Windows: A Book About Stained & Painted Glass. Lewis F. Day
at Monte Cassino with a whole series of windows in 1066—which fixes the date of the Norman Conquest as a period at which stained glass windows can no longer have been uncommon. The Cistercian interdict, restricting the order to the use of white glass (1134), argues something like ecclesiastical over-indulgence in rich windows before the middle of the next century.
Fragments, more or less plentiful, of the very earliest glass may still remain embedded in windows of a later period (the material was too precious not to have been carefully preserved); but archæologists appear to be agreed that no complete window of the ninth or tenth century has been preserved, and that even of the eleventh there is nothing that can quite certainly be identified. After that doctors begin to differ. But the general consensus of opinion is, that there is comparatively little that can be incontrovertibly set down even to the twelfth century. The great mass of Early Gothic Glass belongs indubitably to the thirteenth century; and when one speaks of Early Glass it is usually thirteenth century work which is meant.
The remote origin of glass, then, remains for ever lost in the mist of legendary days. There is even a fable to the effect that it dates from the building of the Tower of Babel, when God’s fire from heaven vitrified the bricks employed by its too presumptuous builders.
Coloured glass comes to us from the East; that much it is safe to conclude. From ancient Egypt, probably, the art of the glass-worker found its way to Phœnicia, thence to Greece and Rome, and so to Byzantium, Venice, and eventually France, where stained glass windows, as we know them, first occur.
It is probably to the French that Europe owes the introduction of coloured windows, a colony of Venetian glass-workers having, they say, settled at Limoges in the year 979.
Some of the earliest French glass is to be found at Chartres, Le Mans, Angers, Reims, and Châlons-sûr-Marne; and at the Musée des Arts Décoratifs, at Paris, there are some fragments of twelfth century work which may be more conveniently examined than the work in sitû. The oldest to which one can assign a definite date is that at St. Denis (1108) but its value is almost nullified by expert restoration.
In Germany the oldest date is ascribed to some small windows at Augsburg, executed, it is said, by the monks of Tegernsee about the year 1000. There is also a certain amount of twelfth century work incorporated in the later windows at Strasbourg. The oldest remains of glass in England are, in all probability, certain fragments in the nave of York Minster. The more important windows at Canterbury, Salisbury, and Lincoln are of the thirteenth century.
CHAPTER II.
THE MAKING OF A WINDOW.
Since it is proposed to approach the subject of stained glass in the first place from the workmanlike and artistic, rather than the historical or antiquarian, point of view, it may be as well to begin by explaining precisely what a stained glass window is.
It is usual to confound “stained” with “painted” glass. Literally speaking, these are two quite distinct things. Stained glass is glass which is coloured, as the phrase goes, “in the pot;” that is to say, there is mixed with the molten white glass a metallic oxide which stains it green, yellow, blue, purple, and so on, as the case may be; for which reason this self-tinted glass is called “pot-metal.” This is a term which will recur again and again. Once for all, “pot-metal” is glass in which the colour is in the glass and not painted upon it.
It goes without explanation that, each separate sheet of pot-metal glass being all of one colour, a varicoloured window can only be produced in it by breaking up the sheets and putting them together in the form of a mosaic: in fact, that is how the earliest windows were executed, and they go by the name of mosaic glass. The glass is, however, not broken up into tesseræ, but shaped according to the forms of the design. In short, those portions of it which are white have to be cut out of a sheet of white glass, those which are blue out of a sheet of blue glass, those which are yellow out of a sheet of yellow, and so on; and it is these pieces of variously tinted glass, bound together by strips of lead, just as the tesseræ of a pavement or wall picture are held in place by cement, which constitute a stained glass window. The artist is as yet not concerned in painting, but in glazing—that is to say, putting together little bits of glass, just as an inlayer does, or as a mosaic worker puts together pieces of wood, or marble, or burnt clay, or even opaque glass.
There is illustrated opposite a piece of Old Burmese incrusted decoration, a mosaic of white and coloured glass bound together by strips of metal, which, were it but clear instead of silvered at the back, would be precisely the same thing as an early mosaic window, even to the completion of the face by means of paint—of which more presently. In painted glass, on the other hand, the colour is not in the glass but upon it, more or less firmly attached to it by the action of the fire. A metallic colour which has some affinity with glass, or which is ground up with finely powdered glass, is used as a pigment, precisely as ceramic colours are used in pottery painting. The painted glass is then put into a kiln and heated to the temperature at which it is on the point of melting, whilst the colour actually does melt into it. By this means it is possible to paint a coloured picture upon a single sheet of white glass, as has been proved at Sèvres.
Strictly speaking, then, stained and painted glass are the very opposite one to the other. But in practice the two processes of glazing and painting were never kept apart. The very earliest glass was no doubt pure mosaic. It was only in our own day that the achievement (scientific rather than artistic) of a painted window of any size, independent of glazier’s work, was possible. Painting was at first always subsidiary to glazier’s work; after that, for a time, glazier and painter worked hand in hand upon equal terms; eventually the painter took precedence, and the glazier became ever more and more subservient to him. But from the twelfth to the seventeenth century there is little of what we call, rather loosely, sometimes “stained” and sometimes “painted” glass, in which there is not both staining and painting—that is to say, stained glass is used, and there is painting upon it. The difference is that in the earlier work the painting is only used to help out the stained glass, and in the later the stained glass is introduced to help the painting.
1. INCRUSTED GLASS MOSAIC, BURMESE (B. M.).
“Photo-Tint,” by James Akerman, London W. C.
That amounts, it may be thought, to much the same thing; and there does come a point where staining and painting fulfil each such an important part in the window that it is difficult to say which is the predominating partner in the concern. For the most part, however, there is no manner of doubt as to which practice was uppermost in the designer’s mind, as to the idea with which he set out, painting or glazing; and it makes all the difference in the work—the difference, for example, between a window of the thirteenth century and one of the sixteenth, a difference about which a child could scarcely make a mistake, once it had been pointed out to him.
Here perhaps it will be as well to describe, once for all, the making of a mosaic window, and the part taken in it by the glazier and the painter respectively. It will be easier then to discriminate between the two processes employed, and to discuss them each in relation to the other.
The actual construction of an early window is very much like the putting together of a puzzle. The puzzle of our childhood usually took the form of a map. It has occurred to me, therefore, to show how an artist working strictly after the manner of the thirteenth century—the period, that is to say, when painting was subsidiary to glazing—would set about putting into glass a map of modern Italy. In the first place, he would draw his map to the size required. This he would do with the utmost precision, firmly marking upon the paper (the mediæval artist would have drawn directly on his wooden bench) the boundary line of each separate patch of colour in his design. Then, according to the colour each separate province or division was to be, he would