Mixture for Rose-Colored Glass.

Mixture for Red Glass.

Mixture for Yellow Glass

Mixture for Blue Glass.

Mixture for Green Glass.

OR

OR

OR

Mixture for Violet Glass.

OR

Mixture for Black Glass.

Mixture for Opalescent Glass.

Mixture for White Opaque Glass.

OR

OR

185. The cartoon is drawn with a stick of charcoal full size on paper strained on a frame of equal dimensions with the window opening, making a strongly defined outline and clearly indicating the lines to be leaded around each piece. The designer, before commencing to use the charcoal, prepares the paper with a coat of glue size when the picture is complete, the charcoal drawing is fixed on the sized surface, by steaming the picture all over with the steam kettle. Each separate portion of the subject is, for the glazier's benefit, numbered, before the cutting of the different pieces of glass is proceeded with. The cartoon is then laid down upon a large table, the painter lining out in color the different pieces, or, in other words, tracing the drawing with a strong white or black line about -1/ 12 inch wide.

186. Glass staining does not, by any means, consist in the mere application of coloring material to the surface of the glass, by methods similar to those employed in oil painting. The colors used are of a peculiar kind, possessing the power of vitrifying at a high temperature and fixing themselves unalterably on the glass. After the paint has been applied, the glass must be exposed to a certain heat in a furnace adapted to this purpose, the application of the vitri-fiable colors being also duly attended to. Take, for example, an ecclesiastical window. It always consists of a great number of pieces of colored glass whose various hues illuminate an ornamental pattern based on a historical or religious subject. These pieces of glass are either symmetrical or irregular, agreeing with the sentiment of the composition itself. Arranged in their proper places, they are encased in lead and united to form one complete piece. The pieces are, in turn, united by an iron framework called the arming.

187. In the successful application of this work, the science of the chemist and the skill of the glazier are invoked to assist the painter. The pigments vary in hardness according to their composition, and must always be sufficiently hard to resist the friction of solid, firm bodies with which they may come into contact; but since the surfaces of stained-glass windows are little exposed to causes harmful to the pigment, the artist is not always to exclude those pigments endowed with moderate hardness only. The pigments must offer such resistance to the chemical action of outside influences as not to be affected by air, water, sul-phureted hydrogen, or other atmospheric gases. But whether or not the pigments are acted upon by bodies with which they accidentally come into contact, expansibility is the principal quality which they must, in precise and accurate degree, possess. The expansibility of the pigment must, in the frequent changes of temperature undergone by the painted plates of glass, during and after burning, be in exact proportion to that of the glass; for, lack of this proportion must, by producing movements in the glass in opposite directions, occasion many fractures. Pigments in this respect ill suited to the glass, split and peel off the vitreous surface, but the glass, on account of its thickness and firmness, remains uninjured.