Fig. 5.—Samian Bowl.
Fig. 6.—Græco-Roman Vase.
A Græco-Roman vase in terra-cotta is shown at Fig. 6.
Roman pottery and fragments of it have been found in every country that was formerly under the Roman rule, and consists of examples both of a very simple kind and artistic. Great quantities have been found in England, and every year almost brings new examples to light, consisting of vases, lamps, and panels in terra-cotta.
Although the Greeks never quite lost the art of making pottery during the Middle Ages, they did not produce much artistic work after A.D. 200, and between this time and the end of the fourteenth century. Artistic pottery as glazed ware was imported into Europe from Damascus through the Arabs or Saracens about this time. Cups from Damascus in glazed pottery were reckoned among the treasures of kings, and it was from Damascus that the Arabs undoubtedly brought the secrets of glazed earthenware to Spain, where they established the potteries that fabricated the famous Hispano-Moresque ware. Before dealing with this ware, it is necessary to note briefly the various kinds of glazed wares anterior to its invention. The process of glazing terra-cotta tiles, bricks, and vessels is of great antiquity. In Egypt, as early as the fourth dynasty (B.C. 3766-3600), examples of glazed terra-cotta tiles were in use. Copper has been employed at these early dates to produce a turquoise blue enamel in Assyria and Babylon, and tin has been used in the glaze mixture on the enamelled bricks from the same countries. These ancient tiles and bricks, therefore, belong to the category of fayences. The word fayence, now of so wide application, is derived from Faenza, a town in Italy, where enamelled earthenware, or maiolica, was manufactured in the fifteenth century, which was distinguished by its fine polished white enamel. Fayence is a ware that is distinct from porcelain; it is a potter’s clay mixed with a marl of an argillaceous and calcareous nature and sand. According to the composition, and the degree of heat required in firing, it is called “Soft” (Fayence à pâte tendre) and “Hard” (Fayence à pâte dure).
English earthenware made from pipeclay is “soft”; stone ware, Queen’s ware, and some other special wares are hard. Soft wares are unglazed, glazed, and enamelled. The glazed or varnished wares, as we have seen, were made by the ancient civilized nations, as well as the coarser terra-cotta or unglazed wares. In medieval and in modern times enamelled ware, as distinct from merely glazed or varnished wares, have been made, as well as porcelain or China ware; the latter is called also Kaolin, and is a fine white earth in which silex is the chief constituent, which is derived from a decomposition of feldspathic granite.
Vitreous glaze (or glass) is composed of sand or other siliceous matter fused with potash or soda; this is ground and mixed with water, forming a liquid in which the clay biscuit ware is dipped, and afterwards fired, in order to make it impermeable to liquids. Oxide of lead in considerable quantities is added to the vitreous glaze, which increases its fusibility, but still keeping it transparent; this is what is known as a plumbeous glaze. This glaze may be coloured yellow by the addition of iron oxide; green by copper oxide; blue by cobalt; and black by manganese. All these coloured glazes were known to the ancients.
A further addition of the oxide of tin to the vitreous or plumbeous transparent glaze, in comparatively small quantities, produces the opaque enamel known as a “stanniferous” or tin glaze. This is the enamelled glaze of the Della Robbia ware, of the Hispano-Moresque, and of the Italian maiolica.