ON GOLD AND SILVEE. 517 



streams, and had largely interfered with the channels of the navigable 

 rivers. In January 1884 the famous lawsuit of Edward "Woodruff v. The 

 North Bloomfield Gravel Mining Company and six others was decided by 

 the U.S. Circuit Court. The decision prohibited the defendants from 

 ' discharging or dumping into the Yuba river, or into any of its forks or 

 branches . . . any of the tailings, bowlders, cobble-stones, gravel, sand, 

 clay, debris, or refuse matter from any of the tracts of mineral land men- 

 tioned in the complaint, and also from causing or suffering to flow into 

 said rivers, creeks, or tributary streams aforesaid therefrom any of the 

 tailings, bowlders, cobble-stones, gravel, sand, clay, or refuse matter re- 

 sulting or arising from mining thereon. And also from allowing others 

 to use the water supply of said several mines or mining claims, or any 

 part thereof, for the purpose of washing into said rivers and streams any 

 earth, rocks, bowlders, clay, sand, or solid material contained in any placer 

 or gravel ground or mine.' ' 



This decree is sufficiently clear and definite, and from it there has 

 been no appeal. As it stands, it practically puts a stop to systematic 

 hydraulic mining in the basin of the Sacramento and San Joaquin. 



The problem which engineers have to solve is whether means can be 

 adopted for impounding the debris at the mines, and so preventing it 

 fouling the streams. Various methods of doing this are under discussion, 

 and upon their success depends the future of Californian hydrauhc mining. 

 The decree reserves to the court the power to modify or suspend the 

 injunction ' upon any showing which the court may deem sufficient that 

 the conditions have been so changed that the discharge of such mining 

 debris . . . may be resumed or otherwise conducted so as not to create 

 ... or continue the nuisance complained of, or a nuisance of similar 

 character.' 



Official estimates widely differ as to the amount of material carried 

 into the rivers by hydraulic mining. In the lower Sacramento basin, as 

 a whole, the estimates for the year 1880 were 38i and 53g^ million cubic 

 yards. In the Yuba river, to which the lawsuit especially referred, the 

 estimates were 19 and 22|- million cubic yards. 



The area affected by the mining debris was 43,546 acres, and the 

 depreciation in value was estimated at ^2,597,634. This district has 

 yielded about ;56OO,00O,O0O in gold. 



The amount of capital invested in hydraulic mining in California is 

 estimated at ,^100,000,000 ; the amount of payable auriferous gravel in the 

 area covered by the injunction, and therefore closed, is estimated at 

 400,000,000 cubic yards. 



There are some cases in which hydraulic mining is said to be a benefit 

 to the lands lower down, by raising the level of the stream-beds, and 

 therefore of the sub-surface waters ; but in the vast majority of cases it is 

 otherwise. 



So far as the United States are concerned, it is only in California that 

 legal restrictions of placer mining seriously affect the production of gold. 

 It may hereafter do so in Oregon and Washington. But in many districts, 

 as population increases and as interests other than mining become im- 

 portant, similar inconvenience will be felt, and doubtless with similar 

 results. 



' See A. J. Bowie, ' Mining Debris in California Rivers,' Trans. Tech. Soc. Pacific 

 Coast, vol. iv. Feb. and March 1887, from which the foregoing information on this 

 subject is taken. 



