purington.] GRAVEL AND PLACER MINING. 43 
as nearly as possible the average cost for each of the seventeen separ- 
ate methods considered in one or more of the three provinces. Where 
the operations from which the averages are derived exceed two in 
number, the fact is so indicated in the table. 
The attempt has been made to reject figures which were evidently 
not representative. The final figure arrived at is not, however, always 
satisfactory. For example, under No. 5 (the method of working open 
cut by shoveling into wheelbarrows, wheeling to bucket, hoisting, and 
conve}ang to sluice by self-dumping carrier on cable) $2.14 is repre- 
sentative for the Klondike, where seepage water is generally pumped 
from the pit, and many operators pump the water for sluicing. On 
the other hand, at a plant in the Birch Creek district of Alaska, mining 
only 22 cubic yards per day and handling the water by a drain, the cost 
of operation was 11.50 per cubic yard. In No. 13 (drifting solidly 
frozen ground, steam or hot-water thawing, hoisting and convejdng 
with the use of the self-dumping bucket) the cost in the Klondike is 
$1.95, while the higher figure given is arrived at by combining the 
expensive American camps of Fortymile and Fairbanks, where the 
cost is $4.63 and $3.56, respectively. 
The high cost of hydraulicking with use of hydraulic lift in the 
Seward Peninsula is caused by the difficulty of moving the gravel to 
the bed-rock sluice a and the expense of the ditches and installations. 
Hydraulicking by means of water under natural head without the use 
of the hydraulic lift, or some other means of elevating the material, 
was not seen by the writer in the Seward Peninsula. It is understood 
that an hydraulic plant is in successful operation at Bluff, 50 miles to 
the east of Nome, but there are no data at hand concerning it. 
In the interior only bench gravels are hydraulicked. Steeper grades 
for sluices can be obtained, and the gravel is more easily moved. The 
high duty of the miner's inch in the Klondike is a large factor in bring- 
ing down the cost of No. 1 and No. 16. 
It should be distinctly understood, if hydraulicking eosts in the 
interior appear attractively low, that the water supply is exceedingly 
variable, and that no reliable estimate can be made beforehand of the 
output of a given season's operations. Furthermore, while much of 
the bench gravel was originally rich, the pay streaks have been largely 
drifted out, and the gold is not disseminated through the upper por- 
tion of the gravel to the extent that it is in the California gravel 
banks. With regard to the pumping of water for hydraulicking pur- 
poses, the practice can not be too strongly condemned. He is a bold 
man who attempts it, and a singularly fortunate one who makes a finan- 
cial success of it. 
a This is caused not only by the exceedingly gentle grades of the streams, but also by the shingly 
character of the material handled. 
