IMPROVEMENTS IN THE MANUFACTURE OF CASTING PROVISIONAL SPECIFICATION
Year: 1870

page_text: LETTERS PATENT to George Baldock and Thomas James Denne, of
Phoenix Works, Cambridge Road, Mile End, and August Hentschel,
of Liverpool Road, Islington, all in the County of Middlesex,
for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF CASTING
PROVISIONAL SPECIFICATION left by the said George Baldock,
Thomas James Denne, and August Hentschel at the Office of the
Commissioners of Patents, with their Petition, on the 13th September
1870.
We, GEORGE BALDOCK and THOMAS JAMES DENNE, of Phoenix Works,
Cambridge Road, Mile End, and AUGUST HENTSCHEL, of Liverpool
Road, Islington, all in the County of Middlesex, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF
CASTING BLOCKS AND PRINTING BLOCKS USED FOR HELIOGRAPHIC AND OTHER
PRINTING," to be as follows:-
The basis of our Invention consists in the following. We take milk
and extract from it the grease in it by the following process:-Skim it

page_text: when sour and set; skim it again; put it into a bag and allow it to
drain for about twenty-four hours; then pour boiling water on it and
subject it to a squeezing process; after this pour water at about half
boiling temperature on it and again squeeze it; now let it stand until
it is cooled down; then wash it well in clear cold water, with continued
squeezing to remove the trace of the milk. This can be used now or
after it is dry, in which state it is of a hard granular substance. This
substance, which is sensitive to light, we for the purpose of this Pro-
visional Specification will call A. From this we make a foundation for
a casting or printing block thus:-We take A and dissolve it in water
with a few drops-of-ammonia._To_1_part_A_we add about (an exact
quantity is not material) 4 to 6 parts of China clay, pipe clay, flake
white, or similar substance, and a small quantity of glycerine or salt
to it, and coat with this composition, paper, wood, slate, metal, or any
required material, smooth the surface and make it insoluble in water by
brushing it over with a weak solution of acetic acid. On this we now
print when it is sensitized, as after shown by the action of light in the
usual way from negatives or positives, at will, and when printed make
the surface in intaglio or relief as desired. It would then be, according
to the nature of the after process required a casting block or printing
block, and from it can be made stereotypes or electrotypes in the usual
and known ways.
Until this composition surface (presumably on cardboard) is printed
upon it would be a plain block, and we now proceed to show how we
should make from this by direct drawing upon it a casting or printing
block. We make an ink composed of bichromate of potass, Indian ink
or lampblack, and gum; to this can be added if required to harden the
drawing a metal oxide. Draw with this on a plain block when the
drawing is made; expose it to the light; this hardens it, and when it is
dry and hardened the other part of the block not drawn upon can be
brushed out with a solution of soap, soda, and water, leaving the drawing
standing in relief.
We now proceed to show how we copy a negative on to a plain block,
and in so doing form a printing block. We brush a plain block over
with a saturated solution of bichromate of potass in a dark room and
expose it under the negative to light to print, and when it is printed as
required the unprinted parts are brushed out with the soap solution,
leaving, a casting or printing block.

page_text: For working thus we make a paper negative in this way:-We take A
in solution, and add to it Indian ink or lampblack, and with this mixture
we draw on paper and cover the whole surface of the paper with litho-
graphic ink; other printing ink will also do; then put the paper in
water to which has been added a few drops of ammonia, and the drawing
with its covering of ink will wash away, leaving the undrawn part black
and the drawn part white.
We now proceed to show our method of making a printing block to
make what is known as half-tone printing. We take the same com-
position as is used to make the plain bloch, and mix with it in a dark
room sufficient bichromate of potass in solution to make it the colour
we require, and coat a negative with this, print through it, and brush
out the parts not wanted with the soap solution.
We also do this by this other method:-Instead of using the com-
position as above we make a composition of 3 parts A and 1 part boiled
soap, preferably of Castile or other pure soap, and proceed as above
shown. From this electrotypes or stereotypes can be taken in the usual
manner.
room.
In making a photo-lithographic print or transfer we proceed as follows:
-We make a composition of 3 parts A and 1 part boiled soap mixed
with bichromate of potass solution, and coat paper with it in a dark
When the composition is dry we expose it under a negative to
light, and print. We then roll the print in with litho ink or other ink
suitable, and, this done, dissolve out in ammonia water those parts that
have not been acted upon by the light, leaving the print covered with
ink ready to transfer upon the stone and print from in the usual manner,
but preferably with a special ink.
We now proceed to show our method of making a printing block on
zinc by zinco-photography. We make a composition of 3 parts A and 1
part boiled soap mixed with the bichromate of potass solution, and give
with this a thin layer on to a piece of zinc and expose it under a negative
to print, and dissolve the unprinted portion away with ammonia water.
We then wash it well with clean water and make it insoluble with acetic
acid. It is then ready for etching.
For the process of zinco-graphotype we cover a zinc plate with a
composition made of two parts of A and 1 part boiled soap, to which is
added Frankfort black ground in glycerine and water. We draw direct
on the plate with a suitable point and brush the drawing over with asphalt.

