How Do You Conserve a Pair of 200-year-old Slippers
|
21.08.2019
At St James’s Gardens, Euston, where we are carrying out archaeological excavations on behalf of CSJV for HS2 Ltd, our conservators are collaborating closely with archaeologists to conserve vulnerable finds, making regular on-site visits. We are very lucky that the site’s wet, low oxygen ground conditions provide prime conditions for the preservation of organic material such as textiles, leather and wood, which are relatively rare in the archaeological record. However, once removed from the ground, the environment change triggers the deterioration process and can lead to irreparable changes in objects, and in extreme cases, to their complete disintegration. In this blog, conservator Lucie gives us a glimpse into the important work she has been doing to stem this process and conserve two of the many fascinating objects being found at St James’s – a pair of slippers…
Back in January, a pair of slippers was retrieved from a lead coffin believed to have belonged to a civil servant with the British East India Company who lived in Bombay (now Mumbai) for over twenty years, at a time when the Company established and expanded its rule over parts of the Indian subcontinent. He returned to England in c.1810 and lived his final years in retirement at a house in Fitzroy Square, St Pancras until his death, aged 70, in April 1825. The slippers were found placed on his lower legs, soles down, with toes facing toward the head.
The slippers before conservation
After a heads-up from the archaeologists on site, the slippers were carefully lifted and brought to the conservation lab. Using the microscope, we were able to tell that they had leather soles and a woven textile upper. If left to dry in the open air, the leather would shrink, warp and completely lose its shape, causing irreparable damage to the object and possibly destroying information that could have been of use to specialists. Specific conservation treatment was required to stabilise the object and preserve its most features:
Cleaning
The first step was to clean the clay and burial soil from the surface of the object, to reveal any surface details but also give a good indication of the fragility of the object and how to treat it. The slippers were placed on large trays, inclined at a slight angle so that the water would run continuously. A very soft brush and a natural sponge were used to gently remove the surface soil. Due to the fragility of the wet fabric uppers, thorough cleaning was postponed until the drying process was complete and the materials strengthened.
Immersion
We needed to stabilise the wet leather to avoid the warping and shrinking air-drying would cause thanks to uncontrolled evaporation of the water held within the object. To avoid this, we used a bulking agent to replace the water. We placed the slippers in a sealable container and filled it with a solution of water and glycerol (a colourless and odourless liquid used as both a sweetener and a humectant – something that retains moisture) until it covered the slippers. They were left in this solution for three days.
Freeze Drying
The slippers were then placed first in the freezer to solidify the water and glycerol solution in the slipper, then in the freeze-dryer. The freeze-dryer sublimates the ice from the object into water vapour, leaving only the glycerol behind and drying out the materials. The length of this process depends on the quantity of material and its condition. For these slippers, it took about three weeks.
Packing
One of the most common reasons for object damage is through manual handling. To minimise these issues, objects are packed in way to ensure maximum visibility but minimum handling, using conservation-grade materials which are designed to not react with or damage the object.
As a result of this process, the slippers can now be handled and examined for further analysis by specialists. Given the initial instability of the materials used to manufacture the slippers, the conservation treatment was necessary to preserve the shape and details of the slippers for future work. All the information gathered during the treatment and details of the treatment itself will be made available for a specialist to consult, and could provide valuable new insight into funerary goods in Victorian Christian burials.
The archaeological programme at St James’s Gardens in Camden, London, is being carried out by our experts on behalf of Costain-Skanska Joint Venture for HS2 Ltd. To find out more about the programme visit www.hs2.org.ukfor information on what is going in your local area or how you can get involved head to https://hs2ineuston.commonplace.is/.Explore the archaeology programme on social media with #HS2digs.
