IMPROVEMENTS IN THE
Year: 1866

page_text: LETTERS PATENT to James Ramage and Thomas Nelson, both of the City
of Edinburgh, Gentlemen, for the Invention of "IMPROVEMENTS IN THE
PROVISIONAL, SPECIFICATION left by the said James. Ramage and
Thomas Nelson at the Office of the Commissioners of Patents, with
their Petition, on the 26th March 1866.
We, JAMES RAMAGE and THOMAS NELSON, both of the City of Edinburgh,
Gentlemen, do hereby declare the nature of the said Invention for "IMPROVE
MENTS IN THE PRODUCTION OF BLOCKS AND PLATES FOR PRINTING," to be as
follows:-
This Invention has for its object improvements in the production of blocks
and plates for printing. A solution of bichromate of potash mixed with
gélatine dissolved in water, or other similar preparation is poured upon a
sheet of glass or other material, and when dry exposed under a negative of
the drawing, engraving, or print for a given time; it is then immersed in
water till the parts not acted on by the light swell. up to the desired extent..
The surface water is then removed, and a solution of gutta percha, bitumen,'
and wax, or other such materials is poured over the surface, forming a skin
thereon. The back of this skin is then filled up to a proper thickness with
melted wax or other materials, and when set the mould thus produced is
separated from the gelatine and, electrotyped, or a stereotype cast is taken::

page_text: For a copper, steel, or other plate a transparency of the drawing, engraving,
or print is used, the same processes gone through, and the plate produced is
used for printing in the ordinary way.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Ramage and Thomas Nelson in the Great Seal
. Patent Office on the 26th September 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES
RAMAGE and THOMAS NELSON, both of the City of Edinburgh, Gentlemen,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of March, in the year of our
Lord One thousand eight hundred and sixty-six, in the twenty-ninth year
of Her reign, did, för Herself, Her heirs and successors, give and grant unto
us, the said James Ramage and Thomas Nelson, Her special licence that we,
the said James Ramage and Thomas Nelson, our executors, administrators,..
and assigns, .or such others as we, the said James Ramage and Thomas"
Nelson, our 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 THE
PRODUCTION OF. BLOCKS AND PLATES FOR PRINTING," upon the condition (amongst
others) that we, the said James Ramage and Thomas Nelson, our executors
or administrators, by an instrument in writing under our or their hands and.
seals, or under the hand and seal of one of us or 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.
.
NOW KNOW YE, that I, the said James Ramage, on behalf of myself
and the said Thomas Nelson, 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:-
This Invention has for its object improvements in the production of blocks
and plates for printing. A solution of bichromate of potash mixed. with
gelatine, dissolved in water, or other similar preparation, is poured upon a

page_text: sheet of suitable material, and when dry exposed under a negative of the.
drawing, engraving, or print for a given time; it is then immersed in water)
till the parts not acted on by the light swell up to the desired extent. The
surface water is then removed, and a solution of gutta percha, bitumen, and,
wax, or other such materials is poured over, the surface forming a skin thereon,,
The back of.this skin is then filled up to a proper thickness with melted wax;
or other materials, and when set the mould thus produced is separated from,
the gelatine and electrotyped, or å stereotype cast is taken..
For a copper or other plate a. transparency of the drawing, engraving, or
-print is used, the same processes gone through, and the plate produced is,
used for printing in. the ordinary way.
. Having thus. stated the. nature of our. said Invention, we will proceed to
describe the manner in which we prefer. to perform the same."
.
i
A quantity of good gelatine is soaked in cold. water until..it is completely..
swelled, and the remaining water is drained off. The dish. containing the :
gelatine is then plunged into boiling water, and so' the gelatine is melted; to,
it there is then added and dissolved in the gelatine as much bichromate of
potash or of ammonia as the gelatine will hold without crystallizing when
poured on a strip of glass, and dried. The solution is filtered, and whilst..
still warm it is employed to coat the surface on which it is to be employed..
The surface we prefer is of tin foil; the metal should be about as thick as
stout, paper, and quite smooth and flat. The gelatine solution is poured
evenly over the surface to the thickness of, say, ordinary cardboard, more or
less, according to the amount of relief desired to be obtained, and the coating
is thoroughly dried; these operations are conducted in the dark. The coated
plate is then exposed to light under a negative, by preference on glass, of the
design corresponding with the printing block desired to be obtained; it may
be a photograph from an engraving, or drawing, or otherwise. The length of
exposure will vary, as a photographer will understand, according to the
quality of the negative, the thickness of the coating, and the intensity of the
light; in bright sunshine, however, it will usually be from 10 to 15 minutes.
The exposure being completed the plate is immersed in cold water till the
parts unaltered by the light swell up to the required height, and then the
plate is removed from the water, and that which remains on the surface is
carefully removed with blotting paper. The next operation is to form a skin
on the surface of the plate by pouring over it a solution in bisulphide of
carbon of one part of asphaltum, three parts of gutta percha, and one part of
india-rubber, which last is dissolved in as small a quantity of benzole as is
necessary for the purpose before adding it to the other ingredients. The

page_text: quantity of bisulphide of carbon should be such as to reduce the solution to
the consistence of ordinary photographic collodion, and the coating of
sólution is applied by pouring it over the prepared plate and running.
off the excess; it sets immediately into a tough hard skin. Next, the
edges of the metal plate are turned up all round so as to form a tray, which is
then filled with a composition consisting of six parts of beeswax, four parts
of paraffin, and two parts of, asphaltum; these substances are melted by heat,
and thoroughly mixed. Before the composition is used it should be cooled
as far as it can be without loss of fluidity. As soon as the composition.is
completely-cold the tin foil is separated all round the edges by bending it
away from the block, and it is then readily removed, leaving a block with a..
perfect mould on its surface. This block we stereotype in the manner in
which a form of type. is usually stereotyped, and so we obtain a surface
printing block. Or with the same object we sometimes electrotype the mould,
as is also well understood, and so we obtain a copper block. Small blocks
or stamps to be used by hand are conveniently produced in this manner..
.For the production of engraved plates för printing in the manner of copper-.
plate printing the process is conducted in a similar manner, the only.
difference being that a positive of the design is employed in place of a¸
negative; we employ by preference a photographic positive on glass:.:
In witness whereof, I, the said James Ramage, have hereunto set my
hand and seal, this Twenty-fourth day of September, in the year of
our Lord One thousand-eight hundred and sixty-six.
JAMES RAMAGE. (L.S.)