Burra island just off the mainland revealed a settlement complex with oval houses and field system with typical features such as clearance cairns and abundant stone implements. Also within the site was a burnt mound, which the excavators believe to be contemporary. If so, and if Shetland burnt mounds have the same date range as those excavated on the Orkneys by the Hedges, then a late date c 1000 bc is possible for the Tougs site, spanning the transition to the more contracted settlement patter n represente d b y burn t mounds.
Another burnt mound has been excavated recently, at Ness of Sound near Lerwick by Alan Small. Its position near water is typical and its internal features of central stone-lined box sunk into underlying peat and an enclosing stone-built shelter match those recently excavated in the Shetlands and Orkneys. A small building attached to the Tougs mound shows that dwellings can be recognised in this phase, but could the emphasis on cooking places, presumably collective, reflect serious problems with fuel supplies at a period after woodland clearance and before the greatest extension of blanket peat?
The potential of areas like the Shetland Islands for answering problems of current interest to prehistorians is great. Not only is the degree of preservation of settlement traces generally good, but we may also hope tha t the effect of man's activities on his surroundings can be more easily detected because the environment itself was in many senses fragile and marginal.
Research at Brouster has been supported by the British Academy; the Shetland Islands Council; the Antiquaries of London and of Scotland; and the Meyerstein Fund.
Alasdair Whittle read Greats at Oxford, followed by a D.Phil on the Early Neolithic. He is now a lecturer in the Department of Archaeology, University College, Cardiff.
BOAT FINDS ON
LAND A guide for Archaeologists by
G. T. Denford, A W. Farrell, C. W. Gregson, S. McGrail,
S. O'Connor (National Maritime Museum, Greenwich)
IT became apparent at the Inter national Symposium on Boat Archaeology held at the National Maritime Museum in 1976, and from contacts with general archaeologists working in the field, that some form of guidance was needed for those non- specialists encountering boat remains. This paper is an attempt to provide such a guide to the recording, lifting and initial conservation of boat timbers. Post-excavation research is probably best dealt with by nautical archaeologists.
No special skills are necessary for recording boat structure, but specialist knowledge is required to appreciate the importance of features and to interpret them. The Archaeological Research Centre at the National Maritime Museum can provide advice on recording, lifting and conserving boat timbers; or can assist on site by invitation, as for example at Wood Quay, Dublin, where staff assisted in the excavation of boat timbers and are now involved in post-excavation research.
The importance of boat timbers will vary depending on their age. Anything earlier than c AD 1650 is of great importance to the history of boat and shipbuilding due to paucity of finds and documentary evidence before that date. After this date contemporar y documentatio n contributes to our knowledge of structures, and by AD 1750 details of ship's structures are relatively well-known, although much remains to be learnt about regional variants and about small boats . If the archaeologist is unable to give a date to any boat-timbers on his site, a specialist's advice should be sought.
'Passive' conservation in-situ
When wood is waterlogged it will often survive the processes of decay. In this state the water within the degraded tissue acts as a support. It is therefore imperative that waterlogged wood should be kept wet to prevent evaporation of the supportive water and consequent cellular collapse and distortion. Exposed timber will require frequent, almost continuous , spraying , depending on weather conditions. Timber covered with strips of wet plastic-foam sheeting sprayed approximately every half hour, will be effectively protected, and the sheets can easily be rolled back for access (Fig 1). If the foam is covered by a layer of light-gauge polythene sheeting, evaporation will be reduced, and spraying the foam twice daily should then suffice. An additional top sheet of opaque polythene will prevent solar gain. Where possible, fresh water