IMPROVEMENTS IN ENGRAVING ON METAL, OR ON OTHER SUBSTANCES DECOMPOSABLE BY ACIDS OR CORROSIVE
Year: 1859

page_text: LETTERS PATENT to Polynice Auguste Viette, of No. 25, Faubourg de
Shaerbeck, near Brussels, a Major in the Service of His Majesty the
King of the Belgians, for the Invention of "IMPROVEMENTS IN ENGRAVING
ON METAL, OR ON OTHER SUBSTANCES DECOMPOSABLE BY ACIDS OR CORROSIVE
Sealed the 13th January 1860, and dated the 29th July 1859.
PROVISIONAL SPECIFICATION left by the said Polynice Auguste Viette
at the Office of the Commissioners of Patents, with his Petition,
on the 29th July 1859.
I, POLYNICE AUGUSTE VIETTE, of No. 25, Faubourg de Schaerbeck, near
Brussels, a Major in the Service of His Majesty the King of the Belgians,
do hereby declare the nature of the Invention for "IMPROVEMENTS IN ENGRA-
VING ON METAL, OR ON OTHER SUBSTANCES DECOMPOSABLE BY ACIDS OR CORROSIVE
SALTS," to be as follows:-
This Invention has for its object improvements in engraving on metal, or on
other substances decomposable by acids or corrosive salts. For engraving in
relief on metal, steel being taken for an example, the process consists or
drawing or writing directly upon the metal without any previous preparation
with an ink similar to the third ink described in the Provisional Specification

page_text: of a Patent granted to me on the 15th January 1859, No. 130. This ink
resists the action of acids. When the drawing is finished the plate is sub-
jected to a temperature of from 25° to 30° centigrade in order to render it
perfectly dry. After this operation the drawing is passed over the smoke of a
lamp, and when the plate is cool, it is placed in a bath of nitric acid. The
action of the acid may be increased as required by passing a current of elec-
tricity through the bath; the acid thus bites into the surface of the steel with
the exception of those parts which are covered by the ink, and thus produces
an engraving in relief.
If it is desired to change sunk engravings obtained by the ordinary processes
into reliefs, the ink is introduced into the hollows of the sunk engraving, the
plate is then dried, and bitten by the acid as above described until the relief
desired is obtained.
I have mentioned nitric acid as being most generally employed, other acids,
however, may be employed, and also corrosive salts, according to the require-
ments of the work and the nature or sort of metal or other substance employed.
The process above described as applicable to steel is also applicable to engraving
in relief on other substances which are capable of being decomposed by acids
or corrosive salts.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Polynice Auguste Viette in the Great Seal Patent Office
on the 28th January 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, POLYNICE
AUGUSTE VIETTE, of No. 25, Faubourg de Shaerbeck, near Brussels, a Major
in the Service of His Majesty the King of the Belgians, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of July, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-third year of
Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Polynice Auguste Viette, Her special licence that I, the
said Polynice Auguste Viette, my executors, administrators, and assigns, or
such others as I, the said Polynice Auguste Viette, my executors, adminis-
trators, 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

page_text: Kingdom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN ENGRAVING ON METAL, OF ON OTHER
SUBSTANCES DECOMPOSABLE BY ACIDS OR CORROSIVE SALTS," upon the condition
(amongst others) that I, the sail Polynice Auguste Viette, 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 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 Polynice Auguste Viette, do hereby
declare the nature of the said Invention, and in what manuer 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 engraving on metal or on
other substances decomposable by acids or corrosive salts. For engraving in
relief by my direct system on metal or on any other suitable substance
decomposable by an acid or a corrosive salt, I draw or write on the object to
bo engraved with one of the inks described in the Specification of a Patent
granted to me on the 15th day of January 1859, No. 130, or with any other
suitable ink. When the drawing is finished it is left to dry for a short time
and then subjected to a proper temperature to dry it thoroughly, and give it a
perfect adherence with the object to be engraved. When the ink is perfectly
dry the object to be engraved is submitted to the corroding action of a proper
acid. The ink resisting the action of the galvanic pile a current of electricity
may be passed through the bath when required. The acid thus corrodes the
surface of the object to be engraved with the exception of those parts which
are covered with the ink, and in a short time an engraving of the relief
required can be obtained. If the object to be engraved be of a nature not
able to support a high temperature the ink must be allowed to dry naturally
and more time must be given. By way of precaution to preserve the work
from any blanks or flaws which may have formed in the Drawing, it may be
passed over the smoke of a lamp when the ink has acquired a certain degree
of siccity, or it may be sprinkled over with the powder of one of the substances
entering into the composition of the inks described in the Specification
annexed to a Patent-granted to me, the 15th day of January 1859, No. 130,
or with any other suitable substance before subjecting the object to be
engraved to the action of heat. For some purposes' I write or draw direct

