But the enameller's art had another influence on that of stained glass. A form of enamelling developed at Constantinople and practised at Limoges was that known as "cloisonné." In this, narrow strips of metal are soldered edgeways to the groundwork and the spaces between are filled with differently coloured enamel, the different colours being thus separated by strips of metal.
When the enameller's attention was first turned to glasswork, in which different coloured pieces of glass were separated by strips of lead, he must have been struck with the similarity of the two arts, and have perceived that the style of design already developed in enamel could be applied with little change to glasswork.
This probably explains not only the apparently sudden birth of the art fully formed, but the strongly Byzantine character of the design in the earliest work, the enameller's art having been brought, as we have seen, from Constantinople by way of Venice.[3]
What, then, is the oldest "stained-and-painted" glass in existence? At Brabourne in Kent there is a small window, of which a coloured tracing may be seen in South Kensington Museum, which may belong to the eleventh century. It consists of a simple pattern of white glass and leading, with small pieces of colour inserted at intervals. Some of these latter, however, have been formed into rosettes of simple design by means of opaque enamel, which is the only painting in the window at all. Whatever the actual date of the window, I think it is not unlikely that it shows the manner in which enamel painting and glazing were first combined.
[Illustration: PLATE IV "NOË IN ARCHA," FROM THE NORTH CHOIR AISLE, CANTERBURY Twelfth Century]
Almost the earliest glass, however, to which any date can be approximately assigned are the panels in Le Mans Cathedral,[4] which are illustrated by a sketch of Mr. Saint's in Plate I.
In a thirteenth century manuscript preserved at Le Mans it is recorded that Bishop Hoel, who occupied the See from A.D. 1081 to 1097, glazed the windows of the Cathedral with stained glass, "sumptuosa artis varietate," and it is just possible that this glass, which was found in 1850 scattered and glazed up among fragments of a later date, may be part of the glass referred to.