22 Colorado Gold Mines. [January, 



approximately 12 dols. per ton. The return of bullion de- 

 rived from the 100,000 tons crushed confirms therefore, what 

 is evident from other considerations, that the mines have, 

 as a whole, merely paid the miner and mill-man their extra- 

 vagant wages, without returning any profit on the capital 

 invested in the mine. Could, however, the heavy loss now 

 sustained be saved, the saving would be nearly clear profit. 

 But, beside that, the very method which would save the 

 waste would enable much of the third quality ore, now 

 broken and raised at considerable cost, to be utilised. But 

 to this subject I shall return after describing the 



Smelting Works now in Operation. 



One establishment — that of the Boston and Colorado 

 Smelting Company — has for five years monopolised the 

 smelting ores raised around Central City, and under the 

 admirable management of Prof. Hill the enterprise has 

 succeeded financially and metallurgically. 



At present there are five calcining and three reverberatory 

 smelting furnaces running. The ores treated are the No. I. 

 iron and copper pyrites, and concentrated tailings, containing 

 gold and silver. Galena ores are not sought for; but a cer- 

 tain amount of galena and blende is necessarily present in 

 the mixture, and the latter is in sufficient quantity to be a 

 source of trouble by carrying silver into the slag. A cupola 

 furnace is employed to re-melt this zincy slag, — an ex- 

 pensive operation, as coke costs between 40 and 50 dols. 

 a ton. 



The fuel used in the reverberatories is wood . The calciners 

 roast 3 tons of tailings daily, with' the consumption of one 

 cord of wood, costing 7 dols. a cord. The smelting furnaces 

 consume about 12 cords of wood, and smelt 4 charges of 

 2 tons each in the twenty-four hours. The lumps of coarse 

 ore are heap-roasted. 



Professor Hill aims at getting a 40 per cent copper matt, 

 containing 40 ozs. of gold and 400 to 600 ozs. of silver to 

 the ton. He has always sold his matt to Vivian and Co., 

 Swansea. His works have been of immense advantage to 

 Gilpin County. Yet he is not in good odour with the miners 

 generally. His scale of prices is low — lower probably than 

 if there were a vigorous competition on the spot. Special 

 arrangements, however, are made with good customers. 

 But in every case the value of most of the parcels of ore is 

 evidently guessed at, as the rough mode of sampling 



