He died before his church was finished, but his nephew, Cardinal Pantaleone Ancher, continued the edifice, which was completed in 1276. Urban's successor, Clement IV, also a Frenchman, patronized the new works at Troyes. While the choir and transept were done by one generation, many a century was to pass before the westernmost bay and façade were finished. [Illustration: _St. Urbain at Troyes (1264-1276)_] In archæological circles St. Urbain is noted, Viollet-le-Duc being the first to discuss its ingenuity. As construction it is a small masterpiece, a model of elasticity, perhaps the lightest and most fragile of all Gothic edifices. To an economy in stone we owe this structural feat. Were the principle of equilibrium pushed a step farther, metal, not stone, would be required. Ground supports have been lessened, and flying buttresses attenuated to the last limit. Despite its science, St. Urbain is not doctrinaire, but immaterial and seductive. On first entering it Montalembert exclaimed, "_Quelle délicieuse église!_" The architect, Jean Langlois, here created the most elegant form of Rayonnant window tracery. At his porch appears the first French arch of double curvature, the earliest interpenetration of archivolts. We know his name because in 1267 a papal bull summoned him to account for sums advanced on the edifice, and Jean was not forthcoming, because he had disappeared in the East, crusading. The chief church at Famagusta, in Cyprus, begun in 1300--the only completed French-Gothic cathedral of the XIV century--shows such analogies with St. Urbain at Troyes that apparently Langlois' architectural influence had spread in the Orient. M. Lefèvre-Pontalis has called Troyes' lantern church inundated with light one of the most original monuments of the Middle Ages. Ten feet above the ground its walls change to opalescent glass. No grisaille is more exquisitely decorated with natural foliage outlines; set in the expanses of the opal-tinted white glass are colored medallions of extreme beauty. The lower row of lights around the choir are of this character. Above them, and almost a part of them, are the choir's upper windows--big prophets and patriarchs with the Crucifixion in the center--transition windows between legend-medallion glass, and the XIV century's single figures in a vitrine architectural frame. The arms of France, Champagne, and Navarre appear in the borders of the choir windows. The transeptal chapel to the north of the choir shows in its quatrefoils some interesting heads of men, women, and children. From the windows of the south transeptal chapel some panels were stolen, but St. Urbain's curé, Abbé Jossier, a learned enthusiast, was able, by sending photographs all over France, to trace his lost panels in a private collection, and it is to be hoped they may be returned.