CERTAIN IMPROVEMENTS IN ENGRAVING ON STONE, EARTHENWARE, CHINA, AND GLASS, AND ALSO IN ORNAMENTING THE SAME
Year: 1856

page_text: LETTERS PATENT to Léon Louis Jardin and Joseph Blamond, of 39,
Rue de l'Echiquier, Paris, and 4, South Street, Finsbury, London,
Engravers, for the Invention of "CERTAIN IMPROVEMENTS IN ENGRAVING
ON STONE, EARTHENWARE, CHINA, AND GLASS, AND ALSO IN ORNAMENTING THE
SAME
"
Sealed the 14th October 1856, and dated the 9th May 1856.
PROVISIONAL SPECIFICATION left by the said Léon Louis Jardin and
Joseph Blamond at the Office of the Commissioners of Patents, with
.their Petition, on the 9th May 1856.
We, LÉON LOUIS JARDIN and JOSEPH BLAMOND, of 39, Rue de l'Echiquier,
Paris, and 4, South Street, Finsbury, London, Engravers, do hereby declare
the nature of our said Invention for CERTAIN IMPROVEMENTS IN ENGRAVING ON
STONE, EARTHENWARE, CHINA, AND GLASS, AND ALSO IN ORNAMENTING THE SAME, to
be as follows, that is to say:-
Our Invention consists, first, in employing hydrofluoric acid in a liquid state
in lieu of employing it in the state of vapour for engraving on hard siliceous
materials, by which improvement we are enabled to obtain various new and
useful industrial and ornamental results.

page_text: And, secondly, in a process for treating the stone in certain cases before
engraving it to produce the effect of enamel.
The stone to be engraved is first covered with a varnish, which is commonly
composed of wax and turpentine, after which the required figures are drawn
on the stone with a needle. A rim is formed all round with engraver's wax,
and the liquid hydrofluoric acid is poured on to the stone. A white cloud will
be formed on the parts of the stone that have been uncovered by the needle,
which increases gradually, and the extent of which is in proportion to the
quantity of acid employed. If on examining the engraving the result is found
to be satisfactory, the varnish coating may be removed; if incomplete, the acid
must first be reapplied until it is complete. For ordinary or lithographic
engravings care should be taken not to allow the acid to act beyond the
necessary time.
Another of our improvements consists in introducing white or colored
glass into interstices made in the stone, and melting it there, by which we
produce the effect of enamel. The glass is pulverized, and the interstices in
the stone filled with it, and then fused, any excess being removed. Substances
containing silica, and consequently subject to the action of hydrofluoric acid,
can be treated by the processes before described. After the acid has ceased to
act on the stone or other hard materials, the lines may be filled in by ordinary
means.
J
Earthenware, porcelain, and glass may be treated in the manner before
described for producing ornaments or articles of utility, and according to the
part on which the hydrofluoric acid is made to act, hollows and reliefs are
obtained, by means of which inverse engravings may be obtained.
The above process of engraving and incrustation may be applied to table
services, and to vases of every kind to obtain a variety of designs, coats of
arms, &c.
The articles may also be gilded or silvered in the desired parts by employing
known means
1.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Léon Louis Jardin and Joseph Blamond in the Great
Seal Patent Office on the 5th November 1856.
元
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Léon Louis Jardin and Joseph Blamond in the Great
Seal Patent Office on the 5th November 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, .we, LÉON
LOUIS JARDIN and JOSEPH BLAMOND, of 39, Rue de l'Echiquier, Paris, and 3
4, South Street, Finsbury, London, Engineers, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her, Letters
Patent, bearing date the Tenth day of May, in the year of our Lord One
thousand eight hundred and fifty-six, in the nineteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
Léon Louis Jardin and Joseph Blamond, Her special license that we,
the said Léon Louis Jardin and Jóseph Blamond, our executors, admini-
strators, and assigns, or such others as we, the said Léon Louis Jardin and
Joseph Blämond, 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 CERTAIN IMPROVE-
MENTS IN ENGRAVING ON STONE, EARTHENWARE, CHINA, AND ALSO IN ORNAMENTING
THE SAME, upon the condition (amongst others) that we, the said Léon Louis
Jardin and Joseph Blamond, or one of us, by an instrument in writing
under our hands and seals, or under the hand and seal of one of us, 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 imme-
diately after the date of the said Letters Patent.
.
NOW KNOW YE, that we, the said Léon Louis Jardin and Joseph Blamond,
do hereby declare 'the nature of our 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:-
Our Invention consists, first, in employing liquid hydrofluoric acid in the
manner herein after described for ornamenting and engraving on hard siliceous
materials.
Secondly, in filling up the interstices of the intaglio design with white or
colored glass or metals for producing enamel and ornamental damask work.
The acids attack with more or less facility marbles and alabasters, according
to their relative resistance, and may be employed in the production of artistic
objects by first covering them with a protecting varnish, the substances to be
operated upon,
and removing the varnish from the parts to be etched, forming
the design by a suitable instrument, the acid of the necessary strength being
then added to act upon the parts exposed to its action, so as to produce an
intaglio and relievo effect, which may be afterwards finished by enamelling,
damaskeening, and gilding processes.
"
Since the discovery of schiele, it is known that in treating fluor spar with
sulphuric acid, the product disengaged acts powerfully on the silicates, which

