PURINGTON. 
COST OF MINING. 35 
definition, which is followed in this report, corresponds for all prac- 
tical purposes to a flow of 1.5 cubic feet per minute. Il is i<> he hoped 
that if the Federal Government ever succeeds in establishing* an ade- 
quate code of. mining law for its possessions a definition of the miner's 
inch will be included. 
The data in the table on page 38 were compiled from statistics col- 
lected during an inspection made in the summer of 1901 of the placer 
fields in Alaska, Yukon Territory, and northern British Columbia. 
Of the statements furnished by operators, only those which are con- 
sidered reliable have been used. The work attempted had no relation 
to the sampling or valuing of mining properties, and time did not 
permit, except in a few cases, the measuring of the ground. 
Owing to the varying conditions governing the cost of mining in 
the North, the Territory has been divided into three provinces. The 
South Coast province includes the Juneau, Porcupine, and Sunrise 
districts of Alaska. The Interior province includes the Atlin district 
of British Columbia, the Klondike district of Yukon Territory, and 
the Fortymile, Eagle, Birch Creek, Fairbanks, and Rampart districts of 
[Alaska. The Seward Peninsula province includes the Nome, Council 
and Solomon districts of Alaska. 
The Nizina district of the South Coast province and the Port Clar- 
ence, Fairhaven, and Kougarok districts of Seward Peninsula, none 
of which were visited, are separately considered. 
In preparing the sheet the working costs of 118 different operations 
were first tabulated with reference to the method employed and to 
situation. A second table was then prepared, in which the working 
?ost was augmented by an amount per cubic yard based on allowance 
or depreciation of plant. In general, six years was taken as the aver- 
ige life of an individual property, and, except in the case of winter 
rifting operations, one hundred and twenty days as the working sea- 
on. It was then assumed that five annual payments are made to a 
epreciation fund. The fund is equivalent to the cost of plant and 
laintenance during the life of the property plus six years' simple 
titerest on the investment at 5 per cent. Each annual payment was 
ivided by the season's output in cubic yards, and the amount thus 
btained was added to the daily working expenses, to get the total 
ntput cost per yard, as far as possible. Prices paid for mining 
roperty are not considered, as they represent an unknown factor. 
In cases where expensive plants have been installed the amortiza- 
on was calculated separately for each case. 
In cases of shoveling-in and small mechanical plants, the installation 
d maintenance cost was taken at an average amount for a group of 
rations in each district. Where the operation implies an additional 
ripping of overburden, which is always separately charged, the cost 
distributed and added to the gravel extraction cost. 
