AN IMPROVED MEANS OF PRODUCING IRIDESCENT COLORS ON GLASS
Year: 1877

page_text: LETTERS PATENT to Thomas Wilkes Webb, of the Firm of Thomas Webb
and Sons, of Stourbridge, in the County of Worcester, Glass Manufacturer,
for the Invention of "AN IMPROVED MEANS OF PRODUCING IRIDESCENT
COLORS ON GLASS."
Sealed the 26th February 1878, and dated the 29th August 1877.
PROVISIONAL SPECIFICATION left by the said Thomas Wilkes Webb at
the Office of the Commissioners of Patents on the 29th August 1877.
THOMAS WILKES WEBB, of the Firm of Thomas Webb and Sons, of Stour-
bridge, in the County of Worcester, Glass Manufacturer. "AN IMPROVED MEANS
OF PRODUCING IRIDESCENT COLORS ON GLASS."
My Invention consists substantially in exposing the surface of glass desired to be
operated upon whilst in its molten state to the vapours or fumes caused to arise from
the evaporation of tin and other metallic salts when acted upon by hydrocloric or
other acids.
I provide for the proper carrying out of the process described a muffle or closed
chamber or vessel, and it is found that the acids evolved have an affinity for the
molten surface of the glass and remain permanently attached thereto; and thus
rainbow or prismatic tints are produced upon the surface of the glass operated upon,
which are not only curious and beautiful, but when applied to articles of
merchandize (chandeliers, decanter stoppers, and the like), have a large commercial
value.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Wilkes Webb in the Great Seal Patent Office on the 28th
February 1878.
THOMAS WILKES WEBB, of the Firm of Thomas Webb and Sons, of Stour-
bridge, in the County of Worcester, Glass Manufacturer. "AN IMPROVED MEANS
OF PRODUCING IRIDESCENT COLORS ON GLASS."
My Invention consists substantially in exposing the surface of glass desired to be
operated upon whilst in its molten state to the vapours or fumes caused to arise
from the evaporation of tin and other metallic salts when acted upon by bydrocloric
or other acids, or by other means, as herein-after described.
The metallic salts I find most useful for my purpose are stannous chloride
(chloride of tin or tin salt), and a small portion of these laid on a hot plate or spoon
immediately generates a fume or steam. A muffle or closed chamber or vessel of
suitable size being provided, the glass to be operated upon, whether hollow or solid,
is blown or fashioned into form in the ordinary way of glass making, and whilst in
a hot or molten state is placed within the said closed chamber or receiver, and
whilst there is allowed by means of a suitable opening or aperture in the bottom of
the said chamber or receiver to receive the fume or steam generatet in the manner
before explained, by the metallic salts, and it is found that the acids evolved have
an affinity for the molten surface of the glass and remain permanently attached
thereto, and thus rainbow or prismatic tints are produced upon the surface of the
glass operated upon which are not only curious and beautiful, but when applied to
articles of merchandise have a large commercial value.
To give more color to the tints and to cause the iridescence to be more complete
I add to the tin salts before mentioned nitrate of barium and strontium, in small
proportions.
The closed chamber or receiver, before spoken of, may be either of metal, clay, or
composition, but I generally employ for the purpose an iron box or cylinder of suit-
able size for the glass about to be operated upon.
It should be mentioned that after the desired degree of iridescence has been pro-
duced upon the molten glass in this chamber or receiver it is conveyed to the
annealing oven in the usual manner.
My Invention is intended to be applied to all descriptions of glass, whether flint,
colored, or other kinds.
Having now described the nature of my Invention, and the manner in which the
same is or may be carried into effect, I desire it to be understood that what I claim
as the Invention to be protected by the herein-before in part recited Letters Patent
is the use or employment of the tin or metallic salts, herein-before mentioned or
referred to (or their equivalent chemical compounds), either alone or in combination
with nitrate of barium and strontium (or either of them), in the manner herein-
before described, for producing iridescent colors on glass, substantially as herein-
before set forth and described.
In witness whereof, I, the said Thomas Wilkes Webb, have hereunto set
my hand and seal, this 27th day of February, in the year of our Lord
One thousand eight hundred and seventy-eight.
THOS. WILKES WEBB. (L.S.)