The windows north and south of the retro-choir probably belong to this period. The roll-moulding appears on the principal curves only of the tracery; ever after it spreads over the whole of the tracery. The lower lights of these windows are lancets; the circles in the head are cusped. The chapels of St. Mary Magdalene and St. Gabriel, on either side of the Lady chapel, seem also to have been remodelled at this time; for the side windows of these two chapels have geometrical tracery earlier than that of the Lady chapel. BISHOP QUIVIL (1280-1292). And now we come to the rebuilding of the whole cathedral. In spite of the great changes that took place in Gothic architecture during the next seventy years, the original design—that of Quivil—was adhered to almost to the very last. With the exception of a few Curvilinear windows in the western bays of the nave, all the main features of the building are as they were designed in the closing years of the thirteenth century. It is, of course, this exceptional unity and harmony of design that makes Exeter what it is—one of the most satisfactory mediæval interiors in this country. In cathedrals such as Rochester and Ely a Norman nave jars on a Gothic choir; or, as at Lincoln and York, two styles of Gothic mingle and conflict. But at Exeter, looking forward from west to east, hardly anything obtrudes on the original design. In no other cathedral, except Salisbury, do we find similar unity of design; but in the design of Salisbury simplicity becomes bareness and poverty. It cannot be compared for one moment with the richness of the lovely decorated work of Exeter. Yet greater unity and harmony is gained by the way in which the battlements and pinnacles, flying-buttresses, and cresting weld together the exterior; and the high vaults the interior, as at Norwich. The adherence, too, for so long a time to Bishop Quivil’s design is interesting, because it shows that in the early years of the fourteenth century there was at Exeter, as at Beverley, Westminster, Ely, and St. Albans, a strong current in the direction of conservation of good design. Piers and vaulting and bosses and corbels and triforium and windows of the nave, built long after he was dead and gone, are all but reproductions of Quivil’s early work. Most remarkable of all, perhaps, is the adherence to Quivil’s window tracery—the rose, the lily, and the wheel. Even the great west window, one of the last works, is but Quivil’s straight-spoked wheel translated into flowing lines. [Illustration: CHOIR AND TRANSEPT.]