Page:The American Cyclopædia (1879) Volume XIII.djvu/810

786 POTTERY AND PORCELAIN the union. The Derby factory still continues in operation. In 1760 a factory for hard paste was established at Plymouth by Cookworthy, the first specially devoted to hard paste in England. In 1772 it was purchased by Rich- ard Champion of Bristol, and the material was transferred to that city, where Champion had founded a factory a few years previously. Bristol porcelain had great celebrity. Pottery was also made there, which had extensive sale in America. Porcelain was first made at Worcester in 1751, and the factory there was of the highest importance from the amount and artistic excellence of its products. In 1753 the Battersea enamel works had used the art of transfer printing on enamel, and the Wor- cester factory was the first to apply the art to pottery and porcelain. The invention is as- cribed to J. Sadler, a Liverpool engraver, and as at first practised consisted in taking an ink impression from a copper plate on paper, which was gently pressed on the surface of the ware in bisque condition. A later im- provement consisted in bat printing, which was taking an impression in oil only on a bat of glue, which being pressed on the ware transferred the oil to the surface, and then metallic color was sprinkled on, the oil causing it to adhere in the form of the^ engraved pic- ture. This simple discovery revolutionized the art, in making beautiful decoration cheap and bringing hitherto expensive works of beauty within the reach of families of small means. It has been greatly improved in more modern times, and is now practised in printing several colors with all the success of chromo-lithog- raphy. The Worcester factory made close imitations of oriental wares, as well as superb works in original designs. In Staffordshire the number of potteries and porcelain estab- lishments which sprang up and attained emi- nence defies our space for enumeration. The most important in a historical point of view are the factory of Josiah Spode, founded at Stoke-upon-Trent about 1770, and that of Thomas Minton, founded at the same place in 1790. Both produced elegant works and be- came large and flourishing manufactories, the former being now the works of Copeland, and the latter of Minton, two houses whose works are unsurpassed if indeed they are equalled in the modern world. Simple mention must suffice of factories at Caughley, Newcastle- under-Lyme, Pinxton, Nantgarw, Lane Delph, Swinton, and Coalport. An important facto- ry existed near the close of the last century at Lowestoft, where hard paste porcelain was made so closely resembling Chinese that it can with difficulty be distinguished from it. The characteristic of the decoration was very deli- cate work in borders, initials, crests, &c., small flowers, usually roses without stems, lines of deep blue with gold stars, and occasional- ly landscapes. A successful attempt was made to establish porcelain works in Philadelphia between 1820 and 1825, by a gentleman named Tucker; but he abandoned the business in a few years, being discouraged at his failure to find artists who could decorate the ware. Since then the "Union Porcelain Works" of Thomas 0. Smith and son have been estab- lished at Greenpoint, Long Island, and entire table sets and other articles of excellent hard porcelain are manufactured and decorated there. Several kilns are employed in baking at this establishment. The first fine stone- ware made in this country is said to have been by Morrison and Carr at South Amboy, N. J. The manufacture of earthenware is now car- ried on to a considerable extent in the United States, its principal seats being at Trenton, N. J., where there are 13, and at East Liverpool, Ohio, where there are 6 establishments devo- ted to fine stoneware and white earthenware. Manufacture. The base of the materials for all kinds of pottery, except the old Sevres chi- na, which is now no longer made, is clay ; and upon the kind of clay and the ingredients with which it is mixed, and also upon the degree of heat used in baking, depends the product. For a description of the different kinds of clay, see CLAY. Common building bricks are made of common blue, brown, or red clay, mixed with varying proportions of sand. (See BEICK.) Land tile for draining is made of much the same material, and is often baked in the field where the draining is required. Drain tile for sewage is made of common plastic clay, the pipes being moulded by pressing the material between a solid cylindrical core and a hollow external cylinder. The baking is done In an ordinary upright kiln, like that shown further on for the baking of earthenware. The tiles are glazed by dipping them when green into a thin mixture of water and a fusible calcareous clay, the baking of the body and the fusing of the glaze taking place at one firing, which re- quires about 48 hours at a white heat. A thin mixture of water and clay or other solid in- gredients of pottery is called "slip." The method of preparing the clay for working is the same as that which will be presently de- scribed for the manufacture of common stone- ware. Fire bricks are made of an infusible kind of clay called fire clay, analogous to kao- lin, mixed with about 33 per cent, of quartz sand (crushed and ground quartz), or ground old brick. Roofing tiles are made of a clay which will fuse in baking, or they are glazed after baking to render them impervious to water. As fusion tends to warp them, glazing is generally regarded as preferable. Floor tiles vary in character, some being compact and glassy, while others are more or less porous, depending on the proportions of clay, flux, and sand or ground quartz of which the body is composed. All kinds of pottery -passing under the names of common stoneware, fine stoneware or stone china, earthenware, or tru( porcelain, as well as English tender porcelaii Parian and Wedgwood ware, are closely al- lied, their different characteristics depending