate thickness
of coating; by such means the whole india-rubber coating becomes as if
originally applied in one substance, the lapping edges and surfaces becoming
by the heat and action of the steam cemented or joined together, and this
without the aid or addition of any solvent or cement. I would remark that
I am aware that conductors of electricity have before been similarly coated
or covered with india-rubber, and then subjected to the action of boiling
water, the boiling point of which has been heightened by combining salts
or matters with it, but I have found that the use of steam offers great
advantages in obtaining the desired result.
Another part of my Invention consists of using heated air in place of steam
when treating metal electric conductors covered with india-rubber as above
described. For this purpose I employ heated air of about 150° of Fahren-

page_text: beit, though the temperature may be varied, and I subject the coated con-
ductors for two, three, or more minutes to the action thereof, when, as in the
case of using steam, the coating or coatings become as if of one substance. A
convenient mode of applying steam or heated air is to move the coated wire
or conductor through a chamber constantly kept supplied with steam or
heated air, so that every part of the india-rubber may be subjected to the
action thereof for a sufficient time to cause the overlapping edges or parts to
go together, and become as one substance.
Another part of my Invention consists of passing wire or metallic conductor
covered with india-rubber, as above described, through a bath of melted sulphur,
which I prefer to be heated to about 290° Fahrenheit, but the temperature
may be varied, by which the outer surface of the india-rubber becomes vul-
canized or changed. I have found that if every part of the outer surface is
allowed to be acted on for about two minutes by the heated sulphur, a very
satisfactory result is obtained, though the time as well as the temperature may
be varied. In some cases before passing the india-rubber covered conductor
through the sulphur bath, as above described, I apply a coating of sulphur
compound of india-rubber external of and in direct contact with the other
coating of india-rubber, then subject it to the action of the sulphur bath.
I would remark that I am aware that it has been proposed, when coating
metallic conductors, to interpose between a coating of india-rubber in its
natural state, and a coating of a sulphur compound of india-rubber, a metal
or other coating to separate the one coating from another. This part of my
Invention consists in employing the sulphur compound of india-rubber directly
in contact with the coating of india-rubber not combined with sulphur.
In witness whereof, I, the said Hugh Adams Silver, have hereunto set
my hand and seal, this Fourteenth day of October, in the year of our
Lord One thousand eight hundred and fifty-nine.
HUGH A. SILVER. (L.S.)