226 MINING INDUSTEY. 



driver is a cap-piece, j, carrying the usual screw and nut arrangement for 

 raising and lowering the muller, the bottom of the screw resting on the up- 

 per end of the vertical shaft. The lower part of the driver has three or four 

 stout lugs, or projections, at its base, which fit into carriers on the circular 

 part of the muller at d, Fig. 4. These carriers are also made to serve as the 

 means of aiding the circulation of the pulp, as they assist in directing the 

 current toward the center when the muDer is revolving. For this purpose 

 they are sometimes cast five or six inches high, presenting a curved surface, 

 (not shown in the case illustrated) to the pulp and forcing it toward the cen- 

 ter of the pan. By this means the guide-plates or wings, usually fixed to the 

 side of the pan, but which, to some extent, obstruct the motion of the pulp, 

 are dispensed with. Grooves for attaching guide-plates are, however, cast in 

 the pan-rim, so that those who prefer may use them. The dies and shoes 

 used in this pan resemble, in many respects, those of other pans. There is 

 an inch and a half space between the outer edge of the die and the edge 

 of the pan, and a similar space between the adjacent edges of the dies. 

 The shoes, between which there are similar spaces, and which also have 

 radial channels, or grooves, on their under side, to facilitate circulation, 

 have the same radial width as the dies. The radial width of the muUer- 

 plate is a little less than that of the shoe and die, in order to allow a freer 

 inlet and outlet to the pulp. The muller makes from 60 to 80 revolu- 

 tions per minute. The pan takes 4,500 pounds of pulp at an ordinary 

 charge, and sometimes more. It is set up very simply, being bolted to 

 timber supports below ; and is put in motion or aiTCsted by the aplication 

 or withdrawal of a tightener to the driving-belt, as shown in Fig. 1. 

 The price of this pan, with its necessary gearing, pulleys, &c., is about 

 $800. 



Fountain's Pan. — The Fountain pan and the Horn pan, each so called 

 from the name of its inventor, have been in use two or three years. They are 

 much alike, differing only in minor details, and both, in many respects, resem- 

 ble that just described. The first-named has been changed somewhat since 

 its first introduction. In its present form, the body of the pan is 5 feet in diam- 

 eter at the top, and 4^ feet at the bottom. The bottom, rim, and central hollow 

 pillar, are cast in one piece, A steam-chamber, when desired, is provided by 



