..Chap; IL O F M A N C.H ESTER. 37 beeji fleeced of their facing of turf and {tone, and now fhew plainly the internal . ftru&ure of the wall; prefenting to the eye the rough undrefled ftones of the quarry, the angular pieces pf rock, and the fmooth round flints of the river, all bedded in the ftrong mortar, and united by it into one. And the white brown, patches of lime and mortar ftand ftrikingly contrafted, on a gene- ral view of the wall, with the green turf that entirely conceals the level line of the rampart, and with the green mofs that half ikiiis over- and half reveals thi proje&ing points of the vallum* The great ditch of the Britift city the Romans preferved along the courier of* their northern wall, for feveral yards beyond the caftern end of it; and for the whole beyond the weftern* They preferved it for more than thirty yards beyond the eaftern end of theif wall; ' and/ as the prefent appearances of the ground ' fully teftify, tfcrnAinated it by an high bank, which was railed upoh the courfedf the ditch, and which was doped away into fehe former part of fit.
- The conftru&ion of the Roman caftrum upon a fmaller fcale
than that • of the Britifli town occafioned- the former to recede
- from th6 eaftern and wdftern barriers of the latter. The garrifon
therefbfe carried on a new ditch from the notth-weftejrn and north-eaftern angles of their vallum in order to fecure both. And, as the foldiers proceeded in the work, the centurions ap- pointed to fuperintend k muft have regularly examined the line of the ditch y and carefully mcafured the depth, of tha- channel, with their ten-feet rods ' ^The north- weftern ditcli was made to flope away north and fouth,. becaufe the Britifh bank and- the morafs below it were a fufficient defence on the weft; But the north-e^ftern^ having no fuch defence of a. bank and, a morafs , before itl_ was floped away eaft arid weft,, and for the fame' rea- j ion , was , funk to. a much', greater depth than .the other. This finks about five feet in depth, and That only about two and'a 'half* Both however were carried* on along a part only of their re- fbe&ive ncles. The north -weftern return was continued only about fh^rty-five yards in breadth, and filled' up in length the wfw>le fpacebetweei^ the. Roman rampart and the Britifh bank.. And: %,~ ,1
