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DRESSING OF ORES 



rod attached to frame, and connected with water-wheel L. N, balance beam, counter- 

 poising the frame, and rendered necessary in order to equalise the motion, r r', balance 

 catches, serving to support the third arbor when elevated. This arbor is also parallel 

 to the other two, but has its position on the top of the guide frame shown in the 

 elevation. It passes immediately under the angle of the L-shaped rods, and is 

 mounted on friction wheels. Its action is as follows : When the scrapers have nearly 

 completed their ascending stroke this arbor is elevated by means of the wedge-shaped 

 projection on the top of the frame, and immediately the balance catch acts so as to 



722 



retain it in this position during the descending stroke, at the termination of which the 

 catch comes in contact with the projecting screw shown in the elevation, thereby drop- 

 ping the scrapers upon the face of the buddle. Consequently, in the ascending stroke 

 these scrapers plough the vein-stuff against the flow of the stream. The orey matter 

 to be operated upon is introduced into the compartment shown on the top of the 



723 



plan, and by means of the diagonal scrapers it is washed and passed slowly across tho 

 table, the heavier portion being delivered into tho bin F, and the lighter matter into 

 the box F', whilst the tails are lodged in tho strips H H. Tho water employed in 

 driving tho wheel is also used for the buddle ; one portion of it servos to introduce the 

 ore, whilst tho other is regularly diffused over the surface of tho table, and washes the 

 waste from the stuff. In case tho quantity of water is too largo for settling tho 

 residues flowing into tho strips HH, and connected with tho bins F F', discharge laun- 

 ders are provided at o, 



