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.
Cæsar’s camp on Greenfield common is forty paces broad, sixty long. Here he received the ambassadors of the Trinobantes, desiring their prince Mandubrace to be restored: they bring forty hostages and bread-corn for the army. For their reception another camp is made around this, which is 80 paces broad, 100 long. Another day came in ambassadors from the Cenimani, Segontiaci, Ancalites, Bibroci, and Cassii. This obliged the camp-master to add the appendix to the camps, which was of the breadth of 100 paces, equal to the length of the last; 130 in length, stretching out to the east: but in the ground-plot of that camp we see an egregious proof of my position, that they went by paces in marking out their camps; and sometimes by guess-work, in the square; which obliged the camp-master to carry his 130 paces beyond the angle of the former camp. Concerning the method of adding new occasional works to a former camp, we observe a like instance in that camp of Chlorus’s between Clarendon palace and Old Sarum; made, we may well presume, on the states of Britain sending their ambassadors hither to him, with submission to his government after the destruction of Allectus.
Cæsar’s camp on Hounslow heath is very perfect, sixty paces square. His camp at Kingsbury is thirty paces broad, and forty in length.
Come we now to our work at Pancras. The prætorium is forty paces broad from east to west, fifty paces long from north to south: the prætorium of Mandubrace is thirty paces long from east to west, forty from north to south: thereby it accommodated itself to that part of the camp, that was called retentura.
The breadth of the whole camp was 400 paces, not reckoning the valley of the brook: the length of the whole is 500 paces. Examine the intermediate parts, they fall into whole numbers: the breadth of the pasture, comprehending the station of the Hastati and Triarii, on the west side of the camp, is 150 paces: that of the horse is forty broad: the correspondent, or eastern part of the camp, is likewise 150 paces broad, comprehending the station of the Triarii and Hastati; so that, subducting the space of the valley where the brook runs, the whole breadth of the camp, where the tents are pitched, contains 340 paces: a space beyond, on each side, of thirty paces wide, is supposed to be left between the tents and the vallum, where a camp is fortified: and then the camp contains just 400 paces broad.
The camp is in length 500 paces: the thirty paces beyond, for the way between the tents and vallum, (where a vallum is made) amounts to 560; so that the proportion of length to breadth is as 3 to 2; where strength and convenience is well adjusted, and is often the proportion of Roman cities. This space of ground was sufficient for Cæsar’s army, according to Roman discipline; for, if he had 40,000 men, a third part of them were upon guard.
The recovery of this most noble antiquity will give pleasure to a British antiquary; especially an inhabitant of London, whereof it is a singular glory: it renders the walk over the beautiful fields to the Brill doubly agreeable, when, at half a mile distance, we can tread in the very steps of the Roman camp-master, and of the greatest of the Roman generals.
We need not wonder that the traces of this camp, so near the metropolis, are so nearly worn out: we may rather wonder, that so much is left, when a proper sagacity in these matters may discern them; and be assured, that somewhat more than three or four sorry houses, is commemorated under the name of the Brill: nor is it unworthy of remark, as an evident confirmation of our system, that all the ditches and fences now upon the ground, have a manifest respect to the principal members of the original plan of the camp.
In this camp at Pancras, Cæsar made the two British kings friends; Casvelhan, and his nephew Mandubrace: the latter, I suppose, presented him with that corslet of pearls, which he gave to Venus in the temple at Rome, which he built to her, as the foundress of his family.—Pliny and Solinus.