IMPROVEMENTS IN ENGRAVING UPON METALS
Year: 1863

page_text: LETTERS PATENT to George Davies, of No. 1, Serle Street, Lincoln's
Inn, in the County of Middlesex, and No. 28, St. Enoch Square, in the
City of Glasgow, Civil Engineer and Patent Agent, for the Invention of
"IMPROVEMENTS IN ENGRAVING UPON METALS."-A communication from
abroad by Louis Charles Emile Vial, of Paris, in the Empire of France,
Chymist.
Sealed the 29th August 1863, and dated the 26th March 1863.
PROVISIONAL SPECIFICATION left by the said George Davies at the
Office of the Commissioners of Patents, with his Petition, on the 26th
March 1863.
I, GEORGE DAVIES, of No. 1, Serle Street, Lincoln's Inn, in the County of
5 Middlesex, and No. 28, St. Enoch Square, in the City of Glasgow, Civil
Engineer and Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN ENGRAVING UPON METALS," (a communication to me from
abroad by Louis Charles Emile Vial, of Paris, in the Empire of France,
Chymist,) to be as follows:-
This Invention, as communicated to me, is based, firstly, on the precipi-
tation of metallic salts by metals; secondly, on the affinity of acids for the
different metals; and, thirdly, on the phenomena of electro-chemistry.
The Invention consists, firstly, in writing or drawing on paper (to be

page_text: afterwards transferred by moisture and pressure), or in writing or drawing
directly on metal with a metallic ink susceptible of precipitation on another
metal by the simple fact of contact under certain conditions. Take, for
example, zinc or steel; on writing upon either of these metals with an ink
formed of a solution of sulphate of copper (any salt of lead, bismutb, or other
metal will answer the same purpose) this metal is immediately precipitated in
red on the steel, and in black on the zinc, and it is only requisite then to
"bite in" with the ordinary acids to have an engraving in intaglio or in relief.
What has been said with reference to zinc and steel applies equally to tin,
copper, silver, and other metals; in this case the metallic ink only must be
varied according to the metal which is to be engraved.
The Invention consists, secondly, in reproducing old engravings by the two
following processes :-
In the first process the original to be reproduced must be soaked in a
metallic solution adapted to the plate to be engraved, and the drawing or
writing then transferred to the plate by simple pressure, to be afterwards
"bitten in "by the ordinary acids. For example, take a solution of copper,
lead, bismuth, gold, or other metal, in which soak the engraving, which is then
to be turned over and transferred on to the plate of steel, copper, or other
metal, and all that is necessary then is to "bite in" by the ordinary acids,
such as sulphuric, azotic, or others. The transfer may also be obtained by
soaking the original in a solution of an alkaline, sulphuret, chloride, bromide,
iodide, or other similar salt, which will leave the image transferred on to the
gold, silver, or other metal.
In the second process, an old engraving is transferred on to steel or zinc by
means of a soap composed of turpentine or petroleum, and the plate is then
plunged in an acid bath of sulphate of copper, which attacks it immediately.
It will be evident that the sulphate can be replaced by any other salt of
copper, and also that salts of lead, bismuth, mercury, silver, and other metals
may be used instead of salts of copper.
The Invention consists, thirdly, in tracing on metal (steel or zinc, for
example), or in transferring by pressure a lithographic, autographic, or typo-
graphic proof, or a copper plate impression, and engraving this transfer by the
process just described; in drawing with china ink or with crayon on steel,
or with perchloride of iron, or with acid, in a word, with any body capable of
resisting tho deposit of copper without opposing the attack of the acid, or with
any body susceptible of roughening or taking off the polish of the steel in
parts which are engraved when the plate is submitted to an acid bath of

page_text: sulphate of copper. This process applies also to heliographic and photographic
engraving.
The principle of the Invention is the application to engraving of a well-
known theory, that is to say, that when a metal belonging to the four latter
sections is plunged into a saline solution containing a metal also belonging to
these sections, the solution is decomposed, and the metal reduced is precipitated
on the former with a considerable degree of adhesion.
The Inventor also proposes to apply electricity to his discovery, and to use
the voltaic pile to deposit the copper on to the steel to effect the "biting in"
direct, the process consisting in dispensing with varnish and "biting in the
steel direct, using copper instead of varnish as a resisting medium.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Davies in the Great Seal Patent Office on the 26th
September 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
DAVIES, of No. 1, Serle Street, Lincoln's Inn, in the County of Middlesex,
and No. 28, St. Enoch Square, in the City of Glasgow, Civil Engineer and
Patent Agent, 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-three, in the twenty-sixth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said George Davies, Her special licence that I, the said George
Davies, my executors, administrators, and assigns, or such others as I, the
said George Davies, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after 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 "Iм-
PROVEMENTS IN ENGRAVING UPON METALS," (being a communication to me from
abroad by Louis Charles Emile Vial, of Paris, in the Empire of France,
Chymist,) upon the condition (amongst others) that I, the said George Davies,
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

