aisle, which in each case has a central pillar in the east arcade, and in each edifice a series of chapels beyond this aisle forms the east end. The details are, as is natural, seeing that the buildings are about two centuries apart in date, entirely different, but it is curious to observe how in both cases even the minute parts of the design are remarkably alike. Thus the triple niche over the central pillar of the east arcade at Glasgow finds a counterpart in the same position at Rosslyn (see Fig. 1078). The east wall and gable of both choirs occupy the same relative position, rising above the eastern aisle and chapels. Churches with an eastern aisle are not unknown in England, such as Abbey Dore, Herefordshire, and Romsey Abbey, Hampshire; but the former has three openings in the east end, thus showing an arch in the centre; while Romsey Church, Glasgow Cathedral, and Rosslyn Church have the peculiarity of having a pillar in the centre of the east arcade. Much has been made of the resemblance between the barrel vaults of Rosslyn and those of the south of France, but there does not appear to be any connection between them. The pointed barrel vault was the form commonly practised in Scotland in the fifteenth century, both in churches and castles. Mr Fergusson says that this kind of vault is “foreign and unlike the usual form of vaults found in Scotland,” but the examples given in this book show that he is mistaken. Pointed barrel vaults are to be found in the churches at Seton, Queensferry, Ladykirk, Whitekirk, Borthwick, Crichton, Corstorphine, Dunglass, and many others, and numerous examples might be given from the castles. There can, therefore, be no doubt that the masons of Scotland were at this period quite familiar with that system of vaulting, some of which, such as the vaults of Borthwick Castle, in the same district and built a little earlier than Rosslyn, are of considerably larger dimensions. The pointed barrel vaults of castle halls and churches are generally covered with sloping stone roofs, as at Bothwell, Borthwick, &c., but at Rosslyn the curved form of the roof has been adhered to, externally as well as internally. The coping of the east gable has been finished to this curve (see Fig. 1077), and there is no indication of any straight roof having been intended. It is possible, however, that it had been originally contemplated to cover the extrados of the choir vault, which still remains unprotected, with an outer stone roof, in accordance with the usual practice; but, owing to the slightness of the clerestory walls, the outer stone roof was omitted in consequence of its great additional weight, which, it may have been believed, would be too great for the side walls to sustain. The roofs of the aisles and east chapels, which are almost flat, are covered with overlapping flags. Until the building was restored some thirty years ago, these parts of the building were