The finer qualities of earthenware or porcelain goods are manufactured from mixtures of. various clays, calcined bones, etc., from which every organic constituent has been burned out. All these iugredients are weighed, and mixed together in a large quantity of water, and strained through very fine sieves. When the clay has been allowed to dry till of the consistency of dough, it is placed by the potter on a horizontal revolving wheel, and the lump of clay may become a bowl, vase, or any other article. When the object is sufficiently dry, it is ready for the "biscuit " kiln, or first firing, where it is only partially baked. The design is then painted or printed on - that is, underglaz.e, or before the metallic glaze has been applied. The ware is uow ready for dipping into glaze, literally a form of ground glass which the half-cooked ware, being very porous, readily absorbs. It then undergoes its final firing at a much lower temperature than that of the biscuit oven. All articles are placed in saggars, or receptacles of coarse clay, which are next packed in a kiln; this is simply an oven arranged with flues in such a way as to equally distribute the heat.

The fire is not allowed to touch either saggars or ware, as in the manufacture of coarser good9 such as bricks or terra-cotta.