IMPROVEMENTS IN COLORED-GLASS WINDOWS
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by William Morgan-Brown at the Office
of the Commissioners of Patents on the 10th June 1880. A communication
from abroad by John La Farge, of Newport, Rhode Island, United States of
America, Artist.
WILLIAM MORGAN-BROWN, of the Firm of Brandon and Morgan-Brown,
Engineers and Patent Agents, of 38, Southampton Buildings, London, and 1, Rue
Laffitte, Paris. "IMPROVEMENTS IN COLORED-GLASS WINDOWS." [A communication
from abroad by John La Farge, of Newport, Rhode Island, United States of
America, Artist.]
This Invention relates to improvements in colored glass windows.
The object of the Invention is to obtain what may be termed opalescent and
iridescent effects in glass windows, to ensure translucency of the glass used therein
and lessen transparency, which is a great fault in ordinary stained or colored glass
windows, the translucency of the class of glass employed by me softening the
light, and by reason of its unevenness of structure and formation, the direct
passage of rays of light and the tendency of the said rays to focus are prevented.
By this Invention glass windows possessing the advantageous qualities herein-
before referred to may be made at less cost than by the use of a good quality of
stained or colored glass.
The colors and effects of light produced in accordance with this discovery and
improvements are greater than can be gained in any way known to me, but some
of the same effects might be secured by the employment of thin sheets of
mother-of-pearl or thin lamince of precious stones, such as onyx and alabaster,
which substances I am informed have been employed in rare instances in other
countries.
Both as architect and artist the communicant has aimed to overcome the objections
commonly urged against colored glass windows and to give to them new qualities
and properties of a pleasing nature, to thereby increase the use of colored glass
windows and give additional variety and beauty to public edifices and private
dwellings, and by experiment he has discovered that opalescent and iridescent
effects may in an eminent degree be obtained for windows by the employment of
that class of glass known as opal glass," it being commonly used for table ware
and fancy articles, such as boxes, but never for windows. This opal glass, in its
customary form, is of a dead white color, and in appearance resembles porcelain, for
which it is employed as a substitute.
"
Opal glass, as at present improved and refined and employed in articles for table
use and boxes, is not, for use in windows, as desirable and pleasing as to its effects
of color as the more transparent quality which was first made.
Opal glass will be more or less opaque or milky in parts, according to the
proportion of the insoluble mass deposited or contained in it. This effect may be

page_text: produced by the use of any materials well known to those skilled in the arts of
glass making, and is usually produced with phosphate of lime or bone ashes mixed
with the usual sand and potash, together with salt, slaked lime, and powdered or
broken glass, either one or more of them if desired or necessary, and with either
one or more of the following materials-Arsenic, peroxide of tin or stannic acid,
antimonic acid, and silver, as is well known to those skilled in said art. These
materials give a white precipitate, consequently a glass of a milky or yellowish
white. By regulating the quantities of these materials the glass may be made
more or less translucent or absolutely opaque, but the latter would not answer for
the purpose of this Invention. By regulating the quantities of the materials above
described it is possible to produce opal glass with a greater or less degree of
translucency, and thus check or graduate the amount of light in this way, to gain
effects as to depth, softness, and modulation of color, which have not been before
gained by the use of colored glass alone, and windows made in accordance with
this Invention may, by the use of opal or translucent and colored glass, be made
to show a variety of shades of color not before gained by transparent glass.
By varying the degree of translucency of any portion of the glass by any of the
ways herein described, it is obvious that great advantages are gained as to realistic
representations of natural objects, as, for instance, the clouding of a blue sky with
more or less intensity of white cloud.
The opalescent and iridescent effects may be enhanced by the greater or less
smoothness of one or both surfaces of the opalescent glass, and by its thickness, and
the glass may be waved, corrugated, or roughened in molds, or be hammered or
rolled, or be stamped or treated to accord with the design or surface finish required
for the glass. This operation may be performed while the glass, in a heated state,
is supported on a suitable bed, as is well understood by workers in glass.
In order to secure other effects of light and color than those so far referred to,
and to retain the advantages due to moderate translucency, and enhance both depth
and quality of color, it has been found by experiment that colored glass may be
taken of either the most common class of window glass, if the item of cost is
essential, or any better class of colored glass at hand may be taken, and either
plate or roll upon it or mix with it in molton state the opal glass compound
hereinbefore described, the coloring being any which can be formed in glass by any
of the usual methods carried on in its manufacture; and it is also obvious, instead
of employing the opal glass as a coating or mixture for the colored glass in its
heated or molten state, that there may be added to the said molten glass the
component parts of which the opal glass compound is formed, or vice versa.
In some instances it is very advantageous to back colored glass of ordinary
construction with independent pieces of opal glass, one or more layers of either
being used, according to the effect desired.
On a cloudy or dark day a window containing opal glass shows such a quantity
of color and appears as if lighted by the sun. In the day time this opal glass
window seen from outside in variety of color resembles mosaic work, and presents a
highly ornamental effect, while ordinary colored glass windows are not ornamental.
Under artificial lights in buildings ordinary colored glass windows become very
dark at the interior of the apartment of which they form a part, which, for
dwelling houses, is very unpleasant in appearance, and this dark appearance can be
obviated only by the use of curtains, shades, or hangings; but by the use of the
opal glass in the windows they will not appear dark under artificial illumination of
the interior of the apartment, but, on the contrary, will appear of light color.
I desire it to be understood that I lay no claim to any improvement in the art
of glass making, either in translucent, opal, or colored glass.