page_text: discovery has been already applied to engraving on glass. Instead of acting on
glass by hydrofluoric acid in a state of vapour, it may be employed in the
liquid state. We take advantage of this property of the hydrofluoric acid for
engraving on hard siliceous materials, and employ it to obtain artistic effects in
the following manner:-We first cover the stone to be engraved on with a coat
of wax and turpentine, or with any suitable varnish, after which the design
intended to be etched is formed upon the stone by means of a steel point; a
wall of wax is then formed round the design, upon which the acid is then
poured, which acts immediately on the exposed portions of the stone. After
the lapse of a suitable time, regulated by experience, the stone is examined,
and if the etching is sufficient, the coat of wax or varnish is removed, but
if not, the acid is again poured on and allowed to remain as long as is
requisite. If necessary, an engraving instrument may be employed to finish
the design.
For ordinary engraving care must be taken not to allow the acid to destroy
the sharpness of the design.
If the design is to be deeply etched, the stone is carefully washed and dried,
and the sides of the parts etched are covered with varnish, so that when the
acid is applied the bottom only is acted upon. If, on the contrary, it is desired to
obtain an etching, in which the parts etched are wider at the bottom than at
the surface, the edges of the etched design are covered with protective varnish,
and a stronger acid is applied, by which the desired effect is produced.
If in the cavities or intaglio parts thus produced we place or fix wire or
plates formed of gold, silver, platina, aluminium, or other suitable metal,
damask and other ornamental metal work may be obtained.
Also, ornamental work, similar to the enamels of the Byzantine or Middle
Ages, are produced by employing colored or uncolored glasses, which are first
reduced to powder, with which the intaglio parts of the design are filled. The
necessary heat is then applied to melt the powdered glass, more being added
as required in the fusion; the excess is afterwards removed by mechanical
means.
We may also employ the electrotype process in certain cases for filling up
or ornamenting the etched surfaces, having previously rendered the parts
where the deposit is required conductible.
:
Having now described the nature of our said Invention, and the manner in
which the same is to be performed, we would have it understood that we do
not confine ourselves to the precise details herein laid down, so long as the
peculiar character of our Invention be retained. But what we claim is,→
First, the employment of hydrofluoric acid for engraving on stone, earthen-
i

page_text: ware, china, glass, and other siliceous materials, preparatory to ornamenting
the same, as herein-before described.
Secondly, in ornamenting the said articles and materials by the application
of white or colored glass or metals, as herein-before described.
In witness whereof, we, the said Léon Louis Jardin and Joseph
Blamoud, have hereunto set our hands and seals, this First day of
November, in the year of our Lord One thousand eight hundred
and fifty-six
L. L. JARDIN. (L.S.)
J. BLAMOND. (L.S.)
L. L. JARDIN. (L.S.)
J. BLAMOND. (L.S.)