THE POTTEK'S ART. 



employed in the establishment, who possessed, according to M. 

 Brongniart, in a high degree, the talent of seizing with the greatest 

 truth and exactitude the characteristic habits of each class of 

 operatives, and their peculiar attitudes and movements in the 

 execution of their work. 



It will be remembered that the materials out of which the 

 potter produces the articles of his fabrication are 1 kaolin, or 

 china clay, and 2 flints. The former ingredient, as has been 

 already explained, is prepared by the clay merchant in Cornwall, 

 or whatever other place the clay is found, and is delivered to the 

 potter ready to be mixed with the flint earth. But the latter is 

 prepared from the natural flints in the potteries by the following 

 process : 



The flint stones are first calcined, and this is effected in a kiln 

 similar to that used for lime-burning. These stones are separated 

 by alternate layers of coal, and the burning usually occupies about 

 twenty-four hours. The flints are then very white and very brittle, 

 and ready to be crushed by the " stamper," a machine composed 

 of upright shafts of wood, six feet long, and about eight inches 

 square, heavily loaded with iron at the lower end, which, by 

 means of applied power, are made to rise and fall in succession on 

 the flints, contained in a strong grated box. It is then removed 

 to the grinding vats, which are from twelve to fourteen feet in 

 diameter, and four feet deep, paved with chert stone, large blocks 

 of which, being also worked round by arms connected with a 

 central vertical shaft, propelled by an engine, become a powerful 

 grinding medium. This peculiar stone is used because of its 

 chemical ainnity to the flint, which, therefore, suffers no deterio- 

 ration from the mixture of the abraded particles, which necessarily 

 results from the friction, a matter of serious moment. In these 

 vats the flint is ground in water until it attains the consistency of 

 thick cream, when it is drawn off and conveyed by troughs into 

 the washing chamber. Here it undergoes a further purification ; 

 more water is added, and it is kept in a state of gentle agitation, 

 by means of revolving arms of wood, thus keeping the finer 

 particles in suspension while the liquid is again drawn away in 

 pipes to a tank below. The sediment is afterwards re-ground. 

 The cleansing process is not yet complete, for when the fluid has 

 passed into these tanks, to about half their depth, they are filled 

 up with water, which is repeatedly changed, until it is considered 

 sufiiciently fine, and free from all foreign matters : it is then fit 

 for use. 



The next process consists in mixing the clay with the flint. 

 This is accomplished by mixing both with water, so as to give 

 them a creamy consistency, and to convert them into what the 

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