DRESSING OF ORES 



129 



launder is placed, about 9 inches deep. The water coming in at A, is lodged in cistern 

 u, flows smoothly over the feather-edged board c, and falls into D ; here the orey matter 



is exposed to its action, and a portion settles in F; theflorrin and other light waste 

 then descends through o, depositing itself in the box H ; and to retain the valuable 

 products as much as possible it is filtered at j, through a perforated plate covering the 

 bottom of the launder. In stripping care must be taken to regulate the overflow of 

 water at c ; rough stuff must be subjected to a stronger current than finer matter, 

 and the bottom of the strip should be constructed with a greater inclination. In some 

 lead mines the buddies and hutchwork is stripped to be re-jigged, whilst the stuff 

 resulting from the filtering box is hand-buddled until sufficiently enriched for the 

 dolly. When ore is associated with a heavy matrix, and the grain breaks into a 

 lesser size than the other particles, the stripping may be performed by inversion, that 

 is to wash the orey product into the cover and filtering hutch, retaining the worthless 

 portions at D. 



The flat buddle, fig. 719, is peculiar to the "Welsh mines, and different from all 

 others in its great proportional breadth as well as in its very trifling inclination. 



The stuff is placed in a small heap 



on one side of the supply of water, 719 



and drawn with a hoe partly against 

 and partly across the stream to the 

 other side of the buddle, losing in its 

 passage all the lighter parts. A heap 

 of ore treated in this manner may be 

 deprived of a portion of blende and 

 pyrites, minerals which from their 

 high specific gravity may have re- 

 sisted previous operations, a, platform of boards, inclined two and a half inches in 

 seven feet, b, catch pit, two feet deep. The width of this buddle varies from ten to 

 twelve feet. 



Lisburne Buddie. This apparatus has been successfully employed in separating 

 blende from lead ores. Fig. 720 represents an elevation, and jig. 721 a ground plan 



of this machine. B, rakes or scrapers set at an angle, depending from rods having 

 their axis of motion on the arbor E. This arbor, as well as a parallel one, are 

 carried on friction rollers o o', and so braced together as to form a kind of frame. #, 

 VOL. II. K 



