HYDRAULIC MINING.

Mount Ida Chronicle, Volume I, Issue 18, 4 June 1869, Page 3

HYDRAULIC MINING.

In Mr. jßron-p Suiyth's work reference is made to the system of hydraulic minim; in ..voguein California. The subject is one of great importance, and doubtless if the scheme adopted on our goldfield-?,. th*> results would be of a most Denetieial character. The writer

says : • . ~ , " In tais in-etUod h' se force, of a jet of" water, with ••Woafc'- 'pressure, is made available both tor excavatm-? and washing the auriferous earth. The wafer,, issuing in a continuous stream with great ioree from a large hose-pipe like that of a fire engine, is directed against the base of a bank of ear hi and gravel, and tears it away. The bank is rapidly undermined, t ! :e gravel is loosened, violently rolled together, and cleaned' from any adhering - -'particles of "gold, while the hue clay and sand are carried off by tae water. In this manner, hundreds of tons of earth and gravel may be moved, and nil the gold which they contained liDer ired and secured with greater ease an d expedition than ten tons could be excavated and war-shed m the old way. Ail tae earth and gravel of a deposit is -moved, washed, and carried oif through sluices bv the water, ioiviu.; tie gold behindSquare acres of earth on the hill sides may thus he swept aw vv' into the hollows without tie aid. of a pick or.shovel in excavation. Water performs all the labor, moving and washing the earth ill one operation 5 while in excavating by hand the two processes are of necessity entirely distinct. The value of this method, and the yield of gold by it, as compared wit.i the older one, can hardly ho estimated. The water acts constantly, uniform effect, and

can be orougnt to bear u->on almost any point w -<ere it would be difficult for'men to work. It, b'• especially*: effective 111 a region covered 1/wifcV""' tiroes, where the tan'.'led roots would greatly retard the laoor ot* workmen." In such place trie stream of water- wa«he=i out the earth from ueiow, and tree after tree tails from the current, any gold which may adhered to the roots being washed away, With a oressure ot sixty icet and a pipe of front one and a half to "two inches aperture, over 1000 bushels, ot earth can' be . washed out from a bank in a day. Earth, which contains only one twenlrf-iifth part ot a grain of gold, equal to onefir feh of a cent, (halfpennr) in valu?- to tee bushel, may be profitably washed by this method: an*l anv e i.rth o? gravel which will, pay the expense of washing in tie oid way, gives enormous profits by tne tt.;w process. To wash .successfully in this way requires a plentiful supply of water at an. elevation of from fifty to nmety feet aDove the bed rock, aiul a rapid slope or descent from the base of tae bank of earth to be washed, so that the waste water will run th rough the .slm ;.'{?!?, bearing- with it gravel, sand, and the 'suspended clay In the case of a deposit in the North Carolina, where ten men were 'required for thirty-', live days to dig the earth with pick and shovel, and wash it" in sluices, two men with a single .jet* of -water wbuM "accom plish the same work in the week. The great economy of this method is manifest from the "fact that many old deposits in the river beds, the gravel of which had been already washed by hand have been again washed with profit by the hydraulic method.'.'