194 
GKAVEL AND PLACER MINING IN ALASKA. 
absence of screening or use of grizzlies, other than the rough, expen- 
sive hand method employed, renders valueless much ground which 
could be worked. A plant costing $5,000, designed to thaw, excavate, 
hoist, convey, and wash 150 cubic yards a day at a cost of $1 a yard, 
could, by an addition of from $500 to $2,000 to the first cost of the 
plant and an addition of 10 cents per yard to the cost of washing, 
recover at least 10 per cent more value in gold from a cubic yard of 
material. 
It may be said that the fine gold found in the Klondike does not 
occur in the Alaska creeks. This is disproved by experiments made 
on small parcels taken from pannings on the various creeks. Fine 
gold from Fairbanks Creek, in the Tanana district, runs 500 colors to 
the cent, the gold being worth $17.70 per ounce. A small proportion 
of gold from Ophir Creek, in Seward Peninsula, was found to run 
O 
OOP 
Punched holes 3/a" 
Punched holes 3/e' 
Alo.9 Iron or steel 
mzmm 
Cross section 
of a hole 
h plate 
ifeet 
Fig. 41.— Modified Caribou undercurrent. 
170 colors to the cent, the gold being worth $18.50 per ounce. No 
means of knowing the proportionate amount of this gold is possible, 
as with the methods at present employed very little of it is recovered. 
Five per cent is considered a fair average of the total gold represented 
by the above fineness of division. This gold, which is not flaky in 
spite of its tine character, could easily be saved with the proper appli- 
ances, and there is no doubt that much coarser gold is lost. 
The question will be asked, Can a cheap and efficient washing plant 
be installed, where gravel must be elevated by power, which will not 
add greatly to the cost, and the parts of which can be easily and 
quickly made with the materials at hand? 
On the principle that gold is best saved in the thinnest sheet of water 
which will carry the tailings away, it is evident that for fine gravel 
a wider sluice is better than a narrow one. In narrow sluice boxes, 
