The dough was placed in a round pan of lava a foot and a half or two feet in diameter. In this a vertical shaft revolved, to the lower part of which two or three wooden arms were attached (three in Fig. 224); the one at the bottom was strengthened by an iron crosspiece on the under side, the projecting centre of which turned in a socket below. The side of the pan was pierced in two or three places for the insertion of wooden teeth, so placed as not to interfere with the revolution of the arms. As the shaft was turned, the dough was pushed forward by the arms and held back by the teeth, being thus thoroughly kneaded. Modern kneading machines are constructed on the same principle, but have two sets of teeth on horizontal cylinders revolving toward each other. CHAPTER XLVIII _THE FULLERS AND THE TANNERS_ The work of the ancient fuller was twofold, to make ready for use the cloth fresh from the loom, and to cleanse garments that had been worn. As the garments used by the Romans were mainly of wool, and needed skilful manipulation to retain their size and shape, they were ordinarily sent out of the house to be cleansed; in consequence the trade of the fuller was relatively important. In the part of Pompeii thus far excavated we find two large fulleries and one smaller establishment that can be identified with certainty; and there were doubtless many laundries, with less ample facilities, the purpose of which is not clearly indicated by the remains. The following account of the processes employed relates exclusively to woollen fabrics. At the time of the destruction of Pompeii, soap, a Gallic invention, was only beginning to come into use; the commonest substitute was fuller's earth, _creta fullonia_, a kind of alkaline marl. For raising the nap, teasel does not seem to have been used, as with us, but a species of thorn (_spina fullonia_) the spines of which were mounted in a carding tool resembling a brush (_aena_); the skin of a hedgehog also was sometimes utilized for this purpose. The fulling of new cloth involved seven or eight distinct processes,--washing with fuller's earth, or other cleansing agents, to remove the oily matter; beating and stretching, to make the surface even; washing and drying a second time, for cleaning and shrinking; combing with a carding tool to raise the nap, brushing in order to make it ready for clipping, and shearing to reduce the nap to proper length; then, particularly in the case of the white woollens so commonly used, bleaching with sulphur fumes; and finally, smoothing in a large press. The process of cleaning soiled garments was more simple.