page_text: dissolved in turpentine. When this is dry we plunge it in weak ammonia
water, which dissolves out all but the parts drawn; then wash it in
clear water, and it is ready for etching.
We now proceed to show our method of photographing, which we can
do on paper, wood, metal, or other substance. Selecting a wood block,
such as is used for wood engraving, for our illustration, we take our
substance A, dissolve it, and add to it sufficient zinc white, white lead,
or other suitable substance mixed with a small addition of chloride of
ammonia, coat the wood block with this, and when dry coat it again
with nitrate of silver and expose it under a negative or positive to print
-in-the-ordinary-way. When-printed_we_fix_it_with_a_solution of hypo-
sulphite of soda, and when fixed and dry it is ready for the wood
engraver.
. By this same process (for wood, &c.) we make an improved photo-
graphic paper, but to make the photograph when printed on this insoluble
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas James Denne and August Hentschel in
the Great Seal Patent Office on the 11th March 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, THOMAS
JAMES DENNE, of Phoenix Works, Cambridge Road, Mile End, in the
County of Middlesex, Manufacturer, and AUGUST HENTSCHEL, of
Liverpool Road, Islington, in the same County, Photographer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of September, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto George Baldock (since deceased), and to us, the said
Thomas James Denne and August Hentschel, Her special licence that
we, the said George Baldock (since deceased), Thomas James Denne,
and August Hentschel, our executors, administrators, and assigns, or
such others as we, the said George Baldock (since deceased), Thomas
James Denne, and August Hentschel, our executors, administrators, and
assigns, should at any time agree with, and no others, from time to time

page_text: and at all times thereafter during the term therein expressed, should and
lawfully might make, usc, exercise, and vend within the United Kingdom
of Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF CASTING BLOCKS AND
PRINTING BLOCKS USED FOR HELIOGRAPHIC AND OTHER PRINTING," upon the
condition (amongst others) that we, the said George Baldock (since
deceased), Thomas James Denne and August Hentschel, our executors or
administrators, by an instrument in writing under our, or one of our,
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.
And whereas the said George Baldock departed this life on the
Nineteenth day of January, One thousand eight hundred and seventy-one.
NOW KNOW YE, that we, the said Thomas James Denne and August
Hentschel, as the survivors of the said George Baldock, 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 first part of our Invention consists of an improved method of
preparing caseine or curd of milk for subsequent use in the formation of
casting blocks and printing blocks, preparing the surfaces of paper, &c.,
as herein-after shewn. We take milk which has become sour and set by
keeping, and we separate from it the grease and other extractive matters
by the following process:-We skim it when sour and set by natural
causes as before stated, put it into a bag, and allow it to drain for about
twenty-four hours, then pour boiling water on it, and subject it to a
squeezing process. After this we find that the best result is obtained
by pouring water at about half boiling temperature on it, we again
squeeze it, and now let it stand till it has cooled down, and then wash
it well in clear cold water with continual squeezing to remove all the
grease and milk we can. When dry the residuum becomes hard and
granular, and is the substance we have referred to in our Provisional
Specification as A. But in this completed Specification we call this
substance our "improved naturally made caseine" to distinguish it from
the caseine of commerce, because in its manufacture no chemicals are
used.

page_text: The next part of our Invention refers to a process of preparing a form
of block for casting and printing whereby we are enabled to reproduce and
multiply at will by ordinary printing operations any required design or
picture. We make the foundation for this casting or printing block as
follows: We take our caseine and dissolve it in water with a few drops
of ammonia. To one part caseine we add about (an exact quantity is
not material) four to six parts of either China clay, pipe clay, flake
white, or similar substance and a small quantity of glycerine or salt to
it, mix these together, and coat with this composition paper, cardboard,
wood, slate, metal, or any required material; we smooth the surface, and
make it
insoluble_in_water_by_brushing-it-over-with-a-weak-solution-of-
acetic acid. When this surface or composition is set and dry it is what
we call a "plain block," and presumably the composition is on cardboard.
Now by sensitizing such a plain block by the ordinary methods pursued
by photographers it can be printed upon by the action of light in the
usual photographic way from negatives or positives, and when so printed
we can by the process of, as it is termed, "washing out" obtain a
surface in intaglio or relief as we desire. And it would be, according to
the nature of the after process desired, a casting block or printing block
from which other blocks can be made by the ordinary method well
understood by mechanics in moulding and casting trades and by sterco-
typers and electrotypers. And the form or shape of such blocks or
patterns can be according to the want and requirement of them, and are
not bound to a particular and fixed form, nor to any particular metal to
be cast in the moulds formed from the casting blocks. We can also
make from the plain block when sensitized as after shewn by direct
drawing upon it a casting or printing block thus:-We make an ink
composed of bichromate of potass, Indian ink, or lampblack and gum,
and with this ink we draw upon the surface of a plain block a desired
object, and when drawn expose it to the action of ordinary (day) light,
this hardens the drawing, and when it is.dry and hardened the parts of
the composition of the block not drawn upon can be washed or brushed
out with a solution of soap, soda, and water, leaving the drawing
standing in relief. If it is desired to harden the drawing more than the
above ink will do it we add to the ink a metal oxide.
We now proceed to shew how we copy a negative upon a plain block
(still presumably made on cardboard), and in so doing form a casting
or printing block. We brush the plain block over with a saturated

