An Improved Method of Producing Marbled Glass.
Year: 1892

page_text: Date of Application, 25th Apr., 1892-Accepted, 28th May, 1892
COMPLETE SPECIFICATION.
An Improved Method of Producing Marbled Glass.
I, CARL FRANZ EMIL GROSSE, of 18 Schiffbauerdamm, Berlin, in the German
Empire, Merchant and Manufacturer, 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 :-
Marbled glass has hitherto only been produced in smelting. The various
colours required make this process very difficult and expensive thus limiting its
application.
Therefore this kind of glass is only used in the manufacture of high class
hollow glass while it is not used for cheap hollow glass ware or as sheet glass, thus
excluding in the latter case its application, for instance to the decoration of walls
and ceilings.
The object of this invention is to overcome these disadvantages and to produce
glass which shall equal in appearance marble and other stones.
According to this invention the marbled appearance is not produced by colouring
the whole body of the glass, as at present in the smelting process, but by colouring
its surface, while the body may be of any colour.
The marble structure is produced for cheap hollow ware by the glass blower in
the course of his work.
As a ground colour any colour may be used but preferably an addled or
opaque colour. This glass is manufactured as sheet glass in a furnace, or placed
on the pipe as usual and worked through the different stages into the various forms
required.
When the blower has brought the last charge to the pipe and has worked the
mass regularly, a finely pulverised glass flux is irregularly incorporated with it by
being either blown on the fluid mass by means of a blower, or spread by means of
a sieve, or conjointly. When this has been done sufficiently the glass blower
replaces the mass which has been somewhat cooled in the meantime into the
furnace until the coloured flux on the surface of the glass has become completely
fuzed and glazed.
When this has been done the blower finishes his work as usual.
In the case of the manufacture of sheet glass the sheets are prepared and
manipulated as in the usual manner, but before the last heating the coloured flux is
distributed over the surface of the sheet by a blower or sieve and after final heating
the sheet is finished as usual.
By the various manipulations in the manufacture, the flux on the surface is
spread into the most varied and irregular forms or grain so that the result is the
production of glass having a marbled surface fully equalling in appearance marble
and other grained natural stones and even surpassing them as regards the diversity
of the nature of the grain.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
A process for the manufacture of marbled or stone grained glass consisting of
the application of pulverised coloured glass flux or other fusible coloured material
to the surface of the fluid or soft body of glass during manufacture by means of a

page_text: blowing or seiving apparatus and subsequent heating in a furnace to a state of
fusion substantially as described.
Dated this 25th day of April 1892.
FELL & WILDING,
1, Queen Victoria Street, London, E.C., Agents for the Applicant.