Ix- PROVED MEANS OF ORNAMENTING GLASS
Year: 1853

page_text: LETTERS PATENT to Emmanuel Barthélemy and Tony Petitjean, of
Upper John Street, Fitzroy Square, in the County of Middlesex,
Mechanists, and Jean Pierre Bourquin, of Newman Street, Oxford
Street, in the same County, Merchant; for the Invention of "Ix-
PROVED MEANS OF ORNAMENTING GLASS."
Sealed the 5th May 1854, and dated the 25th November 1853.
PROVISIONAL SPECIFICATION left by the said Emmanuel Bar-
thelemy, Tony Petitjean, and Jean Pierre Bourquin at the Office
of the Commissioners of Patents, with their Petition, on the 25th
November 1853.
We, EMMANUEL BARTHELEMY, TONY PETITJEAN, and JEAN PIERRE
BOURQUIN do hereby declare the nature of the said Invention for
"IMPROVED MEANS OF ORNAMENTING GLASS" to be as follows:-
This Invention has for its object the production of ornamental designs
upon glass by the action of hydrofluoric acid applied in such manner
that the designs produced shall have the appearance of a painting.
The glass to be operated upon may be either of a uniform tint
throughout, or may consist of a sheet of white or light colored glass

page_text: covered with a layer of enamel or glass of a darker or different
color.
The manner of operating is as follows:-Plates of metal or other
suitable material are prepared after the manner of stencil plates, having
portions of the design cut out of them, each plate representing a certain
shade desired to be produced. The plate in which the dark parts are
in reserve is first applied to the glass, the parts left exposed by the
plate are then covered by a "ground," consisting of some substance
capable of resisting the action of hydrofluoric acid, to which acid the
glass is now exposed. When the acid has eaten to a sufficient depth
to produce the shade desired (which must be determined by experience),
the second plate must be applied. This second plate must be prepared
in such a manner as to protect_the_shades first produced at the same
time that it covers the parts left open by the first stencil plate. The
ground or resisting preparation is then applied to the glass and the
acid allowed to act as before, and this operation is repeated as many
times as there are shades required to complete the design.
It will be understood that, each plate must always protect the work
of the preceding plate.
If necessary various colors may be applied to certain parts of the
design, which would, however, necessitate a subsequent firing of
the close
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Emmanuel Barthélemy, Tony Petitjean, and
Jean Pierre Bourquin in the Great Seal Patent Office on the
25th May 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we,
EMMANUEL BARTHÉLEMY and TONY PETITJEAN, of Upper John Street,
Fitzroy Square, in the County of Middlesex, Mechanists, and JEAN
PIERRE BOURQUIN, of Newman Street, Oxford Street, in the same
County, Merchant, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of November, in the

page_text: year of our Lord One thousand eight hundred and fifty-three, in the
seventeenth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said Emmanuel Barthélemy, Tony
Petitjean, and Jean Pierre Bourquin, Her special licence that we, the
said Emmanuel Barthélemy, Tony Petitjean, and Jean Pierre Bour-
quin, our executors, administrators, and assigns, or such others as we,
the said Emmanuel Barthélemy, Tony Petitjean, and Jean Pierre
Bourquin, our 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 Inven-
tion for "IMPROVED MEANS OF ORNAMENTING GLASS," upon the condition
(amongst others) that we, the said Emmanuel Barthélemy, Tony
Petitjean, and Jean Pierre Bourquin, 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 Inven-
tion, 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 Emmanuel Barthélemy (on
behalf of myself and of the said Tony Petitjean and Jean Pierre
Bourquin), 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 (that is to say):-.
This Invention has for its object the economical production upon
colored glass (through the agency of bydrofluoric acid) of ornamental
designs which will possess the appearance of having been painted by
the brush of an artist.
The glass to be operated upon may be either of a uniform tint
throughout, or may consist of a sheet of white or light colored glass
covered with a layer of enamel or glass of a darker or different
color.
In carrying out this Invention we first prepare a pattern or design
upon paper, in any given number of tints or shades of the same color,

