We may observe a portion still visible of the original boundary of the camp eastward, in that part called _latera prætoria_, being at present a watery ditch; and further downward, the foot-path between two banks observes the like direction; and the ground of the _porta principalis_, between them, is open and unfenced. I judge, I have performed my promise, in giving an account of this greatest curiosity of the renowned city of London; so illustrious a monument of the greatest of the Roman generals, which has withstood the waste of time for more than eighteen centuries, and passed unnoticed, but half a mile off the metropolis. I shall only add this observation, that when I came to survey this plot of ground, to make a map of it, by pacing, I found every where even and great numbers, and what I have often formerly observed in Roman works: whence we may safely affirm, the Roman camp-master laid out his works by pacing. To give some particulars. The measure is taken from the inside of the ditch, or the line between the _vallum_ and the ditch: the space of ground, which the camp-master paces, the workmen throw inward to compose the _vallum_. The camp on Barham downs contains in breadth thirty paces, length sixty. The camp at Wrotham, in breadth thirty paces, in length forty. At Walton by the Thames, it is a square of fifty paces. The foss here is converted into a mote, as here the _prætorium_ of Mandubrace: so the camp at Sheperton is a square of the same dimensions, and the foss turned into a mote, and made an orchard: we observe here at Sheperton the _prætorium_ is made on the bank of the river Thames; the _postica castrorum_, beyond the _via sagularis_, neglected. While Cæsar was pitched here, the turn of the auxiliaries to be in arms all night, with the other part of the troops, whose duty it was, came on: and the general’s intention was but to stay one night in this place; so there was no need to mark out their places in the camp. The stakes placed here in the river, by the Britons against Cæsar, were now a sufficient security behind him. Cæsar practised the same method when he fought the _Belgæ_: passing the river Axona, he placed his camp with the river behind him, that he might not be attacked from that quarter.