Calcined flints 6 parts; Cornish stone or com position two parts, litharge 9 parts, borax (i parts, argillaceous earth 1 part, nitre 1 part, calx of tin 6 parts, purified potash 1 part. 2. Calcined flints 8 parts, red lead 8 parts, borax 6 parts, calx of tin 5 parts, nitre 1 part. 3. Potter's composition 12 parts, borax 8 parts, white lead 10 parts, nitre 2 parts, white marble calcined 1 part, purified potash 2 parts, calx of in 5 parts. 4. Calcined flints 4 parts, potter's composition 1 part, nitre 2 parts, borax 8 parts, white marble calcined 1 part, argillaceous earth ½ part, calx of tin 2 parts. Whichever of the above compositions is taken must be finely powdered, mixed and fused. The vitreous mass is to be ground when cold, sifted, and levigated with water; it is then made into a pap with water, or gum-water. This pap is smeared or brushed over the interior of the vessel, dried, and fused with a proper heat in a muffle. Clean the vessels perfectly before applying.

Enameled Cast Iron

Clean and brighten the ircn before applying. The enamel consists of two coats - the body and the glaze. The body is made by fusing 100 lbs. ground flints, 75 of borax, and grinding 40 lbs. of this frit with 5 lbs. of potter's clay, in water, till it is brought to the consistence of a pap. A coat of this being applied and dried, but not hard, the glaze powder is sifted over it This consists of 100 lbs. Cornish stone in fine powder, 117 of borax, 35 of soda ash, 35 of nitre, 35 of sifted slaked lime, 13 of white sand, and 50 of pounded white glass. These are all fused together; the frit obtained is pulverized. Of this powder, 45 lbs. are mixed with 1 lb. of soda ash, in hot water, and the mixture dried in a stove is the glaze-powder. After sifting this over the body-coat, the cast iron article is put into a stove, kept at a temperature of about 212°, to dry it hard, alter which it is set in a muffle-kiln, to fuse it into a glaze. The inside of pipes is enamelled (after being cleaned) by pouring the above body-composition through them while the pipe is being turned around to insure an equal coating; after the body has become set, the glaze pap is poured in in like manner. The pipe is finally fired in the kiln.