that after the abandonment of the Agricolan fort there came a second occupation, during which the Via Principalis ran on the line of the later Via Quintana.

As we have seen, the ground plan of a Roman fort was laid out on certain well-recognised lines. In every rectangular fort of the type of Newstead there were at least four gates, one on each side. The position of these gates governed the position of the buildings in the interior. The Principia was placed as near as possible to the centre. It stood midway between the two end gates, facing one of them. The road traversing the fort between the two remaining gates passed in front of it.[1] Now if we apply this rule to the second occupation at Newstead, the line then taken by the road traversing the fort from north to south makes it practically certain that the Principia, if it occupied the usual position, must have faced the west, following no doubt in this the position of the corresponding building of the Agricolan occupation.

The strong buttressed building, lying immediately to the south of the Principia, showed evidence that it had faced the west. It was a well-built structure, exhibiting no marks of reconstruction. Its loading platform was placed at the west end. The level of the roads at either end seemed to have risen against it, indicating that it belonged to an early period. It cannot, however, have been associated with the oldest occupation of all, as a pit lay underneath the foundations of the east wall, while the walls of a large building were found to pass below it. These walls correspond in alignment and in method of construction with the early walls lying at the east end of the Principia. The latter enclosed a space projecting from the east end of the Principia into the Via Principalis, and they had been cut through in laying the cobble foundations of the Principia wall. The conclusion suggested was that they belonged to the first occupation of the fort, the Principia of which faced west; that the south buttressed building belonged to the second, or possibly third, occupation, and, with the contemporary Principia, had faced west, but that in the two latest occupations the Principia had been turned round, probably without any alteration of the foundations of its main walls.

1 A seeming exception to this rule occurs in the fort at South Shields, but there is reason to suppose that there the peculiar position of the Principia is the result of an enlargement of the fort, in which the gates had been altered and the building left in its old position. Bosanquet, 'The Roman Camp at Housesteads,' Archaeologia Aeliana, vol. xxv. p. 244.