American Afisociation. 269 



been incapable of this mode of treatment. Tlie adoption of sucli 

 mechanical arrangements has rendered the whole process of ore- 

 dressing one continuous and self-sustaining system, in ^Yllich 

 human labor bears an exceedingly small ratio to the results ob- 

 tained, compared with any system hitherto devised. In this 

 system, the Avaste or refuse material is disposed of exclusively by 

 gravity and moving water, without handling, while the ore is 

 brought up to the' highest mercantile percentage, however poor 

 the original ore may be, no appreciable quantity of ore escaping 

 as the waste. 



The first of the above rcsulLs is accomplished by the use 

 of a new and exceedingly simple hydrostatic apparatus, devis- 

 ed by Mr. Stadtmuller, Mining Engineer to tlie Bristol Mining 

 Company, (A model and sectional drawings of the apparatus were 

 here shown to the audience.) The efficient cause of the success of 

 this apparatus is the movement of a current of Vv'ater in an inverted 

 cone of iron, having an annular space surrounding an inner cone. 

 The ore is admitted at the top, and is distributed over a conical 

 surface to meet the ascending current of water, which is so ad- 

 justed in volume and force by a proper valve, and by a nice pro- 

 portioning of the parts, tliat all the finer and more muddy portions 

 of the ore are carried over the upper lip of the apparatus, while at 

 the bottom escapes, with a more forcible current of water, through 

 an adjustable orifice, all the coarser ore and metallic practicles 

 These are certainly free from all slime, and are dressed upon a 

 continuous arrangement of self-acting jiggs, and are carried im- 

 mediately to a percentage suitable for market. The proportion 

 of the ore, (about one half,) which escapes at the upper portion 

 of the hydrostatic cone, is treated by alternate subsidence in large 

 conical vats, the denser portions from the bottom of which are 

 dressed upon Bradford's ore separators, (a pan of copper having 

 the reciprocal motion of the miner's shovel,) which have been 

 found, Avhea sewed with only the class of ores properly adapted to 

 them, admirably successful and economical. The ores, too fine 

 or small in size for the separator, are treated upon a large conical 

 table of circular form, with a very gentle current of water spreads 

 in a thin sheet over the table, thus clearing the last traces of 

 ore from the finer particles of sand with which they are mingled. 

 This paper was illustrated by models and drawings, and by 

 samples of the ore thus dressed, shewing in a very decided manner 

 the beauty and efficiency of the system. 



