Page:Encyclopædia Britannica, Ninth Edition, v. 19.djvu/644

620 POTTERY [PERSIAN . race or age, excelled in pottery as in other handicrafts. Their enamels and glazes are made and applied with the greatest skill ; their colours are brilliant and yet harmoni ous; and the patterns painted on their pottery are designed with the most wonderful grace and freedom, together with a perfect sense of the right kind of ornament to use for each special place and material. Mate- Materials used by Persian Putters. In most cases the rials. clay body of Persian pottery is completely covered either with a white enamel or with slip, and therefore any sort of clay sufficiently plastic for the wheel suited the purpose, whatever its colour. The enamel was much the same as that used by the ancient Assyrians, except that it con tained a much larger proportion of oxide of lead, of which there were often three parts to one of oxide of tin and five of silicate of soda. The white slip is silicate of alumina with some alkali. The glaze is either a pure silicate of soda, or has in addition a little oxide of lead to increase its fusibility. The pigments are oxides of cobalt and copper for the blues and greens, manganese for the purples, oxides of copper and iron for the reds, magnetic oxide of iron for the black, and antimony for the yellow ; a rich warm orange was produced by a mixture of anti mony and red oxide of iron. It is not always possible without actual analysis to tell whether the white ground of Persian pottery is a tin enamel or a glazed slip, especially as in many cases a glaze is applied over the enamel ; but this is not a point of great importance, as the decorative treatment of the white ground was in either case much the same. The following are the chief varieties of Persian pottery. Lustred 1. Lustred Ware. The application of lustre colours ware. requires a special process of firing. The following descrip tion applies equally to the other two classes of pottery in which lustre pigments were largely used, namely, Hispano- Moorish and Italian majolica. The special beauty of the lustre depends on the decomposition of a metallic salt, usually silver or copper ; the required design was painted in a pigment composed mainly of this salt over the sur face of the smooth enamel or glaze after it had been fired. The vessel with the lustre pigments was then fired again in a kiln specially so arranged that the heated gases and smoke should come into contact with the metallic pig ments ; the minute and heated particles of carbon in the smoke combined with the oxygen of the salt, setting free the metal, which was left, in a finely-divided state, fixed on the surface of the enamel. In this way a beautiful prismatic effect was produced like the colours of mother- of-pearl. The lustre colours when looked at from one point of view are simply various shades of browns and yellows, but when seen at an angle they appear shot with the most brilliant violets, blues, purples, and red. They were used generally, and with best effect, over a white ground (see fig. 45), but also over deep-blue or green enamels. Lustre colours were specially used by the Persians for wall-decoration (see TILES), but they also used them on both white and blue enamel grounds to ornament hookah- bottles, bowls, plates, ewers, and tall rose-water bottles. The lustre is generally used alone, and not, as in the Italian majolica, combined with other non-lustre pigments. Its use is very early in Persia : dated specimens exist of the 10th century ; and its manufacture has continued down to the present time, though that now made is of a very inferior quality. Ancient 2. Coarse pottery covered with a fine white silicious 8 ^V on ^ich arabesques and other simple patterns are painted in black, the whole then covered by a transparent green glaze. This is a very ancient sort of ware, made in Egypt during the XVIIIth Dynasty and many centuries after by Moslem potters, from the early years of their occu pottery pation of Egypt down to a very recent period. To this class belong the "bacini" or large dishes with which some FIG. 45. Persian ewer, white enamelled ground, with pattern in brown copper lustre ; the upper part has a blue ground. The mount ing is gilt bronze, Italian 16th-century work. (British Museum.) of the 12th-century churches in Pisa and other towns in Italy were decorated. They were built in on the outside walls of the campanili, or used in rows to form friezes. In design and method of execution they have nothing in common with Italian majolica, and the oft-repeated story of their being the models from which the Italians learned to make their majolica appears to be a baseless fable. 3. Sgrqffiuto Ware.ThesQ are certain large bowls orSgr jars decorated in a peculiar way, being covered first with a t a coating of white enamel and then with a complete coat ing of brown or deep-blue enamel. The pattern, usually graceful branches of plants with pointed leaves, is formed by cutting through the upper coloured layer down to the white enamel underneath before firing in the kiln. Thus the design appears in white with a coloured ground. The white is, of course, slightly sunk below the coloured layer. Bowls thus decorated are mostly white inside, with a little simple painting in blue, the sgraffiato or incised work being only on the outside. 4. The next class is the reverse of the incised ware in Wl treatment : the whole vessel is covered with brown or blue ena enamel, and the design, either arabesques geometrically^ treated or natural sprays of foliage, is painted over it in white enamel, thickly applied so as to stand out in slight relief. This and the preceding class are usually glazed over the enamels, a common Persian practice, to gain addi tional richness and brilliance of surface. Somewhat akin to this ware in style is a very beautiful sort of pottery with most graceful and delicate designs touched on with a fine brush over a white enamel ground. The pigments are blue, green, grey, and a very rich orange tending to red, and are all thickly but very delicately put on ; these pieces are of extreme beauty both in colours and in design. Tall jars, bottles, bowls, plates, and hookah-jars are the vessels usually decorated in this way. Some of the large plates are perfect marvels of decorative beauty of the most refined and graceful kind. 5. Damascus Ware. Under this head is generally Da included a good deal of Persian pottery made at other cu places besides Damascus, but of similar style and colour ing. It is mostly remarkable for the fineness of its white enamel or slip, its rich glaze, and the beauty of the designs

and colours. One class is painted wholly in various tints