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BAKTHENWABE. 



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pottery, including that found in Oreat Britain, it contain* nuiucr.nw 

 rxam[>W It luu also many pHnvf* o( Celtic and ancient British 

 pottery ; and it hat a varied and rich collection of the Hispano- 

 kooriah. Majolica, and Delft earthenware spoken of above. But in 

 thoie Utter rliatni the South Kensington Museum U still richer. 

 The T~^~~ of majolica in the British Museum number somewhat 

 under 200, in the South Kensington Muwum they are about 500. In 

 thie latter museum the majolica U arranged according to the towns in 

 which it was produced. Both museums, however, contain many very 

 fine and characteristic examplea; and South Kensington is rich in 

 early French and English ware. Finally, at the Museum of Practical 

 Oeology in Jermyn Street, are characteristic, though not numerous, 

 .mpl of the potter's art of almost every period from the most 

 ancient down to the present time ; together with specimens of the 

 diflVnvt kinds of earth, the glazes and the enamels employed in their 

 production. An hour or two spent in "T""'"'"E these collections will 

 give clearer notions on the history of the ceramic art and the cha- 

 racter of it* productions than can possibly be obtained from mere 

 descriptions. 



Although earthenware may be considered as a general term appli- 

 cable to all utensils composed of earthen materials, it is now usual to 

 distinguish such utensils more particularly into three different kinds ; 

 namely, pottery, earthenware, and porcelain. Under the first of these 

 terms are classed the brown stone-ware made into jugs, Sea., the red 

 pans and pots in common use, porous vessels, 4c. [POTTERY.] Por- 

 celain is distinguished from earthenware as being a semi-vitrified com- 

 pound, in which one portion remains infusible at the greatest heat to 

 which it can be exposed ; while the other portion vitrifies at a certain 

 heat, and thus intimately combines with and envelopes the infusible part, 

 producing a smooth, compact, shining, and semi-transparent substance, 

 well known as the characteristic of true porcelain. [PORCELAIN.] The 

 third-class, intermediate between these two, is the subject of the present 

 article. 



The principal ingredients employed in the composition of all kinds 

 of earthenware ana porcelain are clay and flint. The nature of the 

 clay used in the manufacture is of great importance, and so also is the 

 combining of it with a due proportion of flint. The clay principally 

 used in the Staffordshire potteries is obtained from Dorsetshire and 

 Devonshire, and is distinguished into the qualities of brown, biue, 

 Mart, and cracking clays. All these clays are of good working quality, 

 and burn extremely white, being free from any impregnation of iron ; 

 the blue clay is considered the best. About 70,000 tons of Dorsetshire 

 clay is exported yearly from Poole, for the use of the Staffordshire 

 manufacturers. Another description of clay, superior to any of these, 

 and found in Cornwall, is commonly denominated China clay, because 

 similar in its properties to the porcelain earth of China. This Cornwall 

 clay is so indispensable in porcelain, and so valuable in the finer kinds 

 of earthenware, that it may be well to describe here the processes of 

 iU preparation, from a paper recently drawn up by Mr. Stokes, of 

 St. Austell. 



The disintegrated granites of Cornwall, which are commercially know 

 as China ttont and China day, were first used as ingredients in potter's 

 clay about 1768, through the instrumentality of Mr. Cookworthy of 

 Plymouth; and the consumption became greatly increased when it 

 was found that, if fused, the disintegrated granite would form a 

 ruitable glaze for articles made of the clay. This was the China clay, 

 or kaolin. The China stone was not brought into use till 1802, when 

 a Cornish bed began to be worked, comprising felspar, silica, and mica, 

 without any iron or manganese ; if granite contains talc, hornblende, or 

 diallage, it is unfitted to form China stone. The good China stone is 

 found principally in proximity with fissured granitic rocks, near St. 

