Next to these extremely ancient stamped bricks, in point of interest and antiquity, are specimens of the earliest engraving of letters on stone. We are informed by various historical writers that Cadmus, a Phœnician, who lived one thousand five hundred years before Christ, at a period contemporary with Moses, and who was esteemed as the builder of the city of Thebes, was the first who taught the Greeks the use of alphabetic symbols, an art he most likely acquired from the Hebrews. The most ancient specimen of an engraved inscription now known to be extant, is the Sigean Inscription, so called from having been disinterred upon a promontory named Sigeum, situate near the ancient city of Troy, in Phrygia. It is engraved on a pillar of beautifully white marble, nine feet high, two feet broad, and eight inches thick, and which, from the inscription, served as the pedestal of the heathen god Hermocrates. The letters used in this inscription are the capitals of the Grecian language, though rudely cut, but read from right to left like the Hebrew. This specimen of engraving must be about three thousand years old. Another not less interesting relic of the earliest age of printing is found in a Roman signet ring or stamp, approaching in character to that species of stamp now used by the post-office on letters. This curiosity is preserved in the British Museum. It is the very earliest specimen we possess of printing, by means of ink or any similar substance. It is made of metal, a sort of Roman brass; the ground of which is covered with a green kind of verdigris rust, with which antique medals are usually covered. The letters rise flush up to the elevation of the exterior rim which surrounds it. Its dimensions are, about two inches long, by one inch broad. At the back of it is a small ring for the finger, to promote the convenience of holding it. As no person of the name which is inscribed upon it is mentioned in Roman History, he is therefore supposed to have been a functionary of some Roman officer, or private steward, and who, perhaps, used this stamp to save himself the trouble of writing his name. A stamp somewhat similar, in the Greek character, is in the possession of the Antiquarian Society, of Newcastle-upon-Tyne.