In the case of the earlier vases, which are made by hand, after the clay was properly kneaded the potter took up a mass of the paste, and hollowing it into the shape of walls with one hand, placed the other inside it and pressed it out into the required form. In this way also the thickness of the walls could be regulated. When raised or incised ornaments were required, he used modeller’s tools, such as wooden or bronze chisels. The largest and coarsest vases of the Greeks were made with the hand, and the large πίθοι, or casks, such as have been recently found in such numbers in Crete and Thera (p. 152), were modelled by the aid of a kind of hooped mould (κάνναβος): see _ibid._). The smaller and finer vases, however, were invariably turned on the wheel. On a Graeco-Roman lamp from Pozzuoli, in the British Museum,[768] a potter is seen standing and modelling a vase before his furnace, in the manner no doubt employed at all periods. Certain parts of the ancient painted vases were modelled by the potter from the earliest times—_e.g._ on those of the Geometrical period horses are occasionally found on the covers of the flat dishes moulded in full relief, and in other examples the handle is enriched with the moulded figure of a serpent twining round it. This kind of ornament is more suitable to works in metal than in clay, and suggests the idea that such vases were, in fact, imitations of metallic ones. On vases of all periods moulded bosses and heads, like the reliefs on metal vases, are sometimes found; even in black-figured vases the insertions of the handles of hydriae and oinochoae are occasionally thus enriched. In the later styles modelling was more profusely employed; small projecting heads were affixed to the handles of jugs[769] at their tops and bases, and on the large kraters found in Apulia the discs in which the handles terminated (see above, p. 171) were ornamented with heads of the Gorgon Medusa, or with such subjects as Satyrs and Maenads. These portions were sometimes covered with the black varnish used for the body of the vase, but frequently they were painted with white and red colours of the opaque kind.