THE RISE OF THE POTTERY INDUSTRY. 167 



the others in succession. A recent invention has simplified this 

 process very materially. This device is a clay press consisting of 

 a series of sacks in which the slip is placed. The moisture is 

 forced through the bags by strong pressure, and the clay is ready 

 for use Mr. A. J. Boyce, of East Liverpool, Ohio, has recently 

 perfected an improved hydrostatic press, which is being intro- 

 duced into many of the more progressive factories throughout 

 the country. The illustration will convey a clear idea of the clay 



Fig. 15.— The Boyce Clat Press, with twenty-fouk Cfiambkrs. 



press used in reducing the slip to a workable mass. In each 

 chamber is placed a sack made of ten-ounce Woodberry duck, 

 which, if of the proper quality, will last some time. The moist- 

 ure is pressed through the fabric, and the clay, on removal, is 

 ready for manipulation. 



"Jiggers" and " jollies " now greatly facilitate the manutact- 

 ure of circular and swelled vessels, such as jars, jugs, crocks, 

 cuspidors, and umbrella jars. A " jigger " is a machine which 

 carries a revolving mold, in which the clay is shaped by a former, 

 which is brought down into the mold and held in place by means 

 of a lever We give here an illustration of one of the jiggers 

 made by Mr. Peter Wilkes, of Trenton, N. J. A is the jigger- 

 head or receptacle in which the mold is placed, which is screwed 

 fast to the revolving spindle. 5 is a stationary iron column on 

 which the frame or sleeve C slides up or down. D is an iron tork 



