ROMANO-BRITISH LONDON Fig. 27. — Roman Sewer, Little Knightrider Street. Channel about 3 ft. by 2 ft. bath was unearthed in Cannon Street,™ built of yellow tiles and coated with opus signinum ; this was at a depth of 17 ft., and was clearly seen to rest on the undisturbed brick-earth. Many of the remains that have been enumerated show by their position on the original surface, and by the coins and objects associated with them, that London had extended over a large area at a very early period. In this way the City had spread itself out, probably as an open town, its streets not disposed in any regular plan, and its buildings interspersed among trees and streams. Pleasantly situated in surroundings of many natural advantages, the in- habitants were reluctant to forsake it, even when threatened with destruction during the insurrec- tion under Boudicca, as is related by Tacitus.'^' After a period during which the above- described condition prevailed, it was found neces- sary to provide the rapidly growing town with more adequate defences, and the wall was then built. Its irregular course indicates its adaptation to a state of things already existing, but it was evidently carried well beyond the more densely inhabited parts, as everywhere it has been found to rest on the natural surface. The streams were still flowing normally in their beds, and provision was made, as we have seen, for conducting them beneath the wall. In each case that has been observed, the culverts and the wall have been found on the base of the streams, showing that they had not then silted up. At the time of the building of the wall, and probably for a considerable period afterwards, the City appears to have prospered. Houses came to be more closely built and continued to spread over the unoccupied portions, as is shown by the large disused gravel-pit found under the Royal Exchange, which had been first filled with rubbish and finally built over*" (Plan C, 90). Things seem to have continued in this state until after the time when the bastions were added to the wall, which is indicated by the discoveries at AUhallows Church. There was then, as has already been said, an open ditch, cut in the gravel, which was at that point partly filled up in order to build the bastion. The ditch subsequently became filled up through- out its course, but with a light gravelly soil such as would come from the natural surface, the only black mud being where water was obstructed by the bastion. A great change, however, came about after- wards. Precautions for keeping the cul- verts clear were neglected, and the iron bars placed in the openings became choked up with weeds ; the crown of one of them was broken in and the base of a column of some ruined building had fallen in the breach, while human bodies were either Fig. 28. —Painted Base of Column, Royal Exchange " y^rch. Ix, 2 1 6. •^ Cat. Antiq. Roy. Exck. " Annals, xiv, 33. His account implies that the City was then unwalled. 77
