_Floors._—The floors which have been found were most generally of concrete, tiles and mosaic. In Rochester Museum are some lumps of material from concrete floors. There were also floors of “rough stones” and of “chalk stones.” A better kind of concrete floor was that known as _opus signinum_, made of lime and broken pottery polished on the surface; this made an admirable floor. Another excellent and much used surface was obtained by coarse tesseræ of tile from 1 in. to 2 in. square; sometimes pieces of yellow, black and white were intermixed. In Rochester Museum is a tile fragment subdivided by indented lines imitating this coarse kind of mosaic, also a square of light buff tile. At the Guildhall is a tile a Roman foot square, having incised squares. Tiles were of various forms and sizes. In the Reading Museum are round and polygonal tiles, and a very pretty floor formed of such tiles with coarse tesseræ intermixed. Some small paving tiles have been found (not in London) with patterns impressed on the surface (Fowler’s engravings). In the British Museum is a tile 7 in. square, and a large tile about 18 by 14 in. is scored on the surface neatly, like the crosses of a Union Jack (cf. Fig. 7); it seems to be abraded on the surface, and may be a paving tile—if so, it must have made an excellent floor. Roach Smith mentions large tiles about 2 ft. square and 3 in. thick, and some of these are in the British Museum. Such tiles, as large as paving slabs, were useful in covering hypocausts, spanning the intervals between the little piers on which the corners rested. In the British Museum and at the Guildhall are portions of paving of small tiles set on edge in a herring-bone pattern. The former is described as having been found at Bush Lane, the latter near Dowgate Hill on the Walbrook. “Near by was piling and the cill of a bridge which crossed the brook from E. to W.” This seems to be the same pavement as that described in _The Builder_, 1884, as being on the west bank facing the brook; there was a second landing-stage in Trinity Square Gardens, on “the edge of a haven,” with a pavement over oak piling. (The haven at the tidal inlet to Walbrook was doubtless the original port of London.) I have seen similar herring-bone pavement of tiles on edge in Rome. I doubt there having been a bridge here. _Plastering._—External walls would mostly have been plastered. C. Knight mentioned the discovery near the Bank of traces of a Roman building, and of what was “apparently the basis of a Roman pillar (circular?) built of large flat bricks incrusted with a very hard cement, in which the mouldings were formed exactly as is done in the present day.”