MOSAIC, the art of producing artistic designs by setting small square pieces of stone or glass of different colors, so as to give the effect of painting. Both the origin of the art, and also of its name, are buried in obscurity; it was, however, much practiced by the ancient Romans, especially for ornamental pavements, specimens of which are almost always found whenever the remains of an old Roman villa are discovered. Under the Byzantine empire; it was also much used for the ornamentation of churches, in which it formed a large portion of the wall-decoration. It was re-introduced into Italy for the latter purpose about the middle of'the 13th c. by Andrea Tafi, who learned it of some Greek artists employed at Venice in decorating St. Mark's. Since then it has been especially an Italian art, and to such wonderful perfection has it been brought, that most minute pictures are produced by it. Within quite recent years, mosaics of surpass ing, beauty both in design and material, have been produced by Russian artists in the Imperial glass manufactory of Russia: those shown in the Russian department of the international exhibition (1862) have probably never been surpassed. The pieces of glass of every shade of color are technically called smalts; they are generally opaque, and are set in cement in the same manner as tiles or pavement. Some fine pieces of mosaic
pavement have lately been produced in this country by Messrs. Minton & Co. of Stoke upon-Trent, and by.Messrs. Maw of Brosely, proving that the art only wands sufficient encouragement to obtain a high position. In Italy there are two very distinct varieties of mosaic work—i.e., the Florentine and the Roman; the former is entirely formed of pieces of stone or shell of the natural colors, and is limited in its application chiefly to floral and Arabesque designs. The later is made of the glass smelts mentioned above, and has so wide an application, that most of the finest paintings of the best old master& have been copied in mosaic, and the pictures so taken form the almost imperishable decoratious of the finest churches of Italy. The manufacture of the opaque glass or smelts for making the little square pieces called tesserfe of which the pictures are com posed, is a very important one, and is carried on in the Vatican, where 23,000 shades of the various kinds of colored glass are produced.