"Hollow ware is pressed by hand," answered Mr. Marwood. "The process is used for pieces that cannot successfully be made by any other means--such things, for example, as soup-tureens and large covered dishes. The idea is to press the clay over or into moulds so it will be the exact shape required. Of course this necessitates the making of pieces in sections. The two sides of a vase are moulded separately, for instance; also the bottom. Then the parts are pressed firmly together and held in place by strings or thongs of leather until securely joined. Afterward the base is inserted in its proper place. The inside seams are then leveled and sponged away, and the mould sent to the drying room. Later it is returned; the outside seams moistened and smoothed; the moulded handles put on; and the piece is ready to be decorated and fired. It is a difficult ware to make, for unless the workmen are skilled at giving the clay an even pressure it is liable to be thicker in some places than others. Sometimes, too, if the seams are not strongly united the article will crack. It demands a strong, even touch. Remember that hollow ware is pressed from the outside; and that flat ware is just the opposite, and is pressed from the inside. The top surfaces of such things as plates, platters and trays are thus formed, their outer side being shaped by hand or by a jolly, which we shall see presently." Mr. Marwood passed on through the crowded room until he suddenly paused beside a workman at another machine. "This," explained Theo's conductor, "is a jigger. There are two machines very commonly used in the United States for shaping the cheaper wares: one is a jigger, a device of this type; and the other a jolly, an invention very similar in construction but having a tool attached that forms the outside, or bottom of the piece, the inside of which has previously been shaped by the jigger. You may recall that I spoke of the jigger; and told you how a revolving mould was inserted into it, and how afterward a sheet of clay was laid on the outside of this mould and rapidly shaped. The jolly, on the other hand, is used for making such things as covers, the top surface of which has already been moulded. The profile set in the jolly-lever makes the bottom. That, as I told you, is how we get the base of our plates. For certain articles the jigger is preferred; for certain others the jolly; but the aim of both is the same, and the workers at the machines are all called jiggermen. After an article is taken from the jigger or jolly it is dried and carried to the turning-lathe to have its surface smoothed and finished." "And does it take all these men to run a jigger?" whispered Theo, pointing to the moving figures that hurried to and fro.