Читать книгу Stained Glass Work: A text-book for students and workers in glass - Christopher Whall - Страница 3
ОглавлениеCHAPTER I
INTRODUCTORY, AND CONCERNING THE RAW MATERIAL
You are to know that stained glass means pieces of coloured glasses put together with strips of lead into the form of windows; not a picture painted on glass with coloured paints.
You know that a beer bottle is blackish, a hock bottle orange-brown, a soda-water bottle greenish-white—these are the colours of the whole substance of which they are respectively made.
Break such a bottle, each little bit is still a bit of coloured glass. So, also, blue is used for poison bottles, deep green and deep red for certain wine glasses, and, indeed, almost all colours for one purpose or another.
Now these are the same glass, and coloured in the same way as that used for church windows.
Such coloured glasses are cut into the shapes of faces, or figures, or robes, or canopies, or whatever you want and whatever the subject demands; then features are painted on the faces, folds on the robes, and so forth—not with colour, merely with brown shading; then, when this shading has been burnt into the glass in a kiln, the pieces are put together into a picture by means of grooved strips of lead, into which they fit.
This book, it is hoped, will set forth plainly how these things are done, for the benefit of those who do not know; and, for the benefit of those who do know, it will examine and discuss the right principles on which windows should be made, and the rules of good taste and of imagination, which make such a difference between beautiful and vulgar art; for you may know intimately all the processes I have spoken of, and be skilful in them, and yet misapply them, so that your window had better never have been made.
Skill is good if you use it wisely and for good end; but craft of hand employed foolishly is no more use to you than swiftness of foot would be upon the broad road leading downwards—the cripple is happier.
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.
CHAPTER II
Cutting (elementary)—The Diamond—The Wheel—Sharpening—How to Cut—Amount of Force— The Beginner's Mistake—Tapping—Possible and Impossible Cuts—"Grozeing"—Defects of the Wheel—The Actual Nature of a "Cut" in Glass.
No written directions can teach the use of the diamond; it is as sensitive to the hand as the string of a violin, and a good workman feels with a most delicate touch exactly where the cutting edge is, and uses his tool accordingly. Every apprentice counts on spoiling a guinea diamond in the learning, which will take him from one to two years.
Most cutters now use the wheel, of which illustrations are given (figs. 1 and 2).
Figs. 1 and 2.
The wheels themselves are good things, and cut as well as the diamond, in some respects almost better; but many of the handles are very unsatisfactory. From some of them indeed one might suppose, if such a thing were conceivable, that the maker knew nothing of the use of the tool.
For it is held thus (fig. 5), the pressure of the forefinger both guiding the cut and supplying force for it: and they give you an edge to press on (fig. 1) instead of a surface! In some other patterns, indeed, they do give you the desired surface, but the tool is so thin that there is nothing to grip. What ought to be done is to reproduce the shape of the old wooden handle of the diamond proper (figs. 3 and 4).
Figs. 3 and 4.
The foregoing passage must, however, be amplified and modified, but this I will do further on, for you will understand the reasons better if I insert it after what I had written further with regard to the cutting of glass.
How to Sharpen the Wheel Cutter.—The right way to do this is difficult to describe in writing. You must, first of all, grind down the "shoulders" of the tool, through which the pivot of the wheel goes, for they are made so large that the wheel cannot reach the stone (fig. 6), and must be reduced (fig. 7). Then, after first oiling the pivot so that the wheel may run easily, you must hold the tool as shown in fig. 8, and rub it swiftly up and down the stone. The angle at which the wheel should rest on the stone is shown in fig. 9. You will see that the angle at which the wheel meets the stone is a little blunter than the angle of the side of the wheel itself. You do not want to make the tool too sharp, otherwise you will risk breaking down the edge, when the wheel will cease to be truly circular, and when that occurs it is absolutely useless. The same thing will happen if the wheel is checked in its revolution while sharpening, and therefore the pivot must be kept oiled both for cutting and sharpening.
Fig. 5.
It is a curious fact to notice that the tool, be it wheel or diamond, that is too sharp is not, in practice, found to make so good a cut as one that is less sharp; it scratches the glass and throws up a line of splinters.
Figs. 6 and 7.
Fig. 8.
How to Cut Glass.—Hold the cutter as shown in the illustration (fig. 5), a little sloping towards you, but perfectly upright laterally; draw it towards you, hard enough to make it just bite the glass. If it leaves a mark you can hardly see it is a good cut (fig. 10b), but if it scratches a white line, throwing up glass-dust as it goes, either the tool is faulty, or you are pressing too hard, or you are applying the pressure to the wheel unevenly and at an angle to the direction of the cut (fig. 10a). Not that you can make the wheel move sideways in the cut actually; it will keep itself straight as a ploughshare keeps in its furrow, but it will press sideways, and so break down the edges of the furrow, while if you exaggerate this enough it will actually leave the furrow, and, ceasing to cut, will "skid" aside over the glass. As to pressure, all cutters begin by pressing much too hard; the tool having started biting, it should be kept only just biting while drawn along. The cut should be almost noiseless. You think you're not cutting because you don't hear it grate, but hold the glass sideways to the light and you will see the silver line quite continuous.
Having made your cut, take the glass up; hold it as in fig. 11, press downward with the thumbs and upward with the fingers, and the glass will come apart.
Fig. 9.
Fig. 10, a and b
Fig. 11.
But you want to cut shaped pieces as well as straight. You cannot break these directly the cut is made, but, holding the glass as in fig. 12, and pressing it firmly with the left thumb, jerk the tool up by little, sharp jerks of the fingers only, so as to tap along the underside of your cut. You will see a little silver line spring along the cut, showing that the glass is dividing; and when that silver line has sprung from end to end, a gentle pressure will bring the glass apart.
