a ponderous rubble wall crosses the parts above described from north to south, far below the foundations of the modern buildings above, which partially rest on it, and attached to this wall is a curious hollow shaft or cylinder 2 ft. 412 in. in internal diameter, (C in plan,) thus formed; at the bottom, resting on the red mosaic, is a layer of white concrete about 9 in. thick, on this is a layer of line reddish concrete, 112 in. thick, and on this rests a circular curb of elm timber sound and not discoloured, 812 in. wide and rather more than 2 in. thick; on this again rests a very neatly and compactly formed wall of seven courses of ashlared blocks of chalk, each course diminishing in thickness upwards, in all about 4 ft., and above this the cylinder was continued of brickwork for fifteen courses more, measuring between 4 and 5 ft.; it had been worked from within, as the oozing outwards of the mortar is evident; the heavy irregular wall in which this shaft is partly imbedded is formed of rough blocks of chalk, old Roman tiles and bricks, rubble of all kinds, and set in mortar in which there is much pounded brick, and all based on a layer of concrete 9 in. thick; in one part is a mass of excessively hard mortar of a pinkish cast full of small pieces of brick, similar to what is found at the building called the "sette sale" at Rome and also at Pozzuoli, and which bears a good polish[1]. When the shaft was first broken into, it contained at the bottom 2 or 3 ft. of dark black-looking mould and a few pieces of charcoal, the only use which suggests itself seems to be, that it must have been the drain or cess-pit of a privy for the Norman house constructed on the Roman ruins. It is probable too that the more precious mosaics of the laconicum were removed at the same time, as no traces of them were found in the recent operations.
Some other Roman walls, and also a part of another pavement, were discovered near to the north of, but not adjoining the remains above described, but too much ruined to afford any grounds for suggesting their purpose; also many more black oak piles.
Several objects of interest have been met with during the excavations, such as flue tiles like B, (cut p. 27,) the drain tile C; many small tiles about 6 in. square scored with marks, to make the mortar adhere; also some pieces of fine stucco of brilliant
- ↑ This kind of concrete or mortar was used to form the pavement called "opus Signinum," made of tiles beaten to small fragments. Signia was an Italian town famous for the manufacture of tiles.