 Austell. It is believed that the granite has been brought to the states 

 of China stone and China clay by a variety of causes the alternation 

 of hot and cold weather ; the solvent power of rain water ; and the 

 action of chemical agents in the air and water. The chief hill or 

 district of the China stone is divided off into several portions, leased 

 by different individuals or companies. The stone is sufficiently hard to 

 need quarrying by gunpowder and the pick ; it is raised from the pits, 

 and transferred to waggons near the pits' mouths. It undergoes no 

 preparation, but is at once shipped to Staffordshire, where tho potteiti 

 are left to deal with it as they please. The price is greatly increased 

 by the cost of land carriage to the nearest port of shipment ; but now 

 (1859) that the Cornwall Railway is opened, there is a prospect of 

 increased facility of transport. It is supposed that there are about 

 a million tons of China stone in the St. Austell beds. The China stone 

 in iU present state consists of a mixture of quartz, felspar, and mien, 



so as to form a homogeneous mass, much resembling granite, 

 but with a texture less compact. Chemically it is a nearly-pure double 

 silicate of potash and alumina, which, when fused, forms a pearl-white 

 translucent mass, firm and resonant ; it has an opaque body of nearly 

 perfect kaolin, surrounded by and diffused through a glaze of silicic 

 acid, to which its trantlucency is due. The China clay or kaolin is 

 more abundant than the China stone, and is shipped to Staffordshire to 

 the extent of about 100,000 tons per annum. It is not, like China 

 stone, confined to one or two localities, but is distributed in many parts 

 of the county. It is found intermixed with quartz and mica in most 

 of the valleys contiguous to hills of disintegrating granite. The sub- 

 itself as an amorphous whitish-blue powder, often 



lying contiguous to formations of granite, killas, clay-slate, and grau- 

 wacke. The clay assimilates in quality to the granite from which it 

 has been derived ; if the felspar be very white, the clay is whit? ; if 

 there is much mica, the clay becomes strong and tenacious. The clay 

 is worked and filtered in large recesses formed in the surface of the 

 ground ; allowed to remain till solid ; cut into square blocks ; conveyed 

 to a drying-yard ; and there allowed to remain until white and quite 

 dry. There being some difficulty in drying the clay in wet localities, 

 Mr. Stokes has invented a method of expediting the process; it 

 consists in the use of a number of perforated cylinders, having on them 

 shelves similarly perforated, or made of wire-gause ; these cylinders are 

 kept rotating two hundred times a minute, by four attached multiply- 

 ing wheels, worked by wind, water, or steam ; they have several 

 perpendicular screw-like arms, on each of which ore a number of 

 transverse shelves for the carriage of the clay ; the rapid action of tho 

 wheel causes currents of air to be thrown upon the clay, which soon 

 becomes dry. The blocks are kept in a place where cool dry air can 

 reach them, until shipped to tho Potteries. The China clay varies in 

 price from 20*. to 50*. per ton, according to its purity, hardness, 

 whiteness, and freedom from shrinkage when calcined. Not less than 

 7000 men, women, and children, are employed in Cornwall in collecting 

 and preparing the China stone and clay. 



We will now suppose the requisite ingredients to have reached tho 

 pottery establishments in Staffordshire, and will trace the processes of 

 manufacture. In the preparation of the earthenware clay some labour 

 is required before it is in a fit state to be combined with the flint. It 

 is first mixed with very pure water to the consistence of cream : this 

 work is called blunging, and in large establishments is performed by 

 means of machinery. The result is a smooth pulp, which is then 

 passed through a series of sieves of increasing degrees of fineness, till 

 at length it is perfectly fitted to enter into the composition of the 

 ware. If the clay were moulded and dried without the addition of 

 any other body, it would certainly crack ; as the evaporation of the 

 water with which it is mixed, in order to render it sufficiently plastic 

 for the potter's wheel, would cause it to shrink in the proportion of 

 one part in twelve in drying. In combination with siliceous earth in 

 proper proportions, it bears the action of fire without cracking, while 

 the silica materially improves the whiteness of the ware. 



The flints are prepared by being burnt in a kiln, and removed while 

 red hot from the kiln and thrown into cold water. By this operation 

 their attraction of aggregation is lessened, and the labour of grinding 

 them is much facilitated. They are then broken and ground to a very 

 fine powder in a mill constructed for the purpose, the original of which 

 was invented by Brindley. A quantity of water is thrown into the 

 mill with the flints, by which the process is quickened and the health 

 of the workman is preserved, the finer particles of flint being thus pre- 

 vented from flying off and mixing with the atmosphere which the 

 workmen inhale. The flints, when reduced to powder, are transferred 

 from the mill into another vessel, where more water is added, and the 

 whole is violently agitated by mechanical means ; the finer parts are in 

 consequence held in suspension above, and in this state are passed into 

 a reservoir, while the grosser particles are left behind at the bottom of 

 the vat. After subsidence, the supernatant water is drawn off from 

 the reservoir, and the pulverised flint is in a fit state for use. It is 

 considered of a proper fluidity for mixing with the clay when a pint 

 weighs 32 ounces, while an equal measure of the diluted clay should 

 weigh 24 ounces. The proportions in which tho clay and flint are 

 mixed vary with the quality of the clay, with the nature of the ware 

 to be produced, and also with the practice of each manufacturer ; the 

 flint may form a fourth, a fifth, or a sixth part by weight of tho pre- 

 pared paste. The dilutions of clay and flint being brought together in 

 suitable proportions, are intimately mixed by agitation, and passed, 

 while in a state of semi-fluidity, through different sieves, whereby the 

 whole becomes a smooth homogeneous mass. This mixture, technically 

 called dip, is then very care fully . -vaporated, the mass being frequently 

 stirred and turned over lest a part should become improperly hai 

 while the remainder continues too fluid. When the clay or ]taste is 

 removed from the tli/>-Hln, it is well incorporated by beating it with 

 wooden mallets, in order to expel the air which it contains. The next 

 operation is that of cutting it into small pieces, which are thrown 

 together again with all the strength of the workman ; and this process 

 is continued until the mass is considered to be in a complete state of 

 consistence. When in this state, the mass is allowed to remain for a 

 considerable period before being used, since it becomes more intimately 

 united by time tlian by any mechanical means. 



The paste, when taken for use, undergoes the process of tlapping, 

 which is similar in its effect to the last operation, and should incorpo- 

 rate the whole mass so completely, that wherever it is cut it KlmuM 

 exhibit a perfectly smooth and uniformly close appearance. The clay, 

 being thus prepared, is now ready for use. 



The processes in the forming of earthenware are mainly of three 

 different kinds throwing, pressing, and casting, which are respectively 

 employed according to the form of the article required. 



The operation of throwing is performed upon a machine called a 

 potter's lathe, and is used in shaping vessels which have a circular 

 form. By this means the thrower moulds the clay into the form 

 which he desires ; chiefly by the fingers and palms of the hands, but in 

 part also by wooden tools. When finished to his satisfaction, he 



