Rouen. Fifteenth century

244 48. Angel's Head, from Great Rose Window in north transept of St. Ouen's, Rouen. Fifteenth century 248 49. Angel's Head, from Great Rose Window in north transept of St. Ouen's, Rouen. Fifteenth century 256 50. The Prophets Joel, Zephaniah, Amos, and Hosea, from the north aisle of the nave, Fairford. Late fifteenth century 260

I
THE MAKING OF A WINDOW

I
THE MAKING OF A WINDOW

The making of stained-glass windows is one of the arts which belong wholly to the Christian Era. Its traditions do not extend back beyond the great times of Gothic architecture, and it is to the work of those times that the student must turn, as the student of sculpture and architecture turns to that of the ancient world, to learn the basic principles of the art.

In the Middle Ages stained glass formed an important part, but still only a part, of that interior colour decoration without which no church was considered complete; but in spite of its fragile nature it has on the whole survived the attacks of time, the fury of the Puritan, the apathy and neglect of the eighteenth century, and the sinister energies of the nineteenth-century restorer better than the painting which once adorned the walls and woodwork, and for this reason has come to be considered in these days as peculiarly appropriate to churches. So much so, indeed, that whereas I have sometimes found in country parishes a certain amount of opposition to any attempt to revive wall-painting as savouring of popery, no such feeling seems to exist with regard to coloured windows.

The process.

Stained glass is not one of the arts in which the method of production reveals itself at the first glance. Indeed, so few people when looking at a stained-glass window, whether a gorgeous and solemn one of the thirteenth or fifteenth century, or a crude and vulgar one of the nineteenth, realize the long and laborious process by which the result, good or bad, has been obtained, that a short description of that process as finally perfected some five hundred years ago may not be out of place here.

One hears it so often spoken of as "painted glass"—Mr. Westlake calls his book A History of Design in Painted Glass—that it is not surprising that there should be a good deal of misconception on the point. It must be clearly understood then that the colour effects which are the glory of the art are not directly produced by painting at all, but by the window being built up of a multitude of small pieces of white and coloured glass—glass, that is, coloured in the making, and of which the artist must choose the exact shades he needs, cut them out to shape, and fit them together to form his design, using a separate piece for every colour or shade of colour.

In twelfth and thirteenth century windows many of these pieces are only half an inch wide and from one to two inches long, and few are bigger than the palm of one's hand; so the reader can amuse himself, if he wishes, in trying to calculate the number of pieces in one of the huge windows of this date in the Cathedral of Canterbury, York, or Chartres, and the labour involved in this, the initial stage of the process.

When the window is finished these pieces are put together like a puzzle and joined by grooved strips of lead soldered at the joints, just as any "lattice" window is put together (and until glass was made in large pieces this was the only way of filling a window); but before this is done the details of the design—features, folds of drapery, patterns, and so on—are painted on the glass in an opaque brownish enamel made of oxide of iron and other metals ground up with a "soft" glass (i.e. glass with a low melting-point). This is mixed with oil or gum and water in order to apply it, and then the glass is placed in a kiln and "fired" till the enamel is fused on and, if well fired, becomes part of the glass itself. This is the only "painting" involved in the production of a stained-glass window, and its effect, in the hand of an artist, besides enabling him to express more than could be done merely with glass and lead, is to decorate and enrich what would otherwise be somewhat crude and papery in effect.

The two parts of the process.

The process thus consists of two parts. The cutting and putting together of the glass is called glazing, and it is this that gives the window colour; while the enamel work is spoken of as painting, and gives detail, richness, and texture.

I shall presently show that the glazing and painting are really two separate crafts, having separate origins and development, and that stained glass as we know it, or as it should be called in strict accuracy "stained-and-painted" glass, is the product of their union.

There is another method, far inferior in the beauty of its results, by which pictures can be produced in glass, which is to paint on white glass with transparent coloured enamels. As, however, this method was not used till the seventeenth century, and is now once more almost wholly abandoned, it does not concern us here.

The softness of lead which makes it the only practicable metal for joining pieces of glass of complicated shapes, has the disadvantage that a stained-glass window when leaded up has a considerable degree of flexibility, and, if held by the edges alone, would be quite unable to resist the pressure of the wind, which on a big window is enormous,—think of the power even of a fresh breeze on a boat's sail.

The iron-work.

It would not even be able to support its own weight for long, and so it follows that it must be held up by a system of short metal bars fixed firmly into the stone-work. Naturally the design of the window must be so arranged that these bars either do not interfere with it or form an integral part of it. In early windows, especially those of the twelfth and thirteenth centuries and even to some extent in those of the fourteenth, the bars are sufficiently important to form the governing factor in the design.

It must not be thought that stained glass loses in beauty by the presence of these black lines of lead and iron. On the contrary it gains enormously. Large pieces of unrelieved colour in windows are thin in effect and trying to the eye, which needs the continual contrast of the solid black of the lead all over the window to enable it to appreciate the colour and brilliance of the glass. The painting when rightly used is directed to the same end, for it may be said that the smaller and more divided the spaces of clear glass, the more brilliant and jewel-like is the effect.

Silver stain.

To the rule that a separate piece of glass must be used for every change