POTTERY. 229 



Common Pottery, such as coarse brown jugs, 

 &c. are made of the ordinary clays, which are a 

 mixture of sand and chiy, coloured by oxide of 

 iron. The clay is well ground, or kneaded, and a 

 lump of it is put upon the centre of a wheel which 

 is kept in motion ; then, by means of the work- 

 man's liand, or by proper tools, it is formed into 

 the required shape. The pieces are then dried 

 moderately, so as to bear being removed without 

 danger ; they are then covered with a glaze, made 

 from semi-vitreous oxide of lead, and put into a 

 furnace, where they are baked. Some sorts are 

 glazed by throwing sea-salt into the furnace among 

 the different pieces of pottery. The salt is de- 

 composed, and the vapours of it form a glazing 

 upon the vessels ; but this, though a very simple 

 and ingenious method, does not form a good 

 glazing. 



English stone-ware is made of tobacco pipe clay 

 mixed with flints calcined and ground. This ma- 

 nufacture owes its present state of perfection to 

 that enlightened manufacturer the late Mr. Wedge- 

 wood, who spared no pains or expense to improve 

 the art of pottery. He first introduced a superior 

 kind of which he called Queen's ware. The clay 

 of which it is made comes chiefly from the neigh- 

 bourhood of Corfe Castle in Dorsetshire. It 

 burns extremely white. The pipe clay is much 

 beat in water ; by this process tlie finer parts 

 remain suspended in the water, while the coarser, 

 sand, and other impurities, fall to the bottom. 

 The thick liquid, consisting of water and the finer 

 parts of the clay, is further purified by passing it 

 through hair and lawn sieves, of different degrees 

 of fineness. After this, the liquid is mixed (in 

 various proportions for various wares) with another 



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