The Stained Glass
Before the stone work had begun, the stained-glass windows were removed to insure their safety. The stained-glass windows, installed by Franz Meyer of Munich in 1908 and 1931, were in very poor condition. Many of them exhibited serious "bowing." Bowing, in which the lead weakens under pressure of wind, heat, and cold, results in the window bending inward. If not corrected, the glass eventually falls out of its leaden frames. The problem was worsened by the composition of the lead used a century ago. Earlier stained-glass artisans used an alloy of lead and other metals. In the early 1900s, makers decided to use pure lead, not realizing that it was more subject to deterioration than the alloyed lead of previous ages.
Femenalla & Associates, from Annandale, New Jersey was granted the contract for the restoration of the stained glass. Several of the glass panels, particularly the ones in the lower portions of the windows, the moveable ventilators, had been replaced over the years. The glass in the ventilators is most prone to damage due to the continual movement of these windows. It is easy to detect the replacement panes in the scrollwork sections of the windows. They have a whiter appearance than their neighbors.
The restoration of the stained glass was a painstaking process. Each window was removed and taken to the glass studio. There, the old lead was removed, the windows were taken apart, the glass cleaned, and replacement glass fabricated where necessary. Finally, each window, like a great jigsaw puzzle, was put back together with new copper-lined alloyed lead. The restored windows were then returned to their places in the chapel.
No exterior clear protective glass or plastic was placed on the outside. The restorers believe that, unless the building is in danger of vandalism, such glass is not only unnecessary but can cause damage. The exterior "protective" glass or plastic often traps hot air that can damage the lead. The lack of the exterior clear glass also allows light to give a much more beautiful expression to the colors of the stained glass.