page_text: with one of the inks described in the Specification annexed to a Patent granted
to me the 15th day of January 1859, No. 180, or any other suitable ink,
on tin, lead, and their amalgamation with bismuth and antimony, &c., or on
zinc or on lithographic stone, I then wash slightly the object drawn upon with
a mixture of weak acid and gum. Proofs of very large dimensions may be
immediately taken off. When the work is required to be drawn fine and
regular I cover the plate to be engraved with a thin layer of chalk or plaster,
or any other suitable substance made impermeable to fatty matters. I then
draw pointwise and introduce the ink into the lines; after this operation I can
then remove the chalk or preparation, aud either make it eat away for the
purpose of a drawing in relief, or I make use of it to print direct from the
sketch.
To obtain sunk engravings by my direct system I write or draw with an ink
decomposable by turpentine, or any suitable ink attackable by acids. When
the drawing is finished and perfectly dry, I pass with a brush one of the inks
described in. the Specification annexed to a Patent granted to me the 15th
January 1859, No. 130, or any other ink proper for this purpose over the
whole of the drawing, and the object to be engraved being thus entirely
covered I place it in water and move it to and fro from time to time; after a
little time the drawing will appear bare on the object to be engraved, its ground
remaining covered.
In all that relates to the eating away I follow the same method as herein.
before described for engraving in relief.
If some parts of the drawing should not have come out I touch them lightly
with the finger, and again move to and fro in the water. By covering the
plate to be engraved with one of the inks described in the Specification
annexed to a Patent granted to me 15th January 1859, No. 180, I can also
make use of the ordinary process, and draw pointwise.
Another of my improvements, which I call my inverse system, consists in
obtaining by electricity a drawing in relief on a plate or on any other object in
metal or metalized. I begin as for the sunk engraving in my direct system,
taking the same precautions, then I project by galvanic processes a suitable
metal in the lines of the drawing, which will come out in relief and then resist
the eating away after the ink has been removed, provided attention has been
paid to the natures more or less electro-positive of the combined metals.
By the same process I obtain sunk engravings. I begin as described in my
direct system for the engraving in relief. I then project the suitable metal,
and afterwards remove the ink and clean well the plate, and then proceed

page_text: to eat it away.
If a plate inverse is to be obtained from a drawing on the right
side I follow one of the two principles I have just described, in the first case
after having obtained an engraving in relief I obtain from it a stereotype by
means of electricity; in the second case I sprinkle lead dust or any other
suitable substance over the drawing to metalize it and to give a little more
relief, and I then rub it with a fine brush. After this operation I project the
suitable metal, continuing the operation until I obtain the thickness required.
It will always be easy to detach the second plate from the first if the usual
precautions employed in galvanoplasty are taken, or in combining the metals
in such manner as to be able to remove the mother plate either by fusion or
by corrosion of this plate. By these different processes combined all kinds of
mixture of metals may be made and every description of drawing upon metals
in coloring them with the metals projected one on the other protected by
the ink or simply by means of oxidation. I also project a thin layer of
suitable metal on another metal, then draw pointwise, traversing the
layer either with the point or by eating away, I then fill up the lines with a non-
conducting substance, and continue to project the metal necessary for the
thickness required.
The inks described in the Specification of a Patent granted to me the
15th January 1859, No. 130, being autographic black, and of easy application,
I draw with one of them, or with any other suitable on a paper prepared with
gelatine and gum together, or any other suitable, and transfer the drawing on
the object to be engraved, cause it to be eaten away, or use only the
sketch without eating away for the purpose of striking off proofs. The
drawing done on the right side will be inverse on the plate. The paper may
be made transparent for the purpose of tracing, by rubbing over it a mixture
of one half oil and one half turpentine, or any suitable preparation. By this
process the lines are fine and clear.
The gummy preparation may also be applied to a drawing on paper, the
ink then applied over it, and the drawing transferred.
By printing, all kinds of proofs may be also obtained and transferred to
metal plates, and afterwards the eating away effected direct, or by applying to
this process one of the two described above in my inverse or electric system,
but the ink must be kept thicker, and the precautions already mentioned
taken to ensure the quality of the work.
Ordinary printing ink may be employed powdered over and dried as herein-
before mentioned.
In describing these different processes as applied to engraving, I have been

page_text: forced to make allusion to certain processes already in use or abandoned, in
order to describe a complete system of my means of production, made extremely
easy by the use of my inks described in the Specification annexed to a Patent
granted me the 15th January, 1859, No. 130, but I would have it understood
that I only lay claim to the improvements herein described.
In witness whereof, I, the said Polynice Auguste Viette, have hereunto
set my hand and seal, this Twenty-second day of January, in the year
of our Lord One thousand eight hundred and sixty.
P. A. VIETTE. (L.s.)