INGENUITY AND LUXURY 



very minute particles of iron, small enough to pass 

 through the meshes of the lawns, yet large enough 

 to make stains in the finished ware. To remove these 

 magnets are placed in the stream of slip as it comes 

 from the lawn box, and magnets are often placed in 

 the "finish ark," the churning device into which the 

 slip is run from the lawns, and in any other place where 

 a chance particle of the metal might be found. For, as 

 we know, iron is the arch enemy of the potter. It is 

 in the original clay, and as the machinery of the fac- 

 tory must necessarily be constructed of it, it menaces 

 every operation of the manufacturing process. 



The finish ark repeats the stirring process of the 

 mixing ark, and from this the slip is passed on to the 

 filter-presses. In these the water of the slip is squeezed 

 out through strong cotton cloths, until the mass 

 remaining is of the proper consistency for molding 

 into the ware. 



One more operation is necessary, however, before 

 the material is actually turned over to the workmen. 

 This is called "wedging," and is now performed by 

 a machine called a "pug-mill." The object of the 

 operation is to make all the clay coming from the 

 presses of exactly the same consistency. In the old 

 method of wedging by hand the workman cut off 

 pieces of the clay with a wire and threw them repeatedly 

 upon a prepared block until the mass was kneaded 

 thoroughly. This slow hand-process is still used on 

 a small scale in some of the operations of turning 

 or pressing, when the operator's clay may have dried 

 a little on the outer surfaces; but in the main it is 



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