Mont-Saint-Michel and Chartres

by Henry Adams

The claim may not be modest, but it is none of ours. Viollet-le-Duc must answer for his own sins, and he chose the lancet window of the Tree of Jesse for the subject of his lecture on glass in general, as the most complete and perfect example of this greatest decorative art. Once more, in following him, one is dragged, in spite of one's self, into technique, and, what is worse, into a colour world whose technique was forgotten five hundred years ago. Viollet-le-Duc tried to recover it. "After studying our best French windows," he cautiously suggests that "one might maintain," as their secret of harmony, that "the first condition for an artist in glass is to know how to manage blue. The blue is the light in windows, and light has value only by opposition." The radiating power of blue is, therefore, the starting-point, and on this matter Viollet-le-Duc has much to say which a student would need to master; but a tourist never should study, or he ceases to be a tourist; and it is enough for us if we know that, to get the value they wanted, the artists hatched their blues with lines, covered their surface with figures as though with screens, and tied their blue within its own field with narrow circlets of white or yellow, which, in their turn, were beaded to fasten the blue still more firmly in its place. We have chiefly to remember the law that blue is light:—

But also it is that luminous colour which gives value to all others. If you compose a window in which there shall be no blue, you will get a dirty or dull (blafard) or crude surface which the eye will instantly avoid; but if you put a few touches of blue among all these tones, you will immediately get striking effects if not skilfully conceived harmony. So the composition of blue glass singularly preoccupied the glassworkers of the twelfth and thirteenth centuries. If there is only one red, two yellows, two or three purples, and two or three greens at the most, there are infinite shades of blue, … and these blues are placed with a very delicate observation of the effects they should produce on other tones, and other tones on them.

Viollet-le-Duc took the window of the Tree of Jesse as his first illustration of the rule, for the reason that its blue ground is one continuous strip from top to bottom, with the subordinate red on either side, and a border uniting the whole so plainly that no one can fail to see its object or its method.

The blue tone of the principal subject [that is to say, the ground of the Tree of Jesse] has commanded the tonality of all the rest. This medium was necessary to enable the luminous splendour to display its energy. This primary condition had dictated the red ground for the prophets, and the return to the blue on reaching the outside semicircular band. To give full value both to the vigour of the red, and to the radiating transparency of the blue, the ground of the corners is put in emerald green; but then, in the corners themselves, the blue is recalled and is given an additional solidity of value by the delicate ornamentation of the squares.

This translation is very free, but one who wants to know these windows must read the whole article, and read it here in the church, the Dictionary in one hand, and binocle in the other, for the binocle is more important than the Dictionary when it reaches the complicated border which repeats in detail the colour-scheme of the centre:—

The border repeats all the tones allotted to the principal subjects, but by small fragments, so that this border, with an effect both solid and powerful, shall not enter into rivalry with the large arrangements of the central parts.

One would think this simple enough; easily tested on any illuminated manuscript, Arab, Persian, or Byzantine; verified by any Oriental rug, old or new; freely illustrated by any Chinese pattern on a Ming jar, or cloisonne vase; and offering a kind of alphabet for the shop-window of a Paris modiste. A strong red; a strong and a weak yellow; a strong and a weak purple; a strong and a weak green, are all to be tied together, given their values, and held in their places by blue. The thing seems simpler still when it appears that perspective is forbidden, and that these glass windows of the twelfth and thirteenth centuries, like Oriental rugs, imply a flat surface, a wall which must not be treated as open. The twelfth- century glassworker would sooner have worn a landscape on his back than have costumed his church with it; he would as soon have decorated his floors with painted holes as his walls. He wanted to keep the coloured window flat, like a rug hung on the wall.

The radiation of translucent colours in windows cannot be modified by the artist; all his talent consists in profiting by it, according to a given harmonic scheme on a single plane, like a rug, but not according to an effect of aerial perspective. Do what you like, a glass window never does and never can represent anything but a plane surface; its real virtues even exist only on that condition. Every attempt to present several planes to the eye is fatal to the harmony of colour, without producing any illusion in the spectator … Translucid painting can propose as its object only a design supporting as energetically as possible a harmony of colours.

Whether this law is absolute you can tell best by looking at modern glass which is mostly perspective; but, whether you like it or not, the matter of perspective does not enter into a twelfth-century window more than into a Japanese picture, and may be ignored. The decoration of the twelfth century, as far as concerns us, was intended only for one plane, and a window was another form of rug or embroidery or mosaic, hung on the wall for colour,—simple decoration to be seen as a whole. If the Tree of Jesse teaches anything at all, it is that the artist thought first of controlling his light, but he wanted to do it not in order to dim the colours; on the contrary, he toiled, like a jeweller setting diamonds and rubies, to increase their splendour. If his use of blue teaches this lesson, his use of green proves it. The outside border of the Tree of Jesse is a sort of sample which our schoolmaster Viollet-le-Duc sets, from which he requires us to study out the scheme, beginning with the treatment of light, and ending with the value of the emerald green ground in the corners.

Complicated as the border of the Tree of Jesse is, it has its mates in the borders of the two other twelfth-century windows, and a few of the thirteenth-century in the side aisles; but the southern of the three lancets shows how the artists dealt with a difficulty that upset their rule. The border of the southern window does not count as it should; something is wrong with it and a little study shows that the builder, and not the glassworker, was to blame. Owing to his miscalculation—if it was really a miscalculation—in the width of the southern tower, the builder economized six or eight inches in the southern door and lancet, which was enough to destroy the balance between the colour-values, as masses, of the south and north windows. The artist was obliged to choose whether he would sacrifice the centre or the border of his southern window, and decided that the windows could not be made to balance if he narrowed the centre, but that he must balance them by enriching the centre, and sacrificing the border. He has filled the centre with medallions as rich as he could make them, and these he has surrounded with borders, which are also enriched to the utmost; but these medallions with their borders spread across the whole window, and when you search with the binocle for the outside border, you see its pattern clearly only at the top and bottom. On the sides, at intervals of about two feet, the medallions cover and interrupt it; but this is partly corrected by making the border, where it is seen, so rich as to surpass any other in the cathedral, even that of the Tree of Jesse. Whether the artist has succeeded or not is a question for other artists—or for you, if you please—to decide; but apparently he did succeed, since no one has ever noticed the difficulty or the device.