A singular feature of the church, which would have been more apparent had it been finished, is that the choir is almost cut off by a solid wall from what would have been the other divisions of the structure. Fig. 1084 shows the wall as seen from the outside. The openings into the side aisles are about 4 feet 3 inches wide and about 11 feet high, and the opening on the ground level into the central aisle is about 7 feet wide. These three openings are all covered with straight arches. Above the central opening there is a lofty aperture like a window covered with a pointed arch, probably meant to contain the rood. Above the caps of the jambs of the side openings there are two carved figures (Fig. 1085), that on the north being St. Sebastian, and that on the south St. Christopher. Beyond the east end of the church and on a lower level, so as to suit the slope of the ground (Fig. 1086), a chapel has been erected, which is reached from the south aisle by a straight stair of twenty-five steps. This chapel measures 36 feet in length from east to west by 14 feet wide. It is barrel vaulted (Fig. 1087), and is lighted by one window only, at the east end. The window is a simple pointed one, without tracery. There are several ambries in the walls, and an eastern altar with a piscina. There are also a fireplace and a small closet about 11 feet square on the north side. A door leads out on the south to what has been an open court, where there are indications of other buildings having existed or been intended. It would thus appear that in all probability [Illustration: FIG. 1084.--The Collegiate Church of Rosslyn. West End of Choir and East Wall of Transepts.] there was a residence here, and the chapel may have served both as sacristy and private chapel. This chapel or sacristy is supposed to have been built in the lifetime of Sir William St. Clair’s first wife, Lady Elizabeth or Margaret Douglas, daughter of Archibald, fourth Earl of Douglass, and first Duke of Touraine, from the circumstance that her arms (Fig. 1088) are sculptured on the east wall. The shield has two coats impaled: _Dexter_, a coat quarterly, dimidiated, viz.--First a galley within a double tressure, flory counter [Illustration: FIG. 1085.--The Collegiate Church of Rosslyn. Caps of Openings to Choir.] flory, for Orkney; 3rd a cross engrailed for St. Clair, being the 1st and 3rd quarters of the arms of the Earl of Orkney; _Sinister_, in base a heart, and on a chief three mullets, for Douglas, the shield being surmounted of a fess charged with three fleurs-de-lys (2 and 1) for Touraine. Lady Elizabeth died in 1452. The barrel vault of the sacristy (see Fig. 1087) is semicircular, and supports a flat roof formed with overlapping stones. The vault is strengthened with transverse ribs carved with the engrailed cross, which spring from corbels sculptured with figures of angels and saints (Fig. 1089).