IMPROVED PROCESSES FOR INLAYING METALS
Year: 1868

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery
Lane, in the County of Middlesex, Patent Agent, for the Invention
of "IMPROVED PROCESSES FOR INLAYING METALS."-A communication
from abroad by Hugues Antoine Paul Christofle and Charles
Henri Bouilhet, of the Firm of Christofle and Company, of 56, Ruc
de Bondy, Paris, Silversmiths.
Scaled the 4th June 1869, and dated the 16th December 1868.
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 16th December 1868.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of the
said Invention for "IMPROVED PROCESSES FOR INLAYING METALS," to be as
follows:-
The bronze vases inlaid with gold or silver, for which the Chinese and
Japanese are celebrated, are distinguished by the sharpness of the designs
and the perfect smoothness of surface obtained.

page_text: I have sought to reproduce this inlaying work by the ordinary
damaskeening process, but with an imperfect result, on large surfaces;
it is moreover too costly to be of practical value. The processes of
gilding and silvering with "reserves" have also been tried without
however being able to obtain that smoothness of surface which distin-
guishes this kind of work, and after many experiments the following
process of this Invention has been devised:-I take any article in
bronze, copper, aluminium bronze, or other metal or alloy of a different
color to gold or silver, and paint on the surface in gouache color any
kind of ornamental design, flowers or figures, after previously cleaning
the said surface. This being done the different parts of the surface not
occupied by the design are next covered with a varnish such as used
in aquafortis engraving, and the article is then placed in a bath of acetic
acid-at-12 degrees Beaumé in communication with the positive pole of
a battery. The salt of lead of which the-gouache.color is composed then
dissolves, and the metal of which the article is composed is attacked.
When the depth of the channels thus formed is considered sufficient the
article after having been rinsed is placed in a weak bath of cyanide of
silver or gold in connection with a battery. After the precious metal
has become deposited in sufficient quantity the operation is interrupted
and the varnish removed, after which the article is polished by hand
so as to remove any excess of the metal inlaid and make both surfaces
perfectly level and smooth. The article is then bronzed, choosing dark
colors in order to better bring out the gold or silver design. This process
possesses the advantage of preserving the purity of the design and style
of the artist. When, on the contrary, it is desired to repeat the same
design several times on the same or different articles I may avail myself of
the transferring processes used in the decoration of porcelain, afterwards
protecting the surface with a reserve varnish, biting in the metal, and
filling in the design with the galvanic deposit as before.
The above-described process of this Invention produces an entirely
novel class of article, realizing the conditions of damaskeening at but
small cost. This process is distinguished from gilding and silvering with
reserves, inasmuch as the precious metal instead of being deposited in
layers is inlayed in the bronze or other metal on a level with its
surface.
The same result may also be attained in a still more economic and

page_text: perfect manner by the following process of this Invention, which may
be applied in various ways. This process has for its object to dispense
with the delicate and difficult hand application of the varnish as above
described, which I replace by a chemical operation after the design has
been traced. For this purpose I use an clectro-chemical deposit of iron,
which serves as a protecting agent in lieu of varnish when biting in
and electro-chemically depositing the metal in the articles to be
described, which I replace by a chemical operation after the design has
been traced. For this purpose I use an clectro-chemical deposit of iron,
which serves as a protecting agent in lieu of varnish when biting in
and electro-chemically depositing the metal in the articles to be
iniaid,
The following is the mode of operation:- Instead of employing
gouache color for tracing the design on the article to be inlaid I make it
in reserve varnish or in an ink containing a coloring matter insoluble in
salts of iron, either alkaline or acid; the article is then cleaned and
placed in a bath of iron, which metal is deposited on all the parts not
covered by the varnish, and on removing the same by means of an
essence the design appears in perfection on the parts where the iron has
not been deposited. In this condition the article is placed in a bath of
cyanide at 10 per cent. and brought in contact with the positive pole
of a battery. As the layer of iron is inattackable by the cyaride it
follows that the design on the metal article to be inlaid (consisting either
of copper and its alloys as well as gold, silver, and their alloys) will be
bitten in at those parts not occupied by the iron by connecting the
hydrocyanic acid either with the positive pole or with the article which
is itself in connection therewith. When the channels are sufficiently
deep the articles after being previously rinsed is placed in an alkaline
bath of silver, gold, copper, or alloys of these metals, the metal to be
inlaid becoming deposited in the channels. But as precautions are
taken to prevent the metals from adhering to the iron, the latter forming
the reserve in both operations may be afterwards readily dissolved
by immersing the article in sulphuric acid and any surplus metal
detached.
When the design to be executed is susceptible of frequent reproduction
I may employ the mode of transferring adopted for engraving on glass
with hydrofluoric acid, the bituminous ink being inattackable by the
bath of iron. Thus after making the transfer a layer of iron may be
deposited, the design being bitten in by the cyanide at 10 per cent., and
the different metals to be inlaid afterwards deposited by electro-chemical

