Part 4

Pottery may be decorated in a great number of ways, and the operations are so varied that I cannot describe them all intelligibly, should I attempt to do so in my limited space. I shall consequently speak only of the paintings executed on the surface. This necessitates the use of colours specially prepared and made from two distinct materials; the bases and the fluxes. The bases are generally metallic oxides or highly oxidized compounds; the fluxes are vitreous substances, similar to the glazes, but softer, whose function is, to fix the colours permanently on the ware. When both, after being intimately ground together, are fired at a moderate heat on the article, the fluxes will cause the colour of the bases to look more vigorous and brighter, the effect being rather similar to that of an oil or transparent varnish on ordinary body colour. For this object, they must have very little chemical action, and be sufficiently soft to act in a moderate quantity. If, by carelessness or accident, the temperature is raised to a degree higher than the one exactly required, new compounds are formed, and the alteration of the colour is the consequence. There are some instances in which no fluxes are required; this is the case, when the ware has been coated with a glaze sufficiently fusible to allow the bases to sink in it, as soon as it begins to soften under the influence of heat. By this process more force and effect are obtained. It is, however, seldom used, for this reason, that from the care and attention which it requires in the superintendence of the firing, the manufacturer would run greater risks, and, being unable to use large ovens, would not turn out the same quantity of ware. Altogether it is a very expensive process.

Modern chemistry has placed at the disposal of colour makers new compounds which have made the preparation of fluxes comparatively easy. At the present time two classes are required: those in which the oxides of lead predominate, and those chiefly made with borax, which on account of its great purity is used in almost every flux, and is of great service for those colours which, like the pinks and purples, would suffer from the presence of lead.

The preparation of painting colours is a little more complicated, and each requires a different treatment. The number of those found in the trade is rather large, and each artist has his favourite maker. In this, as in any other kind of painting, beginners are apt to think that they will be assisted by the use of a great variety of tints, when they will learn by more experience, that a very limited number is sufficient. I cannot undertake to give any receipts for those who might wish to prepare these themselves; I only mention the name of the substances necessary to secure each of the essential colours.

White is not a colour, but when wanted on a coloured body, it is procured by an enamel prepared with the oxide of tin. Light yellow requires the oxides of lead and antimony. Orange will require the same, with an addition of deutoxide of iron. The hydrate of peroxide of the same metal will give a golden buff. The subchromate of lead gives a very bright red, but it is very unsafe and mixes badly; the reds made by calcining the common sulphate of iron are preferred. From this, according to the degree of fire, all shades of red may be got, from an orange red to a deep purple brown. The pinks, purples, and crimsons are made from the precipitate of cassius; this is obtained by pouring a weak solution of tin in the chloride of gold. The dark blue is a triple silicate of cobalt, which, by the admixture of the white oxide of zinc, may be converted into a brighter blue. The green oxide of chrome is the base of all greens, the tint of which is modified by cobalt for the blue greens, and antimony for the yellow greens. The chromate of iron, a mineral coming in large quantities from South America, is the base of all browns. The black may be got from the mixture of various oxides, but the best is that made from the oxide of iridium. Besides the above, there is another class of colours in which the oxides are thoroughly combined with the fluxes, such as the greens made from copper and the transparent blues, which are ground colours, and must be classified with the glazes. When painting colours are fired with their respective fluxes, they are very permanent, and will not only resist ordinary atmospheric influences, but also the action of every gas or mineral acid (the fluoric excepted). This seems an advantage in favour of painting on pottery, and one which ought to give them an additional value; in reality, however, artistic merit ranks above all other considerations, and unless the work is original, connoisseurs in pottery will hardly take this into account.

Several oils possessing drying properties, such as those of lavender, aniseed, or turpentine, are mixed with the colours, which, from the fact of containing vitreous substances, would work badly; even with their assistance, it requires a certain amount of skill to master the process. We must not make too much, however, of this difficulty, generally exaggerated by the ignorance of apprentices in what constitutes the very principles of their profession. When parents, in perfect ignorance of the abilities of their son, have decided, after putting their heads together, that he shall be a painter, sometimes for no other consideration than that they can get him admission into a porcelain manufactory, or that this is the nearest to their home, the boy has not the least notion of what is before him, and hardly knows that he will have to learn that very difficult thing, drawing. No wonder then, if his deficiency in this will not allow him to produce, we will not say good, but saleable paintings, unless he has spent a dozen years on his trial. On the contrary, to one well prepared by the study of art--one who, before he sets to his work, has a clear conception of the effect which he wishes to produce--the process will not stand in the way, and he will master it in the course of a few weeks.

