IMPROVEMENTS IN PHOTOLITHOGRAPHY, PHOTOZINCOGRAPHY, AND PHOTOGRAPHIC ENGRAVING ON COPPER OR STEEL PLATES, OR ON ANY OTHER * SUITABLE SUBSTANCES
Year: 1863

page_text: LETTERS PATENT to William Toovey, of No. 3, Rue de la Pompe,
Brussels, in the Kingdom of Belgium, Lithographic Printer, for the In-
vention of "IMPROVEMENTS IN PHOTOLITHOGRAPHY, PHOTOZINCOGRAPHY, AND
PHOTOGRAPHIC ENGRAVING ON COPPER OR STEEL PLATES, OR ON ANY OTHER
* SUITABLE SUBSTANCES."
Sealed the 17th December 1863, and dated the 23rd June 1863.
:..
PROVISIONAL SPECIFICATION left by the said William Toovey at the
Office of the Commissioners of Patents, with his Petition; on the 23rd
June 1863.
*...I, WILLIAM TOOVEY, of No. 3, Rue de la Pompe, Brussels, in the Kingdom
of Belgium, Lithographic Printer, do hereby declare the nature of the Inven-
tion for IMPROVEMENTS IN PHOTOLITHOGRAPHY, PHOTOZINCOGRAPHY, AND PHOTO-
GRAPHIC ENGRAVING ON COPPER OR STEEL PLATES, OR ON ANY OTHER. SUITABLE
SUBSTANCES," to be as follows:—
In order to produce on a lithographic stone an impression suitable, to be
printed from I proceed as follows:-From a negative on glass or paper a
positive impression is taken on paper prepared in the following way:―I take
sized paper very smooth and even in texture, which I coat with a solution of
gum arabic in pure water saturated with bichromate of potass; it is known
that bichromate of potass, in combination with an organic substance such as
gum, gelatine, and starch, becomes insoluble in water after a certain exposure
to light. The paper prepared as above I then expose to light behind a

page_text: negative, and when the photographic image is sufficiently developed, such
parts of the gum impregnated with bichromate of potass which receive the rays
of light become insoluble, or partly so, exactly according to the gradation of
tone in the negative employed. The sheet of prepared paper with the photo-
graphic image thus printed I place face downwards on a lithographic stone,
grained very fine or polished according to the nature of the image to be repro-
duced, and previously arranged in a percussion press (it' can be done in the
lithographic press, but the result is uncertain). I then place several sheets of
damped paper upon the stone over the photographic proof, and apply a heavy
pressure; the water contained in the damp paper is pressed through the pho-
tographic proof, and dissolves the parts of gum remaining at liberty; the dis-
solved gum attaches itself to the surface of the stone. When the stone has
remained a certain length of time in the press, sufficient to allow the small
quantity of soluble gum in the dark shadows to attach itself to the surface of
the stone, I remove the pressure, and withdraw-the photographic proof care-
fully from the stone; a negative image is then visible in gum on the stone,
with all the gradations of tone. I then dry the stone; either spontaneously
er by gently warming it; when well dried I cover the whole surface of the
-stone with greasy ink, which may be applied with a roller or otherwise; the
greasy ink is thus brought into contact with all the parts of the stone un-
touched by gum; the coating of ink is then removed by passing through the
lithographic press, by spirits of turpentine, or otherwise, and all the gum re-
moved from the surface by washing. The stone is then rolled in with ordinary
printing ink, and the positive image appears in black; it is then printed as every
lithographic drawing, but has the great peculiarity of requiring no etching, the
gum having so far penetrated by pressure into the substance of the stone as
to allow of a great number of impressions being taken off. I prefer gum
arabic, but similar substances can be used instead, such as gelatine, dextrine,
and mucilaginous solutions.
⋅
In photozincography I proceed as above described, substituting a zinc plate
for a lithographic stone.
In photographic engraving on copper, steel, or other metal plates, the pre-
liminary operations are the same as those I employ for stone or zinc, excepting
that a positive image on glass or paper should in the first instance be used,
instead of a negative. When the plate is withdrawn from the press, and the
photographic proof detached from it, it should be well dried, as I have said for
the stone. The plate is then covered with a thin coating of varnish, and when
dry may be soaked in water to remove the gum, or immediately plunged in a
weak solution of acid, and etched in the usual way of etching on steel or

