higher branches of ceramic manufacture.
It is not unlikely that plumbeous glaze may have been introduced by Greek or oriental potters into southern Italy. We learn from the monk Theophilus that the art of decorating fictile vessels with vitreous colours was practised by the Byzantine Greeks, who would have carried it there. This statement, in all probability, refers to the lead glazed wares and not to the tin enamel, the former of which, as we have seen, was known earlier than his time to the potters of Tarsus, Pompeii, &c., and it is reasonable to believe that the art may have been preserved in Byzantium when lost, or nearly lost, in Italy. Perhaps, in combination with incised ornament the use of this glaze never ceased in that country from the eighth and ninth centuries until the introduction or discovery of the stanniferous enamel in the fifteenth century; and we find that the earliest glazed wares of that country, the sgraffiati, the painted, and the mezza maiolica wares, are covered with this description of vitreous surface.
In the eleventh century churches built in various places were decorated with discs and “ciotole” of glazed and painted terra-cotta. The researches of the abbé Cochet at Bouteilles have shown that glazed pottery was in use in the north of France in the Anglo-norman period of the thirteenth and fourteenth centuries, or perhaps even in earlier time. Examples of glazed and painted tiles of the fourteenth century are preserved in the British museum. As before stated, this glaze is composed of silica with varying proportions of potash or soda and of oxide of lead, by which addition it is rendered more easily fusible but remains transparent.
To obtain a white surface was, however, desirable, the colour of the paste beneath the glaze being generally of a dull red or buff and ill-adapted as a ground for the display of coloured ornamentation. To supply this want, before the invention of the tin enamel, an intervening process was adopted. A white argillaceous earth of the nature of pipeclay was purified and milled with water, and thus applied over the coarser surface of the piece in the same manner as the glaze: again dried, or slightly fixed by fire, it was ready to receive the translucent coat through which the white “slip” or “engobe” became apparent. It is easy to conceive that by scratching a design or pattern through this white applied surface to the darker clay beneath, before fixing in the fire, a ready mode of decoration presented itself without the use of colour, to be covered with but visible through the glaze; hence the early incised or “sgraffiato” ware, one of the primitive modes of decorating glazed pottery.
Passeri states that pottery works existed from remote periods in the neighbourhood of Pesaro, as proved by remains of furnaces and fragments of Roman time and tiles with the stamp of Theodoric; that during the dark ages the manufacture was neglected, but that it revived after 1300, and that it then became the fashion in that city to adorn the church towers and façades with discs and “bacini” of coloured and glazed earthenware; a practice which had been in use at Pisa and other cities as early as the eleventh century. The origin of this custom has been much discussed; and the reader will find an account of it in the introduction to the detailed catalogue of Maiolica in the South Kensington collection. Occasionally, or rather frequently, circular and square slabs of porphyry and serpentine were used on the same building, concurrently with the glazed earthenware, as on the tower of Sta. Maria Maggiore at Rome; and, indeed, this mode of enrichment attached to the architecture of the 11th, 12th, and 13th centuries is in accordance with that produced by the enamelled discs and inlaid stones on processional crosses and church plate of the same period.
The only instance, observed by the writer, of the occurrence of these “bacini” of glazed ware in domestic architecture is seen over the windows of the palazzo Fava in Bologna. This style of decoration ceased entirely during the course of the fourteenth century.
Passeri instances the use of glaze on tiles upon a tomb in Bologna, opposite the church of S. Domenico, dated about 1100; and he further states, but we know not upon what authority, that it was about the year 1300 that the method of covering the clay with a “slip” or “engobe” of white earth, or the coarser earth of Verona, was first adopted. Slightly baked, it was glazed with “marzacotto” (oxide of lead and glass), applied wet and again fired; and this glaze was variously coloured yellow, green, black, and blue, by iron, copper, manganese, and cobalt. A similar method of coating the rough and porous baked clay seems to have been known also at a very early period in the north of Europe, and to have been in use throughout France, Germany, and England.
CHAPTER II.
Enamelled or Stanniferous Glazed Wares.
It was found that by the addition of a certain portion of the oxide of tin to the composition of glass and oxide of lead the character of the glaze entirely alters. Instead of being translucent it becomes, on fusion, an opaque and beautifully white enamel, the intervening process of covering the surface of the clay with a stratum of white earth before glazing being unnecessary. It, moreover, was found to afford a better ground for the application of coloured ornament. The process of application was the same as for the “slip;” after immersion in the enamel bath, and subsequent drying, the painting is applied upon the absorbent surface; the piece being then subjected to the fire which, at one application, fixes the colours and liquifies the glaze. This “enamelled” pottery (émaillée) is by far the more important group of the glazed wares, being susceptible of decoration by the lustre pigments, as well as by painting in colours of great delicacy; and it comprises the Hispano-moresque, the real Maiolica, and the perfected earthenware of Italy and other countries.
It is true that the first trace of the application of oxide of tin to produce a white opaque glazed surface is to be met with upon Babylonian or Assyrian bricks, but we are disposed to think that it was then merely used as a pigment to produce a white colour, and not as an application to pottery for the production of a white opaque glaze capable of receiving coloured enrichment by painting in other pigments. A corroboration of this opinion would seem to exist in the fact that throughout Asia Minor, Syria, Persia, and Egypt, a purely stanniferous glaze on pottery has never been generally adopted, or taken the place of that simple and beautiful siliceous coating, so dexterously applied and with such richness of effect upon the Persian and Damascus earthenware. Engraved is an example of an early Damascus plate (no. 6590), at South
Kensington. Perhaps isolated and lying dormant in remote localities for centuries, its use may have been learned by the Arabs, for its next appearance is upon fragments of tiling apparently of their manufacture or fashioned under their influence. How the knowledge of this enamel travelled, when and where it was first used, and to what extent applied, is still doubtful. We meet with an occasional fragment generally upon mural decoration of uncertain date on various Arab sites, till at length it becomes palpably appreciable in the Moorish potteries of Spain and of the Balearic islands. The baron J. Ch. Davillier, in his excellent work on pottery, states that he has not been able to discover any piece which could reasonably be ascribed to a date anterior to the fourteenth century, some two hundred years after the expulsion of the Saracens from Spain. In Valencia, however, anterior to its conquest by Jayme I. of Arragon in 1239, potteries had been long established, and were of such importance that that monarch felt himself bound to protect the Moorish potters of Xativa (San Filippo) by a special edict.
We must bear in mind that there were two periods of Mahommedan sway in Spain, the first on the expulsion of the Gothic monarchy by the Arabs and the establishment of the Caliphate at Cordova, in the eighth century. Of the ceramic productions of this early period we have no accurate knowledge, but we should expect to find them of similar character to the siliceous glazed wares prevalent in the east. The second period is after an interval of five centuries, in 1235, when the Moors founded the kingdom of Granada, having driven out the Arabs. Then first appear the wares usually known as Hispano-moresque, like the fine vase (engraved) no.
