It was long thought that the ancients did not understand, or at most practiced in a very imperfect manner, the art of making glass; but the vast number of beautiful specimens which have at length been brought to light, have completely dispelled all doubts of their high proficiency in the manufacture of a great variety of vessels from this material. The blowing of glass is an art of high antiquity, and, together with that of casting the fused material into moulds, was probably derived from the East. Even in later times Alexandria was, perhaps, the chief mart from which Rome derived her supply, though manufactories were established in Italy. In the conception and execution of the more elegant designs, the Greek artists, doubtless, found a peculiar province for the display of their taste and ingenuity. Glass was most extensively employed, both for use and ornament: so common, indeed, did it become, that drinking-vessels were sold in Rome at a cheaper rate than they now are in our own country. The methods of working in glass were, probably, very similar to those now in use. “Some glass is fashioned by blowing, some ground on the lathe, and some chased like silver,” says Pliny; and we know that the diamond was used in this last process. One beautiful specimen yet remains to demonstrate the skill with which they worked the brittle material, in the shape of a cup of opaline hue, round which a blue net-work and a green inscription have been carved; the meshes of the net-work, and the letters of the inscription, being united to the body of the cup by slender supports left during the engraving process. The celebrated Portland vase, now in the British Museum, is composed of a rich, dark-blue glass, covered with designs beautifully executed in opaque white enamel, and afterward fined into union with the body of the vessel. This cup was long supposed to have been cut out of a real sardonyx. The Greeks and Romans were adepts in the art of imitating precious stones by colored glass. To use the words of Beckman--“In the Museum Victorium, for example, there are shown a chrysolite and an emerald, both of which are so well executed, that they are not only perfectly transparent and colored throughout, but neither externally nor internally have the smallest blemish.” The metallic oxides were employed to produce the various colors, and with such success, that frauds by palming false stones on the ignorant were as common then as in our own day. Glass was sometimes made in layers of different colors, and then cut cameo-fashion; or colored stems were united longitudinally in a column, so that the horizontal sections displayed a beautiful pattern. Slips of grass were used, as we have seen, in mosaic pavements; glass in panes was employed for windows, or inserted in walls and ceilings for ornament. A story, perhaps fabulous, is told of an invention by which glass was so far deprived of its brittle qualities, that, when thrown