TESSELLATED PAVEMENT.

63

of objects, or various patterns and figures, composed by joining pieces of stone, glass, shells, or other suitable substances, very neatly, so as to form one smooth surface. In ancient times, the floors of apartments were often paved in Mosaic; and I think you must all have heard of the Roman pavement at Bignor, which is of this kind, and has often been visited by the curious. The patterns are formed by the nice arrangement of different coloured pieces. Our modern floor-cloths appear to be painted in imitation of Mosaic pavement; the pattern is formed by coloured spots. The Romans, however, did not always employ stones of different colours in their pavements. The remains which were some years since discovered at Fishbourne, were all, I believe, like these specimens. They are a rude kind of Mosaic, formed, you see, of separate pieces, joined by a strong cement. pavements are called " tessellated," from a Latin word, which means variegated by squares; but they are, in fact, a very coarse kind of Mosaic. These separate pieces may represent the pins of

66

Such

64

GLASS PICTURES.

glass, which are so minute in the delicate works I am going to show you, that perhaps you will hardly think it possible they can be put together in the same manner.

Here is a miniature representation of the castle of St. Angelo, and also the triumphal arches of Severus and Constantine, relics of the grandeur of ancient Rome. You would, at first sight, think they were paintings, and perhaps by candle-light you may not be able to distinguish any thing like the joining of distinct substances; but I assure you that the materials used in composing these little pictures, are pieces of glass, of every shade and colour that the subject requires. The glass is first cast into thin cakes, which are afterwards cut into long pieces. This mode of forming pictures was, about the beginning of the last century, employed on a larger scale, in decorating some of the churches in Rome. The original paintings being in a perishing state, from the dampness of the walls, this method was adopted of supplying the place of the old pictures, with copies made

MODE OF FORMING MOSAICS.

65

of a substance that would not be spoiled by damp.

When the glass picture was intended to be looked at from a distance, the pieces used were large in proportion; but in fine works, or ornaments like this, where the objects represented are small, and designed for close inspection, the artists employed pieces of glass no thicker than a common needle or small pin; so that a picture of four feet square, would take two millions of these glass pins to complete it. It is a very tedious operation to make such pictures, and requires a great deal of method, as well as patience and ingenuity.

In the first place, the glass pins must be carefully sorted, according to their shades and colours, and laid ready before the artist, in a case, or frame, divided into compartments, as the letters are sorted and laid before a compositor in a printing-office. A paste made of calcined marble, fine sand, gum, white of eggs, and oil, must then be spread, as a ground to receive the glass pins. The paste should be so

66

HERCULANEUM GLASS.

soft, that the pins may easily be put in, and, if necessary from any mistake, taken out again, and their position changed. When all is thus prepared, persons skilful in the art, will imitate the finest strokes of a painter so accurately that the glass picture can be distinguished from the original only by its lustre, and the greater brightness of the colours.*

The ancients were in possession of a still more delicate and curious method of forming pictures, by joining filaments, or threads of various coloured glass. Many specimens are preserved in the British Museum, but the art of producing such pictures is now lost. We only know that it once existed by the specimens which have been accidentally discovered. They are mostly in small pieces, like those composing this elegant bracelet, which were found in the ruins of Herculaneum. You will perceive that the various pieces constituting each plate, are so accurately united, that I believe, even with the help of a magnifying-glass, you will be unable to

*Lardner, 285.

HERCULANEUM GLASS.

67

discover any thing like a join. No particular object seems to be designed on these plates; but I have read of one specimen, not quite an inch long, and one-third of an inch broad, on which a duck, in colours as lively as those of a Chinese painting, was represented with a delicacy equal to that of the most highly finished miniature. The pupil of the eye, the feathers on the breast and wings, all were there; and to complete the wonder, on turning the glass, the bird appeared as perfect on the reverse side! This circumstance led to the conclusion, that such pictures must have been formed by joining slender threads of glass, in the way I have mentioned, and afterwards subjecting them to heat, so powerful as almost to melt them into one compact body; but how they managed to effect this remains a secret.*

The most celebrated specimen of ancient glass is a vase, or urn, of exquisite workmanship, from which the plaster cast on the table is modelled. The original was found, about the middle of the sixteenth century, in closed in a

*Lardner, 283.