A. The chief characteristic in the windows of this style, and which renders them easily distinguished from those of an earlier era, consists in the vertical bearing of the mullions, which, instead of diverging off in flowing lines, are carried straight up into the head of the window; smaller mullions spring from the heads of the principal lights, and thus the upper portion of the window is filled with panel-like compartments. The principal as well as the subordinate lights are foliated in the heads; and in large windows the lights are often divided horizontally by transoms, which are sometimes embattled. From the continued upright position of the mullions and tracery-bars is derived the term PERPENDICULAR, as applied to this style. The forms of the window-arches vary from the simple pointed to the complex four-centred arch, more or less depressed. The windows of the clerestory are sometimes arched, but oftener square-headed; and some large windows of the latter description nearly cover the sides of the clerestory walls of Chipping Norton Church, Oxfordshire. Q. What do we frequently observe in buildings of this style? A. The interior walls of churches are often completely covered with panel-work tracery, arched headed and foliated, from the clerestory windows down to the mouldings of the arches below. The walls of Sherborne Church, Dorsetshire, present in the interior a surface almost entirely covered with panel-work. Several large churches in this style have also long ranges of clerestory windows, set so close to each other that the whole length of the clerestory wall seems perforated: we may enumerate as examples the churches of St. Michael, Coventry; Stratford-upon-Avon, Warwickshire; and Lavenham and Melford, Suffolk. Walls covered on the exterior with panel-work are also far from uncommon: the Abbots’ Tower, Evesham, the tower of the church of St. Neot’s, Huntingdonshire, and of Wrexham, Denbighshire, and many other rich towers, (especially those of the churches in Somersetshire, where rich specimens in this style abound, more so perhaps than in any other county,) are thus decorated. The exterior of many rich structures in this style are also covered with panel-work, as the Beauchamp Chapel, Warwick, the west front of Winchester Cathedral, and Henry the Seventh’s Chapel, Westminster Abbey. [Illustration: Parapet, St. Peter’s Church, Oxford.] Q. How are the vaulted roofs of this style distinguished?