Pottery-moulding

The Encyclopedia of Founding (1892)

Pottery is a term applied to all objects made in clay and baked. The potter's art has been practised by even semi-barbarous races from the remotest period. Vases of baked earthenware were in use at the earliest period of Egyptian civilization, and Babylon and Assyria were noted for their pottery, which was of a red color and more refined shape than that of the Egyptians. The Greeks claimed the invention of the potter's-wheel. Etruscan ware, famous for the bas-relief ornaments moulded--evidently from metal ores on its surface, was in use 500 years B.C., and was the source of Roman pottery. The existence of unglazed earthenware in North America dates from remote times. This ware is of the rudest kind, and bears a striking resemblance to the earliest specimens of Northern Europe. Mexico and Peru were excellent workers in pottery in the earlier ages, to which the moulding, coloring, and ornamentation of preserved specimens bear ample evidence; but they never acquired the art of glazing. The knowledge of glazes was first acquired by the Egyptians and Assyrians, and descended from them to the Persians, Moors, and Arabs, the latter race introducing into Spain the art of making glazed tile about 711 A. D. The first appearance of Italian enamelled faience, the precursor of modern porcelain, dates about 1420, being then used by Lucca della Robbia for subjects in relief. A century later the works of Raphael were copied on plates and other ware, and painted in brilliant colors. Enamelled ware passed into France in 1590 with Catherine de Medici. The celebrated Palissy discovered at Saintes, 1555, the art of enamelling a gray paste, from which he moulded fruit, animals, etc., for decorating dishes. Glazed earthenware delft was first made at Delft about 1360; but none of these wares was equal to the Chinese porcelain, which, brought to Europe by the Arabs in the thirteenth century, became known in Italy 1330, in France 1370, and later in England. Wedgwood, the great English potter, was born at Burslem in Staffordshire 1730. Pottery and porcelain differ chiefly in this, that the superior quality of the materials used for making the latter gives it the peculiar quality of translucency it possesses. (See PORCELAIN.) Inferior materials used for making pottery, include phosphate of lime, bone-ashes, calcined flint, etc., which are added to the native clays. Besides the common methods of moulding by the wheel and forming with the hand, improved moulding machinery has been introduced, which facilitates operations to a great extent. Large numbers of articles are made in plaster-moulds, which being porous rapidly absorbs the moisture from the creamy clay with which they are filled; a stopper at the bottom of the mould is withdrawn when it is known that a sufficient thickness of the paste has adhered to the mould, and the superfluous paste runs out. If it is found that the article thus produced is not thick enough the operation is repeated. Another method of obtaining the desired form from plaster-moulds is to roll the clay into thin sheets and press it upon the surface with a sponge. See PORCELAIN.