QUARTZ MINING IN CALIFORNIA.

Westport Times, Volume IV, Issue 702, 25 August 1870, Page 2

QUARTZ MINING IN CALIFORNIA.

Quartz mining in California was first started by the Mexicans, who had been accustomed to it in their own country. The richest tract of country, in the State of California, so far as quartz-mining is concerned, is about 200 miles long, by 50 wide. The Hepburn machines are generally considered the best for crushing the quartz. The patentee is seeking to get them introduced into this colony. The rock examined, in which the quartz is encased, is principally slate, granite, or greenstone. Statistics are given in respect of twenty-five mines, as to the width of vein, cost of extracting, carriage, and crushing, per ton, and the gross and net yield per ton. The gross yield per ton varies from six to sixty dollars, and the net yield from two to fifty-five and a half dollars. The cost of extracting the ore varies from two to twenty-five dollars per ton. Glancing at these statistics, and remembering the returns, required by our Mining Act to be furnished half-yearly by each company, we may suggest that the latter are entirely useless. Government should have a half-yearly statement of the expenditure on the mine in permanent workings, in getting the quartz, including wages and mining requisites, the cost of crushing, and the number of tons obtained and crushed the value of the gold obtained, calls made, dividends paid, and average number of men employed, and average rate of wages. If this

were done by every company, and by the claim holders not formed into a company, we should then bare some very valuable information, which would be of use in many ways. Mr Baldwin gives a short statement on extraction of gold from tailings. It appears that all the plans tried to effect this very desirable object have failed except the chlorinization process, which is now used with signal success. The operation consists in roasting for about twenty hours in a furnace at a red-hot heat, and the tailings are then allowed to cool, when they are sprinkled with water and shovelled over. They are then put into tubs with false bottoms, perforated, and the chlorine gas ascends and penetrates the mass. The soluble parts are then filtered away by means of cold water, and the gold is precipitated by sulphate of iron. The average cost of the chlorinization process is fifteen dollars a ton. Another practical hint is given as to powder. It appears that " giant powder " is now largely used, and is found more powerful and economical than the ordinary powder. The latter requires an inch and a-half holo, the former one of an inch in diameter only ; and this saving is considerable. Two men, says Mr Baldwin, will drill 200 inches of the smaller hole in the same time that it takes them to drill 84 inches of the larger. The action of the giant powder is more powerful also: it tears to the very " bottom, never seeking an outlet by the least resisting portion of the surrounding surface." We have thus briefly referred to some of the most important points of this interesting report. Its having been obtained by the Government appears to be an earnest of the anxiety of the Ministry to obtain the best information to aid in the development of one of the great industries of the country. It may be well to mention that the report states that there is a gradual decline in the production of gold and silver in the Pacific States, and that for the year 1869, as compared with 1868, the decline is estimated at no less than eight millions of dollars.—" N. Z. Herald."