page_text: solution of bichromate of potass in a dark room, such as is used in
ordinary photographic operations. This block when sensitized we expose
under a negative to light to print, and when it is printed to the required
degree the unprinted portions of the block are washed and brushed out
with soap and soda solution, leaving the picture standing in relief, from
which a casting or printing block can be made.
We now proceed to show our method of making a paper negative
for working on a plain block, by means of which we are enabled to
reproduce and multiply facsimile impressions of drawings, designs, or
writings.
We take our caseine in solution and add to it Indian ink or lamp
black, and with this mixture we make a drawing, presumably on paper.
After this we cover the whole surface of the paper with lithographic
ink (other printing ink will also do), and then put the paper in water to
which a few drops of ammonia have been added, and the drawing with
its covering of ink will wash away, leaving the undrawn parts black,
through which light cannot penetrate, and the drawn part white. This
paper being, as it is termed, photographically exposed to light upon a
sensitized plain block the light penetrates through the parts that have
been drawn upon, prints that part of the sensitized plain block on
which it can act, rendering it insoluble to the soap and soda solution
which dissolves those parts of the block lying under the black parts of
the negative through which the light cannot penetrate, and which not
being acted upon remain insoluble to the solution, and by the washing
and brushing out this portion of the sensitized plain block is removed,
leaving the drawing standing in relief.
We now proceed to show our method of making a printing block to
print what is known as half tone printing, whereby we are enabled to
obtain a stereotype or electrotype plate directly from a negative without
employing a separate plain block. We here produce the printing block
upon the surface of the negative itself.
We take the composition with which we make the plain block or a
composition of three parts caseine and one part soap boiled together (the
exact proportions are not material), and to either or both of these
compositions we mix sufficient bichromate of potass in solution to make
it the colour we require. This composition is then from the admixture
of bichromate of potass sensitive to light. We then take a glass negative
and coat it with this composition in a dark room, expose it to the light,

page_text: and print the composition through the negative, and when it is suffi-
ciently printed we wash and brush out those parts of the composition on
which the light has not acted with the soap and soda solution, leaving
the composition picture on the negative, and from this electrotypes or
stereotypes can be taken in the usual manner.
It will be seen that in whatever manner our compositions formed by
the admixture of caseine and China clay, pipe clay, or flake white, to
which has been added glycerine or salt or caseine and boiled soap, as we
have shown, spread upon another surface, which for clearness we have
-confined-to-cardboard-and-sensitized-that-this-sensitized-composition-
can be printed, and will harden under the influence of light, and that
those parts remaining unprinted by reason of the light not acting upon
them can be, as it is termed, photographically washed out, leaving the
drawing in relief or intaglio, as required. And it must be borne in mind
that although we have all along in these descriptions dealt with our
improved naturally made caseine" for the purpose of distinguishing
it from the caseinc, which is well known in commerce, yet that the
caseine of commerce if used in the way we have shewn will also give
like results, but inferior ones, and this arises from difference of the
manufacture of the two caseines, although both are from the same base,
milk, and this remark holds good throughout this Specification whenever
the substance caseine forms part of a composition to be employed in
carrying out our Invention.
We now proceed to shew our method of photo-lithography, which is
simply a method of transferring copies of photographic pictures on to a
lithographic stone, and thus of obtaining a printing surface or block on
stone to be printed from.
We make a composition of three parts caseine and one part soap
boiled together (the exact proportion is not material), and add to this
bichromate of potass solution, allow it to cool, and then coat paper
with this in a dark room. When the composition is dry upon the paper
we expose it under a negative to the light to print. We then roll the
print in with litho or other suitable ink thus -Roll a stone up, black,
lay on it the picture, and pull it through the printing press; this covers
the whole surface of the picture with the ink. We then plunge the
picture in water to which has been added a few drops of ammonia; this
dissolves out the parts that have not been acted upon by the light (as
it is termed,) washes them away), leaving the picture still covered with

