30 parts borax, 30 flint, 18 Cornish stone, 2 tin oxide. The materials must be calcined, and particular caution observed in the course of chipping from the seggars, that not the least particle of any colouring matter be mixed with it, for it is very susceptible of being materially injured in its colour; when ground, a small quantity of muriatic or nitrous acid should be added, and at the same time quickly stirred about, and the motion continued for some time, in order to prevent it setting at the bottom of the vessel; in all other respects treated the same as common glazes, except with regard to dipping, in which case it must be used very thin.
72 parts litharge, 36 Cornish stone, 20 flint glass, 17 flint, 12 frit for glazes (6), 1/5 blue calx. The blue and green edged ware when dipped in this glaze should be perfectly dry previous to being placed in the seggars, and the green edge should be seated in the coolest part of the glazing oven.
65 parts litharge, 40 Cornish stone, 20 flint, 6 frit for glazes (6).
90 parts white-lead, 45 Cornish stone, 22 flint, 20 flint glass, £ blue calx. To this, after being properly ground and sifted, add 1 lb. common salt and 1/2 lb. borax, which forms a smear or flow, as it is generally termed, but must not be put into the glaze until the blue stain is perfectly incorporated with it; the ware dipped therein must be placed in seggars washed with glaze.
85 parts white-lead, 40 Cornish stone, 22 flint, 16 flint glass, 8 frit for glazes (6).
75 parts litharge, 40 Cornish stone, 23-flint, 10 flint glass.
105 parts Cornish stone, 90 borax, 60 flint. 50 red-lead, 12 crystal soda, 10 tin oxide, 1/4 blue calx. This glaze produces very superior white earthenware, and, for the purpose of enamelling, the colours, lustres, and burnished gold appear to considerable advantage; it is also adapted for ironstone, and makes superior blue printed earthenware; it has a singularly striking effect on printed brown and mulberry. When used for dipping it must be considerably diluted, and requires but little shaking from the hand of the operator. It requires the heat of a china glazing oven, but to answer the earthenware oven a small addition of white-lead must be made, according to the temperature of firing. The materials must be mixed and calcined, and the ware fired in lime and slip seggars, well washed.
70 parts litharge, 30 flint, 25 Cornish stone, 10 drab slip.
90 parts white-lead, 35 Cornish stone, 20 flint glass, 20 flint, 60 frit for glazes (6), 1/4 blue calx.
85 parts white-leal, 35 Cornish stone, 22 flint, 15 flint glass, 24 frit for glazes (6), 1/5 blue calx. These glazes, when ground, to be sifted through a fine lawn; the former glaze is of the finest texture, and will require rather a thinner coating when dipped than those of common glazes. Fire in seggars, either washed with common glaze, or a mixture of lime and slip without flint.
60 parts Cornish stone, 40 flint, 30 crystal soda, 8 tin oxide, 10 borax. This frit is used in small quantities, in china and ironstone bodies.
(a) 40 parts Cornish stone, 36 flint glass, 20 red-lead, 20 flint, 15 potash, 10 white-lead, 3 tin oxide. This frit is intended to be used in glazes, in lieu of those which contain a large proportion of borax; therefore substituting it when the price of that article is high, will, of course, be advantageous, and the texture of the glaze will still be good and admissible.
(b) 36 parts Cornish stone, 30 red-lead, 20 flint, 20 borax, 15 crystal soda, 5 tin oxide. These two frits may be calcined in the easy part of the glazing oven, in seggars lined with flint; particular care should be observed that they are clean chipped, and free from pieces of seggars, or any dirty substance.
3 parts blue vitriol, calcined, 1 flint glass, 1 flint. When ground, take 4 qt. of this mixture to 30 of the following mixture, ground: - 35 parts litharge, 20 flint, 10 Cornish stone, 10 frit for glazes. This glaze is sufficiently fired in the coolest part of the glazing oven. Particular attention should be observed as to the proper wash used for the seggars, for much depends on that simple process. The brightness and lustre of the glaze will be secured by adopting the following wash: - 5 parts solution of quicklime, 1 of clay slip, free from the least particle of flint, and applied about the thickness of common glaze.
36 parts Cornish stone, 30 borax, 20 flint, 15 red-lead, 6 crystal soda, 5 tin oxide, 1/8 blue calx. With the above frit is to be added 15 parts white-lead, 10 Cornish stone, 10 flint, when ground together, the composition is ready for use; should the glaze prove too thin for dipping, add a small quantity of muriatic acid.
40 parts Cornish stone, 45 red-lead, 38 borax, 32 1/2 flint, 22 1/2 flint glass, 13 crystal soda, 5 tin oxide, 1 enamel blue. The particles are made small and well mixed together, then calcined in the coolest part of the glazing oven, in seggars thickly lined with flint; care must be observed that the frit is not too highly calcined, or brought into a high state of vitrification; if so, it will render it difficult to grind, and injure its good qualities in dipping. The frit likewise if too finely ground will cause the glaze to be uneven on the surface of the ware; if any inconvenience of this nature arises, by adding a solution of potash in hot water, that defect will be instantly obviated.
35 parts Cornish stone, 20 borax, 10 crystal soda, 20 red-lead, 1/8 blue calx. Calcine and then pulverise coarsely, and grind with 20 lb. white-lead, 10 lb. Cornish stone, and 5 lb. flint.
(6) 1 qt. linseed oil, 1/4 pint rape oil, } pint common tar, 1 oz. balsam sulphur, 1 oz. balsam capivi. The linseed oil should be boiled for some time alone, then add the rape oil and the balsam capivi, allow the boiling to be continued until it begins to approach the proper consistency, and add the remaining ingredients. The mixture should be allowed to cool a short time, after which the whole mass may be boiled slowly until it has assumed the proper thickness; the vessel must be generally covered during the process, and the sulphur previously to being mixed with the oil should be perfectly pulverised, as by that means it is less liable to curdle the oil.