An anthracite stove with the pipe running into the large room warmed the workshop in winter, but no wet or half-dry pots were left where the frost could get at them. The glaze materials, oxides, colours, painting paraphernalia, finished pots, trials, and trial kiln were in the small room. The wheel had a good top and side light. The drying cupboard, plaster bin, and moulds were at the end nearest the stove; the clay bin, damp-box, and sink farthest away. All the walls were copiously supplied with brackets and shelves and handy benches. Outside, in a well-built lean-to, was the muffle kiln for onglaze and lustre decoration. This was well bracketed and shelved for the biscuit, and here was done the glazing, handy for packing in the brick kiln just outside. This was protected from the weather and other lean-to’s held the saggars, coke, and coal.
EQUIPMENT FOR SCHOOLS
The teacher with ample funds and a free hand will find the previous chapter all-sufficient, but in many cases the purchase of a kiln will nearly exhaust the allowance and the rest of the equipment becomes sketchy.
The indispensable appliances are as follows:
A kiln, with fire tiles or shelves, props, spurs, and stilts, etc., for packing. A good clay bin and sieve for slip (No. 80) with a tub and two pails. Scales and weights, pestle and mortar and glaze lawn (No. 100), shot for weights. Plaster, for drying bats and working discs. Large drip pan and three round pans. Several jugs and bowls. Spoons (wooden), knives, and big brushes. Oil, gum, boards, strips, rolling pin. Hammer, saw, iron straight-edge, sponges. Glass slab and muller, palette knife and brushes for painting.
An atomizer or spray pump. Glaze materials: Kaolin, China stone, flint, silver sand, whiting, felspar, borax. A supply of ground pitchers and grog, cones. Metallic oxides: Tin, white, oxide of, iron, copper, manganese, cobalt, etc. Under-glaze colours to taste. Glass jars with lids to contain materials. Gummed labels, India ink.
For a school in the country or where ground is available, a kiln like the one shown at p. [164] should be practicable. It costs very little to build or to fire. Next comes the question of the clay. This is one of the most abundant of nature’s materials, and almost any river bank or creek will supply clay of some kind. Any sort of clay near to hand should be thoroughly tested before going to other or distant sources.
The clay should be dried, then broken up with a hammer, and mixed with water, and the resultant “slurry” passed through a sieve (No. 80). The slip is allowed to settle and the water siphoned off. The thick slip is then dried on the plaster bats until stiff enough to work up between the hands. From this clay a tile, a plate, and a vase should be made and fired. If the pieces stand a fire of about 1100° (cone .03) without buckling, splitting, or crumbling, the clay should do quite well for school work. Possibly when screened fine enough for working, the clay may be too rich or long and will split at a moderate fire. Then the screenings might be pounded in the mortar, passed through the sieve, and added to the slip. Again, ground pitchers, fine grog, kaolin, or calcined flint could be tried as stiffening agents. In the unlikely event of the clay being too refractory or short, a portion of rich, fusible, or fat clay might be added, or the addition of powdered spar tested. (See chapter on Clays.) The colour of the body will hardly matter for schools; indeed
a brown, red, or cane-coloured clay will give better results than a staring white paste, when working out simple school problems.
Where necessary, tin glaze could be used for a white ground, or an engobe; that is, a dip of white clay slip over the coloured body. For glazing, a leadless glaze is strongly to be advised. Lead is often indispensable to the craftsman, and with care need not become a danger; but in schools a lead glaze is positively harmful.