To induce talented men to devote their time to the decoration of pottery, is perhaps the greatest difficulty met with by our leading manufacturers. As long as the making of the ware only was concerned, they had to call for the assistance of practical men, such as potters, chemists, or engineers, the number of whom is fortunately great in England, and whose services can be secured by money. The same thing is not so easy in the matter of art. Up to a recent date, painting on pottery was not considered as the high road to fortune, and artists preferred to try their chance in oil or water-colour painting, fully aware that they would have to fight against an army of competitors, and to be satisfied with very small incomes, unless, by their, then problematic, genius, they could cut their way to the front. Since, however, the rage (there is no other word for it) for well decorated pottery has spread in almost every class of society, the prices paid for good work are more remunerative, and artists like Solon, Mussill, and Coleman, can make artistic pottery their special business.

Royal Academicians like Poynter and Marks have thought it not beneath them to prepare cartoons for Minton, and it is probable that others would follow in the same path if, with the assistance of our chief potters, they could be initiated into some of the mysteries of the craft. No doubt they would find the study attractive, and there is no fear that, having once begun, they would not keep faithfully to it. For myself, I know of no such example.

In addition to the painting colours, there are a few metals which are used to enrich pottery; unfortunately, the number of those which can undergo exposure to a red heat without oxidizing is very limited. There are only three, viz. gold, silver, and platinum, which can stand it, and, among these, silver is of little use, on account of its proneness to tarnish under the action of sulphurous gases. Gold, on the contrary, affords to the decorator one of his greatest resources. We cannot say when the Chinese began to use it; we only know that in Europe it was thought a great discovery, when, in the sixteenth century, it was used in the Italian majolica. From that time to the introduction of hard and soft porcelain in Europe, it was rarely and sparingly used; and it was at Meyssen, soon followed by the other continental and English manufactories, that they began to use it extensively. At the present time, its annual consumption by our Staffordshire potters alone represents a very large sum of money. There are several ways of preparing gold for pottery purposes; the oldest consists in grinding gold leaves on a slab, adding to it gum water, honey, or any other mucilaginous liquid. This laborious process surpasses all others; it has a very artistic effect when used thin, in the Chinese fashion, and, when laid thick, as we find it in the Old Sèvres ware, it answers beautifully for chasing; the only drawback is the expense. The most usual way is to have it amalgamated with mercury, and afterwards ground in turpentine; it has then the appearance of a blackish substance, which will regain its colour, as soon as the mercury is volatilized by the application of a gentle heat. When it comes out of the kiln, the gold is dull, and requires to be burnished with agate and bloodstone tools, to be in possession of all its brightness.

There is another decorated pottery, called lustre ware, now out of fashion, but most successfully executed at one time by the Moors, the Persians, and the Italians on their respective majolicas; the glaze of this ware being more favourable than any other for the display of the process. It simply consisted in painting over the fired ware with the protoxide of some metal, such as that of copper, taking care that from the moment the kiln began to get to the red heat, a constant supply of thick smoke should be kept up. The partial reduction of the metal which adheres to the surface has a very pleasing effect, as may be noticed in the large Hispano-Moresco dishes, considered the finest specimens of this class. Those produced in Italy by Georgio Andreoli fetch, however, a higher price, on account of the redness of their colour; the process is fully described in the celebrated manuscript of Piccolo Passo, now in the library of the South Kensington Museum. Lessore, the French painter, lately dead, and M. de Morgan, in London, have succeeded in producing very fair specimens of that kind. Some of our Staffordshire potters can make another lustre by mixing chloride of gold with lavender oil, sulphur, resin, and other carburated ingredients, and laying this mixture very thinly on the surface of the glazed ware; the iridescent pinkish colour which it takes when it is fired in an ordinary kiln is rather peculiar. This has no connection with the old process, and is only used for the commonest kind of goods.

The kilns in use for firing the painted or gilt ware, are called muffles or enamelling kilns; they are in the form of a D, laid on its straight side, and of a length proportionate to the size and number of pieces which they are to hold. The fireplaces are arranged on one of the sides, and the flues contrived in such a manner, that the flame should travel round the whole of the outer surface, great care being taken that it should not have access to the interior through any cracks or joints which might exist in the brick-work. For ordinary goods one firing may suffice; for those highly decorated, as many as five or six may be necessary.

