the investigation was resumed early in 1909 with a view to determining the system to which both apparently belonged. It proved to be the defence of a rectangular enclosure 1590 feet in length by 1340 feet in breadth, enclosing an area of forty-nine acres. The corners of the camp were rounded, and there were four entrances, one on each side. While the gates on the north and south occupied a central position, those on the east and west were placed nearer the northern end of the parallelogram. The ditch varied somewhat in dimensions, in part no doubt owing to the alteration of the surface through long years of tillage; but on an average it appeared to measure about seven and a half feet in width with a depth of five feet. It terminated on either side of the gates to allow the roads to pass out. Probably the rampart of the camp was built up from the spoil of the ditch, for there was no trace of any more permanent form of defence.
The gateways on the south, east, and west were carefully examined. But little could be done at the north gate beyond fixing its position, as it lay beneath a young plantation. The south entrance extended for forty-six feet between the ends of the ditches; the west entrance for forty-two feet ; the precise dimensions of the eastern entrance were not ascertained. Each gate had been covered by a long straight ditch, known as a titulus, dug in front of it. These tituli appeared to have been from seven to eight feet wide, and they were placed directly in front of the openings at distances varying from thirty-eight feet in the case of the north gate to forty-seven feet in the case of the west gate. If the soil thrown up in digging them was heaped up behind, the entrances must have been reduced to comparatively moderate dimensions. The obvious purpose of the titulus was to mask the gateway, and so to render a frontal attack more difficult.
A glance at the plan will show better than any description how skilfully the strategic position of the great camp has been chosen. The dominating factor has been the course of the Tweed, the lines following the bend of the river. The highest point of the ridge, which must have served as the centre of the whole enclosure, commands a view in one direction of the ridges of land over which came the road from the Cheviots. In another it looks across the opening of the Leader valley, with the conical peak of the Black Hill standing high in the middle distance. A force planted here would have had complete control of the crossing of the river, and would have held the
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