Pottery Manufacturers

Porcelain Production

[Newspaper]

Publication: The Brooklyn Daily Eagle

Brooklyn, NY, United States
vol. 49, no. 186, p. 2, col. 5 - 6


FOR WOMEN.


A Chapter on the Manufacture

of Pottery.

 

How the Fineness and Finish of Wedgwood,

Flaxman, and Other Favorite Ware Are

Produced — The Material and the

Method of Workmanship.

 

The great false god Cheapness is worshiped in the potteries. Beauty is canonized, but cheapness receives the highest homage. It is enough to make men of a hundred years ago turn in their graves. A day or two since the writer looked over a publication of copperplate designs issued by the great firm who at that time were making Leeds pottery one of the richest delights of that and future ages. At that time Josiah Wedgwood was redeeming and glorifying the ancient craft. His appeals to the scholar Bentley to unite with him in pursuing the creation of beauty are simply eager breathings of the rare atmosphere of art in excel sis. Wedgwood lived for his art, loved it; never was conscious that he toiled for it, and when nature yielded to his laborious search rich secret after secret he made the knowledge free to all, that the art he served might be better served by all around. Of all his inventions he only patented one — and that some minor improvement. But he is dead, and another people have arisen who know not Josiah. And the great false god Cheapness has the bended knee.

A potting factory — what is it? We must give a Scotch answer by asking another question. What is meant by a pottery manufacturer? One can point out to-day several instances of men who have now enormous outputs, and who started potting practically without capital, but with a factory. One man's factory at one time consisted of nothing more than the little room in which he decorated plain ware which he had bought and the one oven in which he fired it and the little place where he stored it till he could sell it to the hawkers. He progressed, flitted from his one oven works to a larger pot bank, flitted again and yet again, till to-day he pays two or three hundred pounds every week for wages, receives every week a check from one man in London who buys a great part of his goods, and has become one more added to the enormous number of self made and substantial pottery manufacturers. In his early days, as now, he had a factory. Hence it must be understood that you cannot from a description of one pot bank form an idea as to all the number — perhaps three hundred — whose mingling smokes and shooting oven sparks proclaim the district's art. Nor, indeed, can you judge all factories which are of the same size by hearing the details of one. "Aw maek nelly all sorts of weer," says one, a town councilor of Longton, mayhap, and not necessarily the worse town councilor for an occasional lapse into his mother dialect. "I make only two or three things," says another, "and I should be better pleased if I was making only one."

With these cautions we introduce the reader to some of the main processes which our makers employ in their efforts to improve on what China has done so wonderfully for many long centuries. We divide ware roughly into Class 1, opaque earthenware, and Class 2, translucent porcelain, or china. Flint — burnt and then powdered — Cornish stone, Cornish clay and calcined bone enter into porcelain. Flint is to porcelain what the bones are to the human body, it gives strength and support. Gravesend or other flint, Cornwall or Dorset clays, and bone from anywhere — largely, perhaps, from South America — are our potter's first essentials. A bone ring was recently spoken of. It appears to have vanished like a smoke ring, but it is easy to see that if it were really formed it might hasten the failure of small one oven manufacturers. So many fail now that we trust bone rings may never add a curse.

The staples above mentioned are most carefully mixed. A powerful blunger or plunger works up various clays in pure water till stony substances have sunk to the bottom and smooth pulp is obtained, a pint of which must weigh 31 ounces or 32 ounces, according to the body to be produced. A pan in which hard chert stones revolve lightens this work in this labor saving day in many "pot banks." Such chert stones revolve also in a flint pan and pulverize flint which has first been burnt and by a variety of treatments made as brittle as possible. Prepared clay and flint are united by agitation and the resultant is passed through sieves of hard spun silk. Even the false god Cheapness cannot so order things that exclusion of impurity shall here cease to be important. The sieved and purified mixture called slip has to be brought to a doughy consistence, and to that end is boiled, being diligently stirred the while. The riddance of all superfluous water is naturally most important. Here, as everywhere, science has improved on old custom. In a word, invention has altered the whole aspect of the better class factories in the last twenty years. So powerful is the influence of steam.

Throwing — pressing — casting. These are the clay's three processes. According to their choice of great divisions of labor, men are throwers, jiggerers or jolliers, flatpressers, hollow ware pressers, modelers, etc. To the most ancient potter's wheel we need not pay more than a passing homage. The thrower, seated at the wheel which gives rotating motion to his lump of doughy clay, contrives by an exquisitely fine touch of thumb and finger and palm to shape the plastic ductile compound to its intended form. His power is limited; he can only produce a perfect circle. Handles and all appendages must be separately made and fastened on by means of slip.

The green ware, fresh from the thrower, is turned by a process like the turning of wood, ivory, or metal. A treader — a female — will keep up by foot action the required motion of the lathe, her foot not knowing what her hands are doing, for her hands are occupied with moistening the upper edges of the green ware, and generally preparing it for her male companion. The vessel is smoothed and solidified before it leaves the turner's hands.

In connection with these earlier processes some danger lurks. Potters are not, alas, a very long lived race, but, by means of improved ventilation by fans and other contrivances the danger of taking the enemy dust into the lungs to steal away the life is a good deal lessened. While clay continues to yield powder when dry, and while the leads used in glazing continue to have poisonous properties, potting will always present certain grave risks. These, however, science can minimize and encounter. A great deal depends upon the workman himself.

