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.