Both, however, are very lovely, and the more I look at them the more I admire the nameless workers who could so use red and blue--such difficult colours to combine well. For red and blue are everywhere the groundwork of the colour scheme--green, purple, brown, and yellow being only used in small quantities to relieve them. It must be remembered, too, that the artist _could never see the effect of his work till it was finished_. Nowadays the stained-glass painter can put his work together temporarily by fastening it with beeswax to a large sheet of white glass, and can work on it so; but the artist of the twelfth and thirteenth centuries, as we know from Theophilus, and as was probably the case for long after, did all his work "on the bench." The most he could do would be to hold a few pieces together in his hands up to the light, but for the rest he had to trust to his experience and training. Not quite always did he succeed. Much depended upon his getting just the right quality of blue, and sometimes this seems to have failed him. I have already noticed the rather purplish blue which is found in some of the windows at Lincoln, and this occurs again at Chartres in the central lancet of the apse, and the one next it on the north containing the big angel illustrated in Plate X. This purplish blue when interspersed with red produces at a distance the effect of a rather unpleasant mauve, making these two windows less attractive in colour than the others. This purplish blue occurs again in the north rose of Notre Dame at Paris, but there the artist has countered it by the use of a good deal of a rather sharp pale green, which completely balances it and turns the window into perhaps the most glorious of all the great rose windows of France. [Illustration: PLATE XVIII BORDER AND SHIELDS, FROM PETER DE DENE WINDOW, NORTH AISLE OF NAVE, YORK MINSTER, WITH DETAILS FROM WINDOW IN SOUTH AISLE AND SKETCH OF CLERESTORY WINDOW Fourteenth Century] [Sidenote: The apse.] Five of the seven great lancets of the clerestory of the apse are devoted to the glorification of the Virgin Mother, or perhaps one should say, to the fact of the Virgin Birth. This is what one would expect at Chartres. Not only is the church dedicated to Notre Dame, but the place in the Middle Ages was held sacred to her above all others in France. Tradition says that the Church occupies the site of a grotto in which the Druids worshipped "the Virgin that shall bear a child," of whom they had set up a wooden image, which was preserved by the Christians when the grotto became a Christian church. Certain it is that down to the Revolution a very ancient and quite black wooden statue was worshipped in the Chapel of Notre Dame Sous-terre--the ancient grotto--where it had been at all events since the days of Fulbert, who built the eleventh century Cathedral. The Sansculottes burnt it, and its place has been taken by a modern work which professes to be a copy of it.