AND THE MANNER OF WORKING THEM. 17 



work. It is especially effective in a region covered by trees, where 

 the tangled roots would greatly retard the labor of workmen. la 

 such places, the stream of water washes out the earth from below, 

 and tree after tree falls before the current, any gold which may 

 have adhered to the roots being washed away. With a pressure 

 of sixty feet, and a pipe of from one and a half to two inches 

 aperture* over a thousand bushels of earth can be washed out 

 from a bank in a day. Earth which contains only one twenty- 

 fifth part of a grain of gold, equal to one-fifth of a cent in value 

 to the bushel, may be profitably washed by this method ; and 

 any earth or gravel which will pay the expense of washing in the 

 old way, gives enormous profits by the new process. To wash 

 successfully in this way requires a plentiful supply of water, at an 

 elevation of from fifty to ninety feet above the bed-rock, and a 

 rapid slope or descent from the base of the bank of earth to be 

 washed, so that the waste water will run off through the sluices, 

 bearing with it gravel, sand, and the suspended clay." 



" The above description, and the added details are copied from 

 a report on the gold mines of Georgia, by Mr. William P. Blake, 

 who has carefully studied this method of mining in California, and 

 by whose recommendation it has been introduced into the southern 

 states. He states that in the case of a deposit in North Carolina, 

 where ten men where required, for thirty-five days, to dig the 

 earth with pick and shovel, and wash it in sluices, two men, with 

 a single jet of water, would accomplish the same work in a 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 process. He tells us that in California the whole 

 art of working the diluvial gold deposits was revolutionized by 

 this new method. The auriferous earth, lying on hills, and at 

 some distance above the level of the^ water-courses, would, in the 

 ordinary methods, be excavated by hand, and brought to the 

 water ; but by the present system, the water is brought by aque- 

 ducts to the gold deposits, and whole square miles, which were 

 before inaccessible, have yielded up their precious metal. Ife 

 sometimes happens, from the irregular distribution of the gold in 

 the diluvium in California, that the upper portions of a deposit do 

 not contain gold enough to be washed by the ordinary methods ; 

 and would thus have to be removed, at a considerable expense, in 

 order to reach the richer portions below. By the hydraulic 

 Can. Nat. 2 Vol. YIII 



