T. E. Lawrence’s Undergraduate Dissertation – Page 56

ditches cut in solid chalk like those of old Sarum,were to all intents and purposes walls, and no one would require further defences : but ditches in earth were often, in stony places, strengthened by a wall on their inner face. In places this wall is very formidable and disposed in the manner of Iliad XII, 258, as at Worlebury in Somerset (Plan 8) though this seems to have been occupied in pre- Roman times. Where the soil was suitable the earthworkers often faced their vallum with retaining walls of stone.(Plan 8) Caesar describes the Gauls as building walls of mixed timber and stone : these of course would be too perishable to have survived, though at Murcens, above the valley of the Lot, there is a much-dilapidated camp with timber ties in a dry stone wall. All that can be said of earthworks in the present state of our knowledge is that they all, almost without exception, show "concentric" plans. Old Sarum is almost a perfect example of a ring-fortress, (Plan 9) and it has probably no Norman (and certainly no Roman) work in it, while at Maiden Castle in Dorchester (Plan 8) there is in one part no less than 8 lines of defense, one within the other. The gates of earth-camps are often fortified with almost trivial elaboration, as at Dumpton: (Plan 9) and in a great camp in Devon,at Hembury near Honiton, (Plan 10)