One who does not own a wheel can make a mould by setting the clay bowl, bottom up, in the centre of a small shallow bread or dish pan, which must then be well oiled on its inner surface. The plaster of paris is mixed and poured around and over the clay mould, as already described.
If one uses a great deal of clay, plaster basins may be made for drying out the superfluous water from the clay after it has been mixed. These are moulded in the form shown in Fig. 34, the straight-sided circular cavity in the centre being about three inches deep, and the whole slab perhaps sixteen inches square. The basin part, like the bowl-shaped mould just described, is first formed in solid clay, and the mould is made in the same manner.
Plaster slabs, both round and square, to hold the pieces of pottery while they are being made and dried, may also be moulded.
Rose-Bowl Started in a Mould
Materials required:
A bowl-shaped mould of plaster, 3½ inches in diameter at the bottom and 9½ inches at the top,
About 3½ pounds of clay,