page_text: ink upon the paper, and this is transferred down upon a lithographic
stone in the ordinary manner, to be printed from it in the usual way.
Either our **
improved naturally made cascine," or the caseine of
commerce can be used for this purpose, as shewn, but the latter gives
inferior results.
We now proceed to shew our method of making a printing block on
zinc by what is termed zinco-photography, thus:-We make a com-
position as for photo-lithography mixed with the bichromate of potass
solution, and give with this a thin layer on zinc, and expose it under a
negative to print; when printed we dissolve the unprinted portion away
with ammonia water. We then wash the surface well with clean water,
and make the print insoluble with acetic acid, and it is then ready for
etching in the usual and well-known manner.
We now proceed to shew our process of making a printing block on
zinc by what is termed zinco-graphotype thus:-We cover a zinc plate
with a composition made of two parts caseine and one part soap
boiled together (the exact proportion is not material), to which is added
Frankfort or other black ground in glycerine and water. We draw
upon the covered plate with a suitable point so as to remove the coating
and brush the drawing over with asphalte dissolved in turpentine; when
this is dry we plunge it in weak ammonia water which dissolves away
all but the parts drawn, and from which the original coating has been
removed, it is then washed in clear water and it is ready for etching in
the usual and well-known manner. This process is also applicable to
other metals. Either our "improved naturally made caseine" or the
caseine of commerce can be used for the purpose of zinco-photography
or zinco-graphotype, as shewn, but the latter gives inferior results.
We now proceed to shew another method of preparing the surfaces
of wood, metal, paper, or other substances which is especially applicable
to the preparation of a printing block on wood, and which also gives
valuable results in ordinary photographic printing. We take our
"improved naturally made caseine," dissolve it, and add to it a sufficient
quantity of zinc white or white lead; to give substance and tone there
must also be an admixture of a small quantity of chloride of ammonia,
and coat the wood with this composition, the wood is by preference an
ordinary boxwood block such as is usual for wood engravers to work
upon, and when this coating is dry we coat it again with nitrate of
silver in solution, and then expose the block under a negative or positive

page_text: to print photographically in the ordinary way, when printed we fix the
print with a solution of hyposulphite of soda and it is then ready for
the wood engraver to engrave it. We have said that we make this
composition from our "improved naturally made caseine," we do this by
preference because it gives a finer picture with more sharpness and
detail. But the caseine of commerce can be used although it gives in
proportion to the other very indifferent results.
In printing on wood we may modify the composition by substituting
for the zinc white or white lead such substances as China clay, pipe
clay, flake white, &c.
If it be required to make a photograph printed in this manner upon
paper insoluble we wash it with acetic acid. This photograph can be
if preferred toned in the usual way, but we think it is unnecessary, as
the picture comes up so well otherwise. In making the composition
for covering wood, metal, paper, or any required materials, no particular
proportions of quantity can be given as fixed because widely different
proportions will give pictures whose chief difference will be in their
colour.
Having now described and particularly ascertained the nature of our
said Invention and the manner in which the same is or may be used or
carried into effect, we observe in conclusion that what we consider to be
novel and original, and therefore claim as our Invention is,-
Firstly. The method of preparing the substance in the Provisional
Specification called A as shewn, and which substance we have called
our "improved naturally made caseine" believing it to be when thus
manufactured a new article possessing properties which may be correctly
described as being held in a more intense degree for photographical
purposes than those held by the caseine of commerce.
2. The preparation of the surfaces of casting and printing blocks to
be formed in intaglio or relief by means of a composition consisting of
an admixture of cascine, China clay, &c., as herein-before described,
and which composition is also applicable for the preparation of a printing
block in intaglio or relief directly upon the negative for half tone
printing as herein-before described.
Here as well as in all our subsequent claims of Invention we use
by preference our "improved naturally made caseine," according to the
statement already fully explained.

page_text: 3. The preparation of the surface for an artificial negative on paper
by means of a composition formed of caseine and Indian ink or lamp-
black as herein-before described.
4. The preparation of the surface of paper by means of a com-
position containing caseine, soap, and bichromate of potass, whereby
we are enabled to transfer any drawing, design, or writing to a litho-
graphic stone for lithographic printing as herein-before described,
and which composition may also be applied in the preparation of the
surface of zinc as in the process of zinco-photography herein-before
described.
5. The preparation of the surface of zinc by means of a composition
containing caseine, soap, and Frankfort or other black to be used in the
zinco-graphotype process as herein-before described and which com-
position may also be applied to other metals.
6. The preparation of surfaces on wood, paper, &c., by means of a
composition containing caseine, zinc white or white lead, with a small
addition of chloride of ammonia or the modification thereof as herein-
before described.
In witness whereof, we, the said Thomas James Denne and August
Hentschel, have hereunto set our hands and seals, the Tenth
day of March, One thousand eight hundred and seventy-one.
THOMAS JAMES DENNE. (L.S.)