In the ruins of Nineveh and Babylon, there have been found, side by side with ordinary fired or unfired bricks, others of which one extremity was glazed and even enamelled with different colours. The surface of these bricks is not smooth, it has designs in relief. It is probable that the bricks were collected together when in a fresh state, and that, after lines had been grooved on them to mark the outline of the design, and a sign to aid in fitting them together, each piece was coated with an enamel and carried to the kiln. The pieces were afterwards fitted together and fixed with water.
This Assyrian style of decoration has been observed in various forms throughout Asia Minor and even in ancient Persia, where, thanks to the remarkable discoveries made at Suse by M. and Mme. Dieulafoy, magnificent and irrefutable proofs of the use of enamelled bricks have been found.
These enterprising explorers have removed from the palaces of Artaxerxes Mnemon (4th century B.C.) and of the great Darius (6th century B.C.), the ruins of which lie one over the other, some important examples of enamelled decoration in a fine state of preservation, which can be admired to-day in the Louvre Museum in Paris.
One represents lions, another the facing of a staircase, and finally there is an admirable frieze on which twelve arches of the Royal Guard are represented in bas-relief. This work, whose harmonious tints are now mellowed by time, is treated with noble simplicity; there is something imposing in it which astonishes and compels admiration. Th. Deck has examined this frieze from the point of view of execution. The bricks,
The enamels are of tin base, and the colours are formed by the metallic oxides at present used by us. These enamels are more alkaline than ours, however, because of the large quantity of silica contained in the clay. The conclusion of the eminent ceramist is that this example of manufacture is an extremely remarkable one, and quite worthy of serving as a model for architectural ceramic decoration.
Muller has reproduced these friezes on enamelled stoneware, and we have been able to examine this fine example of pottery-work at the Chicago Exhibition and at the annual Paris Salons.
The Greeks and Romans were certainly acquainted with the art of enamelling pottery, but for some unknown reason they rarely used colours, a strange circumstance with a people usually so fond of them. Even under Hadrian (2nd century), when the Egyptian style was very fashionable, the Romans did not carry their imitations so far as to use the enamelled facings of which they could have found such fine examples in Asia Minor.
This was evidently the cause which retarded the appearance of faience in Europe. It was at Troyes, in 1220, that plumbiferous glaze first appeared on terra-cotta roof ornaments. It was frequently used for varnishing facing bricks and the pureau (part uncovered) of tiles intended for roofing public buildings. To make those mosaics in colours, which adorn the roofs of many cathedrals of that period, especially that of Troyes, the tiles were coated with a coloured dip, red, black, yellow, or green, and the whole was covered with a lead glaze.
The popularity of these products lasted till the 16th century, then declined. Bricks which become varnished black in wood-firing were, however, always used in architectural decoration.
The enamelling of bricks suffered the same fate as their glazing, and it was only in the 19th century that it was revived, not only for decoration, but also for the hygiene of dwelling-houses. England, which is always at the head of any movement in pottery, anticipated us in the use of enamelled brick for the inner courts of houses, for servants' staircases, privies, etc. The imperviousness of these products gives them precious qualities from the point of view of hygiene and cleanliness.
The movement is much slower in France; people fear that enamelled products will not wear, and their high price is objected to. When we look at some of our facades crowded with costly sculptures, we ask ourselves whether a little economy could not be realised here, and whether, in less beautiful but equally indispensable parts of the houses, materials could not be used which present incontestable advantages over painting and are less costly to maintain.