88 GRAVEL AND PLACER MINING IN ALASKA. [bull. 26l 
pay streak, and low enough to drain all the ground which it was pro- 
posed to work. The drain was covered and lagged with poles and! 
thus rendered permanent. A shaft was then sunk at the lower end ofi 
the ground, 4 by 8 feet in dimensions and 20 feet deep. This waa 
timbered only for the upper 14 feet, and was sunk in three days by 2j 
men. A tunnel was then run upstream the length of the ground, 
wide enough to admit 8-foot caps. Posts were 5 feet long, all timber] 
being 9 inches square. Sets had 4^-foot centers, and the tunnel was 
lagged overhead with 2^-inch flattened poles. A set of timbers deliv- 
ered cost $4, there being 34 caps to a cord of wood. Lateral drifts! 
8 feet wide were driven at intervals of 8 feet, 4J feet in thickness oi 
gravel being taken. The gravel was wheeled to the shaft and wind- 
lassed to surface, about 25 cubic yards being raised in ten hours. 
The lamentable lack of any tramming arrangement for transporting 
the gravel to a distance resulted occasionally in the caving in of the 
ground from the added weight of the dump. The gravel so laboriously] 
raised was thus lost. Some idea of the difficulties of operating on Eagle 
Creek may be seen from the following figures: Wood was $10 a cordj 
not excessive^ high; lumber, $180 a thousand; and freight-packing 
rates from Circle on the Yukon, 25 cents a pound in summer and 8 
cents in winter. Considering the remoteness of the district, the won 
carried on was remarkably good and systematic. 
THAWING. 
One who has never visited the interior of Alaska finds it difficult 
to conceive the formidable condition of solidly and perpetually frozen 
alluvium which is there encountered by the placer miner. The quan- 
tity of water in the form of ice which occurs in the frozen gravel 
averages about 25 per cent; while in the overlying fine, black silt 
which forms the overburden the quantity of ice varies from 50 to 75 
per cent. Whatever may be the physical composition of the material, 
it forms a mass as solid and as difficult to penetrate as solid stone, andj 
can be disintegrated only by exposure to the sun's rays or by the long- 
continued application of some form of energy artificially applied. 
In any open-cut operations the dense blanket of moss, from 12 to 
18 inches in thickness, which covers the frozen ground, must be 
broken into and turned over either by adzes or plows before the action 
of sun and water can take any effect on the underlying muck. As has 
been said, this effect is remarkably rapid when the water is allowed to 
run over the exposed black and icy mass. 
A curious condition exists in the treeless areas of Seward Peninsula. 
Wherever a growth of stunted willows occurs, the ground beneath is 
found to be thawed, and wherever the willows are replaced by moss 
the ground is frozen solid. The rule is not without exceptions, but 
has been found to have rather general application. The distribution 
