250 Porcelain and Earthenware. 



levigated, and to reduce the whole to the utmost uniformity and 

 smoothness, in which state it is called slip. It is next poured into a 

 large vat or cistern, called a slip kiln built with flues under it, con- 

 nected with a furnace large enough to produce an ebullition in the 

 mixture, which is continued until so much of the water is evaporated 

 as will bring the mass to the desired consistence. When the mate- 

 rials have thus been consolidated into a paste, it is removed from the 

 slip kiln, beaten with mallets and turned over with spades until it is 

 as thoroughly tempered as it can be by this mode of operation. It 

 should not be forgotten that this prepared clay is a mixture of all the 

 ingredients for the body of the ware. After the beating comes the 

 process of slapping, which is done by placing a large lump on a 

 bench or table; when a workman cuts through its diameter with a 

 brass wire, or a twine, and lifting one half with both hands as high 

 as his head, brings it down with all bis force upon the lump. He 

 cross cuts and unites it again and again until all the air bubbles 

 of which it was full are driven off. This is an extremely laborious 

 operation, but it is essential to expel all the atmospheric air, before 

 it is exposed to heat, otherwise when it became expanded in the 

 furnace, it would blister and ruin the goods. Mr. Wedgewood and 

 others have employed machinery to effect the results produced by 

 the severe labor of slapping and blunging, which by some is thought 

 equally efficient. 



The prepared paste when brought to this state, it is much improv- 

 ed by being kept a long time, the materials thus acquiring a union 

 which they do not acquire by mere mechanical force. It is usual in 

 China to keep the prepared clay fifteen or twenty years, before it is 

 thought fit for use. " In some districts it is the custom for the father 

 to prepare as much clay as will be sufficient for the son, throughout 

 the whole period of his life."* 



The French manufacturers of porcelain do not observe so much 

 mystery about their operations as do those of Dresden, and many other 

 European potters. Little is known of the Dresden works, except 

 that they employ none but rain water that has been purified and make 

 their fires only with white wood that has been seasoned. Such was 

 the rivalry between the three royal establishments of Dresden, Ber- 

 lin and Sevres, that for a long period each made a profound secret 

 of every process and improvement. The same spirit actuates many 



* Parkes* Essay. 