Let me now say a few words respecting the various wares produced by our English potters.

The first earthenware made after the time of Wedgwood and Josiah Spode was far from being so good as that made at present, and several attempts were made to bring out a pottery which should be intermediate between earthenware and porcelain. The most successful was that made by Mr. Mason, of Fenton, who, in 1813, took out a patent for an ironstone china, the body of which was fluxed by the scoriæ of ironstone and the ordinary Cornish stone. But eventually this last was found sufficient for that purpose. The name of ironstone remained to that class of pottery which is strong and resistive. Since then, however, earthenware has so much improved, that ironstone has gone out of fashion; the nearest to it is the ware called _white granite_, made for the American market, which is richly glazed, and made thick to compete with the French hard porcelain, which is also exported to the United States for the same class of customers. About fifty manufactories are specially engaged in producing this ware; and those in the occupation of Messrs. Meakin, Shaw, Bishop and Powell, and G. Jones, may be considered the largest. The best earthenware is made for the home market, some of which is so perfect that, if it were not opaque, it might be mistaken for porcelain. When it is richly decorated and gilt, like that made by Messrs. Minton, Wedgwood, Furnival, Copeland, Brown-Westhead, Brownfields, and several other leaders of the trade, very high prices are obtained for it.

Some of these makers do not devote all their attention to earthenware, but produce other classes of pottery. Amongst the sorts which are most connected with earthenware are majolica, Palissy, Persian ware, and flooring and wall tiles. I have given the name of majolica to that class of ornament, whose surface is covered with opaque enamels of a great variety of colours. It is only connected with the Italian or Moorish in this respect, that the opacity of the enamels is produced by the oxide of tin; but as we have not in England the calcareous clay for making the real article, we have been obliged to adapt, as well as we could, the old processes to the materials at our disposal.

At present, English majolica is very popular, and without a rival for garden decoration, as it stands exposure to the weather better than ordinary earthenware, besides the impossibility of the latter receiving the opaque enamels without crazing or chipping.

Majolica was produced for the first time by Messrs. Minton, in 1850, and they have been for many years the only producers of this article. It is only five or six years ago that Messrs. Maw, of Broseley, in Shropshire (and very lately the Worcester manufactory), have made a pottery of the same kind. The name of majolica is now applied indiscriminately to all fancy articles of coloured pottery. When, however, it is decorated by means of coloured glazes, if these are transparent, it ought to be called Palissy ware, from the name of the great artist who used these for his beautiful works. Messrs. Wedgwood, George Jones, and a few other makers of less importance, are reproducing it more or less successfully. To Messrs. Minton, however, we owe the revival of the ware, which, in connection with their majolica, created such a sensation in the French International Exhibition of 1855; and credit must be given to those gentlemen, for being on that occasion the promoters of that demand for artistic pottery, which has so largely developed of late. It is to satisfy this craving for novelties, that they have undertaken the imitation of the faïence d'Oiron, better known by the name of Henri Deux ware, a rare and costly one, which can only be produced in small quantities; and also their most recent improvement, the reproduction of the Persian wares.

In the old Persian pottery we find a real earthenware taking a precedence of several centuries over our own. There is little doubt that it can be connected with the early Arabian, Assyrian, and Egyptian, by the similitude of the processes common to all. I have no room to explain how it is that, being an earthenware, it is so much richer in colour than the modern ware made on this side of Europe. I can only mention that the body of the Persian ware may be converted into a transparent porcelain by firing it hard, which shows that the sandy clays from which these are made are sufficiently saline to become vitreous. To this they owe the property of receiving, without crazing, glazes of the softest kind, and consequently of exhibiting those colours which can only stand at a low temperature, such as the Persian red, the turquoise, and that purple or violet which makes so valuable the specimens on which it is laid. If we had in England sandy clays like those which abound in Persia, the reproduction of Persian ware would have been an easy undertaking; but in trying to reconstitute it by synthesis, there were several obstacles. Within the last three years, however, Messrs. Minton have sold a great many specimens of the ware, some of them of very large size. They may be recognized by the depth of the turquoise, which is sometimes as rich as Sèvres pieces of the best period. Their only competitors for this class of pottery are the manufactories of Worcester and of Messrs. Maw and Co.

