from the present surface. The character of the bottom has already been indicated. The pottery found appeared to be indistinguishable from that recovered from the ditch of the early fort. The quantity, however, was not very large. The corresponding portion of the inner ditch at the north gate was not excavated further than was necessary to determine its position. That opposite the south gate produced almost no relics.

An interesting circumstance connected with these 'clavicula-shaped ditches' has still to be recorded. It was definitely ascertained, on evidence which will be produced later, that there had been at some time or other a reorganisation of the defences which had resulted in the filling up of those portions of the inner ditch which projected in front of the north, south, and west gates. That is, the use of this form of obstacle was deliberately abandoned. Nor was recourse had to it again in the subsequent reconstruction, when the area of the fort was so much reduced that the original north and south gates had to be closed and new ones opened some distance further east. Similarly, in the south annexe the early gate was covered by an overlapping ditch, but there was none in front of the later one. Whatever may have been the reason for the difference in the plan of the defences which distinguished the east gate from the gates on the other sides of the fort, it is clear that the method of protecting the gate was in all of them based upon the same principles, and the fact that the protection of the gates, which on the north, south and west was insured by means of an overlapping arm of the inner ditch, was on the east accomplished by the prolongation of the outer ditches, seems to prove that the triple ditches which surround the enlarged fort all belong to its original plan.

The Wall

Behind the inner ditch of the fort lay the berm, a narrow platform, the existence of which was no doubt due to the fact that the heavy wall had to be placed sufficiently far from the ditch to prevent its weight causing subsidence. For the greater part of the circuit all that remained of the wall were the cobbles which had formed the foundation, with here and there a piece of red sandstone among them. Where it had crossed the ditches of the early fort, or where, as was the case on the west front, it was placed above one of them, the cobbles were carried down to the bottom. The superstructure itself had been almost entirely removed. Fortunately, however, on the west side near the south angle of the fort, a portion was discovered showing the lower courses in sufficiently good preservation to