page_text: and we then provide a corresponding number of stopping out plates or
stencil plates for covering the glass, while the ground for resisting the
action of the acid is being laid on, and thereby protecting those portions
of the glass which are required to be exposed to the acid from receiving
the coating or ground.
These plates we so construct that they will severally correspond in
form to the touches of shadow made in one of the tints or to the lights
of the pattern required to be reproduced upon the glass, and thus we
are enabled, without employing skilled labour, to coat the glass with a
ground or resist, after each successive biting at those parts which have
been sufficiently reduced by the action of the acid, and thereby to obtain
the touches of light and shade desired..
The manner of constructing these stopping out or stencil plates is as
follows-Having prepared a pattern or design after the fashion of
patterns for calico printing, that is, with the shadows, demi-tints, and
lights combined as they are in designs adapted to the process of printing
in colors, we transfer the outline of each shadow, tint, or light to the
surface of thin sheets of lead or other suitable material, and we cut
therefrom forms that correspond to the outline of the various tints and
of the lights of the pattern so transferred.
The superfluous fragments of each sheet of lead we then remove
without disturbing the other portions of the sheet, and thus we obtain
counterpart figures of the several tints and of the lights required to be
reproduced in the design. To give consistency to these counterpart
figures we connect them to a bed of fine metallic wires or threads of
other suitable material stretched on a frame and lying in parallel lines
at about half or a quarter of an inch apart, more or less, according to
the pattern. Or, in lieu of parallel lines of wires we employ a net work
of fine wire or other material, and place the same upon the divided
portions of the sheet of lead and connect them, whether isolated or not,
to the wires or threads by means of adhesive straps or bands of gummed
paper, cloth, or other suitable material. One or more of the sides of
the frame we prefer to make moveable for the purpose of keeping the
wires or net work in tension by means of nuts and screws that act upon
the moveable side of the frame. It will be understood that each degree

page_text: of shadow, tint, or light in the design to be produced on the glass
requires a separate plate, and the number of plates, therefore, required
will depend upon the degree of elaboration of the pattern.
Thin sheets of lead we employ in preference to other substances,
because lead being inelastic can easily be made to fit exactly the even
or uneven surface of a piece of glass. The adhesive composition spread
on cloth or paper, and used to connect to the bed of wires or network
the fragments of sheet lead forming portions of the pattern or design,
is made as follows:-Equal parts by weight or thereabouts of gutta
percha and spirits of turpentine are mixed together, set on fire, and
made to burn until the mixture forms a perfect liquid of equal con-
sistence throughout, that may be spread while hot on cloth or paper.
The fabric coated with this material is cut into straps or bands of
any convenient length or dimensions. These are again severed to
suit the parts to be connected, and they are placed as bands upon
the wires and forms of sheet lead, and heated by a hot iron passed
over them to melt the adhesive substance, and cause it to attach
itself to the wires and the sheet lead, and bind the two together.
The composition used as a protecting ground or resist to the hydro-
fluoric acid is made as follows:-From two to five parts of resin
are fused by heat, and one part of bees' wax, according to the
temperature of the place in which the work is done. Below freezing
point about two parts of resin to one of wax is most convenient
for the purpose. At the high temperature of one hundred degrees
or more of Fahrenheit, about five parts of resin to one of wax
would be required. For intermediate degrees of temperature in the
surrounding atmosphere intermediate proportions are required, the wax
remaining always as one to two or more parts of resin. When the
resin and the wax are fused together in a mass, the mixture is reduced
to a state of fine powder. This powder is dusted over the surface of
the glass, the improved stencil plate having first been applied thereto,
and the powder will cover the portions of the glass left uncovered by
the stencil plate. When this dusting operation is effected the stencil
plate is removed, and the glass is subjected to a moderate degree of
heat to fuse the powder into a smooth ground that will protect the

page_text: covered surface from hydrofluoric acid. The degree of heat required
to fuse the dusted ground depends upon the proportion of resin in the
mixture, but a moderate heat suffices in all cases, generally about one
hundred and fifty degrees of Fahrenheit. The glass is then subjected
to the action of the acid, and when sufficiently bitten to produce the
tint next in gradation to the full colour of the glass, the acid is thrown
off. The stencil plate corresponding to the second gradation of the tint
required is then applied to the glass and a second ground laid. Hydro-
fluoric acid is then applied as before, and a second gradation of tint is
produced, and in like manner the other tints are obtained, the lights,
when such are to be given to the design, being obtained last by the
biting of the acid down to the clear glass. It will be understood
that by superimposing one color on another by the fusing of two
pieces of colored glass together, and also by tinting the glass on
-opposite sides with different colors, a variety of effects may be produced
in connection with the use of this Invention.
Having now set forth the nature and object of our Invention, and
explained the manner of carrying the same into effect, we wish it to be
understood that under the above in part recited Letters Patent' wo
claim producing, ornamental designs or patterns upon colored glass by
the use of stencil plates, as above described.
In witness whereof, I, the said Emmanuel Barthélemy, have
hereunto set my hand and seal, the Twenty-fourth day of
May, in the year of our Lord One thousand eight hundred and
fifty-four.
Witness,
FRED. WALKDEN,
66, Chancery Lane.
E. BARTHÉLEMY. (L.S.)