The materials used for writing have varied in different ages and nations. Stone and bronze, linen and papyrus, wax and parchment, have all been used. But the Assyrians and Babylonians employed for their public archives, their astronomical computations, their religious dedications, their historical annals, and even for title-deeds and bills of exchange, tablets, cylinders, and hexagonal prisms of terracotta. Some of these cylinders, still extant, contain the history of the Assyrian monarchs Tiglath-pileser and Assurbanipal, and the campaign of Sennacherib against the kingdom of Judah; and others, excavated from the Birs Nimrud, give a detailed account of the dedication of the great temple by Nebuchadnezzar to the seven planets. To this indestructible material, and to the happy idea of employing it in this manner, the present age is indebted for a detailed history of the Assyrian monarchy; whilst the decades of Livy, the plays of Menander, and the lays of Anakreon, confided to a more perishable material, have either wholly or partly disappeared. The application of clay to the making of vases was made effective by the invention of the potter’s wheel. Before the introduction of the wheel only vessels fashioned by the hand, and of rude unsymmetrical shape, could have been made. But the application of a circular table or lathe, laid horizontally and revolving on a central pivot, on which the clay was placed, and to which it adhered, was in its day a truly wonderful advance. As the wheel spun round, all combinations of oval, spherical, and cylindrical forms could be produced, and the vases not only became symmetrical in their proportions, but truthfully reproduced the potter’s conception. The invention of the wheel has been ascribed to all the great nations of antiquity. It is represented in full activity in the Egyptian sculptures; it is mentioned in the Scriptures, and was certainly in use at an early period in Assyria. The Greeks and Romans attributed it to a Scythian philosopher, and to the states of Athens, Corinth, and Sikyon, the first two of which were great rivals in the ceramic art. But, as will be explained hereafter, it was introduced at a very early stage in the history of civilisation upon Greek soil (see p. 206). Although none of the very ancient kilns have survived the destructive influence of time, yet among all the great nations baked earthenware is of the highest antiquity. In Egypt, in the tombs of the first dynasties, vases and other remains of baked earthenware are abundantly found; and in Assyria and Babylon even the oldest bricks and tablets have passed through the furnace. The oldest remains of Hellenic pottery in all cases owe their preservation to their having been subjected to the action of fire. To this process, as to the consummation of the art, the other processes of preparing, levigating, kneading, drying, and moulding the clay were necessarily ancillary.