366 TRANSACTIONS OF TUIC CANADIAN INSTITUTE. [VoL. IV. 



thus forming^ an annular groove round the outer edge of the bottom of 

 the basin. Through the centre of the bottom of the pan or basin, where 

 there is an opening, a short upright piece of shafting passes, which fits at 

 the bottom into a journal in the centre of the base. After passing 

 through the opening in the bottom of pan, it is attached at its top 

 extremity to a false bottom, which fits upon the true bottom, almost 

 completely covering the above-mentioned groove, leaving only a small 

 space open communicating with the upper part. The sides of this false 

 bottom, as also the sides of the pan at the same level, have steel castings 

 attached to them. On the area formed by the steel castings, which form 

 also a groove which forms a half circle and a comnlete ring round the 

 pan, balls of iron are placed wiiich revolve when the false bottom, which 

 is attached to the upright shaft, is set in motion by gearing attached to 

 the shaft between the bottoin of pan and base of stand ; over the pan is 

 bolted a doine, which at its apex continues perpendicular to form a pipe, 

 round which near its top is a circular stage with a spout ; inside this 

 " pipe " fits a second, whose mouth is e.xpanded to a filler ; the bottom 

 extends down further than the commencement of the apex of the dome 

 to almost the level of the tops of the balls ; this acts as the hopper through 

 which the ore is fed. To the bottom, at one side of the first-mentioned 

 -annular groove, is attached a mercury pipe, through which the mercury 

 is fed to the mill ; a water pipe enters at that part of the centre of the 

 bottom where the upright shaft, bearing the gearing for driving, enters ; 

 an oil supply pi|)e also supplies oil to the bearing of the shaft as it enters 

 the bottom of pan. 



The ore is fed by the hopper and is ground by the circular motion of 

 bottom and balls to one hundred to two hundred (iOOto200) mesh. 

 The first-mentioned annular groove, is filled with mercury, into which the 

 finely divided gold gravitates through the water ; the matrix and other 

 mi-nerals being finely divided and having a less specific gravity than gold 

 are forced up and carried off by the water, the water passing oft" by the 

 opening formed by the pipe of the hopper and the continuation pipe of 

 the dome, it rises through this space, falls over on the circular stage and 

 flows away by the spout ; the water enters with a considerable upward 

 pressure, which keeps everything but the gold from reaching the mercury, 

 this pressure is exhausted by the lateral sweep of the balls and expan- 

 sion in the wide dome. The mill is claimed to be able to treat any and 

 every ore of gold, arsenical, pyritical, antimonial or the most refractory 

 ore and save over (90%) ninety per cent., requiring less power than 

 "stamps," and one-fourth (^) less water, and one very good thing about 

 it, I think, is that the tube by which the amalgam is drawn off is securely 