Jiggerers and jolliers are employed to do what the thrower can better do. When time is everything, and shapes are not going to be criticized by a Josiah Wedgwood, jiggering will do, and, as a matter of fact, has to do in the case of an enormous quantity of stock, but the best jiggered pieces cannot give you the form which will be produced by the thrower, for whom the jigger is invention's substitute. Plates and dishes are made by pressing. Plaster molds of enormous variety stock the warehouses. At once when the clay is placed on the mold the principal surface of the required article is given. The platemaker stands at a whirling table moved by a horizontal pulley or jigger turned by a boy.   When he has pressed a plate it remains perhaps two hours in the mold before it can be removed; and the mold has absorbed too much moisture to be used again till it has been dried. The whirling table may have an elliptical instead of a circular motion, to be adapted for dishes. Deeper vessels than plates are made by hollow ware pressing or squeezing. An article, when dry, is removed from the mold and fetted or trimmed to remove all appearance of seams. The fettling and towing of flat was recently the subject of a long discussion in a local paper — the burden of the article being that this was a process which, unless great care was taken, was especially dangerous to health.

Casting is the mode of forming delicate articles for ornamental purposes — the cast being, of course, carefully examined and touched by the modeler. Thus are porcelain statuettes made. Sometimes lace adorns them; as a fact, lace was used in the making; it was dipped into slip and the heat of the fire destroyed the thread, leaving the porcelain material which took its place. Parian, Carrara, or statuary porcelains is a variety of the manufacture which has been invented by English makers.

The making of mosaic, plain, and encaustic tiles is a most interesting special manufacture. A curious feature of this work is the exposure process — a period of exposure of the clay to weathering or wintering being allowed. Compression of tiles is produced by forcing down a steel plate upon the yielding substance with a weight which may amount to hundreds of tons. Mr. Minton's tiles, manufactured to imitate terra cotta stone, appear to have attracted no small notice at the great exhibition of 1851.

For firing articles are quite dried and packed — separated from each other — in saggars (rough oval receptacles) of a course, very refractory fire found in the neighborhood. They are then placed in what is called the biscuit oven. Temperature is everything, and good ovenmen are paid high wages, even to £5 a week, whether or not the payment is calculated by the oven or by time. A man who feels his responsibility and takes pride in his work will have long periods of wakefulness when firing the biscuit oven or the glost oven. A number of trial pieces are so placed in the oven that the fireman can insert a long iron rod and extract one of the pieces when he likes and see how the heating of the ware is going on. The heat to which telegraph insulators are exposed is enormous; in any case the fire is intense enough. When after enduring forty or fifty hour's biscuit oven heat the clay has been converted into a kind of semi-vitreous substance and the oven has been sufficiently cooled down, the ware, shrunken in size, is removed. It is less earthy in texture and is clearer in color.

"Something nice and lingering — something with boiling oil in it" — is desired by the Mikado to satiate his appetite for torturing. If our common dinner plate has a pattern which wears well, is "nice and lingering," it is partly because there has been some "boiling oil in it." Would you print in blue that famous old willow pattern — famous, perhaps because so full of incident and feature — well, you must procure your blue, your oxide of cobalt, ground flint, and sulphate of baryta (fritted and ground), and you must mix it (that the color may be well fixed) with a flux of ground flint and thick glass powder, and finally with a composition formed of boiled linseed oil, resin tar, and oil of amber. You must spread the mixture on a hot iron plate, and thence, with a suitable implement, transfer it to engraved copper plates also made hot. From these copper plates the pattern is taken by a workman, who uses for the purpose a sheet of certain prepared paper, dipped in soapy water, laid moist upon the copper plate and then passed through a cylinder press. The pattern thus received is taken by a transferer and placed, with the printed side next the ware, and a gentle rubbing in follows. So simple a contrivance as a tub of water is next resorted to, and when the paper has been washed off and the moisture driven away by the heat of an oven, the article is ready for glazing.

Some ware receives no glaze. The famous Jasper, which Wedgwood originated, is of this class. Glazing, however, is the common lot, and must have a word. Glaze, practically, is glass. Glass is variously compounded; so is glaze. The main ingredients which contribute to the liquid glaze in which the dipper dexterously dips his varied articles are common salt, potash, boracic acid, phosphate of lime, and sulphate of baryta (for non-metallic glaze), and silica, lead, or the enamels of silica, tin or lead; or again a third class, including pure metallic oxides or sulphurets, such as oxide of lead in the form of litharge or minium, oxide of manganese, oxide of copper. Glazes and colors can be bought by a manufacturer who does not care to make them, as also his flint can be ground for him. Glazing naturally caused anxious thoughts long centuries ago. Peruvian potters have rendered their ware impermeable by rubbing it while hot with tallow, which, being partly charred, has filled up the pores and given the ware a black color. We read that "even the refined Etrusean and Greek vases are covered with a black carbonaceous non-vitreous varnish, which wears off in the handling," and this may have been produced by a process similar to that of the Peruvian.

We must leave the reader, having brought him to the point where imagination can easily lead him further. It would be pleasant to speak at length of the porcelain paintings; of the pate sur pate process; i. e., painting on figures in relief, using with a brush a fine slip as a painter uses color. We should like to lift the curtain upon Wedgwood in his modeling room, talking earnestly of his art with Flaxman, the sculptor whom he had engaged; we should like to show old Enoch Wood surveying his nonsuch warehouse of busts or notables; we should gladly speak of the imitation of marble; of Doulton ware, of Minton's, of majolica, and of various lusters, but space forbids. — Leeds Mercury.

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Keywords:Porcelain Insulator
Researcher notes: 
Supplemental information: 
Researcher:Glenn Drummond
Date completed:August 17, 2006 by: Glenn Drummond;