page_text: copper; wherever- the plate is protected from the varnish by the gum, it will'
be attacked by the acid, and an engraving is produced, which is then printed:
as an ordinary etching on metal plate.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Toovey in the Great Seal Patent Office on the
22nd December 1868. .
:
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ToOVEY, of No. 3, Rue de la Pompe, Brussels, in the Kingdom of Belgium,
Lithographic Printer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of June, in the year of our Lord
One thousand eight hundred and sixty-three, in the twenty-seventh year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said William Toovey, Her special licence that I,. the said
William, Toovey, my executors, administrators, and assigns, or such others
as,I, the said William Toovey, 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 PHOTOLITHOGRAPHY, PHOTOZINCOGRAPHY, AND PHOTOGRAPHIC
ENGRAVING ON COPPER OR STEEL PLATES, OR ON ANY OTHER SUITABLE SUBSTANCES,"
upon the condition (amongst others) that I, the said. William Toovey, 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 William. Toovey, 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.:-.
In order to produce on a lithographic stone an impression suitable to be printed
from I proceed as follows:-From a negative on glass or paper a positive im-
pression is taken on paper.prepared in the following.way :-I take sized. paper

page_text: very smooth and even in texture, which I coat with a solution of gum arabic in.
pure water, saturated with bichromate of potass; it is known that bichromate of
potass in combination with an organic substance, such as gum, gelatine, and
starch, becomes insoluble in water after a certain exposure to light. The paper
prepared as above I then expose to light behind a negative, and when the pho-
tographic image is sufficiently developed, such parts of the gum impregnated
with bichromate of potass which receive the rays of light become insoluble, or
partly so, exactly according to the gradation of tone in the negative employed.
The sheet of prepared paper with the photographic image thus printed I place
face downwards on a lithographic stone, grained very fine or polished, according
to the nature of the image to be reproduced, and previously arranged in a
percussion press (it can be done in the lithographic press, but the result is
uncertain). I then place several sheets of damped paper upon the stone-over
the photographic proof and apply a heavy pressure; the water contained in the
damp paper is pressed through the photographic proof and dissolves the parts of
gum remaining at liberty; the dissolved gum attaches itself to the surface of
the stone. When the stone has remained a certain, length of time in the press,
sufficient to allow the small quantity of soluble gum in the dark shadows to
attach itself to the surface of the stone, I remove the pressure and withdraw.
the photographic proof carefully from the stone; a negative image is then s
visible in gum on the stone, with all the gradations of tone. I then dry the
stone, either spontaneously or by gently warming it; when well dried I cover
the whole surface of the stone with greasy ink, which may be applied with a
roller or otherwise; the greasy ink is thus brought into contact with all the parts
of the stone untouched by gum; the coating of ink is then removed by passing
through the lithographic press, by spirits of turpentine, or otherwise, and all the
gum removed from the surface by washing. The stone is then rolled in with
ordinary printing ink, and the positive image appears in black; it is then
printed as every lithographic drawing, but has the great peculiarity of
requiring no etching, the gum having so far penetrated by pressure into the S
substance of the stone as to allow of a great number of impressions being
taken off. I prefer gum arabic, but similar substances can be used instead,
such as gelatine, dextrine, and mucilaginous solutions...
In photozincography I proceed as above described, substituting a zinc plate
for a lithographic stone.
In photographic engraving on copper, steel, or other metal plates the
preliminary operations are the same as those I employ for stone or zinc,
excepting that a positive image on glass or paper should in the first instance
be used instead of a negative. When the plate is withdrawn from the press,
$

page_text: and the photographic proof detached from it, it should be well dried; as
I have said for the stone. The plate is then covered with a thin coating
of varnish, and when dry may be soaked in water to remove the gum,
or immediately plunged in a weak solution of acid, and etched in the usual
way of etching on steel or copper; wherever the plate is protected from the
varnish by the gum it will be attacked by the acid, and an engraving is
produced, which is then printed as an ordinary etching on metal plate.
In witness whereof, I, the said William Toovey, have hereunto set my
hand and seal, this Twenty-fifth day of November, in the year of our
Lord One thousand eight hundred and sixty-three.
WILLIAM TOOVEY. (L.B.)
Witness,
THOMAS NASMYTH.