328 TRANSACTIONS OF TOE 



eight or ten dollars to the ton, and in some localities it is said to have 

 been -worked Avithout loss, though yielding not more than half that 

 amount. Where this can be done, all tlie conditions essential to cheap- 

 ened reduction must, of course, be present. It frequently happens that 

 ledges which foil to pay at first become remunerative when opened to a 

 greater depth. Sometimes, though not often, the reverse is true, the 

 vein stone growing poorer or giving out as descended upon. In almost all 

 true veins there is an improvement with depth. The Eureka Mine, 

 Amador County, at a depth of more than a thousand feet, is paying as 

 well as at any point above. The shaft of this company is the deepest in 

 the State, though there are several others of nearly as great depth ; yet 

 in none of these cases of extreme depth has thei'e been any visible, 

 impoverishment in the ores so far as reported. At Grass Valley, where 

 many of the ledges have been developed to a considerable extent down- 

 wards, the same general facts hold good. 



The most common mode of exploitation in this State is by shafts sunk 

 upon the ledge, tunnelling also in many cases being resorted to as afford- 

 ino- facilities for the extraction of tlie vein stone and effecting drainage. 

 Many of these shafts are from one to three hundred feet deep — the 

 tunnels varying in length from one hundred to a thousand feet, and 

 occasionally much more. The cost of excavating these works, estimated 

 b}' the linear foot, depends upon the nature of the material to be pene- 

 trated, the distance to be run, and similar conditions, and is therefore 

 extremely variable, but may be roughly stated at ten dollars per foot for 

 sinking shafts, and fifteen dollars for excavating tunnels. The wages 

 paid miners for this kind of work runs from fift}" to seventy dollars per 

 month, with board, the average being about sixty dollars, or three dol- 

 lars per day. Aided and stimulated by the liberal investments being 

 made, there is now much prospecting going on, both in the way of open- 

 ing ledges already located and in searching for new ones. In most cases 

 miners who dispose of their interests employ the proceeds in prospecting 

 for others, or in working the claims they may still own. 



The quartz mills throughout this State vary in capacity from three 

 stamps to fifty; the number contained in the mills built at an earlier 

 day generally running from five to twenty. Latterly the number has 

 been larger. Most of the mills are employed in crushing rock from the 

 ledges belonging to their several proprietors; and hence there is in 

 many districts a need for mills to do custom work. It is usually esti- 

 mated that each stamp has a capacity to crush one ton of rock in twenty- 

 four hours. The earnings of some of these mills and mines are enormous. 

 The average monthl}^ yield of four mills on the Fremont Mariposa estate 

 was over sixty thousand dollars. Tiie net earnings of the Crescent Com- 

 pany, Plumas County, have been at the rate of one hundred thousand 

 dollars per annum, while, as we have ah-eady seen, many of the leading 

 mines about Grass Valley have produced still more munificently. The 

 total yield of the Allison Kanch Mine, at that place, since operations 

 were first commenced upon it, has exceeded two million five hundred 

 thousand dollars; the group of claims on Massachusetts Hill have turned 

 out about three million five hundred thousand dollars; the North Star, 

 and otiier mines on New York Hill, have yielded two million five hun- 

 dred thousand dollars, and the Norambagua alone one million dollars. 

 The complement for Gold Hill has been three million dollars, and for the 

 Lone Jack Mine, Ophir, Osborne, and Ilueston Hills, the aggregate lias 

 been fully three million five hundred thousaiid dollars. The product of 

 the Eureka during the past two years has exceeded five hundred thou- 



