Ch. 1: Gold and Silver in 1910

Page of 44

Text size:



	GOLD AND SILVER.	129

	of mine output and the other the metal actually recovered in marketable form. The two methods will not produce exactly corresponding results nor should they be expected to do so. In addition to factors already noted as causing differences between the two sets of figures, it must be remembered that it is not always a simple matter for smelters to distribute their output according to the exact origin of the ore, and it is still more difficult for refiners to do so. It is therefore always possible that some ore of Canadian or Mexican origin is contributing to the output of metal thought by smelters to be of domestic origin. The calendar year covered by both investigations is the same, but the period or mine production naturally corresponds to a period earlier than the period of actual production of marketable metal by the interval of time necessary for transporting, sampling, and treating the ore and for refining the products. This interval is E racticallv negligible in the case of placer and mill bullion, but may e several months in the case of crude smelting ores and especially of ores concentrated before smelting. The figures for the mint report and the mines report for a period of years sufficiently long to compensate for overlap or lag should agree within allowable limits of error due to the complex nature of the ores and of the methods of treatment. The figures of the mines report may be expected, on the whole, to fall normally below those of the mint report for the reasons outlined. For the last six years the final figures for mint and mine returns have been as follows:



	These figures show an excess of gold, according to mint reports, for the six years of $4,510,260, or a difference of a little over 0.8 per cent, and a corresponding excess of silver production of 1,909,767 fine ounces, or a difference of less than 0.6 per cent. As figures for Alaska placers are not claimed to be as close as these, the differences for the United States proper are even lower. It is thought these relatively small differences may be accounted for by the explanations already given. For figures of any one year an excess of mining over smelting and refining, whether of gold and silver or of base metal ore, or both, is indicated by larger figures in the mine reports for gold or silver, or both; and normal relations, or perhaps excess of smelting and refining over mining by drawing upon stocks, is suggested by the reverse figures. 21235°—m K 1910. n- 1------9

Page of 44