66 GRAVEL AND PLACER MINING IN ALASKA. [bull.2 
(namely, 15 feet) for open-cut operations in general. The operate 
adopts this method because there are thawed streaks and channe 
in his deposit. If such ground is drifted, the chances are that he w 
increase his expense to a prohibitive amount through excessive tir 
bering and through pumping of seepage water, whereas by the ope 
cut method the water is handled by drain. The cost sheet shows th 
whereas $2.14 is the average cost of the above-mentioned 8 operatic 
in the Klondike, 7 drifting operations in similar deposits, with * 
average depth of 25.3 feet, gave an average cost of $1.95 per cub 
yard, the depth of the pay or thickness of gravel actually sent to tl 
sluice being almost exactly the same in both cases, and the capacity 
the drifting being only 17.5 cubic yards less in twenty-four houi 
Granting, however, that in a given deposit carrying $3 to the cub 
yard of pay, the depth being 16 feet, drifting is impossible, and tl 
rich pay, 75 feet in width, must be worked by open cut. Whatev 
method be adopted the moss must first be plowed up and about 6 fe 
of muck ground sluiced off at a cost of 17 cents per cubic yard. Ne 
6 feet of barren gravel or sand must be removed, either b} 7 hor 
scrapers at 60 cents per cubic yard, or, if the plant warrants the opei 
tion, by steam scraper at 49 cents per cubic yard. The 4 feet of pj 
being laid bare, what method shall be adopted to get it into the sluice 
On account of the necessarily short life of the operations, a pla 
whose first cost exceeds $5,000 is out of the question. The greate 
expense will then result from the hand shoveling in the pit. The g( 
ting of the material into the receptacle in which it is conveyed to t 
sluice is the principal item of expense in the operation. It is thei 
fore necessary that the high-priced shovelers get as much gravel in 
the wheelbarrows or buckets as possible. The bucket, 37 inches squa 
on top, 35 inches square on bottom, and 25 inches deep, holding t^ 
thirds of a cubic yard, is dropped into a crib built in the bottom 
the pit, to which the shovelers wheel their dirt in wheel barrow 
From 4 to 6 wheelbarrows are necessary to fill the bucket. The 
is no mobility to the bucket; it must always rise and fall to t 
same spot. Men instead of occupying all their time in shoveling m 
employed nearly half of it in wheeling and dumping. Five operatic 
are necessary to get the gravel from the bank to the sluice, name 
(1) shoveling into wheelbarrows, (2) wheeling to bucket, (3) dumpi 
to bucket, (4) raising bucket to carrier. a (5) conveying and dumping 
sluice. (See PL VI, B.) 
This may now be compared with the derricking system. On Pec 
Creek, Fairbanks district, an open cut 15 feet of depth with 9 feet 
pay gravel is worked by derricking. The plant has a capacity of £ 
cubic yards a day, which is handled at a co*t of $1.75 per cubic yd 
The plant costs no more than the average price of a self-dumpi 
«The Dawson self-dumping carrier and its use is described under the heading " Drift raining," p 
