CEILING, the interior overhead surface of an apartment usually formed of a lining of some kind affixed to the under side of joists supporting the floor above, or to rafters; the horizontal or curved surface of an interior opposite the floor. The word seems to have been suggested by the use of arched coverings for churches, and even for rooms, which pre vailed in the Middle Ages, and were not un known to the ancients. In Egyptian temples the undersides of the flat stone roofs were ornamented with blue paint and yellow stars and other hieroglyphics of the heavens. The ceil ings of Babylonia and Assyria were often gilded and stuccoed. Greek roofings were dec orated inside with ornaments. Arched ceil ings among the Romans were known by the name camera or camera, the Greek origin of which seems to furnish an argument in favor of the view that the arch was known to the latter people. The camera was formed by semi circular beams of wood, at small distances from each other, over which was placed a coat ing of lath and plaster. In later times the camera were frequently lined with plates of glass, when they were termed vitrea. But the ceilings most common among the Romans were flat, the beams, as in modern times, having been at first visible and afterward covered with planks and plaster. Sometimes hollow spaces or panels were left between the planks, which were frequently covered with gold and ivory, or paintings. The arched ceilings of the Romans were commonly of brick or concrete covered with stucco, and were of three kinds: barrel vaults, grouted vaults, and domes. The Roman ceilings were always elaborately dec orated with stucco or paintings, as seen in those of the Pompeian baths. After the decline of
Roman art, ceiling decoration became obsolete in the to be revived after the Roman esque Period. But Byzantine art, with its in ventions of glass, developed new and wonder ful types, using curved roofing and mosaics wherever possible. Good examples are the Saint Mark's in Venice, and the churches at Salonica and Constantinople. Mohammedan art developed a similar form. In the West, in the Middle Ages, the ceiling design took the form of bare rafters, which was later replaced by vaulting of stone and flat wooden ceilings. In England, the simpler forms prevailed; while in France, the multiple rib vault and the elabo rate fan vault developed. The wooden ceilings were decorated in the hammer-beam types of English churches and halls, which lasted. until the 17th century. During the Renaissance, Italy used three types of ceiling, the smooth vault; the same with penetrations, having a flat central field and curves; and the flat paneled ceiling of wood or plaster, of which the most magnifi cent example is that in the 'palace at Venice, highly decorated with paintings by Titian, Tintoretto and Veronese. In England, at Coleshill, Berkshire, a ceiling by Ingo Jones (1650) shows a type which became predominant for a century: deeply sunk panels with medal lions around and bands enriched with foliage, fruit, etc., in bold relief. The present type generally used is the one developed by Robert Adam. Modern ceilings are generally flat and are of plaster or wood. When the ceiling is divided Into deep panels it is said to be coffered.