Some of the rarest surviving 18th-century stained glass in Britain has been fitted with environmental protective glazing to protect it from weathering which has been worsened by “climate change”.
The National Trust has embarked on the conservation work to help protect the artwork by John Rowell in a gothic tomb chamber at the property The Vyne in Basingstoke, Hampshire.
The stained glass in a gothic tomb chamber dates back 250 years but the charity is taking the action following increasing rainfall and heat from the sun.
A National Trust spokeswoman said: “Recently, climate change exacerbated the fragile condition of the window, causing the painted detail to flake, lead-work to warp and leak, and cycles of condensation to eat away at the surface of the glass.
“The marble tomb featuring an effigy of Chaloner Chute, The Vyne’s original 17th-century owner, has also been affected, the surface starting to erode into small crystals, known as ‘sugaring’.”
The glass window, which depicts the Adoration of the Shepherds after Van Dyck, is considered to be the most important surviving example of Rowell’s work.
The spokeswoman said: “Originally a plumber, Rowell was a self-taught glass-maker and although accomplished, his paint was not durable enough to withstood the test of time and would ‘vanish’ from the glass. Very little of his work remains.
“The window is one of two stained glass panels in the tomb chamber to receive protective glazing.
“The second, which depicts the same scene, was made by Rowell’s great rival and another prominent glass-maker, William Price. The two craftsmen regularly competed for commissions.”
The work was carried out by specialist conservators Holy Well Glass of Wells, Somerset, following year of monitoring.
The glass was removed before cracks were repaired and it was was cleaned under binocular microscopes which involved rolling cotton buds soaked in ethanol and de-ionised water gently across the surface to ensure none of the original painted detail was lost.
A secondary glazing layer was then added in lead and hand-made glass, replicating the traditional methods found in the stained glass.
This was mounted in the original timber frame, with the historical stained glass mounted in a bespoke bronze frame marginally inside its original position.
The interspace between the layers was also ventilated to avoid creation of a microclimate, which could lead to condensation.
Jack Clare, director of Holy Well Glass, said: “This highly significant glass is exceptionally fragile, and showed clear signs of deterioration due to its environmental conditions.
“We are seeing increasingly frequent extreme weather events, which are exacerbating the deterioration of our historical buildings.
“This is becoming a major consideration in caring for our nation’s historic buildings, with concerns affecting the approach of a wide range of works, from guttering to glazing.”
Dominique Shembry, National Trust curator at The Vyne, said: “It’s wonderful to see these two beautiful windows back in their rightful place, looking so clean and free from mould.”
The Vyne was transformed from a cluster of medieval buildings into a Tudor palace between 1500 and 1520 by William Sandys, who became Lord Chamberlain to Henry VIII in 1526.
The ostentatiously designed tomb chamber, which remains empty, was created as a family mausoleum by John Chute in the 1770s, who also designed part of Horace Walpole’s Strawberry Hill.
