These
figures show an excess of gold, according to mint reports, for the
seven years of $4,190,034, or a difference of a little, over 0.6 per
cent, and a corresponding excess of silver production of 797,628 fine
ounces, or a difference of less than 0.02 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.
UNITS OF MEASUREMENTS.
Gold
and silver are measured by the fine ounce. The computing tables to six
decimals used by the Bureau of the Mint and the United States
Geological Survey are based on the exact valuation for gold of
$20.671834625323 per fine ounce. The average commercial price in New
York for silver per fine ounce in 1910 was taken at 54 cents and in
1911 at 53 cents. The standard Survey unit for ore production is the
short ton of 2,000 pounds.
PRODUCTION OF GOLD AND SILVER REPORTED FROM THE MINES.
The
following table gives the quantity and value of gold and silver by
States reported from the producing mines in 1911 to the United States Geological Survey. The increase or decrease of production shown results from comparison with the corresponding Survey mine figures for 1910.
