Improvements in Photographic Enamel Plates, Plaques, Dishes, Window Panes, and like Articles of Decoration or Ornamentation.
Year: 1898

page_text: Date of Application, 2nd July, 1898-Accepted, 8th Oct., 1898
COMPLETE SPECIFICATION.
Improvements in Photographic Enamel Plates, Plaques, Dishes,
Window Panes, and like Articles of Decoration or Ornamentation.
I, ALPHONSE JOSEPH ANTOINE BERTHELIER, of 32, Rue Servient, Lyons,
Department of the Rhone, Republic of France, Ceramist, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement;-
-
Hitherto photographic enamels have been made on plates of enamelled copper
of somewhat high price or on plates of porcelain in very limited sizes in conse-
quence of the deformation of porcelain in baking.
The present invention has for its object an improved application of trans-
parent or coloured glass plated with enamel or with opal on one or both sides for
the production at a low price of improved photographic enamels imitating the said
enamels on porcelain but capable of being also employed for window panes and
the like.
The improved application of these enamelled or opal-plated glass plates and
the like for the imitation of enamels on porcelain is rendered possible by devitri-
fying completely or incompletely the glass forming the backing of the enamel
or opal after this enamel or opal has received its decoration by any suitable
means. This total or partial devitrification is effected by heating the plates or
the like in order to bring the enamel or the opal to the necessary temperature
to cause the vitrifiable colours forming the decorative design to impregnate them-
selves therein, after which the glass, forming the backing, having reached a point
approaching fusion is suddenly cooled by causing the fire of the furnace to fall,
and becomes devitrified without breaking by an annealing produced by a gradual
cooling during a certain number of hours, the duration of the annealing vary-
ing according to the degree of devitrification which it is desired to obtain, or
according to the season in which the operation is carried out, or according to the
thickness and the nature of the glass constituting the backing of the enamel
or opal.
This glass, devitrified in this manner, yields products resembling enamels on
porcelain plaques or plates because devitrified glass is a product which by its
molecular constitution approaches the nearest to porcelain in beauty, colour,
solidity and sonority.
It may also be pointed out that these improved enamels may he obtained at a
reduced price and also in dimensions much greater than has hitherto been the case
with enamels on plates of enamelled copper or plates of porcelain.
These improved enamelled or opal plated glass plaques are applicable for any
suitable pictures, religious subjects, views, portraits, landscapes, reproductions
of pictures, engravings, paintings or the like, plates and dishes and in general
for all the applications which it is desired to make of photographic enamels on
the said enamelled or opal plated glass plaques herein before mentioned.
In the novel application of these enamelled or opal plated glass plates for
window panes, the glass forming the backing of the enamel or opal is not sub-

page_text: jected to devitrification in order that its transparency may not be impaired. It
is sufficient to simply fire it in the ordinary manner in order to bring the enamel
or the opal to the desired temperature so that the vitrifiable colours impregnating
themselves therein become unchangeable.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The application of transparent or coloured glass plated with enamel or
opal on one or both sides for the production of photographic enamels, the decora-
tion of which may be effected by any suitable process, said enamelled or opal
plated glass after decoration being finally devitrified or not according to the
purpose to which it is to be put, that is to say whether it is intended for imita-
tions of enamels on porcelain or for window panes or the like, substantially as
herein before described.
2. As new articles of manufacture: photographic enamel plates, plaques, dishes,
window panes, and like articles of decoration or ornamentation, consisting of
transparent or coloured glass having an enamel or opal plating on one or both
sides and devitrified, or not, according to the requirements of the article, sub-
stantially as hereinbefore set forth.
Dated this 1st day of July 1898
W. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.