IMPROVE- MENTS IN COATING AND PROTECTING THE SILVERED SURFACES OF LOOKING GLASSES OR MIRRORS
Year: 1861

page_text: LETTERS PATENT to James Edgar Cook, of Greenock, in the County of
Renfrew, North Britain, Booking Clerk, for the Invention of "IMPROVE-
MENTS IN COATING AND PROTECTING THE SILVERED SURFACES OF LOOKING
GLASSES OR MIRRORS."
Scaled the 15th August 1861, and dated the 22nd February 1861.
PROVISIONAL SPECIFICATION left by the said James Edgar Cook at
the Office of the Commissioners of Patents, with his Petition, on the
22nd February 1861.
I, JAMES EDGAR Cook, of Greenock, in the County of Renfrew, North
Britain, Booking Clerk, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN COATING AND PROTECTING THE SILVERED SURFACES OF LOOKING
GLASSES OR MIRRORS," to be as follows, that is to say :-
This Invention relates to a system or mode of rendering the backs or
silvered surfaces of looking glasses or mirrors impermeable to moisture or
atmospheric influence, and at the same time afford an efficient protection to
the surface from abrasion or other similar injuries. The back of the tin foil
or silvered surface of the glass or mirror is first coated with copal varnish,
which is applied in the ordinary way with a brush. The varnish may be used
alone, or, if preferred, mixed with any suitable color. For the edges of the
glass it is preferred to mix with the varnish a proportion of "drop black," so
as to impart to the varnish a pure black colour. When the varnish is dry,

page_text: the varnished surface is coated with a solution of shellac dissolved in any
suitable solvent. The solution of shellac is preferred to have mixed with it a
proportion of fusel oil, or in lieu thereof a small quantity of "gum thus," which
addition prevents the shellac from drying too quickly, or the same end may be
accomplished by the addition of a little glycerine. The coating of shellac is
finally gone over with a thin and quickly drying shellac solution. Looking
glass coated in this way may be immersed in water for a long period of time
without injury, and from the hardness of the protective coating they are not
liable to be injured by scratching, as it requires considerable force to remove
the varnish.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Edgar Cook in the Great Seal Patent Office on the
21st August 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
EDGAR COOK, of Greenock, in the County of Renfrew, North Britain, Booking
Clerk, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of February, in the year of our
Lord One thousand eight hundred and sixty-one, in the twenty-fourth year of
Her reign, did, for Herself, Her heirs and successors,, give and grant unto
me, the said James Edgar Cook, Her special license that I, the said James
Edgar Cook, my executors, administrators, and assigns, or such others
as I, the said James Edgar Cook, my executors, administrators, or 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 COATING AND PROTECTING THE SILVERED SURPACES OF LOOKING
GLASSES OR MIRRORS," upon the condition (amongst others) that I, the said
James Edgar Cook, my executors or administrators, by an instrument in
writing under my hand and seal, or under the hand and seal of one of them,
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.

page_text: NOW KNOW YE, that I, the said James Edgar Cook; do hereby
declare the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the fol-
lowing statement, that is to say:-
In order that my said Invention of improvements in coating and protecting
the silvered surfaces of looking glasses and mirrors may be properly under-
stood, I shall now proceed to describe the best mode I am acquainted with
under which my improvements may be judiciously carried ont in practice.
My said Invention relates to a system or mode of rendering the backs or
silvered 'surfaces of looking glasses or mirrors impermeable to moisture or
atmospheric influence, and at the same time afford an efficient protection to
the surface from abrasion or other similar injuries. Prior to coating the
silvered surface the upper edge of the glass should be rounded with a file, and
this edge coated first, then the back of the tin foil or silvered surface of the
glass or mirror is coated with copal or carriage varnish, which is applied in
the ordinary way with a brush. The varnish may be used alone, or, if
preferred, mixed with any suitable colour. For the edges of the glass it is
preferred to mix with the varnish a proportion of "drop black," so as to
impart to the varnish a pure black colour. When the varnish is dry, the
varnished surface is coated with a solution of shellac dissolved in any suitable
solvent. The solution of shellac is preferred to have mixed with it a
proportion of one part fusil oil, or in lieu thereof, a small quantity of gum
thus, which addition prevents the shellac from drying too quickly. Or the
coating may be composed of three parts knotting mixed with one part of fusil
oil. The coating of shellac is finally gone over with a thin and quickly drying
shellac solution. Looking glasses coated in this way may be immersed in
water for a long period of time without injury, and from the hardness of the
protective coating they are not liable to be injured by scratching, as it requires
considerable force to remove the varnish. Neither is the protective coating
injured by alterations of temperature, for the glass may be immersed in water
heated to 140° or 150° without affecting the coating or the brilliancy of the
silvering.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe, in conclusion, that what I consider novel and
original, and therefore claim as the Invention secured to me by the herein-
before in part recited Letters Patent is, the system or mode of protecting the
silvered surfaces of looking glasses or mirrors by means of the coating or

page_text: coatings of compositions, as herein-before described, or any mere modification
of the said process or mode of operation.
In witness whereof, I, the said James Edgar Cook, have hereunto
set my hand and seal, this Nineteenth day of August, One thousand
eight hundred and sixty-one.
JAMES EDGAR COOK. (L.s.)