The PERPENDICULAR period extended from 1380, or thereabout, well into the sixteenth century. Its salient features were the use of fan-vaulting, four-centred arches, and tracery of predominantly vertical and horizontal lines. The tardy introduction of Renaissance forms finally put an end to the Gothic style in England, after a long period of mixed and transitional architecture. [Illustration: FIG. 129.--RIBBED VAULTING, CHOIR OF EXETER CATHEDRAL.] +VAULTING.+ The richness and variety of English vaulting contrast strikingly with the persistent uniformity of the French. A few of the early Gothic vaults, as in the aisles of Peterborough, and later the naves of Durham, Salisbury, and Gloucester, were simple four-part, ribbed vaults substantially like the French. But the English disliked and avoided the twisted and dome-like surfaces of the French vaults, preferring horizontal ridges, and, in the filling-masonry, straight courses meeting at the ridge in zigzag lines, as in southwest France (see p. 200). This may be seen in Westminster Abbey. The idea of ribbed construction was then seized upon and given a new application. By springing a large number of ribs from each point of support, the vaulting-surfaces were divided into long, narrow, triangles, the filling of which was comparatively easy (Fig. 129). The ridge was itself furnished with a straight rib, decorated with carved rosettes or _bosses_ at each intersection with a vaulting-rib. The naves and choirs of Lincoln, Lichfield, Exeter, and the nave of Westminster illustrate this method. The logical corollary of this practice was the introduction of minor ribs called _liernes_, connecting the main ribs and forming complex reticulated and star-shaped patterns. Vaults of this description are among the most beautiful in England. One of the richest is in the choir of Gloucester (1337-1377). Less correct constructively is that over the choir of Wells, while the choir of Ely, the nave of Tewkesbury Abbey (Fig. 130), and all the vaulting of Winchester as rebuilt by William of Wykeham (1390), illustrate the same system. Such vaults are called _lierne_ or _star_ vaults. [Illustration: FIG. 130.--NET OR LIERNE VAULTING, TEWKESBURY ABBEY.]