MANUFACTURE. A better grade of clay is re quired for terra cotta than for brick. Oftentimes clays from different localities must he mixed to secure the right, color, while such vitrifying in gredients as pure white sand, old pottery or fire lm•ick finely ground, and burned clay, are added to secure partial vitrification. After weathering, the selected clay is ground o• washed (see CLAY, par. Clay-Mining), mixed with the vitrifying, ingredients and water; next, the various sorts of clay are piled in layers. Vertical slices from this mass are taken to either a pug mill o• rollers for tempering. The material is next sent to the molding room in cakes of convenient size. If only one piece is required, the clay may be mod eled by hand, ready for baking: hut if the design is to he repeated a model is made and a mold taken, into which the clay is forced by hand. After partial drying the product is turned over to the finisher, who may be more o• less skilled. according to the character of the design. After the forms are baked or burned, as de scribed under KILN.
BIBLIOGRAPHY. Lecuyer, Trrres elates (Paris, Bibliography. Lecuyer, Trrres elates (Paris, 1SS2-S5) ; Cherret, Die Terrakotten (Berlin, 1SS6) ; Pottier, Les statuettes de Jerre enite (Paris, IS90). The Greek statuettes are well
treated in Hutton, Greek Terracotta Statuettes (London, 1899), and less accurately though in more detail in Iluish, Greek Terracotta Statuettes (ib., 1900). Of special value are: Kekule, Griechische Thonliguren aus Taaagra (Stuttgart, 1878). A catalogue of ancient terra cottas is in preparation by the Berlin Academy of Sciences under the editorial supervision of Kekule, of which two volumes have appeared. The Etruscan funeral urns are collected by Brunn and Korte, I rilievi, (Hie nrac etrusehc (Rome, 1870 et seq.). On the use of terra cotta in architecture consult: Dorpfeld, ((Tither, Borrmann, and Siebold, Ueber die rerwendang von Tcrrakottca am Geisoa and Dache gricehischcr Rau werke (Berlin, 1881). For application of ornamental terra cotta to buildings, eonsult Kidder, Building Construction, and Superintcndenec, part i., "Mason's Work" (New York, IS90). For the manufacture of the various wall and floor fireproofing materials, roof coverings, and other clay goods often going under the name of terra cotta, also for porous terra cotta and terra cotta lumber, see BRICK;