A NEW OR IMPROVED PHOTOGRAPHIC PROCESS FOR PREPARING PRINTING SURFACES
Year: 1869

page_text: LETTERS PATENT to John Clayton Mewburn, of 172, Fleet Street,
in the City of London, Patent Agent and Consulting Engineer,
for the Invention of "A NEW OR IMPROVED PHOTOGRAPHIC PROCESS FOR
PREPARING PRINTING SURFACES."-A communication from abroad by
PROVISIONAL SPECIFICATION left by the said John Clayton Mewburn
at the Office of the Commissioners of Patents, with his Petition,
on the 30th October 1869.
I, JOHN CLAYTON MEWBURN, of 172, Fleet Street, in the City of
London, Patent Agent and Consulting Engineer, do hereby declare the
nature of the said Invention for "A NEW OR IMPROVED PHOTOGRAPHIC
PROCESS FOR PREPARING PRINTING SURFACES," to be as follows:-
The object of this Invention is to allow of impressions equal to those
obtained by lithography being taken on common paper with printing
black or printing ink from photographic negative plates.

page_text: I proceed as follows:-I take a photographic negative, preferably a
I prepare a mixture of gelatine, albumen, and chrome by
beating up the white of eggs with gelatine and chrome, and with this
mixture I give a first coat to a thick plate or sheet of glass, by preference
looking glass. When this coat of chrome, gelatine, and albumen has!
been dried by heat, the plate is exposed on the reverse side to daylight
for a time and then I give the plate a second coat of gelatine and
chrome and again dry it by heat. On the pellicle thus formed on the
glass I copy the photographic negative by means of daylight, after
which operation the plate when washed and dried is able to give
impressions. By employing a lithographic printing or other suitable
press, roller, and printing black or printing ink any number of prints or
impressions can be taken.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Clayton Mewburn in the Great Seal Patent
Office on the 30th April 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
CLAYTON MEWBURN, of 172, Fleet Street, in the City of London,
Patent Agent and Consulting Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of October, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
third year of Her reign, did, for Herself, Ier heirs and successors, give
and grant unto me, the said John Clayton Mewburn, Her special licence
that I, the said John Clayton Mewburn, my executors, administrators,
and assigns, or such others as I, the said John Clayton Mewburn, 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 "A NEW OR
IMPROVED PHOTOGRAPHIC PROCESS FOR PREPARING PRINTING SURFACES," (com-
municated to me from abroad by E. Rye, of Odense, in the Kingdom of
Denmark) upon the condition (amongst others) that I, the said John
Clayton Mewburn, my executors or administrators, by an instrument in

page_text: 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 Clayton Mewburn, 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 :-
The object of this Invention is to allow of impressions equal to those
obtained by lithography being taken on common paper with printing
black or lithographic printing ink from photographic negative plates.
I proceed as follows:-Over a very thick piece of plate glass, highly
polished or plain, I pour a mixture composed of
5 to 8 parts of gelatine
33
20 4.0
albumen
"
"
"
"
distilled water.
and 8 10
93
When this mixture has been poured over the glass, the latter is
placed in a suitable oven to dry, after which the glass is exposed on
the reverse side to the light; the glass is then washed, dried and another
mixture poured over it, this mixture is composed of :-
10 to 15 parts of gelatine dissolved in 100 to 110 parts of water,
", albumen,
3
"
5
8,, 10
"
33
33
bichromate of potash
bichromate of ammonia
"
"
2
"
"gum myrrh
3
1
"
99
5
1 .. 2
"
1/10th part
1/10th
1/10th
"
"
,, gum benzoin
"
"
dissolved in 10 parts
of water,
previously dissolved in 15 parts
of alcohol,
nitrate of silver, dissolved in 4 parts of water,
iodide of cadmium previously dissolved in
bromide of potassium 8 parts of distilled water.
When this mixture has been poured over the glass the latter is again
dried in the oven, after which it is ready for copying. This is effected
by placing a photographic negative on the glass thus prepared; the
copying will require from half an hour to two hours. When the negative
has been copied on the glass the latter is washed under strong pressure
of water so as to extract all the chromate, the glass is again dried and
is then ready for printing. The printing can be effected with common

page_text: lithographic ink by means of a lithographic or other suitable press and
rollers of leather or gluc.
In witness whereof, I, the said John Clayton Mewburn, have here-
unto set my hand and scal, this Twenty-ninth day of April,
One thousand eight hundred and seventy.
J. C. MEWBURN. (L.S.)