TILE. 286 TILEFISH. tiles have a great variety of thickness and shape. In the preparation of the chi.v for mold- ing some one or more of the processes described imder Clat (paragraph on Clai/ Miiiiiiy and Working] are employed, varying with the class of clay and the final product. For tile-burning see Kiln; Terra Cotta. Encaustic Tiles, for floors, ^valls, and other purposes, are decorative tiles in which the main body is of one color of clay and a pattern is in- laid in a contrasting color of clay. The term is a mere trade name, without special signifi- cance. Those which are small, inglazed floor tiles in plain colors, the design being made by the combination of tiles of different colors and shapes, are commonly called mosaic tiles. Glazed porcelain tiles bearing fixed designs in vitrifiable colors are also sometimes called encaustic tiles. The famous Dutch tiles are simply enameled earthenware, usually in blue, but sometimes in colors, and generalh' with Scriptural subjects for the design. They were first made in the iSJether- lands during the Renaissance period. Floor Tiles are now made by machinery in metal dies, in which they are subjected to heavy pressure. Tlie clay is first prejiared as for or- dinary ceramic work and then dried again and ground in powder. Wall iilcs are made with tlie back surface broken by 'undercutting,' so the cement may have a better hold. They usually liave a highly glazed surface. Floor tiles are generally preferred unglazed. Tliej' are made from a mixture of barytes and very hard clay, which vitrifies throughout its surface. When the tiles are to be figured the old process of fill- ing in the embossed surface with liquid clay has been replaced by a method of dry filling. The pattern is produced by the use of brass plates, an eighth of an inch thick, a separate one being used for each color. Thus, for an ornament in red and white on a blue ground, one plate is perforated so as to enable the red portion of the clay power to be filled in, an- other is cut for the white portion, and a third for the blue ground. When all are filled up the tile is pressed in a screw-press and fired as in the ordinary plain tile. FlKEPBOOFING, StBUCTUBAL, OR HoLLOW TiLES are rapidly growing in use (see Firepboop Construction), particularly for fitting around steel columns and girders forming partitions, floor arches, and ceilings. Their lightness is greatly in their favor. They are divided into three classes: Dense, porous, or terra cotta lumber, and semi-porous. Dense tiles are pre- pared for molding much like terra cotta. They are given lieavv pressure and a long burning, and are sometimes made from fire clay. Par- ous iiles are made by mixing one part by bulk of soft wood-sawdust or finely cut straw with two parts of clay, passing the mixture through a disintegrator or cutter, and then between two sets of corrugated rolls, one below the other. From the rolls conveyors take the mixture to the tile machines described below. The subsequent burn- ing destroys the sawdust or straw, leaving a very porous tile into which nails may be driven, or which may be cut with a saw; hence the name, terra cotta lumber. Semi-poroiis tiles are made of good fire clay containing 60 per cent. of silica, calcined fire clay, and coarsely groJnd bituminous coal. These materials are mixed, molded, and burned much like porous tiles. Hollow Tile ilACiUNES are of various forms according to the character of the clay. The tempered clay is forced through forms and around plugs. The forms give the outer and the plugs the inner shape to the tiles. The plugs are of metal, with their front ends just inside the form. Plungers force the clay over or around the plugs, then through the forms. The con- tinuous sliapes are separated by wires or knives. Some of the special forms require partial hand- shaping. RooriNG Tiles, when of clay, are something like terra-cotta (q.v. ) in their composition and maiuifacture. They are made in various colors and shapes, the shapes being governed largely by the kind of vertical joints employed. BiisLiOGBAPHT. Ome, Les carrelages emaillcs du moyen uge et de la renaissance (Paris, 1859) ; Bourgoin. Les arts arahes. Architecture (ib., 1873) ; Prisse d'A venues, L'art arabe d'aprcs les monuments de Kaire, etc. (ib., 1877): Jleurcr, Italienische ilajoUkafliesen, etc. (Berlin, 1881) ; Jacobstal. Siiditalienische Fliesenornamcnte (ib., 1886) ; Knochenliauer, Xiederlatidische Fliesenor- nanieiite ( ib.. 1888) ; Foy, La ccramiquc dcs con- structions (Paris, 1883) ; Sparkes and Gandy, Potters, Their Arts and Crafts (New York, 1899) ; Freitag, The Fireproofing of Steel Build- ings (ib.. 1899). TILEFISH (name coined from penultimate syllable of generic name). A deep-sea fish (Lopholatilus chameleonticeps) chiefly remark- able for its strange history. It was accidentally discovered in large numbers in 1879 by fishermen trawling for cod south of Nantucket, and was found again in 1880 and 1881. In the spring of 1882 shipmasters reported that an immense area of ocean surface about 300 miles south of Long Island was covered with many millions of float- ing fisli, dead or dying, chiefly tilefish, which showed no marks of injury' or disease. Verrill and other ichthyologists, judging by various circumstances, explained this as the result of an incursion of cold water, forced by the hea-y northerly gales of that spring, into the warm area of the Gulf Stream. This fish represents a genus of the family MalacanthidiB, which includes several edible fishes of the seas of both sides of tropical Ameri- ca, one of which, the blanquilla or 'whitefish' {Vaulolatilus princeps), is a well-known food fish of southern California. The tilefish is a large, big-headed, brilliantly colored, active fish, sometimes 40 pounds in weight, but ordinarily from 10 to 20 pounds. It is characterized by a high adipose protuberance upon the nape in ad- vance of the long dorsal fin, and by a short bar- bel at the angle of the lips on each side. Its fiesh was found to be excellent, and the United States Fish Commission made great efforts to learn where it might be found, Ijut the disaster of 1882 seemed to have wholly exterminated the species. Some ten years later an occasional one was captured, and investigation of the edge of the continental plateau was resumed by the Fish Commission. It was finally determined that the area of their distribution extends along a band of sea-bottom from about 39° N. latitude southward between 69° and 73° W. longitude to an unknown distance, in water from 60 to 80
