The curvature of the two parts of the nave wall still remaining gives an interior diameter of about 19 feet, thus corroborating the diameters given by Pope and Sinclair. Neither of these persons had seen the church perfect; and the differences in the measures given by them show that their informants did not speak from exact data. The “61 feet perpendicular wall” is a gross mistake either of printer, or translator, or his informant. Even the “20 feet high” seems over the mark, though this may be a loose approximation to the height of the side walls. [Illustration: FIG. 112.--Church at Orphir. Elevation of Apse, and Details.] Supposing the preceding conjectures as to the shape of the roof to be correct, the top of the “fleche” surmounting the lantern would be about 40 feet. Then, supposing that Pope was told that the height was 41 feet, and the height of the side walls 20 feet, he might have added them together. The diameter was less open to error than the height. One writer, however, might give the outer diameter and the other the inner. It is built of yellow Orphir freestone. The nave walls are 3 feet 9 inches thick, well built; and probably the entrance was at the west, as in the other round churches. It is highly improbable that Pope is right in stating that “the light was all from the open”--that is, that there were no windows in the nave walls. Probably there were four single lights. The chancel, which is little more than the apse, is 7 feet 2 inches wide and 7 feet 9 inches deep, or long, with wall 2 feet 8 inches thick. The arch into it is semicircular, and forms part of a plain unribbed vault, as at St. Margaret’s Chapel at Edinburgh. (See Fig. 111.) The impost of the vault arch is 6 feet 5 inches above what appears to have been the floor, and the top, consequently, 10 feet 6 inches high. Outside the vault was originally probably a solid stone roof, the apex of which was about 14 feet [Illustration: FIG. 113.--Church at Orphir. Elevations of Apse.] from the floor. This height (supposing also that there was a step at the chancel arch) would oblige the walls of the nave to be about 15 feet high. The chancel has no buttresses. There is one window in the chancel, in the east end, 2 feet 5 inches by 10½ inches clear, opening with jambs splayed inward to 1 foot 8 inches wide. (Fig. 113.) The outer edges are chamfered, and the head semicircular. The impost is at the same level as of vault. It has a groove for glass. A stone lying down appears to be part of a stoup. The exterior width of the chancel is half the exterior width of the nave. On the south side of the nave is the trace of a building in the form of a parallelogram, and other indications of buildings. Pope states that before his visit in 1758, large foundations had been found in digging earth for the Bow of Orphir, near the Gerth-house.