Today (9th December), Trust director Philip Crummy was working at Roman Circus House on the plan of Colchester’s Roman circus. The Trust has recently been excavating part of the site of the circus in front of our building and produced more evidence about the pattern of buttresses around the cavea (seating-stand) external wall. The circus was approximately 450 metres long, and the external wall was supported by exterior buttresses, as the external wall itself supported the earth bank on which the tiers of wooden seating were constructed. Philip has discovered that the pattern of buttresses along the part of the wall, the foundations of which we have recently excavated, is not a mirror-image of the same part on the opposite side of the arena, as he expected. In fact, the pattern of buttresses on the opposite side of the arena is different to the other patterns of buttresses which we have recognised around the site of the circus so far. We have now, in fact, recognised six different patterns of buttress around the circus site. From the evidence so far, we now think that the circus was built in thirteen sections. Earlier on in our investigations of the circus site, when we had already recognised a few of these variations in the pattern of the buttresses, we thought that this indicated that the circus had been built in sections, one section at a time, perhaps very slowly, and with sections having been designed by different architects. Now it seems likely that all thirteen sections were different and that this may have been a deliberate design feature of the circus. This idea is rather puzzling, but the variations in the buttress pattern can be rationalised in terms of Roman feet (1 Roman foot = 0.295 metres), which also suggests the involvement of an architect or architects.
The image shows some of Philip’s calculations today.