POTTERY and Stone-ware. Under this name may be classed all those wares, from the common butter-pot mentioned by Dr Plot, to the finer kinds of earthen-ware, which, in contradistinction to porcelain, possess neither transparency nor any degree of vitrification, except on the surface after being glazed.

The most famous manufacture for this common ware, as Dr Plot states in his History of Staffordshire (1686), was at Burslem, in that county, now one of the principal towns, forming a part of that extensive and populous district called the Staffordshire potteries, in which it is calculated that no less than 30,000 persons, or one half the population, are directly employed in the manufacture of porcelain and earthen-ware. It is proved, however, that the manufacture of common wares had existed long before Dr Plot’s time; but of its first introduction no tradition remains.

These common wares were made of the clays found in the district, and were of a red body covered with a glazing of lead ore, with a portion of manganese added to make a black when that colour was wanted.

About the year 1690, two ingenious artisans from Germany, of the name of Eller, settled near Burslem, and carried on a small trade for a little time. They brought into this country the method of glazing stone-ware, by casting salt into the kiln while it is hot, and some other improvements of less importance; but finding they could not keep their secrets to themselves, they left the place rather in disgust. From this time various kinds of stone-ware, glazed by the fumes of salt in the manner above mentioned, were added to the wares before made. The white kind, which afterwards became, and for many succeeding years continued, the staple branch of pottery, is said to have owed its origin to the following accident. A potter, Mr Astbury, travelling to London, perceived something amiss with one of his horse’s eyes; an hostler at Dunstable said he could soon cure him, and for that purpose put a common black flint-stone into the fire. The potter observing it, when taken out, to be of a fine white, immediately conceived the idea of improving his ware by the addition of this material to the whitest clay he could procure. Accordingly he sent home a quantity of flint-stones of that country, where they are plentiful among the chalk, and, by mixing them with tobacco-pipe clay, produced a white stone-ware much superior to any that had been seen before.

Some of the other potters soon discovered the source of this superiority, and did not fail to follow his example. For a long time they pounded the flint-stones in private rooms by manual labour in mortars; but many of the poor workmen suffered severely from the dust of the flint getting into their lungs, and producing dreadful coughs, consumptions, and other pulmonary disorders. These disasters, and the increased demand for the flint-powder, induced them to try to grind it by mills of various constructions; and this method, being found both effectual and safe, has continued in practice ever since. With these improvements, in the beginning of the present century, various articles were produced for tea and coffee equipages. Soon after, attempts were made to furnish the dinner-table also; and before the middle of the century, utensils for the table were manufactured in quantity as well for exportation as home consumption.

But the salt glaze, the only one then in use for this purpose, is in its own nature so imperfect, and the potters, from an injudicious competition among themselves for cheapness rather than excellence, had been so inattentive to elegance of form and neatness of workmanship, that this ware was rejected from the tables of persons of rank; and about the year 1760, a white ware, much more beautiful and better glazed than ours, began to be imported in considerable quantities from France.
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The inundation of a foreign manufacture, so much superior to any of our own, must have had very bad effects upon the potteries of this kingdom, if a new one, still more to the public taste, had not appeared soon after. In the year 1763, Mr Josiah Wedgwood, who had already introduced several improvements into this art, invented a species of earthen-ware for the table, quite new in its appearance, covered with a rich and brilliant glaze, bearing sudden alternations of heat and cold, manufactured with ease and expedition, and consequently cheap, and having every requisite for the purpose intended. To this new manufacture the queen was pleased to give her name and patronage, commanding it to be called Queen’s ware, and honouring the inventor by appointing him her majesty’s potter.

The common clays of the district are now mostly used for making the saggers or cases in which the finer wares are fired, for bricks to construct the ovens and kilns, and for some kinds of inferior wares, while the clays for the improved article are brought from Devonshire and Dorsetshire by sea to Liverpool, and by the canal to the potteries. The flint-stone is obtained mostly from London, so that it would appear the cheapness of coals has been the principal reason for the establishment of extensive potteries in this inland district, notwithstanding the heavy charges of transport on the raw materials to the seat of manufacture, and, so far as the export trade is concerned, again on the manufactured articles to the shipping ports.

Before the introduction of steam power to machinery purposes, the flint-stones were ground by water-mills at a considerable distance from the manufactories; but many of the manufacturers have now erected steam-engines of great power, for the purposes of grinding flint, and other materials used in the different processes of the manufacture.

The article of queen’s ware, before mentioned, was composed of the Devonshire and,Dorsetshire clays, mixed with a proportion of ground flint, covered with a fine soft glazing, composed of siliceous earths and carbonate or oxide of lead. This glazing, covering a very porous body, made of the above clays and a portion of flint-stone, was liable to crack or craze, and become discoloured in the using, causing a prejudice against it, under an erroneous idea that, by its coming in contact with acids and salts, the glaze had been decomposed, that the lead it contained was poisonous; and a premium was accordingly offered by the Society of Arts for the discovery of a glaze without lead, which was only cancelled on the books of the society a few years ago. It appears singular that it did not immediately occur to scientific men, that all the chemical vessels made of glass contain as large a portion of lead in their composition as there is in the glaze on queen’s ware, and that the vitrification is as complete in the one case as the other. The fact is, that, through the cracks in the glazing, it was the earth composing the body of the ware which the acids and salts acted upon, leaving a coloured deposit, visible through the extreme thin lamina of glazing which covers it.

