190 GRAVEL AND PLACER MINING IN ALASKA. [bull. 263. 
handled, but screening devices for saving coarse gold are essential. 
Bucket rather than belt stackers are preferable, for ice on the faces of 
the driving pulleys would cause slipping. The climatic conditions 
demand that the dredges should be completely housed, and that those 
driven by electricity should be equipped with electric heaters to sup- 
ply hot water to the gold-saving appliances and thus permit contin- 
uing operations after cold weather has put a stop to hydraulicking 
and open-cut mining. 
Open connected buckets will do better work in the heavy bed rock 
usually encountered in Alaska, and teeth on bucket lips will probably 
be effective. The use of several powerful digging teeth in the bucket 
chain, instead -of toothed buckets, to excavate heavy bed rock, was 
suggested by a manager of wide experience, and has worked well in 
several instances. A larger factor of safety should be allowed in 
designing dredging machinery intended for Alaska, and strenuous 
efforts made to minimize lost time in every feature of the construction, 
so that full advantage may be taken of the short available season. 
SLUICES AND GOLD-SAVING APPLIANCES, EXCLUDING 
HYDRAULIC OPERATIONS. 
Creek miners in the Klondike and Alaska placer fields have met, 
with extraordinary vigor and a considerable amount of success, the 
peculiarly difficult conditions attendant on mining operations in the 
Northwest. Inventive genius has been called largely into pla} r , since, 
except in parts of Seward Peninsula, t^draulic mining in working 
the creek deposits is not practiced. It is evident, however, to one 
who visits the Klondike district, that the methods there in vogue 
for working the rich creek deposits have been developed with special 
attention to the economical mining and conveying of the material to 
the sluice, while the washing of the gravel in the sluice is not, as a 
rule, conducted with a view to the saving of the greatest economic 
amount of the gold. Whereas in the hydraulic-sluicing methods the 
benefit of long experience has resulted in generally commendable 
practice, the smaller hand and mechanical creek operations frequently 
exhibit gross carelessness in the matter of gold-saving appliances. 
The method of shoveling by- hand into a string of sluice boxes is 
naturally the one first tried by the miner in a remote district, working 
in shallow ground, after he has passed the panning and rocking 
stage. In these operations the cost, even under present northern con- 
ditions, varies from $1.25 to $2.50 per cubic yard (averaging $1.63), the 
capacity per man per shift averaging 5i cubic }^ards. The most prim- 
itive appliances are the most economical. From three to six boxes, 
12 or 14 inches in width by 12 inches deep by 12 feet long, on a grade 
of 6 or 7 inches to the box length, fitted with 6-foot 3-inch pole riffles 
made of saplings, form the customary rig in the interior where timber 
