96 GRAVEL AND PLACER MINING IN ALASKA. [bull. 263J 
easily shoveled into the boxes, from both sides, beginning at the lowest 
point and working upward. Boards are generally laid over the top 
of the boxes, and a portion of the gravel rests on these. The boards 
are taken off as the work of shoveling in progresses. 
The expenses of winter work are much greater than those for sum- 
mer, and the tenor of the gravel must in consequence be much higher. 
In the first place it is to be remembered that the gravel dumped in 
winter must be all rehandled in the spring. In thawing also the 
amount of steam used in winter is greater than in summer, and al] 
pipes and hose conveying steam both above and under ground must be 
coated with asbestos or other nonconducting material. On the other 
hand, labor is generally cheaper in winter than in summer, and the 
possibility of striking thawed streaks of ground is much less. 
DRIFTING IN THE FAIRBANKS DISTRICT. 
As has been stated, the only mining practiced at Fairbanks is creek 
mining. In the open season, although the bulk of the ground can be 
worked by drifting, a smaller proportion is workable by open cutting. 
B}' far the larger portion of the ground must be worked by drifting 
on account of the depth to bed rock and, in many cases, the thinness 
of the pay. The ground is in the main frozen, but thawed streaks 
occur. The gravels are of the angular and subangular character 
which marks all the gravels deposited in recent time in the northwest. 
The angularity is more pronounced than in the Birch Creek district 
or the Klondike. 
One characteristic feature of the Fairbanks gravel has an important 
bearing on the method of thawing the frozen gravel. This is the fact 
that while the la}^er of so-called muck is comparatively thin, from % 
to 7 feet in the workings on the creeks themselves, exclusive of the 
slopes, the gravels, which are from 6 to 15 feet in thickness, do not 
carry pay throughout their section, but only in the lower part. The 
pay is sometimes as thin as 6 inches in the gravel, and rarely exceeds! 
8 feet. It is then frequently necessary to take only a portion of the: 
gravel down, and to run the drifts as low as possible, i. e., not to 
exceed 3£ feet. To do this economically, and so that the top and bar-i 
ren gravel will not be continually caving and falling during the drift- 
ing, the ground must either be timbered or the method of steami 
thawing must be abandoned. Another reason why the method oi 
steam thawing has a limited application in the Fairbanks district is the 
fact that the gravel is very argillaceous in its pay portion, and the 
thawing and drying with the steam result in a baking of the ground. 
Thus the gravel which was frozen becomes in its dry state cemented, 
and the difficulty of getting it out is not avoided but only lessened. A 
Thawing by means of hot water driven through a force pump and 
conducted to the bank by means of cotton hose and piped against the 
