IMPROVEMENTS IN COATING METALLIC CONDUCTORS FOR ELECTRIC TELEGRAPHS
Year: 1859

page_text: LETTERS PATENT to John Macintosh, of North Bank, Regent's Park,
for the Invention of "IMPROVEMENTS IN COATING METALLIC CONDUCTORS
FOR ELECTRIC TELEGRAPHS."
Sealed the 29th November 1859, and dated the 5th October 1859.
PROVISIONAL SPECIFICATION left by the said John Macintosh at the
Office of the Commissioners of Patents, with his Petition, on the 5th
October 1859.
I, JOHN MACINTOSH, of North Bank, Regent's Park, do hereby declare the
nature of the Invention for "IMPROVEMENTS IN COATING METALLIC CONDUCTORS
FOR ELECTRIC TELEGRAPHS," to be as follows:-
This Invention has for its object improvements in coating metallic con-
ductors for electric telegraphs. For these purposes lampblack, napthaline,
and gutta percha are combined into a plastic compound, and the same is
applied to wire or other forms of metal conductors in like manner to that in
which gutta percha is now used; but it is preferred to employ such compound
as an external coating to gutta percha or other insulating coating or coatings.
I also, in some cases, employ a compound of india-rubber, or india-rubber and
gutta percha combined with lampblack, in preparing compounds for coating
metallic conductors for electric telegraph purposes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Macintosh in the Great Seal Patent Office on the
5th April 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
MACINTOSH, of North Bank, Regent's Park, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of October, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-third year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said John Macintosh, Her special licence that I, the said John
Macintosh, my executors, administrators, and assigns, or such others as I, the
said John Macintosh, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times there-
after 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
COATING METALLIC CONDUCTORS FOR ELECTRIC TELEGRAPHS," upon the condition
(amongst others) that I, the said John Macintosh, my executors or adminis-
trators, 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 John Macintosh, do hereby declare the
nature of the 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:-
This Invention has for its object improvements in coating metallic con-
ductors for electric telegraphs. For these purposes lampblack, napthaline,
and gutta percha are combined into a plastic compound, and the same is
applied to wire or other forms of metal conductors in like manner to that in
which gutta percha is now used; but it is preferred to employ such compound
as an external coating to gutta percha, or other insulating coating or coatings.
I also, in some cases, employ a compound of india-rubber, or india-rubber and
gutta percha combined with lampblack, in preparing compounds for coating
metallic conductors for electric telegraph purposes.
Having thus stated the nature of my said Invention, I will proceed more
fully to describe the manner of performing the same.

page_text: In preparing a composition, and applying it according to my Invention, I
prefer to use at the rate of about fifty parts by weight of gutta percha, twenty-
five parts by weight of napthaline, and twenty-five parts by weight of lamp-
black, though other proportions may be used. I apply heat of about 170° of
Fahrenheit to the napthaline, which melts it, and I introduce and mix there-
with the gutta percha; the heat and the fluid napthaline dissolve the gutta
percha. The fluid compound is run off from the impurities, and then mixed
with the lampblack, and such compound is then used as a coating material in
the ordinary manner, and by preference as an outer coating on a previous
coating or coatings of gutta percha or other insulating material. When the
materials are pure, or comparatively pure, they may be mixed by masticating
machinery, as when mixing gutta percha with other materials. In some cases
I combine lampblack with india-rubber for external coatings on insulated
wires or electric conductors, and I use as much lampblack with the india-
rubber as the india-rubber will take, and yet retain a plasticity such as will
enable it to be applied by rollers, or by being forced through dies as a coating
to a previously insulated or coated wire or other electric conductor, or in place
of india-rubber being used alone, gutta percha may be combined therewith.
In witness whereof, I, the said John Macintosh, have hereunto set
my hand and seal, this Fifth day of April, in the year of our Lord
One thousand eight hundred and sixty.