A clear and calculating brain may be used for statesmanship or science, or merely for gambling. You, we will say, have a true eye and a cunning hand; will you use them on the passing fashion of the hour—the morbid, the trivial, the insincere—or in illustrating the eternal truths and dignities, the heroisms and sanctities of life, and its innocencies and gaieties?
This book, then, is divided into two parts, of which the intention of one is to promote and produce skilfulness of hand, and of the other to direct it to worthy ends.
The making of glass itself—of the raw material—the coloured glasses used in stained-glass windows, cannot be treated of here. What are called "Antiques" are chiefly used, and there are also special glasses representing the ideals and experiments of enthusiasts—Prior's "Early English" glass, and the somewhat similar "Norman" glass. These glasses, however, are for craftsmen of experience to use: they
require mature skill and judgment in the using; to the beginner, "Antiques" are enough for many a day to come.
How to know the Right and Wrong Sides of a Piece of "Antique" Glass.—Take up a sheet of one of these and look at it. You will notice that the two sides look different; one side has certain little depressions as if it had been pricked with a pin, sometimes also some wavy streaks. Turn it round, and, looking at the other side, you still see these things, but blurred, as if seen through water, while the surface itself on this side looks smooth; what inequalities there are being projections rather than depressions. Now the side you first looked at is the side to cut on, and the side to paint on, and it is the side placed inwards when the window is put up.
The reason is this. Glass is made into sheets by being blown into bubbles, just as a child blows soap-bubbles. If you blow a soap-bubble you will see streaks playing about in it, just like the wavy streaks you notice in the glass.
The bubble is blown, opened at the ends, and manipulated with tools while hot, until it is the shape of a drain-pipe;
then cut down one side and opened out upon a flattening-stone until the round pipe is a flat sheet; and it is this stone which gives the glass the different texture, the dimpled surface which you notice.
Some glasses are "flashed"; that is to say, a bubble is blown which is mainly composed of white glass; but, before blowing, it is also dipped into another coloured glass—red, perhaps, or blue—and the two are then blown together, so that the red or blue glass spreads out into a thin film closely united to, in fact fused on to, and completely one with, the white glass which forms the base; most "Ruby" glasses are made in this way.