82 
GRAVEL AND PLACER MINING IN ALASKA. 
[BULL. 203. 
The shovel is moved by rollers running on skids, power being 
obtained from the shovel winch. The dipper is furnished with soft 
steel prongs which wear very 
rapidly. 
DRIFT MIKING. 
INTRODUCTION. 
Northern gold-gravel deposits, 
that are sufficiently rich to war! 
rant the method, can generally be 
exploited by- drifting beneath the 
overburden at all times of the 
year. In drift mining creek de- 
posits the gravel is hoisted through 
shafts, and where bench gravels are 
worked it is generally trammed 
through adits. In all portions 
§ of the interior of Alaska and in 
1 the Klondike the drifting of aurif- 
te erous gravels has been carried 
§ on with fully as much activity ini 
2 the winter as in the summer. As 
a may be seen by the cost sheet, 
o the expense of winning the gold 
« by winter drifting and spring thaw- 
[ ing is greater by over $1 per cubic 
^ yard than that of summer work. 
*■ This increase is due to the necessity 
of rehauling and, in many cases, oi< 
rethawing the dumps in the sepa-i 
rate process of sluicing. In con 
sequence, only the richer ground 
running from $6 to $10 to thi 1 
cubic } 7 ard, can be profitably j 
drifted. The price of labor dur* 1 
ing the winter in the interior i 
only 25 per cent less than in sumij 
mer, so that this does not afford 
great offset to the increase of cos j, 
from other causes. In Sewar 9 
Peninsula, where the price fo j 
winter labor is only $2.50 a da 1 
and board, as against $5 in summei 9 
it would seem that winter drifting can be undertaken more generall ] 
than heretofore. A reliable operator of Nome is of the opinion thf 