I cannot leave earthenware without mentioning the plain and encaustic tiles, articles of comparatively recent manufacture in England, but whose consumption is increasing so fast, that it may be expected in time to afford a most valuable compensation, should circumstances restrict the production of some other branch of the trade. There is no need to dwell on the advantages offered by the use of tiles. They are clean, invaluable in a sanitary point of view, free from further deterioration and expense for maintenance, and susceptible of a variety of treatment which makes them admirably fitted for decorative purposes. To the Eastern nations we owe the idea of using ornamental tiles, and it is likely that it is from the numerous buildings existing in Western Asia and the north of Africa, at the time of the Crusades, that our forefathers took the notion of introducing in Europe the encaustic tiles; their ceramic knowledge being too limited to undertake the making of painted or enamelled tiles, an essentially Saracenic and Moorish production, whose specimens nearest to us are those to be seen in the Alhambra, or in the Alcazar at Seville. An inspection of those made afterwards in Spain, in the time of Charles V., or in Italy for the Vatican, and some of the palaces in Genoa, would prove that they were made exactly in the same way. From the contrast between the opaque and transparent enamels, these tiles have a very forcible and harmonious effect, not to be met in others (the Persian excepted, though these, exclusively decorated on a cool scale of colours, cannot answer so well the requirements of modern architecture). The majolica and Delft tiles, chiefly the last, have been almost exclusively used during the seventeenth and eighteenth centuries, and it is only within the last forty years, that we began to make them in earthenware. With the revival of this manufacture, and of almost any other sort of tiles, the name of Herbert Minton is closely associated. It was during his time, and with the assistance of Mr. Michael Daintry Hollins, that this great undertaking was carried out with such success, that hardly a new church or public building is erected where these tiles are not introduced. The making of plain tiles is new and peculiar. They are made from dry clay reduced to dust, which, being submitted in metallic moulds to a pressure of several hundred pounds to the inch, becomes so compact, that further contraction is almost suppressed, and they can be handled without risk of breaking. Encaustic tiles are made from plastic clay, in which the different portions of the design are sunk below the surface, so as to form recesses, in which slips of different colours are poured according to a set pattern. When these become as hard as the body of the tiles, the surface is made smooth and level with a steel scraper, which removes all the superfluous material, till the colours are shown standing neatly side by side with the greatest precision. It is a pretty process and interesting to witness. Besides the flooring tiles, there are many other sorts made for lining walls and fireplaces, varying considerably in style and material. There are two very extensive and perfected tile works at Stoke, viz. those belonging to Mr. Hollins and the Campbell Brick and Tile Company, in both of which all sorts of flooring and wall tiles are made. In the second, recently built, Mr. Colin Minton Campbell, the proprietor, has introduced new arrangements and contrivances in almost every department; all operations being performed on the ground floor, and in such manner that the goods shall travel the shortest possible distance from the moment they are begun to that of their completion. He has been the first to use Maw's patent steam presses for plain tiles, each of which can make twelve thousand tiles weekly, requiring only the assistance of a single person, to remove the tiles as they come out from the mould. It is by the intelligent use of these mechanical processes, that we may expect a reduction in the price of such a useful article. The firm of Mintons still continue to make their plain white printed and artistic tiles, along with their patent process for painting on mosaics. The Broseley Works, in Shropshire, belonging to Messrs. Maw and Co., have also a great name, and carry on an extensive business in tile making. Next are those of Messrs. Edge and Malkin, of Burslem. Messrs. Simpson, of London, are well known for their wall decorations in tiles painted by hand, and Messrs. Copeland, of Stoke, for their painted slabs.

The various porcelain biscuits known under the name of Parian or statuary biscuits, are specially used for statuettes, busts, and other articles for which it is desirable to get the appearance of white marble. This is a kind of hard porcelain made from a mixture of kaolin and felspar, in which the degree of hardness or fusibility is regulated by the proportion of one material towards the other. Of course, similar biscuits may be made by more complicated receipts, but the principle is always the same, viz. the taking advantage of the fusibility of felspar or Cornish stone, to secure the required amount of transparency. The light being allowed to penetrate to some depth below the surface, imparts to these biscuits a softness which is wanting in the similar productions of Sèvres, Germany, and Denmark.