page_text: means; in this manner the same result is obtained as when the design is
produced by hand, and at much less cost.
By engraving metals according to the above modes, or by means of
aquafortis or a graver, I produce patterns which may be readily repro-
duced by galvanoplasty. The proofs are finished in the ordinary
manner, and are then covered with a reserve varnish, such as used by
gilders on all the raised parts, the channels only being filled with the
electro-chemical deposit of the precious metal. This constitutes an
expeditious mode of obtaining articles with channels ready to be filled
up with the inlaying metal. Whatever may be the mode of inlaying
employed the articles are finished in the manner first herein described.
These several processes may be applied either for inlaying precious
metals-on-copper, or for inlaying copper, silver, or gold in articles of
jewellery, whether of silver or of different kinds of gold---
I have before mentioned that I employ a reserve varnish for protecting
the raised parts, and fill in the exposed channels with the galvanic
deposit. This is always a delicate process, and I will now proceed to
describe a more economical. mode. The article to be ornamented by
inlaying is first produced by the aid of galvanoplasty and scraped in the
ordinary way. I then heat it slightly, and when it has attained a
sufficient temperature I rub on the surface some virgin wax previously
colored by mixing when melted with some suitable powder. When the
wax on the surface is melted and has penetrated all the cavities I allow
it to cool, and afterwards remove any surplus wax with a very thin bone
blade or other tool made of bone, ivory, or other semi-hard substance.
This being done I complete the cleaning of the surface with fine pumice-
stone and a soft brush. In this condition the article to be inlaid is
placed in the bath of iron, and then in the bath of cyanide and finished
in the manner before described. This mode facilitates the application
of the process before described without however varying the principle of
the Invention, which consists in the galvanic inlaying of all kinds of
gold, silver, and bronze wares or jewellery in different colors, as hercin-
before described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 15th June 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of December, in the
year of our Lord One thousand eight hundred and sixty-eight, in the
thirty-second year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Alexander Melville Clark,.
Her special licence that I, the said Alexander Melville Clark, my
executors, administrators, and assigns, or such others as I,. the said
Alexander Melville Clark, 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 "IMPROVED PROCESSES FOR INLAYING METALS," a
communication to me from abroad by Hugues Antoine Paul Christofle
and Charles Henri Bouilhet, of the Firm of Christofle and Company,
of 56, Rue de Bondy, Paris, Silversmiths, upon the condition (amongst
others) that I, the said Alexander Melville Clark, my executors or ad-
ministrators, by an instrument in writing under my, or their, or one of
their hands and scals, 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 Alexander Melville Clark, 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 (that is to say) :-
The bronze vases inlaid with gold or silver, for which the Chinese and
Japanese are celebrated, are distinguished by the sharpness of the
designs and the perfect smoothness of surface obtained.

page_text: I have sought to produce this inlaying work by the ordinary
damaskeening process, but with an imperfect result on large surfaces.;
it is moreover too costly to be of practical value. The processes of
silvering and gilding with "reserves" have also been tried without
however being able to obtain that smoothness of surface which
distinguishes this kind of work, and after many experiments the
following process of this Invention has been devised:-I take any
article in bronze, copper, aluminium bronze, or other metal or alloy of
a different color to gold or silver, and paint on the surface in gouache
color any kind of ornamental design, flowers or figures, after previously
cleaning the said surface. This being done the different parts of the
surface not occupied by the design are next covered with a varnish, such
as used in aquafortis engraving, and the article is then placed in a
bath of acetic acid at 12 degrees Beaumé in communication with the
positive pole of a battery. The salt of lead-of-which-the-gouache_color
is composed then dissolves, and the metal of which the article is.
composed is attacked. When the depth of the channels thus formed is
considered sufficient the article after having been rinsed is placed in a
weak bath of cyanide of silver or gold in connection with a battery.
After the precious metal-has-become-deposited in sufficient quantity the
operation is discontinued and the varnish removed, after which the
article is polished by hand, so as to remove any excess of the metal
inlaid, and make both surfaces perfectly level and smooth. The article
is then bronzed, dark colors being chosen in order to better bring out the
gold or silver design. This process possesses the advantage of preserving
the purity of the design and style of the artist. When it is desired to,
repeat the same design several times on the same or different articles I
may avail myself of the transferring processes used in the docoration
of porcelain, afterwards protecting the surface with a reserve varnish,
biting in the metal, and filling in the design with the galvanic deposit
as before.
The above described process of this Invention produces. an entirely.
novel class of article, realizing the effect of damaskocning at but small
cost. This process is distinguished from gilding and silvering with
reserves, inasmuch as the precious metal instead of being deposited in
layers is inlaid in the bronze or other metal on a level with its
surface.

