IMPROVEMENTS IN INSULATORS FOR TELEGRAPH WIRES
Year: 1866

page_text: LETTERS PATENT to George Davies, of No. 1, Serle Street, Lincoln's Inn,
in the County of Middlesex, and No. 87, St. Vincent Street, in the
City of Glasgow, Civil Engineer and Patent Agent, for the Invention of
"IMPROVEMENTS IN INSULATORS FOR TELEGRAPH WIRES."-A communication
. from abroad by David Brooks, of Philadelphia, Pennsylvania, United
States of America.
Sealed the 26th October 1866, and dated the 1st May 1866.
PROVISIONAL SPECIFICATION left by the said George Davies at the
Office of the Commissioners of Patents, with his Petition, on the 1st May
1866.
I, GEORGE DAVIES, of No. 1, Serle Street, Lincoln's Inn, in the County of
Middlesex, and No. 87, St. Vincent Street, in the City of Glasgow, Civil
Engineer and Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN INSULATORS FOR TELEGRAPH WIRES," (a communication
to me from abroad by David Brooks, of Philadelphia, Pennsylvania, United
States of America,) to be as follows :-
This Invention consists of the improved mode hereafter described of
constructing insulators for electric telegraph wires, whereby the inconveniences
resulting from the collection of water on or about the insulators during rainy
and foggy weather are obviated.

page_text: The insulator consists principally of three parts, an outer hollow cylindrical
casing of cast iron, having a projection whereby it is attached to the telegraph
post, an hollow glass cylinder of smaller diameter and shorter than the casing,
and a double hook or wire holder, the stem of which is smaller in diameter
than the interior of the glass cylinder and is indented at the sides, so that
when fixed (as hereafter described) it cannot be withdrawn from the glass by
the weight of the telegraph wires.
In preparing the improved insulators the glass is in the first instance placed
on a suitable table or slab, and melted sulphur is poured in the opening; the
stem of the wire holder is then deposited in the opening of the glass, which is
perfectly secured to the holder when the sulphur has become hard by cooling;
after this a strip of paper made in the form of a cylinder is cemented to the
upper edge of the glass, when the glass with its wire holder is ready for
attachment to the casing. In order to do this the casing is in the first
instance heated, and a suitable quantity of molten sulphur is then poured into
it; and into this mass of sulphur the glass block and its paper cylinder are
deposited. As the paper extends to the upper edge of the casing there will
necessarily be a body of sulphur between the casing and the paper; the
sulphur and paper at the upper edge of the casing are then trimmed off,
after which, while the insulator is still in an inverted position, the space
above the glass within the paper cylinder is filled with melted paraffine;
the insulator is then turned upside down, and the greater portion of the melted
paraffine is poured out, the remainder adhering to the paper and to the upper
edge of the casing and sulphur, for care should be taken that the coating of
paraffine extends over the edge of the casing. When the covering of paraffine
has become congealed it is covered with a varnish composed of bees'-wax,
rosin, and paraffine, when the insulator is complete. and ready for being
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Davies in the Great Seal Patent Office on 'the
1st November 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
DAVIES, of No. 1, Serle Street, Lincoln's Inn, in the County of Middlesex,
and No. 87, St. Vincent Street, in the City of Glasgow, Civil Engineer and
Patent Agent, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of May, in the year of our Lord One
thousand eight hundred and sixty-six, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said George Davies, Her special licence that I, the said George Davies,
my. executors, administrators, and assigns, or such others as I, the said
George Davies, 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 Invention for "IMPROVEMENTS IN
INSULATORS FOR TELEGRAPH WIRES," (a communication to me from abroad by
David Brooks, of Philadelphia, Pennsylvania, United States of America,)
upon the condition (amongst others) that I, the said George Davies, 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 per-
formed, 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 George Davies, 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 in writing, and on reference to the accompanying Sheet of Drawings,
that is to say:-
This Invention consists of the improved mode hereafter described of
constructing insulators for electric telegraph wires, whereby the inconveniences
resulting from the collection of water on or about the insulators during rainy or
foggy weather are obviated.
The insulator consists principally of three parts, an outer hollow cylindrical
casing of cast iron, having a projection whereby it is attached to the telegraph
post, a hollow glass cylinder of smaller diameter and shorter than the casing,
and a double hook or wire holder, the stem of which is smaller in diameter
than the interior of the glass cylinder and is indented. at the. sides, so that
when fixed (as herein-after described) it cannot be withdrawn from the glass.
by the weight of the telegraph wires.
In preparing the improved insulators the glass is in the first instance,
placed on a suitable table or slab, and melted sulphur poured in the opening;.