This defect in the glazing arises from several causes; the want of a corresponding contraction of the body and the glaze, from too sudden a cooling of the oven, and other mismanagement of the workmen.

Since the introduction, however, of a better clay from the mines in Cornwall (about 1777), together with a stone containing a notable quantity of feldspar, the potter has been enabled to bring his earthen-ware to a very great degree of perfection; the defect in glazing above noticed has been greatly diminished on the queen’s ware, and other glazes introduced, in appearance possessing much of the texture and whiteness of porcelain, though still deficient in the solidity and compactness of the old white stone-ware which it had superseded.

About the year 1805 an article was produced called Ironstone-ware, in which, however, not a particle of iron stone was introduced, it being a compound principally of the Cornish materials above mentioned.

This ware has nearly all the properties of the Japan porcelain; it possesses great hardness and density; is sonorous, but is deficient in whiteness and transparency, although the vitrification is as complete as in that of the Japan. It continues to be made in great quantities, and being more durable, is perhaps, though higher in price, as economical as earthen-ware. It is a cheap substitute for porcelain, but its nature does not admit of those fine paintings and splendid decorations which are applied with so much success on that more elegant production.

From the common earthen-ware to the finest porcelain, the manipulations are nearly similar. The materials being finely ground and levigated, are mixed together in their proper proportions in a liquid state, and this mixture being put into broad shallow pans or kilns, is subjected to a heat sufficient to evaporate the extra water until the clay is of a proper consistency for use, and it is then prepared by beating with wooden andiron paddles until it becomes one ductile homogeneous mass, fit for the operation of the workman. The operations of throwing on the wheel, turning in the lathe, and moulding, are similar to those already described in the article on porcelain.

The potter’s wheel consists of a triangular bench, whereon the workman sits, having before him a small horizontal circular block on which he places the portion of clay made into a ball, according to the size of the piece of Avare wanted to be made, and with his hands fashions it into the shape wanted; the inner surface being smoothed by a piece of slate, iron, or earthen-ware, cut to the form required. This workman has two assistants; one employed to prepare the balls of clay, and remove the piece when formed; the other to turn a larger vertical wheel, which gives motion to the horizontal block, or whirler, as it is called, before mentioned as being before the workman. The ware is then taken into a stove and dried sufficiently hard to be put upon the lathe and undergo the operation of turning or smoothing the outer surface.

This lathe is of the like construction as the common lathe used in wood turning, and needs no description here.

The ware is then given to another workman, who puts on the handles and feet, or such ornaments as may have to be fixed on the body of the ware; and after being thoroughly dried, it is ready for the first or biscuit firing.

It must be observed, that only articles of a circular form can be produced on the wheel or from the lathe. All others, as well as the feet and handles and ornaments, are made by different workmen, from moulds of gypsum or of baked ware. An earthen-ware called dipped ware is made of different colours, some of which are very striking, by being dipped into a slip or wash of the same clay, or of other clays coloured by metallic oxyds finely ground and mixed up with the wash. This operation is performed at the lathe, before the ware has had time to get dry or hard.

The ware being made dry, is placed in saggers (cases), which are piled on each other until the oven is filled up nearly to the top of the dome. Fire is then applied in mouths round the outside of the oven, having flues round the inside, and under the bottom of the oven, communicating with the mouths. The fire is applied very gradually, the operation requiring from forty-eight to fifty hours. As a test to show when the necessary degree of heat is obtained, small round caps made of common brick-clay are put into a sagger, opposite a small opening in the oven, which the fireman draws out from time to time, judging, from the degree of colour the test or trial had acquired, which was produced by the oxyd of iron contained in the day, how to regulate his further operations.

The operation of glazing is similar to that detailed in the article on porcelain, but is performed with much lesß diffi [7:18:502]culty, and with a greater degree of certainty, on a porous than on a vitrified surface. After the ware is glazed (a considerable portion of which is first painted, and printed on the body, a biscuit), the ware is then again placed into the saggers or cases, and placed as before to undergo the second firing. In this second firing for the glazing, a much lower degree of heat is applied than for the biscuit-ware, and the operation is performed in fifteen or eighteen hours, according to the size of the oven. The painting or enamelling, and the printing on earthen-ware, are done in the same manner as that described on porcelain, which need not here be repeated.

The extent to which the manufacture of pottery wares is now carried on in this country, in which porcelain may be included, together with its usefulness and excellence, has rendered it a subject of great national importance. The raw materials are of home production, and of little intrinsic value, the transport of which affords to the coasting trade a freightage of from 40,000 to 50,000 tons annually. The manufactured articles are wholly produced by manual labour, which is not likely to be superseded by machinery, while the export of the biflky article of earthen-ware to all parts of the world gives employment, to an immense extent, to the shipping of this and other countries. Nor is this interesting manufacture without some claim in furthering the progress of the fine arts, by the cultivation of painters, engravers, and modellers, many of whom have displayed talents of a superior order in their respective lines. In flower-painting, the specimens exhibited in the work of English artists cannot be excelled. In figurepainting, owing to the want of schools for design, the porcelain painters of this country have not made much progress; but in flower-painting, and in decoration generally, our British artists cannot be surpassed.

There are some considerable manufactories of pottery ware in the north of England, and one or two in Yorkshire; but the principal site of both pottery and porcelain wares is in the newly created borough of Stoke-upon-Trent, which contains a population of nearly 60,000 persons, engaged either directly or indirectly in these mannfactures. On the passing of the reform bill, this borough was considered of sufficient importance to have its great interests represented by two members in parliament. (b. a.)