page_text: wing proceSS OF
be applied in various ways. This process has for its object to dispense
with the delicate and difficult hand application of the varnish as above
described, which I replace by a chemical operation after the design has
been tracod. For this purpose I use an electro-chemical deposit of
iron which serves as a protecting agent in lieu of the varnish when
biting in and clectro-chemically depositing the metal in the articles to
be inlaid,
The following is the mode of operation:-Instead of employing
gouache color for tracing the design on the article to bo inlaid, I make
it in reserve varnish, or in an ink containing a coloring matter insoluble
in either alkaline or acid salts of iron. The article is then cleaned and
placed in a bath of iron, which metal is deposited on all the parts not
covered by the varnish or ink design, and on removing the same by
means of an essence the design appears in perfection on the parts
where the iron has not been deposited. In this condition the article
is placed in a bath containing ten per cent. of cyanide and brought in
contact with the positive pole of a battery. As the layer of iron is
inattackable by the cyanide, it follows that the design on the metal
article to be inlaid (consisting either of copper and its alloys as well
as gold, silver, and their alloys,) will be bitten in at those parts not
occupied by the iron by connecting the hydrooyanic acid either with
the positive pole or with the article which is itself in connection
tlicrewith.
When the channels are sufficiently deep the article after being
previously rinsed is placed in an alkaline bath of silver, gold, copper,
or alloys of those metals, the metal to be inlaid becoming deposited
in the channels. But as precautions are taken to prevent the metal
from adhering to the iron, the latter (forming the reserve in both
operations) may be afterwards readily dissolved by immersing the article
in sulphuric acid, and any surplus metal detached.
When the design to be executed is susceptible of frequent reproduction
I may employ the mode of transferring adopted for engraving on glass
with hydrofluoric acid, the bituminous ink being inattackable by the bath
of iron. Thus after making the transfer a layer of iron may be deposited,
the design being bitten in, in a bath containing ten per cent. of cyanide,
and the different metals to be inlaid afterwards deposited by clectro-

page_text: chemical means; in this manner the same result is obtained as when the
design is produced by hand, and at much less cost.
By engraving metals according to the above modes, or by means of
aquafortis or a graver, I produce patterns which may be readily rc-
produced by galvanoplasty. The proofs are finished in the ordinary
manner, and are then covered with a reserve varnish, such as used by
gilders on all the raised parts, the channels only being filled with the
electro-chemical deposit of the precious metal. This constitutes an
expeditious mode of obtaining articles with channels ready to be filled up
with the inlaying metal. Whatever may be the mode of inlaying
employed the articles are finished in the manner first herein described.
These several processes may be applied either for inlaying precious
-metals on copper or for inlaying copper, silver, or gold in articles of
jewellery, whether of silver or of different kinds of gold.
I have before mentioned that I employ a reserve varnish for protecting
the raised parts, and fill in the exposed channels with the galvanic
deposit. This is always a delicate process, and I will now proceed to
describe a-more-economical_mode. The article to be ornamented by
inlaying is first produced by the aid of galvanoplasty and scraped in the
ordinary way; I then heat it slightly, and when it has attained a
sufficient temperature I rub on the surface some virgin wax previously
colored by mixing when melted with some suitable powder. When the
wax on the surface is melted and has penetrated all the cavities I
allow it to cool, and afterwards remove any surplus wax with a very
thin bone blade or other tool made of bone, ivory, or semi-hard
substance. This being done I complete the cleaning of the surface
with fine pumice stone and a soft brush. In this condition the article
to be inlaid is placed in the bath of iron and then in the bath of
cyanide, and finished in the manner before described. This mode
facilitates the application of the process before described without how-
ever varying the principle of the Invention, which consists in the
galvanic inlaying of all kinds of gold, silver, and bronze wares or
jewellery with metals in different colors, as hercin-before described.
Having described the nature of this Invention, and the manner of
performing the: same, I declare that what I claim as the Invention to
be protected by the hercin-before in part recited Letters Patent is, the
several processes of inlaying metals or alloys by the aid of galvanism

page_text: herein-before described, such processes being applicable in the manu-
facture or ornamentation of all kinds of gold, silver, or bronze wares or
articles of jewellery in any metal.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and scal, this Fifteenth day of Junc,
in the year of our Lord One thousand eight hundred and sixty-
nine.
Witness,
JAMES DAISI,
53, Chancery Lane,
London.
A. M. CLARK. (L.S.)