| Gum-arabic | 50 |
| Sugar | 10 |
| Water | 50 |
| Oil of turpentine | 10 |
The gum, sugar, and water are first carefully combined, and then the turpentine well stirred with the mixture.
Salle’s cement for glass:—
| Muriate of lime | 2 |
| Gum-arabic | 20 |
| Water | 25 |
Not commended by Lehner, as being too soluble. To close bottles:—
| Powdered resin | 6 |
| Caustic soda | 2 |
| Water | 10 |
To be thoroughly mixed and left for several hours. Before using, stir well into it eight to nine parts of calcined plaster of Paris. This will in half-an-hour take firm hold or “set,” and is waterproof. A good filler for cracks.
The reader who desires to be perfectly informed as to glass in all its relations can obtain, by application to J. Baer, Rossmarkt, Frankfort on the Main, Germany, a catalogue which is perhaps the most extensive on the subject ever published.
Coloured or stained glass windows may be repaired or made by the following process, which has the advantage of being quite as durable as any in which the colours are burned in:—Take two panes of glass, and paint on one your pattern with fine varnish and transparent colour mixed. When dry, go over the whole, with a broad, soft brush, with a liquid mastic cement, which must be quite transparent and thin. Any transparent strong cement will serve, but it is advisable to use the mastic in all cases as a narrow border and at the edges. If you have an engraving, especially one on very soft spongy paper, take a pane of glass, cover it with a coat of varnish, and just before it dries press the engraving face down, on it. When quite dry, with a sponge slightly damped and the end of the finger, peel away all the soft paper, leaving the lines of the engraving. These may now be coloured over, with even very little skill and care. A very good effect may be produced, so that a very indifferent artist can in this way produce very tolerable pictures. Then, to better preserve this, double it with the other pane.
By painting and shading also on this second pane, as I have discovered, very beautiful and striking effects of light and shade can be developed, so that this forms, as it were, a new art by itself. This will remind the reader of the porcelain lamp-shades, which so much resemble pictures in Indian ink; but the effects of the double panes are more singular and far more varied. There may be even a third pane employed. As the materials for this art are far from expensive, and as it is extremely easy, I have no doubt that it will be extensively practised. Protecting one glass picture by another is not a new art; but I am not aware that the obtaining a series of lights by thus reduplicating the panes has been practised.