[ibington.] DRIFT MINING. 87 
rig, 10 men and two 2-horse scrapers were used to a shift. The 
iroduct of the operations was $160,000; and the cost, including pre- 
iminary prospecting, was 59 per cent of the output. The work was 
one in 1901-2, and the opinion was given by the operator that the 
ost could be decreased 20 per cent under present conditions. 
In drifting operations on high benches lying between Anvil and 
)exter creeks near Nome the gravel must be hoisted through shafts. 
t is said that powder is efficient in extracting the frozen ground, 
"his is contrary to experience in the Alaska interior, and is doubtless 
ue to the fact that the gravel is not nearly so solidly frozen. In fact, 
b is said that the powder is used for only a portion of the time, 
^rom the main shaft, which must be in some cases 230 feet deep to 
each the second pay streak, a drift is run the length of the pay 
round. From this, transverse drifts are run at alternate intervals of 
feet in each side of the main drift. Some operators sink the shaft 
n the side rather than in the center of the ancient channel, as by this 
aethod the shaft is less likely to u squeeze." The shafts are 3 by 6 
eet, timbered with 2- by 12-inch plank laid up on the sides, with 2- by 
-inch timbers set vertically on the corners inside. 
The face can be carried from 50 to 100 feet in length in the winter, 
s the constant slight freezing renders the gravel less heavy. In sum- 
ler, on the other hand, the ground must be worked in small blocks. 
Vith the methods of timbering in use, 6- by 6- to 10- by 10-inch sawed 
losts are put in, on base block, and with a short 4- b}^ 12-inch plank 
ap, posts having 3-foot centers in all directions. A space of 3 sets in 
ridth is generally carried before the ground is allowed to cave. When 
he ground is ready to cave a bulkhead is nailed to the second set, the 
gibers are pulled with ropes from the third, and the caved ground is 
aught by the bulkhead. The breast is then carried forward as before, 
(o lagging is used except in the shaft and the main runway. In sum- 
mer work the area of bed rock exposed in one stope rarely exceeds 10 
eet square. 
In sluicing tlie dumps from winter operations on the high Anvil 
►enches, the expedient is adopted of building small dams of sod and 
recting snow fences behind them to catch snowdrifts, so that sluic- 
ng water may be afforded in the spring from the melting snow. The 
emarkable phenomenon of deep-lying pay streaks on the Anvil 
enches has been considered by Mr. A. J. Collier a in his geological 
ccount of the Nome district. 
On Eagle Creek, in the Birch Creek district, an interesting drifting 
Operation was seen. It is especially difficult to work the creek claims 
iy drifting on account of the partially thawed character of the gravel. 
L bed-rock drain was run in winter at one side of and parallel with the 
a The placer deposits of Seward Penuisula: Bull. U. S. Geol. Survey, in preparation. 
