Tile

All of the classic forms of clay tile continued in use in various parts of the world during the mediaeval period, but their su premacy as a roofing material gradually yielded to lead and zinc for churches, public buildings, palaces, etc., and to slate, stone and thatch for the smaller private houses.

Clay roof tiles used at the present day remain of substantially the same form ; improvements have been only in methods of manufacture and not in design. The flat tile designed to hook over roof battens or boards, is perhaps the most common type of small house roof covering in England and parts of France, and the combination of concave under tile and convex over tile is almost universal on pitched roofs in Italy, Spain, Greece and Turkey. The S-shaped tile is also common around the Mediterranean. The curved tiles are almost always laid in a heavy bed of water proofed mortar, with ridges and hips covered by courses of over lapping tiles, similarly bedded ; with flat tiles, the use of mortar is restricted to the convex or pointed tiles covering the hips and ridges. The best modern usage in laying tiles of this type de mands the complete covering of the roof surface with a water tight material such as slaters' felt or heavy water-proofed paper, before the tile is applied. The tiles themselves are held in place sometimes by copper nails which secure the under tiles direct to the roofing and the covering tiles to wood battens which run up the slope of the roof under each row of covering tiles, and some times by copper wire brought up through two holes in each tile and twisted together. In America the popularity of houses of Spanish and Italian types has led to widespread manufacture of tiles both of the S-shape and alternately concave and convex.

Although various attempts have been made to imitate clay tiles in stamped metal and concrete, these imitations are so lacking in the individual variation typical of ceramic ware that their use has been restricted to the cheapest type of jerry-built construc tion; their use, even there, is seriously questionable. Quite differ ent are the roofing tiles of reinforced and water-proof concrete, which are common in industrial buildings, especially in Europe, although their use in America is increasing. These modern, in

dustrial tiles are usually of large size—sometimes running to 4 ft. in length, and arranged to interlock, with the exposed surfaces grooved or channelled in such a way as to lead the water away from any joints. In these concrete tiles colouring matter is usually added in the material itself.

Roofing Tiles in the Far East.

Although the principle of the roofing tiles of China and Japan is the same as that in the West, there are many differences in detail. Thus, in temples and palaces in China, the under tiles are slightly concave and over lap, much like those of classic roofs; the covering tiles, however, are made absolutely cylindrical in general contour, with rebated ends, so that they form long, unbroken lines of shadow down the roof. Moreover, instead of the upright antefix of the classic roof, the Chinese tiles have ornaments that project downward, in generally scalloped shapes, over the face of the cornice. There is also, particularly in north China, a tremendous elaboration of ridge and hip tiles, which are frequently of great height, with an elaborately moulded section, and carry at their ends rows of animals, a great dragon or the like. At the ends of the ridge are large, grotesque beasts with their heads pointing inward ; all these ornaments are modelled and baked in the tile itself. One of the chief glories of the Chinese roof tiles is their colour. This is produced by a shiny glaze that reveals the expected Chinese ceramic skill. The usual colour of temple and palace roofs is bright yellow but other colours frequently occur. In central and south China, even temple roofs are frequently black. The cheap roof tile of the ordinary house is also almost black, but without lustre and with overlapping covering tiles like those of the West.

The same pattern of rebatted, continuous, cylindrical covering tiles is common in the Buddhist shrines of Japan, but colours are rare, the ordinary tile being grey, with a very effective and artis tic silvery lustre.