A HISTORY OF LONDON it appears that a total height of 14 ft. 4 in. of Roman work was seen, there being five rows of tiles, the lower four of which were in places perfect. Accompanying this account is a sectional diagram, on which the lowest course of tiles is shown as a bond going through the wall, but this is evidently an error, as Mr. Fox,^^ who at first states this to be the case, says later that transverse sections were subsequently found, one of which, 27 yds. west of Aldersgate, showed that the lowest band of tiles did not run through the thickness of the structure and was composed at that point of two not three layers. Near King Edward Street were discovered foundations of a ' tower ' of a semicircular plan which Mr. Fox regards as mediaeval, as it contained carved stones of the Norman and Early English periods. In other respects this struc- ture resembles the bastions, and these stones may have been inserted in repairs. It may have been, however, a post-Roman bastion (Plan C, 44). A point of great interest in connexion with the finds at Aldersgate was the discovery of the Roman ditch. Between the wall and the edge of the ditch was a flat space of ground about 10 ft. wide, forming a ' berme ' similar to that at New Broad Street. The ditch at Aldersgate, however, was very much larger, being 74 ft. in width at the top and 14 ft. deep ; the bottom and sides were puddled with clay. In the section close to Aldersgate Street a slightly raised mound was found in the bottom which may possibly have served as the support of a wooden trestle bridge, similar to that found at Silchester.^ Crossing King Edward Street the wall continues its westerly course in a direct line through the site of Christ's Hospital until within about 100 ft. of Giltspur Street, where it turns to the south, having a bastion on the angle, and two others on the line between the angle and King Edward Street. The vicissitudes of the old religious house of the Grey Friars have necessitated many changes in important buildings requiring deep foundations, and these have done much to destroy the portion of the wall within the conventual precincts, though its record has been preserved in the old plans. At the present time much of the site is being dug out to a great depth for the foundations of further buildings for the Post Office, and at various points detached portions of the old wall have been brought to light. The base has been found to rest at a depth of 1 2 ft. to i 3 ft. below the present level, with the usual clay and flint bed cut in the brick earth which mostly covers the gravel on this site. Near King Edward Street a nice section of the wall was exposed (Plan C, 45). There was about 10 ft. of Roman work, reaching almost to the present surface, and showing three bonding courses, the lowest of three tiles, the upper two of two tiles each. A little to the west a portion of the base of a bastion was found built into foundations which consisted of a compact mass of irregular ragstones and hard white mortar (Plan C, 46). Of the middle bastion, which had been cut into in 1827 by the foundations of the great hall of the school, a hollow footing about 23 ft. in diameter and 5 ft. in thickness remained for a height of 4 ft. 5 in. (Plan C, 47). This rested at a depth of 22 ft. 6 in., or nearly 10 ft. below the base of the City wall, which in this part must have been entirely cleared away when the great hall was built. This exceptional depth would seem " Jrci. Hi, 609-16. "' Jrri. Iv, 427. 64