page_text: the stem of the wire holder is then deposited in the opening of the glass,
. which is perfectly secured to the holder when the sulphur has become hard by
cooling; after this a strip of paper made in the form of a cylinder is
.cemented to the upper edge of the glass, when the glass with its wire holder
is ready for attachment to the casing. In order to do this the casing is in
the first instance heated, and a suitable quantity of molten sulphur is then
.poured into it, and into this mass of sulphur the glass block and its paper
cylinder are deposited. As the paper extends to the upper edge of the casing
there will necessarily be a body of sulphur between the casing and the paper;
the sulphur and paper at the upper edge of the casing are.then trimmed off,
after which, while the insulator is still in an inverted position, the space above
the glass within the paper cylinder is filled with melted paraffine; the
insulator is then turned upside down, and the greater portion of the melted
paraffine is poured out, the remainder adhering to the paper and to the upper
edge of the casing and sulphur, for care should be taken that the coating of
paraffine extends over the edge of the casing. When the covering of paraffine
has become congealed it is covered with a varnish composed of bees'-wax,
rosin, and paraffine, when the insulator is complete and ready for being
attached to the pole.
Such being the nature and object of the said Invention for "Improvements
in Insulators for Telegraph Wires," I will now proceed to describe more in
detail the manner in which the same is to be or may be performed or carried
into practical effect, and in order that the same may be distinctly understood
I have annexed hereunto a Sheet of Drawings illustrative thereof, and have
marked the same with figures and letters of reference corresponding with
those in the following explanation thereof, that is to say
Figure 1 is an exterior view of the improved insulator for telegraph wires;
and Figure 2, a vertical section of the insulator inverted; Figure 3, a plan
view; Figure 4, an inverted plan view.
A is the exterior cast-iron casing of the insulator, the projection a of which
serves as a means of attachment to the arms of the telegraph poles; B is a
cylindrical block of glass between which and the interior of the casing A
intervenes a .body D of sulphur, the glass being considerably shorter than the
casing A. In this glass block is a circular opening for the reception of the
wire holder G, which is secured by means of sulphur H, the stem of the
holder being made concave at opposite sides, so that it cannot be withdrawn
from the glass by the weight or tension of the telegraph wires.
In preparing the improved insulators the glass is in the first instance placed

page_text: on a suitable table or slab, and melted sulphur poured in the opening; the
stem of the wire holder is then deposited in the opening of the glass, which is
perfectly secured to the holder when the sulphur has become hard by cooling;
after this a strip of paper h, made in the form of a cylinder, is cemented to
the upper edge of the glass, when the glass with its wire holder is ready for
attachment to, the casing A. In order to do this the casing is in the first
instance heated and a suitable quantity of molten sulphur is then poured into
it, and into this mass of sulphur the glass block and its paper cylinder / are
deposited. As the paper extends to the upper edge of the casing A there
will necessarily be a body of sulphur between the casing and the paper; the
sulphur and paper at the upper edge of the casing A are then trimmed off,
after which, while the insulator is still in an inverted position, the space above
the glass within the paper cylinder is filled with melted paraffine; the insu-
lator is then turned upside down, and the greater portion of the melted
paraffine is poured out, the remainder adhering to the paper and to the upper
edge of the casing and sulphur, for care should be taken that the coating i of
paraffine extends over the edge of the casing. When the covering of paraffine
has become congealed it is covered with a varnish composed of bees'-wax, rosin,
and paraffine, when the insulator is complete and ready for being attached to
the pole in the position seen in Figure 1. Although sulphur affords an
excellent medium for securing the wire holder to the glass, and the latter to
the exterior casing of the insulator, and although sulphur when dry is a com-
paratively good non-conductor of electricity it has a great affinity for water,
with which during rains or fogs it soon becomes charged to such an extent as
to neutralize its non-conducting properties, hence during rainy weather the
sulphur would have a tendency to conduct the moisture from the edge of the
casing to the wire holder, and through the paper, were it not for the coating of
paraffine, which penetrates the sulphur, adheres to the surface of the same,
and effectually prevents the access of moisture to the wire holder, the stem of
which is also coated with paraffine and varnished.
Having now described the nature and object of the said Invention for
"Improvements in Insulators for Telegraph Wires," together with the manner
in which the same is to be or may be performed or carried into practical effect,
I would remark in conclusion that I claim as the Invention (communicated
to me by the said David Brooks),-
Firstly, the use in the manner described of a hollow cylinder h of paper or
its equivalent in connecting the glass block E to the casing A by means of

page_text: ⚫ Secondly, coating the exterior of the space above the glass block as well as
the edge of the casing and of the sulphur near the same, also the stem of the
wire holder with paraffine or its equivalent in the manner and for the purposes
described.
In witness whereof, I, the said George Davies, have hereunto set my hand
and seal, this First day of November, in the year of our Lord One
thousand eight hundred and sixty-six..