PURIS'OTOK.] 
SLUICES AND GOLD-SAVING APPLIANCES. 
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Fig. 48 shows an excellent iron riffle used in the smaller sluices of 
Seward Peninsula for saving gold of average fineness. The castings 
are light, can be easily handled, and can be set in the sluices so that 
the long dimension of the slots lies either transversely or longitudi- 
nally. The longitudinal arrangement has been found to be the better. 
The use of quicksilvered copper plates is not likely to give increased 
saving in Alaska placer operations. Blankets, mats, or other fabrics 
are not generally used on account of their expense. 
Mr. H. W. Young a has designed for the Waiwhero Sluicing Com- 
pany, of New Zealand, a form of apparatus for the saving of fine 
gold which is used in New Zealand beach deposits where the gold 
is accompanied by an excessive 
amount of black sand. A few of 
Mr. Young's remarks are here 
quoted: 
The modern fine gold washing plant, 
as used on the West Coast, consists of 
three main essential parts. The first is 
the hopper box with stone shoot, which 
receives the water and gravels from the 
tail race connecting with the sluicing 
face, and separates the stones and shin- 
gles from the water and sands. The 
second comprises the "sand box" or 
"boil box," with its discharge ducts 
and other accessories, intermediate be- 
tween the hopper and the tables. The 
third comprises the washing tables and 
their accessories. The three essential 
parts deal with the stuff from the face, 
and reduce it to concentrated gold and 
heavy sand ready for amalgamation. 
The introduction of a sand box or agitation box, in which the mate- 
rial is kept in agitation by being made to pass over and under a system 
of baffle boards before passing to the tables, as described by Mr. 
Young, is of obvious advantage in connection with the plant described. 
The principle will undoubtedly be of use in some of the washing plants 
of Alaska, as it provides a moderate stirring action without the use of 
mechanical power. The quantity of water economical for such a plant 
as the one described, with material screened to seven -sixteenths inch 
size on tables with a grade of 12 inches to 12 feet, is in the proportion 
of 40 miner's inches to each 10 feet of width of table. As at Oroville, 
the value of separate ducts from the feeding or sand box to each table 
has been proved. 
The clearing of the gold from the accompanying minerals of high 
specific gravity is often difficult. In the creek workings on Bonanza 
6 inches 
Fig. 48.— Iron-grate riffle, Seward Peninsula. 
i Report of the New Zealand Minister of Mines, 1902, p. 20. 
