On either side, north and south, are three recesses, or _exedrae_, two of which are circular and one (the centre) rectangular. The south rectangular one is 17ft. wide by 7ft. deep; the north one is nearly a foot wider, and one foot less in depth. Greater variations exist in the circular recesses; for, commencing in the western one, on the south side, the width is 17ft. 3in., and the depth 7ft. 6in.; the eastern one is 14ft. 3in. wide, and 6ft. 9in. deep; the _exedrae vis-a-vis_ on the north is 17ft. 3in. wide, and 8ft. 4in. deep; the remaining one, to the west, is 17ft. wide, and 7ft. deep. I give these dimensions irrespective entirely of the pilasters which are attached to the walls on either side the reveil of the recesses, and in the rectangular recesses in the enclosing angles also. Piers are now standing on the margin of the bath, dividing the north and south sides each into seven bays. These piers are built with solid block freestone, but as there are continuous vertical joints on either side of the central division of each pier, it is clear that an alteration was made in the design either previous to its entire completion or subsequently. I will endeavour to describe the bath as originally designed. Along the margin of the bath, north and south, stood six piers, equally divided (about 14ft. apart), as far as the length of the bath, but allowing a lesser distance from the attached pilaster at either end. These piers are cut out of a block (in plan, 2ft. 10½in. from east to west by 2ft. 8in. from north to south), so as to form a pilaster of three inches projection on either face. As the original pilasters on the north and south walls do not correspond with these piers, I am led to conclude that the _schola_ and _exedrae_, north and south, were not vaulted at first, and were the only portion of the hall that was roofed, and that the roof was only of timber, supported by an arcade, the arches not exceeding 17ft. in height, and that the eaves of the roof of about 22ft. in height dipped towards the bath. This was a very usual arrangement in the _Atrium_ of a Roman house with the _impluvium_ in the centre. A _crypto porticus_ would thus be formed on the two longer sides of the bath, but the _schola_ on the east and west ends was open to the sky. Practical experience, either on the completion of this plan, or previously to its entire execution, led to its abandonment. At any rate a roof over the whole was found essential to the comforts of the bathers. The piers were accordingly strengthened. Pilasters were erected, projecting 2ft. 9m. into the bath, with smaller pilasters on the other side projecting on the _schola_, 1ft. 4in. by 1ft. 11in. wide; and _vis-a-vis_ to these pilasters corresponding ones were affixed to the side walls. Unfortunately this brought into prominence the irregularity of the size and position of the _exedrae_, and the pilasters were affixed correctly with reference to the arcade, as was absolutely necessary,