Can anyone provide any references discussing the representation of the firmament, and the waters above the firmament, in mediaeval art? My interest derives from the re-use of related symbolism by artists working within the Scottish Arts and Crafts movement of the late 19th / early 20th centuries.
It is common for example to find on those tympana of mediaeval France which represent scenes taking in both earth and the heavenly world, e.g. the Last Judgement, a wavy line separating the two worlds. It is easy to assume that this represents clouds, but the line is continuous and sometimes surrounds the whole scene. It may therefore be not clouds but the firmament. In the mural of S Michele in Africisco, Ravenna, (now in the Bode Museum, Berlin), the “ground” of heaven is provided by wavy lines through which you can see the angels’ feet, and so represent water more probably than clouds. Does the wavy line that we meet in mediaeval art in fact represent “the waters over the firmament” rather than the firmament itself?