Micro-focus X-ray CT scanning of two rare wooden objects from the wreck of the London, and its application in heritage science and conservation

Two wooden objects, a tuning peg from a stringed musical instrument and a stopper from a smoking pipe, were recovered from the 1665 CE wreck of the London and selected for wood identification. So far, they are the only recoveries of these object types from this wreck. To preserve their integrity and completeness, destructive sampling was not desirable. Instead, micro-focus computed tomography (mu-CT) scanning was carried out. The objects were scanned both pre-conservation (waterlogged/saturated) and post-conservation (PEG impregnated; freeze-dried). Although the aim was to non-destructively explore the internal structure of the objects for wood identifications, information was also gained on their manufacturing characteristics and internal condition. 1 mu m voxel resolution - sufficient for positive identifications of these wood types to genus level (as is standard for wood identifications) - was achieved. This study has established that the conservation treatment used here does not obscure the microscopic anatomical features of these wood types and therefore recommends that mu-CT scanning is best undertaken after conservation, when the objects are stable.