STONEWORK AND MORTAR REPAIRS

Project overview
The James Bateman Geological Gallery (1862) at Biddulph Grange contains a selection of fossils and geological strata. These are set into the length of the gallery wall, in chronological sequence as understood by nineteenth-century geologists. Over time, many of the rock samples had disintegrated or gone missing. Cliveden Conservation was commissioned by the National Trust to source the missing stones and restore the display.

Summary of the conservation work carried out
A total of 28 sections were identified as missing from the display of nearly 100 samples. Sourcing the stones fell into three categories; stone still being quarried for commercial use, historically used building stone and unexploited geology.

With their industry knowledge and contacts, Cliveden Conservation identified the appropriate quarries in England, Scotland and Wales to place orders. Stones which were no longer actively quarried required knowledge from local contacts and the expertise of consultant geologist Alan Holiday to locate abandoned quarries and seek permission of landowners to collect samples. The search led the Cliveden team to sites across the UK from a Shropshire nature reserve, to a Dorset chalk pit, even a Forest of Dean coal mine!

The biggest challenge was sourcing stones which had never been quarried commercially. Where possible, fallen fragments from natural outcrops such as coastal cliffs were collected. This included Aberystwyth Grit, found in Pembrokeshire and Cornbrash from Buttersreet Cove in Dorset. However, the Bunter pebble found on the Devon Coast was impossible to extract, therefore materials were collected and ‘reconstituted’ in the workshop to form a facsimile panel.

Each of the sections were cut to their final dimensions on site and where necessary fixed into place with stainless steel pins. Old mortar was removed with hand tools and replaced with mortars to match the surrounding material or provide neutral fills.

Results
Cliveden Conservation successfully sourced all the missing stones to restore The James Bateman Geological Gallery. The Comley sandstone and Tertiary sands were successfully displayed on boards. Many of the stones were donated including a piece of Hertfordshire puddingstone gifted by Alan Holiday.