John Hughes and Siân Jones
Stone deteriorates under the influence of a variety of physical and chemical agencies. ‘Weathering’, biofilms, and climatic variability have a significant impact on preservation. The cut and inscribed surfaces of carved stone create additional vulnerabilities. In recent decades, conservation-driven research has focused on the development of scientific methods and materials for measuring change, analysing materials, protecting them and consolidating vulnerable components. As a result, the deterioration of carved stone can be arrested to some degree.
Science-based modification of processes of material transformation can help to maintain the historic and evidential values associated with carved stone surfaces. Yet deterioration contributes to the experience of authenticity, providing a tangible mark of age and ‘the real’. As Alois Riegl recognised in 1902, visible decay and disintegration of material fabric embodies the passage of time, creating ‘age value’, whereupon ‘time’ becomes tangibly and aesthetically accessible. This begs the question of how the use of science-based conservation impacts upon these values and qualities. Despite long-standing recognition of the values surrounding aging, decay, patina and ruination, there has been little research in this specific area.
The AHRC-funded Materiality, Authenticity and Value Project (grant ref. AH/K006002/1, 2013–15), examined the values associated with material transformation and the impact of science-based conservation on these values. The research team combined expertise in heritage science (John Hughes), cultural heritage (Siân Jones) and social anthropology (Rachel Douglas-Jones and Thomas Yarrow). In partnership with the National Trust for Scotland and Historic Scotland (now Historic Environment Scotland), the project focused on three case studies: Charles Rennie Mackintosh’s Hill House, Dryburgh Abbey and Skelmorlie Aisle. The latter two monuments contain significant quantities of carved stone (Figures 1 and 2). At each of the sites, qualitative social research methods were used to gain insights into values, including interviews with heritage professionals and visitors and participant observation.
The research results showed that values associated with material transformation emerge in particular contexts, informed by differing combinations of materials, processes, practices, visitor expectations, use patterns, building types and forms of expertise (Douglas-Jones et al. 2016). In some contexts, weathering and decay of stone can accrue ‘age value’, marking the passage of time, contributing to the experience of authenticity, and creating aesthetically pleasing ‘patina’ and ‘ruination’. In other cases, material transformation and decay is associated with a loss of value and authenticity. As the values associated with material transformation emerge in particular contexts, so does the application of science to understanding, controlling and arresting material transformation. It is not just a case of identifying pre-existing values that then inform how ‘problems’ are framed, and when and how heritage science is applied. Rather, the application of science in heritage contexts is embedded in dynamic modes of valuation.
The use of scientific techniques to measure, understand and control material transformation is informed by these values, but these very processes also have the potential to change those values. Integrated qualitative research methods can increase our understanding of these important, site-specific conditions and processes, and contribute to more nuanced and productive applications of conservation science, sensitive to the values associated with heritage sites in general, and carved stone monuments in particular.
Figure 1: View of the north transept of Dryburgh Abbey illustrating deterioration of carved stone. Crown Copyright: Historic Environment Scotland
Figure 2: The elaborately carved loft of the Montgomery Tomb at Skelmorlie Aisle. Crown Copyright: Historic Environment Scotland
Return to Section 3.6: Scientific analysis
Return to Section 5.3.1: Issues and dilemmas