The Jesse Window Project – An Update (November 2012)
The Jesse Window at Wells Cathedral is one of the most splendid examples of 14th century stained glass in Europe.
It dates from about 1340 and, considering its age, is still remarkably intact. Fortunately, the window has survived the vicissitudes of time and British history (narrowly escaping destruction during the English Civil War) and so what we see today is basically how medieval glaziers designed and created it and how our ancestors viewed it before us.
There have been sensitive repairs over the centuries, of course, and steps were taken during World War II to protect the Window.
The Cathedral has embarked, however, on a major project to conserve the Jesse Window. The first phase has been completed and saw the installation of external, protective iso-thermal glazing.
Medievalists and heritage experts agree the Jesse Window at Wells Cathedral is one of the most splendid examples of 14th century stained glass in Europe. It dates from about 1340 and, considering its age, is still remarkably intact. Fortunately, the window has survived the vicissitudes of time and British history (narrowly escaping destruction during the English Civil War) and so what we see today is basically how medieval glaziers designed and created it and how our ancestors viewed it before us. There have been sensitive repairs over the centuries, of course, and steps were taken during World War II to protect the Window.
Why is the Jesse Window in peril?
There had been growing concern over the past few years that the Window may deteriorate and be beyond repair unless urgent conservation work is carried out. Inspections showed that some of the lead was bowing and needed attention and that some of the leaded panels of glass were bulging and loose. More significantly, the medieval glass was suffering the effects of condensation and consequent mould growth. This, in turn, was attacking the painted layers on the glass: the paint was peeling and the glass was suffering corrosion; consequently, the whole medieval structure was at risk.
A successful fundraising campaign to save the Jesse Window enabled the Cathedral to seek the advice and assistance of a team of the best medieval glass experts in the country, as well as an eminent German consultant conservator, Dr. Ivo Rauch, to inspect the window and advise on the best course of action to save it. Careful assessment and the completion of a first phase of conservation – providing a protective barrier to the exterior of the medieval window- has now been completed.
During the last eight months, the team have been working full time on the 14th Century glass of the Jesse Window itself. The two lights and tracery above to the right hand side of the window (as viewed from the choir) were removed a year ago; this is to comprise the first of three phases of conservation work.
The first few months of the project were spent examining pre-conservation condition of the panels and designing a format in which this condition could be recorded. The recording format needed to have the potential to contain information about each piece of glass, its paint, and each section of lead within each panel. As well as this, the format needed to be easy to read, and suitable for distribution to and for approval by the Cathedral’s conservation bodies. Once the condition was recorded, a conservation proposal was drawn up for each panel, following a set of self-imposed rules to ensure consistency not only through this phase, but also for the rest of the project.
Finally, work began on the panels themselves. First both faces of the panels were photographed on a light box in both reflected and transmitted light, then cleaning began, first of all under a microscope to ensure that the paint was not damaged in any way. The panels were wet cleaned with cotton wool swabs (tens of thousands of them) and a mixture of acetone and deionized water to remove surface dirt. Leaded light cement that had been smeared over the glass during previous works was cleaned back by careful use of the scalpel.
Panels where the all or part of the lead matrix was judged in need of replacement were stripped, ready for full or partial re-leading. The conservators report that a few vital areas of paint have been lost, and they have managed to find reference to paint 1mm reinforcing plates which will be assessed when the panels are reinstated. Bronze support frames that will stabilize the window panels once they are re-installed and prevent them from bowing are now part–constructed.
The conservators will be completing works to this first phase shortly after Christmas 2012 before removing the next phase (central three lights and tracery) in early 2013. This exciting project is on schedule and will be completed during 2014.