century a new chancel arch was inserted, north and south doorways made, sacristy built at the west end, and a porch and parvise made outside the south doorway. After it became domestic the changes before described were made in the chancel. At a later date other additions were made. (Fig. 89.) If we suppose that the west building is the original _chancel_, the original _entrance_ was in the place now occupied by the chancel arch. [Illustration: FIG. 89.--Enhallow. View.] The proportion of the inside of the nave is that of the “vesica piscis”--the width to the length as the base of an equilateral triangle to the length of two such triangles on opposite sides of that base, and the internal length of the chancel is equal to the diagonal of the square of the internal width. Barry mentions a tradition that neither rats, mice, nor cats will live on the island, which tradition agrees with the name of the island. CHAPEL AT LINTON, IN SHAPINSAY. This chapel is near the shore at the south-east part of the island. It consists of nave and chancel, and stands nearly exactly east and west. (Fig. 90.) The extreme length is 35 feet 9 inches, and the width 19 feet [Illustration: FIG. 90.--Linton Chapel. Plan and Elevations.] 5 inches. About 7 feet in height of the east end of the nave, including the arch into the chancel (Fig. 91), remains; but of the rest only about 2 feet and 3 feet remain. It is built of whinstone without any freestone dressings. The nave is 18 feet by 13 feet 7 inches inside. The walls are 3 feet thick. [Illustration: FIG. 91.--Linton Chapel. View.] The entrance is in the south wall near the west angle, differing in this point from most of the early chapels, and is 2 feet 8 inches wide with parallel unrebated jambs.[127] The upper part of the entrance is gone, but probably it was a semicircular arch. (Fig. 92.) Nothing can be stated [Illustration: FIG. 92.--Linton Chapel. Section and Elevations.] of the windows. The chancel arch (see Fig. 92) is semicircular, of rough stone, 3 feet wide, with plain parallel jambs, and the arch is set back on the jambs at the impost, which is about 5 feet 6 inches high from the supposed floor of the nave. The inside is much filled with rubbish. It is uncertain whether there was a step at the chancel arch. The chancel is 7 feet 6 inches by 7 feet inside, narrower than the nave by the thickness of the walls. The north and south walls are 2 feet 10 inches thick, and the east wall 3 feet 4 inches. Only about 2 feet in height of the east wall remains, though within the memory of man the east gable was standing and a cross on it. Nothing can be stated of the windows. The exterior length of the nave and the interior width are in the proportion of the vesica piscis. The chancel is nearly square.