IMPROVEMENTS IN THE MANU- FACTURE OF DECORATIVE TRANSPARENCIES FOR ORNAMENTING WINDOWS,
Year: 1882

page_text: LETTERS PATENT to James Mitchell, of 191, Rue du Temple, Paris, in the
Republic of France, for an Invention of "IMPROVEMENTS IN THE MANU-
FACTURE OF DECORATIVE TRANSPARENCIES FOR ORNAMENTING WINDOWS,
COMPLETE SPECIFICATION filed by the said James Mitchell at the Office
of the Commissioners of Patents on the 16th May 1882.
JAMES MITCHELL of 191 Rue du Temple, Paris in the Republic of France.
"IMPROVEMENTS IN THE MANUFACTURE OF DECORATIVE TRANSPARENCIES FOR
ORNAMENTING WINDOWS, SCREENS, BLINDS, LANTERNS, AND OTHER OBJECTS."
The material which I employ is thin sheet gelatine of different colors or else thin
sheets of the transparent variety of one or other of the nitrocellulose products
which are sold under the names of celluloid, xylonite, &c. I limit my use of those
materials for glazing to that style wherein small pieces are joined together
according to any given pattern, thereby imitating as to appearance the colored and
leaded window glazing which has hitherto been made of glass, not thereby how-
ever, restricting myself to the use of plain colored pieces, but in certain cases
painting upon the said pieces, or printing thereupon in colors as in chromolitho-
graphy.
I reproduce whatever pattern is to be represented by the arrangement of the
individual pieces or "quarries" by shaping into the forms required therefor the
said pieces, precisely as is done in making ordinary leaded window glazing and
thereafter joining them together according to the pattern. The above mentioned
materials as regards consistence being like isinglass, are easily shaped by scissors,
knife, cutting stamp or other instrument. But on account of their flexibility as
well as for other reasons, the joining together of the individual pieces or "quarries
requires to be effected by special means, the leaden strips used in colored glass
glazing not being suitable."
"3
The means which I prefer are the following-Having at hand the piece or
quarries" necessary for any particular work, I lay them out according to the

page_text: pattern on one or more sheets of paper whereon the said pattern has been distinctly
delineated and there retain them by means of pieces of lead acting as weights.
I then bind them together by attaching with paste, gum, or glue, strips of dark colored
paper over the lines of junction in such a way as equally to overlap the margins of
the pieces on either side of the said lines, removing as I proceed the leaden weights
to permit of the application of the strips. The junctions are thus concealed by
bands which, when seen from some little distance, resemble the leaden work of
colored glass glazing. As regards color and width, the strips may be whatever
is thought best to imitate lead, and in order to make the imitation more complete,
the said strips may be covered with lead or tin foil.
One side of the work having been so far completed, the reverse is now to be
treated in the same manner unless it be found that sufficient stability is obtained
from the treatment of one side only. As soon as the strips are dry, the work is to
be cleaned on both sides and then carefully varnished, gelatine work being the
better for a double coating. The strips wherewith the individual pieces are joined
together need not be of paper as skin, leather, ribbon, tape, or metal foil might be
used. Entirely different means of construction might also be employed such as
fixing by binding, rivetting, gluing, or inserting the pieces or quarries to frames of
metal, wood, rattan, &c., but the above described method being easy of execution
and inexpensive, is preferable.
When set up vertically in the position it is to occupy against panes of glass or
otherwise, this kind of work to which I give the name of "chromophane" being
flexible, requires to be supported. A second pane of glass makes the best support,
the work in that case being enclosed between two panes of glass. There are cases
wherein the weight of the second pane is objectionable; in such the requisite
support may be in the shape of a frame of wire or metal work, said frame being
accurately adjusted over certain of the strips which cover the lines of junction and
attached thereto by string, fine wire, or other means and maintained in contact
with the pane by a wooden or other beading made fast to the bars of the sash.
Colored paper when treated in the manner above described for sheet gelatine
and celluloid, gives results which differ only from the above chromophane in
deficiency of transparency and I therefore use paper for a lower class of products.
All work constructed of separate pieces of thin gelatine or thin transparent
nitrocellulose material or paper arranged according to pattern and held together by
one or other of the means which I have mentioned so as to imitate colored and
leaded window glazing I claim to be my Invention "chromophane."
Having described the nature of my Invention and the manner of performing the
same, I declare that what I claim as new and desire to secure by Letters Patent is.
The manufacture of decorative transparencies for ornamenting windows, screens,
blinds, lanterns, and other objects substantially as herein specified.
In witness whereof I the said James Mitchell have hereunto set my hand
and seal this Fifteenth day of May. A.D. 1882.
J. MITCHELL. (L.S.)