I 



THE COMSTOCK MINES. 151 



incidental expenses of cariying on tlie entire operations of the mine. It is ob- 

 vious that if the expense of all this work, generally very large, be applied to the 



quantity of ore raised from the productive poiiion of the mine, the costs, per || 



ton, will appear much larger than they would if only the actual expense of 



extraction were considered. Thus in the tabular statement here presented the I 



lowest cost of mining, per ton, in the Savage mine, is given at $7 21 ; 

 while in the Imperial the cost in one year is as low as $3 54, for the 

 Holmes mine, and is generally less than $5. In the case of the Savage 

 every item of expense that may reasonably be charged to the business of 

 mining is included in the account, whereas in the Imperial the given figures 

 apply only to work performed in reaching and extracting the quantity of ore 

 on which the calculation is based, including nothing of the cost of sinking 

 the new shaft, unproductive work or other incidental expenses. If the ac- 

 counts of the several mines were prepared on exactly the same basis, the 

 differences in the figures would be but httle. 



Another cause of difference in the cost of mining in the several mines, 

 or between various years of the same mine, is to be found in the varying 

 relation existing between the amount of unproductive work performed and 

 the quantity of ore extracted. Thus in the Savage mine the costs of extrac- 

 tion, per ton, in the year ending June 30, 1866, are stated at $18 06 ; while 

 in the two succeeding years the average is about $1 55, the difference being 

 mainly due to the fact that in 1866 the outlay for dead work, improvements, 

 and equipment was large, while the quantity of ore extracted in that year 

 was but httle over one-third of the quantity produced in either of the two 

 years following ; the proportionate expense of this work, per ton, of course, 

 increasing as the quantity decreases. 



It is difficult therefore to give a correct idea of mining costs except by 

 minutely analyzed accounts, and these are given for some of the companies, 

 with more or less detail, in the statements which follow. 



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