160 



DRESSING OF ORES 



2. Jiggers . . . For getting rid of worthless vein-stuff and increasing tho 

 metallic percentage of tho resulting product for subse- 

 quent treatment. 



SEPARATING AND ENRICHING MACHINERY. 



1. Hough jiggers 



2. Coarse sand jiggers 



3. Fine sand jiggers 



4. Slimo sand jiggers 



5. Convex and concave 



buddies . 



6. Side and end blow' 



tables 



7. Brunton and slime 



tables 



For dividing stuff into (1) castaways, (2) orey stuff, 



(3) ore, tho stuff ranging in size from 10 mm. to x. 

 For separating grains from 2 mm. to 10 mm. into ( 1 ) waste, 



(2) orey stuff, (3) ore. 

 For separating sand from f mm. to 2 mm. into (1) waste, 



(2) oroy stuff, (3) ore. 

 For separating sand from mm. to f mm. into (1) waste, 



(2) orey stuff, (3) ore. 

 For separating sand from f mm. to 2 mm. into (1) waste, 



(2) orey stuff, (3) ore. 

 For separating sand from mm. to f mm. into (1) waste, 



(2) orey stuff, (3) ore. 

 For separating sand from mm. to mm. into (1) waste, 



(2) orey stuff, (3) ore. 



General Table relating to Ore Dressing Machines. 



In the year 1857, Herr Von Sparre, of Eisleben, Prussia, patented four machines 

 for separating substances of different specific gravities, in all of which water is em- 

 ployed, either as a medium through which the said substances fall under the action 

 of gravity, or as an agent for facilitating the motion of portions of tho said substances 

 along inclined surfaces. Tho particulars, together with illustrations, will be found in 

 Patent No. 1405 for the year 1857. 



Tho mechanical preparation of tin and copper ores has from time to time been 

 noticed by several writers. In 1758 Borlaso described the method employed in tho 

 west of Cornwall. Twenty years later, Price, in his Mineralogia, added to Borlase's 

 description, and illustrated some of the apparatus then in use. Afterwards Dr. Boase 

 published, in the second volume of tho Transactions of the Geological Society of Corn- 

 wall, an article upon the dressing of tin in St. Just. In volume four, Mr. W. Jory 

 Henwood inserted a paper on dressing ; and some general remarks will bo found on 

 the subject in De la Beche's Report on the Geology of Cornwall. Tho enrichment of 

 lead ores has been noticed by Forster, in his 'Section of Mineral Strata ; also by 

 "Warington W. Smyth, in his memoir Chi the Mines of Cardiganshire, in the second 

 volume of the Memoirs of the Geological Survey of Great Britain. In 1868, Mr. 

 James Henderson presented a paper to the Institution of Civil Engineers 'on the 

 Methods generally adopted in Cornwall in Dressing Tin and Copper Ores,' to which wo 

 are indebted for some of our illustrations. In the ' Proceedings of Mechanical Engi- 

 neers, 1873,' will bo found valuable papers on the ' Mechanical Appliances for Dressing 

 Tin and Copper Ore,' by Mr. Henry T. Ferguson, and on the ' Tin Stream Works in 

 Eestronquet Creek,' by Mr. Charles D. Taylor. 



In France, Dufrcnoy, Elie do Beaumont, Coste, Pcrdonnot, Huot and Goylor, and 

 Moissenet have treated on tho mechanical enrichment of copper, tin, and lead ores. 

 The latter gentleman has frequently visited this country, and givwu tho results of his 



