THE POTTER S ART. 



of industries; and it is worthy of note, that, simple as were 

 its original processes and rude its primitive productions, no art 

 has more ministered to luxury ; none has produced more gor- 

 geous specimens of ornamentation ; in none does the value of 

 the finished article bear so enormous a ratio to that of the raw 

 materials ; none has so steadily and continuously advanced and 

 improved with the progress of knowledge ; none is more largely 

 indebted to the resources and discoveries of science ; nor has 

 any more constantly received the homage of the great and the 

 admiration of mankind in all countries, and especially in those 

 which have attained the highest condition of civilisation and 

 refinement. 



2. The materials of the potter are certain sorts of clay which 

 possess the property, when moistened with water, of acquiring 

 the consistency of dough. This dough being shaped into the 

 desired form, the water which gave it softness and plasticity 

 is expelled from it by evaporation, produced by exposure in 

 ovens to intense heat. The article is thus rendered hard and 

 strong, so as to retain its shape, and to resist fracture from slight 

 causes. 



In this state however, the surface is rough and the material is 

 porous, so that it would imbibe any liquid in which it might be 

 immersed, or which might be poured into it. To give it a more 

 brilliant surface, and to render it impervious to liquids, it is 

 therefore covered with a thin coating of some vitrifiable matter, 

 which being exposed to the action of fire, is converted into a skin of 

 glass. This gives increased beauty to the article, and at the same 

 time renders it impermeable by liquids, and enables it also to 

 resist their chemical action. 



The ornamentation of the article is produced either by the 

 beauty of form imparted to it, or by figures in relief produced by 

 moulds pressed upon it while yet soft, and before the process of 

 baking ; or, in fine, by designs painted in colours either upon the 

 surface before glazing, or upon the glaze. In either case the 

 colouring-matter is submitted to the action of fire, and the process 

 has more or less of the character of enamelling. 



The plastic clay of the potter does not usually exist in its pure 

 state in the earth. It is found, on the contrary, like the metals, 

 mixed, or chemically combined, with many heterogeneous sub- 

 stances, from which it is separated by a variety of complicated 

 processes. 



When it is reduced to a sufficient degree of purity, it is 



necessary to mix with it such a proportion of water as will convert 



it into a dough of a certain consistency. This is a process of some 



difficulty and labour, for the water will at first be unequally 



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