St. Michael’s Mount, St. Ives, Cornwall. National Trust

17th and 18th Century

The in-situ cleaning and repair of 5 windows to the north elevation of the Chevy Chase room at St. Michael’s Mount.

 St. Michael’s Mount is a rocky tidal island, linked to the town of Marazion in Cornwall. its medieval church and castle, are managed by the National Trust.  Today it is only accessible along a man-made causeway, between mid to low tide.  Traditionally, as its old Cornish name of Karrek Loos yn Koos suggests (“the grey rock in a wood”), it was set within woodland, which became submerged circa. 1700BC.

The focus for Holy Well Glass centred on the five windows of the north elevation, in the Chevy Chase Room.  These contain a superb collection of high quality European roundels, dating from the 15th to the 17th centuries.  For instance, north window I has a collection of English fragments of the early 15th century including a lovely Adoration of the Magi. There are many biblical scenes throughout the five windows, also an interesting 16th century allegorical roundel with a serf herding a cow, with birds and bees. There were failings in all the windows to some degree; lost mortar, clumsy leadwork and heavy soldering, very dirty glass both inside and outside.  There are also some poorly painted and unsympathetic inserts from a previous restoration, slightly misaligned earlier resin repairs, and severely corroded tie bars. However the condition is basically sound, and there was no reason to intervene in any major way, as the panels remained structurally stable.  Therefore light touch conservation was adopted. Failing mortar was raked out and re-applied with new gauged lime mortar to make weatherproof.  The inside and outside surface of the glass was cleaned in-situ, with deionised water and cotton wool swabs. Importantly, the corroded tie bars, which were beginning to damage adjacent stonework, were removed in-situ and replaced with non-ferrous bars, with copper ties also being replaced.