page_text: 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 George Davies, 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 in writing, that is to say :-
This Invention, as communicated to me, is based, firstly, on the precipi-
tation of metallic salts by metals; secondly, on the affinity of acids for the
different metals; and, thirdly, on the phenomena of electro-chemistry.
The Invention consists, firstly, in writing or drawing on paper (to be
afterwards transferred by moisture and pressure), or in writing or drawing
directly on metal with a metallic ink susceptible of precipitation on another
metal by the simple fact of contact under certain conditions. Take, for
example, zinc or steel; on writing upon either of these metals with an ink
formed of a solution of sulphate of copper (any salt of lead, bismuth, or other
similar metal will answer the same purpose) this metal is immediately preci-
pitated in red on the steel, and in black on the zinc, and it is only requisite
then to "bite in " with the ordinary acids to have an engraving in intaglio or
in relief. What has been said with reference to zinc and steel applies equally
to tin, copper, silver, and other metals; in this case the metallic ink only
must be varied according to the metal which is to be engraved.
The Invention consists, secondly, in reproducing old engravings by the two
following processes:―
In the first process the original to be reproduced must be soaked in a
metallic solution adapted to the plate to be engraved, and the drawing or
writing then transferred to the plate by simple pressure, to be afterwards
"bitten in" by the ordinary acids. For example, take a solution of copper,
lead, bismuth, gold, or other similar metal, in which soak the engraving, which
is then to be turned over and transferred on to the plate of steel, copper, or
other metal, and all that is necessary then is to "bite in " by the ordinary
acids, such as sulphuric, azotic, or others, the acid attacking one metal and
leaving the other untouched. The transfer may also be obtained by soaking
the original in a solution of an alkaline sulphuret, chloride, bromide, iodide, or
other similar salt, which will leave the image transferred on to the gold, silver,
or other metal.
In the second process, an old engraving is transferred or set off" on to

page_text: steel or zinc by means of a soap composed of turpentine or petroleum, and the
plate is then plunged in an acid bath of sulphate of copper, which attacks it
immediately, depositing metal upon every part unprotected by the "transfer."
It will be evident that the sulphate can be replaced by any other salt of
copper, and also that salts of lead, bismuth, mercury, silver, and other
metals may be used instead of salts of copper.
The Invention consists, thirdly, in tracing on metal (steel or zinc, for
example), or in transferring by pressure a lithographic, autographic, or typo-
graphic proof, or a copper plate impression fresh from the press, and engraving
this transfer by the process just described; in drawing with china ink or with
crayon on steel, or with perchloride of iron, or with acid, in a word, with
any body capable of resisting the deposit of copper without opposing the
attack of the acid, or with any body susceptible of roughening or taking
off the polish of the steel in parts which are engraved when the plate is
submitted to an acid bath of sulphate of copper. This process applies also
to heliographic and photographic engraving.
The Inventor also proposes to apply electricity to his discovery, and to use
the voltaic pile to deposit the copper on to the steel in order to effect the
"biting in" direct, the process consisting in dispensing with varnish and
"biting in" the steel direct, using copper instead of varnish as a resisting
medium.
The principle of the Invention is the application to engraving of a well-
known theory, that is to say, that when a metal belonging to one of the
four latter sections is plunged into a saline solution containing a metal also
belonging to these sections, the solution is decomposed, and the metal reduced
is precipitated on the former with a considerable degree of adhesion.
It is the application of this principle to the art of engraving which the
Inventor wishes to secure to himself without reference to the method of
"biting in ;" and although he gives the preference to certain solutions and
certain plates yet he can work equally as well upon tin, copper, silver, or
other metal by employing a solution belonging to a superior section to the
metal, that is to say, a solution of a metal capable of precipitating itself
thereon.
This Invention can be applied with advantage to the reproduction of old
engravings, to tho execution of lithographic, autographic, heliographic, and
other engraving, to the damaskeening and engraving of arms, to engraving
rollers for calico printing or embossing, matrices for bank notes, and to a
variety of other analogous purposes, and constitutes not only a new method of

page_text: reproducing old engravings, but also two new processes of engraving as above
described.
In witness whereof, I, the said George Davies, have hereunto set my
hand and seal, this Twenty-sixth day of September, in the year of
our Lord One thousand eight hundred and sixty-three.
GEORGE DAVIES. (L.B.)