RECTILINEAR, 1360-1550 [Illustration: PLATE VIII] PLATE IX PERPENDICULAR [Illustration: PLATE IX] PLATES VIII AND IX PERPENDICULAR, 1377-1547 RECTILINEAR, 1360-1550 The term “perpendicular” was applied to the work of this period, the last of English Gothic, on account of the predominance of vertical lines in the whole architectural design, and especially in window tracery. A comparison of Plate VII., Fig. 5, net tracery, with Plate IX., Fig. 5, rectilinear, will explain how the latter was developed from the former by extending the sides of the _meshes_ of the _net_ by straight lines into the summit of the window. But as the term _perpendicular_ is only a _relative_ one, not necessarily meaning vertical, the term _rectilinear_ was substituted, being descriptive of the general character of the whole design in mass and detail. In this work, however, the term “perpendicular” is preferred as the one most generally known. Windows became so large, chiefly for the display of stained glass, as to reduce the wall spaces between them to little more than piers, and _transoms_ (horizontal mullions) had to be introduced to strengthen the vertical _mullions_. [See Plate IX., Figs, 1 and 2 (a.b.), belfry windows in these examples.] Loftiness is a special trait of the Perpendicular period. Walls were carried to a greater height than previously. The external roof was frequently covered with lead, and inclined at an angle easy to walk upon. The roof-timbers were supported by ornamental principals exposed to view from the interior, or there was a stone-vaulted internal roof of rich design, the increased thrusts upon the walls being counteracted by larger buttresses. Tall towers were built, such as those of York Minster, Gloucester, Worcester, and the churches of Boston (Lincolnshire), Wrexham, Taunton, and many others of magnificence. Plate IX., Figs. 1 and 3, give varieties of smaller parish church towers. In these the Tudor arch and square-headed window are shown. Spires are not so common as in the preceding periods. _Buttresses_ were placed _diagonally_ at all corners, scientifically the best position (Plate IX., Figs, 1 and 2). In large churches external wall surfaces were enriched with panelling, covering in some cases the whole from ground to summit, and combined with open tracery in the battlements. In the interior the same kind of decoration prevailed, and in some cases the window tracery was carried below the glass down to the floor as panelling. Plate IX., Figs. 4A and 4B, gives the comparative shape of _battlements_.