Tuesday 19th April 2011; Interventions & Participant Presentations

Week 2 of 12
Module 2: History and Theory of Conservation


We received a second morning of lectures from Gionata Rizzi today, starting with 'Types of Intervention: Marrying Theory with Practice' followed by a case study on Palma Cathedral.


A few thoughts from the lectures:
- It is possible for limestone to turn into quicklime during a fire. Clearly significant temperatures would need to be reached and sustained for this to occur, but consider the reaction then if water is used to put out the fire.
- When discussing conservation a saying that Gionata mentioned is that 'we don't know what we don't know'. We do the best we can with the knowledge we have at the time. In hindsight we can see the mistakes we have made and this should warn us to approach with increasing caution but to make the best of the knowledge that we have.
- We are used to seeing large volumes of white stone when looking at historic sculpture and architecture; a large amount of this however is believed to have been highly painted and colourful when first complete; why do we accept the restoration of the structure in many cases but not the colour?
- The finish (tooling) on a stone can vastly affect its appearance and colour, which is also true of the use of certain cleaning techniques; small fractures in a stone can dramatically change its appearance in the same way that a block of ice turns from clear to white when fractured.


This afternoon we had the first set of presentations from course participants from Australia, Belgium, Brazil, China, Czech Republic, Denmark, Georgia and India. This group includes a wide range of backgrounds including a geologist, theoretical and practical conservators and architects. Many of the issues and materials discussed bore similarities to Scotland; notably from Australia and Denmark. Sydney appears to have faced similar problems in terms of locating appropriate replacement stone to many Scottish cities due to the cities eventually engulfing the quarries. They now have legislation allowing the bed rock to be investigated for quarrying and stockpiling prior to any construction works. The Indian participant is based in Goa and her local building stone is a laterite, which is vastly different to any type of stone I know of that we use in Scotland, it's bright yellow to bright red in colour and has a powdery surface but appears to be very hard. The other countries discussed similar rock types to those present in Scotland; sandstone, granite and limestone.