Wedging.
But even at this stage the clay is not yet ready for use; it has first to go through the important process of kneading or “wedging.” This consists of cutting a ball of clay in two against a wire (fig. [1]), slapping the two parts on a plaster or wooden board, one on top of the other (fig. [2]), then lifting up the whole lump, cutting it in two again, and slapping it down as before. The purpose is to remove all air bubbles and to correct irregularities in hardness. The operation has sometimes to be repeated fifteen or twenty times before a good texture is secured.[5]
Fig. 1. Wedging (a)
We learn from the above survey that the fine consistency of the clay in Athenian and in some other Greek wares is not necessarily due to its natural state, but to the careful washing and kneading undergone in its preparation for use. When different particles are found in the fired clay they are due to indifferent washing. And the varying shades of pink and red of Greek vases likewise do not presuppose different kinds of clay, but are due largely to the various temperatures to which the vases were fired. We have too often made our analyses of clays of Greek vases without due cognizance of these facts.
FASHIONING THE VASES
(1) WHEELWORK
There are three principal ways of making vases—fashioning them on the wheel, building them, and making them from moulds. Let us examine first the work on the wheel, the potter’s tool par excellence.