146 



DRESSING OF ORES 



the frame water, and immediately the frame assumes a vertical position striking in its 

 movement a catch at M, which, upsets the V-shaped launder N, containing pure water, 

 in such a way as to wash the ore on the table into two coffers o and p. The frame 

 then returns to its horizontal position, and the orey matter is again admitted through 

 H. One boy can manage twenty of these frames. When employed in cleaning tin 

 stuff, the two coffers o and p are discharged into separate pits about 16 feet long, 6 

 feet wide, and 12 or 15 inches deep. The refuse from the end of the frames as well as 

 the slimy water from the displacing box, is either thrown away or subjected to further 

 treatment ; the coffer o is usually taken to the hand frames, after which it is tossed 

 and packed, whilst the stuff from coffer P is again submitted to machine framing. 



HancocVs Slime Frame. The ores and accompanying waste are brought into a 

 state of suspension by water, and arc then by adjustment made to pass over a slight 



