EDO4150 - Former St John Ambulance Hall, North Square, Dorchester; excavation 2001

The excavation was carried out prior to redevelopment of the site of the former St John Ambulance Hall, North Square. An evaluation excavation in 2000 had shown that significant archaeological remains were likely to survive relatively intact was along the Friary Lane frontage of the site. The excavated area was broadly parallel to the east side of Friary Lane and was about 9.5m long and 2.1m at its widest point (Figure 1). The east edge of the excavation was formed by the remains of a cellar wall, the north edge was effectively bounded by a 19th century wall with cellars beyond and the southern limit of excavation was truncated by modern disturbance. The area was also truncated by a 1.4m wide band of modern disturbance approximately 2.6m from the southern edge of excavation. Pre-Roman activity was limited to a relatively limited area of brown clay soil in the southern part of the site, which probably represents the remnants of a pre-urban land surface. The remains of an extensively robbed Roman building were exposed, comprising a single wall running NW-SE, with a return to the SW at the northern end indicated by a robber trench. It is unclear as to whether or not this represented an external wall. There was some evidence of further Roman occupation layers, possibly internal, directly to the north of this robber trench. There was some evidence for a partition wall 3m to the south of the assumed return. The building was built upon solid rammed flint footings 0.6m wide and 0.4m deep and the exposed remains of the walls were constructed from limestone slabs and blocks, bonded with a yellow sandy mortar. The depth of the footings suggests that the building had only one storey. Two drains were incorporated into the main NW-SE wall, draining out to the NE, suggesting that this was an external wall probably at the rear of the building. The extent of later robbing and disturbance means that no true estimate of the building floor plan can be made. It is arguable that the position of the building in relation to the Roman street plan suggests that it may have fronted the Roman street, in which case the footprint of the building would have continued eastwards for about another 5-10m. The internal floors of the building were partially preserved and consisted of rammed chalk, which survived in patches to the west of the wall. A small amount of possible occupation debris was revealed at the south end of the building, in the form of a greyish soil containing charcoal and ash, but no artefacts were recovered. The usage, nature and status of the building remain elusive due to the lack of domestic or industrial features such as ovens or hearths and the lack of any high quality artefacts. A small amount of tesserae were recovered but not enough to suggest that this building had tessellated floors. The finds recovered suggest a 3rd-4th century date for this building. There was no structural evidence of occupation on the site during the medieval period. There is some slight evidence for a late 18th century building on the site, but this had been almost completely destroyed by the construction of two 19th century houses fronting on to Friary Lane, with cellars to the rear.