Another point should be noticed. Although the nave is in nearly all important respects of late Geometrical design—the exception being some Curvilinear windows with flowing tracery in the westernmost bays of the nave—yet the architects were not such purists as to carry out their minor work in anything but the style of their own day. Even in the choir, the architecture of which is Geometrical both in character and in date, all the minor work is developed Curvilinear—_e.g._, the great screen with its depressed ogee arches, the throne of the bishop, the sedilia. PERPENDICULAR WORK (1360-1485).—Much minor work remained to do. In the remaining years of the fourteenth century the west front, which seems to have been heeling over, was buttressed by the erection of the western screen. The west and south walks of the cloisters were added. The great east window was substituted for an earlier Geometrical one which seems to have fallen into decay. In the fifteenth century the towers were crowned with battlements and turrets, as we see them now. The upper part of the chapter-house was rebuilt. Bishop Stafford erected canopies over monuments in the Lady chapel. TUDOR WORK (1485-1519).—The Tudor work is exceptional in importance. It includes the north entrance and other late portions of the western screen, two exquisite chapels, both built by Bishop Oldham—his own chantry (St. Saviour’s) on the south side of the retro-choir, the Speke chantry (St. George’s) on the north—and in addition, Prior Sylke’s chantry in the north transept. All this work is admirable in design and execution. In Oldham’s chantry is a charming series of owls, with the scroll DAM, a rebus on his name, proceeding from the beak of each little owl. To Bishop Oldham also (1504-1519) is due the grand set of stone screens—one of the glories of the cathedral—no less than ten, which veil all the nine chapels and Prior Sylke’s chantry, and add fresh beauty to the beautiful choir.