[Illustration: Fig. 179.—General plan of Broch of Clickamin, near Lerwick, Shetland, showing the walled island and causeway leading to it. (From a plan by Sir H. Dryden.)]
[Illustration: Fig. 180.—Diagrammatic Section of East Broch of Burray. (From _Archæologia Scotica_, vol. v.)]
The East Broch of Burray, in Orkney, explored by Mr. Farrer, presented the appearance of a green mound 20 feet high, surrounded by an embankment. The mound when excavated was found to cover the lower portion of a circular tower of uncemented masonry (Fig. 180). The wall of the tower was 15 feet thick, enclosing a central area 36 feet in diameter. The entrance passage as usual went straight through the wall, and had a guard-chamber opening from it on either side. The entrance to one of these is shown in the section and the bar-hole behind it. There were two other chambers constructed in the thickness of the wall opening from the central area, and the entrance to the stair was placed as usual to the left of the doorway, but on a higher level. In all its features it closely resembles all that have been described, but in one feature it differs from them. Close to the doorway, but outside the wall, there is a well with a passage and steps leading down into it. There are other examples which exhibit the same feature.
[Illustration: Fig. 181.—Diagrammatic Section of the Broch of Borrowston, showing the well in the area. (From _Archæologia Scotica_, vol. v.)]
[Illustration: Fig. 182.—Broch at Manse of Harray. (From a Plan by Mr. George Petrie, 11⁄16 inch to 1 foot.)]
The Broch of Borrowston, in Shapinsay (Fig. 181), also in Orkney, consisted of a wall 13 feet thick, enclosing a central area 33 feet in diameter. Within the central area of the Broch there was a well 10 feet deep, the lower part dug out of the solid rock, and the upper part faced with dry-built masonry. The Broch of Okstrow, at Birsay in Orkney, which consisted of a wall 12 feet thick, enclosing an area 45 feet in diameter, had a well within the area and a drain from it leading out to the outside of the structure. The Broch near the Manse at Harray (Fig. 182), excavated by Rev. Dr Traill, consisted of a wall 12 feet thick, enclosing an area about 33 feet in diameter. It was surrounded by outbuildings, which were not properly explored. There were no guard-chambers on either side of the passage (B), which shows the checks for the door, at 6 feet within the outer face of the wall. To the left of the main entrance is the usual chamber (H) at the foot of the stair (G), of which 19 steps remain; and two other oval chambers (E and F), placed at nearly equal distances in the circumference of the wall, complete the resemblance to the general type. Near the middle of the area a subterranean passage terminating in five steps led to a well (D) 9 feet deep excavated in the rock. The subjoined sectional diagram (Fig. 183) shows the construction of the well, which still retained water when the excavation of the Broch was made. The Brochs of Skinnet, Harpsdale, and Kettleburn in Caithness, had each a well within the central area. The well of the last-mentioned Broch is still utilised as the existing water supply for the cottars, who live in houses close by constructed of the stones removed from the site of the ancient structure.