Many fragments of an unusual type of combed brick were found in association with combed and roller-printed box-flue tiles during the excavation of a room with a sub-surface level mortar floor. The majority of flue tile fragments from the site having been found in the fill of this room, the excavation team is of the opinion that the room was furnished with a functional hypocaust system. Evidence of a stoke-hole, finds of tufa voussoir fragments and the depth below ground of the mortar floor serves to corroborate the supposition. However, no pilae were found within the fill and neither the mortar of the floor, nor such masonry as had escaped the attentions of robbers, exhibited compelling evidence of exposure to intense heat.

The combed bricks vary considerably in thickness, although they can be said to fall within two groups.

1. The first grouping seems to be the more consistent in terms of depth, with 3 fragments of 50mm thickness. Of course, it is possible that the 3 fragments considered are from one individual brick, so it would perhaps be unwise to draw too many conclusions from the apparent triple representation.
   
   
2. The second grouping is more reliable in so far as it is represented by multiple items, although considerably more variable in terms of thickness of those items. The range of thickness measurements within the grouping varies between a minimum of 76mm and a maximum of 93 mm, with an example of 86mm also found.

The bricks in the second grouping are combed, whilst those in the first grouping do not appear to be. However, the fabric and general surface appearance is identical one with the other, so the team feel confident that the two groups should be considered as parts of a coherent whole.

The combing patterns are created with several combs but devolve into two types.

• Coarse combing created with combs of 5 or 6 “teeth” with a wavelength of 9mm.
  
  
• Fine combing created with combs of 13 to 17 “teeth” with a wavelength of 3-4mm.

Some fragments were combed with both types of comb, whilst others exhibit only one type. The combing strokes applied are either in straight lines or waves; sometimes both together. No conclusions are drawn as to whether there is any functional reason for the variation in combing, although it must be noted that the combed flue tiles also exhibited two types of combing.

The bricks of both thickness groups are fabricated in a shelly fabric which has a light-buff fired surface with occasional reddening. The core of the fabric has a noticeably purple tint and has a tendency to flake away from the body until consolidated with PVA treatment.

Fragments within the greater depth grouping are endowed with rows of perforations within the core of the fabric. These 1-2mm perforations appear to run from top to bottom yet are not visible at the surface, appearing to truncate around 3mm short of penetration, probably due to subsequent surface treatment such as combing, smoothing or slip application. It is supposed that they were intended to assist in the conveyance of heat through the fabric during kiln-firing, a supposition borne out by the observation that the colour of the clay around the walls of the perforations indicates that higher temperatures have been attained there than in the surrounding core.