556 MmiNG mDUSTET. 



$23 33 per cord, or, converted into tc^ns as above, $3 11 per ton. This does 

 not include anything for hauling from the mine to the mill, which, in the 

 instance last given, was $11 per cord. Mills run by water power are proba- 

 bly able to treat ore for a considerably lower figure, but, as a rule, they are 

 further from the supply of ore, involving not only a greater cost for hauling, 

 but being more liable to interruption; the roads, at certain seasons prevent- 

 ing, or being liable to prevent, the delivery of the rock. The occasional lack 

 of water, and the consequent interference with steady operations, is also a 

 contingency of a water-power mill that tends to increase the costs of work- 

 ing, somewhat, in the long run. 



The chief items of expense in steam mills are fuel, labor, and repairs, 

 including in the last term the replacing of shoes, dies, and other wearing 

 parts. Besides these are water, when purchased, quicksilver, and other in- 

 cidental expenses. Judging from all available data, the consumption of fuel 

 is about equal to one cord of wood for six tons of rock stamped. In the 

 Ophir mill, in 1868, in which the accounts were kept with much care, the 

 quantity of ore crushed, per cord of wood consumed, during June, July, and 

 August, was respectively 4.23, 5.66, and 5.23 tons. According to the tabu- 

 lar statement, on a following page, showing, in detail, the operations of a 

 number of mills, the quantity of ore crushed per cord of wood used, varies 

 from 5 to 15, and appears to average about 6. The price of wood varies 

 from $5 50 to $7 50 per cord. The cost of fuel, for milling, may therefore 

 be placed at about $1 per ton of ore. 



The number of men required in a steam mill of ordinary capacity is 

 seldom less than four, and more frequently five. In a mill of 24 stamps 

 there are usually 2 engineers, 2 stamp-feeders, 1 foreman, who may attend 

 to the cleaning up and retorting ; in addition to these an ore-passer is needed 

 in some mills, assisting the feeders, wheeling in the rock and sledging the 

 larger pieces, if there be no stone-breaking machine ; and a general helper, 

 in front of the batteries, attending to the disposition of the tailings or residue. 

 In some mills these last-named men may be dispensed with ; in others, two 

 would not be sufficient for the work, the demand varying in different mills 

 according to local conditions, the conveniences for handling the material, and 

 the disposition made of it after having passed over the amalgamating tables. 



