afforded by the method of the Geological Survey, bjT means of which the progress of the industry can be accurately gaged; neither is it possible, without such data, to classify properly the gold and silver ores according to the plan outlined in this report and to ascertain the tonnage and average contents of those ores.
UNIT OF MEASUREMENT.
The standard unit for ore production adopted is the short ton of 2,000 pounds. Gold and silver are measured by the fine ounce, and the average commercial price of silver during 1904 is considered to be from 57 to 57.843 cents per ounce, the figure varying slightly in the several State reports.
In addition to gold and silver, data have been obtained for the production of copper, lead, zinc, and for several States at the following prices for 1904: Copper, at 12 to 13 cents per pound; lead, at 4.30 to 4.375 cents per pound; zinc, at 5 cents per pound.
Crude platinum is valued at from $12 to $15 per ounce. It should be understood that in most cases, owing to high reduction charges, the miner failed to obtain these prices for his product.
PRODUCTION.
The production of gold in the United States for 1904 reported by the mines to the Geological Survey was 3,910,729 fine ounces, of the value of ยง80,835,648. This represents an increase of $7,243,948 over the production of 1903 as given by the Director of the Mint. After a period of very rapid advance in the gold production from 1892 to 1900, during which an increase from $33,000,000 to $79,171,000 took place, there followed two years of nearly stationary output and one year, 1903, of very decided decrease. It is therefore very gratifying to find that the production has risen again with a bound to record figures, the largest previous output in 1902, according to the figures of the Director of the Mint, amounting to $80,000,000.
The production of silver in 1904 reported b\T the mines to the Geological Survey was 55,999,864 fine ounces, of a value of $32,035,378. This represents an increase of 1,699,864 ounces over the production of 1903, as given by the Director of the Mint, and an increase in value of $2,713,378. There is, therefore, a total increase of $9,957,326 in the value of gold and silver produced in 1904 over that of 1903. The record output of silver in 1892, amounting to 63,500,000 fine ounces, has not been reached in late years, nor has the commercial value attained the figures of that year, which amounted to $82,101,000. The price of silver in 1904, accoi'ding to the Director of the Mint, varied from 55 to 61 cents per fine ounce, representing a decided increase over the prices of 1903, which varied from 48 to 59 cents and only exceptionally rose to 61 cents in October, 1903.
