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.

The southern lancet represents the Passion of Christ.  Granting to Viollet-le-Duc that the unbroken vertical colour-scheme of the Tree of Jesse made the more effective window, one might still ask whether the medallion-scheme is not the more interesting.  Once past the workshop, there can be no question about it; the Tree of Jesse has the least interest of all the three windows.  A genealogical tree has little value, artistic or other, except to those who belong in its branches, and the Tree of Jesse was put there, not to please us, but to please the Virgin.  The Passion window was also put there to please her, but it tells a story, and does it in a way that has more novelty than the subject.  The draughtsman who chalked out the design on the whitened table that served for his sketch-board was either a Greek, or had before him a Byzantine missal, or enamel or ivory.  The first medallion on these legendary windows is the lower left-hand one, which begins the story or legend; here it represents Christ after the manner of the Greek Church.  In the next medallion is the Last Supper; the fish on the dish is Greek.  In the middle of the window, with the help of the binocle, you will see a Crucifixion,