Mohave County miner., 1915-03-13
Mineral Exhibit at San Francisco.


 the Geological Survey exhibit at the Panama Pacific International Exposi- tion included a graphic representation of the output of the various mineral products of the country, based on the production per capita during the cen tennial year, 1876, and at the present time. Bituminous coal is represented by a block of coal weighing 1,60O pounds, the per capita production in 1876, and by another block weighing 5 tons QO,OOO, the per capita output in 1913. The anthracite blocks, on the other hand, indicate relatively small from l, 14O to l, ,8S0 pounds.
 The per capita production of coke has increased from 134 pounds in 1876 to 700 pounds in 1913. At the earlier period no other than beehive coke was manufactured in the United States, but since then the interesting feature of coke manufacture has been the de- velopment of the retort oven, by which valuable constituents of the coal other than coke are recovered. The exhibit at San Francisco shows the quantity of coal consumed in retort ovens in this country in 1913, the quantity of coke produced from it, and the quantity of coal tar, benzol, and sulphate of am- monia recovered as by-products. The quantity of gas recovered and utilized is also properly shown.
 The production of petroleum in the United States shows an increase which is fairly comparable with that of bi- luminous coal. The per capita output in 1876 is represented by half-barrel of oil containing 22 gallons; the output in 1913 is represented by hogshead containing 2.6 barrels, or 10S gallons.
 The per capita production of copper, which in late years has been so sig nificantly influenced by the development of electric power transmission, has in- creased from 1 pound in 1876 to l3 pounds in 1913, and this is illustrated by ingots of copper of the two weights.
 The per capita production of lead has increased from pounds in 1876 to g pounds in 1913, and the output of zinc from little less than 1 pound to 6 pounds.
 The quantity of iron ore produced shows an increase from 314 pounds per capita in 1876 to 1,434 pounds in 1913, and the vuantity of pig iron obtained from it has increased from 150 to 717 pounds.
 Since the Centennial Exposition an entirely new industry in mining and metallurgy has been developed through the production of aluminium. No alumi- mum was produced on commercial scale in 1876, but a cube weighing 12 ounces represents the per capita pro- duction in 1913.
 The acturl production of gold and sil yer in 1913 is little more than twice as much as it was in 1876, but as the population has also nearly doubled the per capita output of both metals has kept nearly even with the increasing population. In 1876 the per capita pro- duction of gold was r grains; in 1913 it was 2l gruins. The production of silver in 1913 was 1852 grains per capita; in 1876 it was 2S7 grains.
 In 1876 the total production of Port land cement in the United States was less than 40, 900 barrels. In 1913 it was over 92, 900, 900 barrels. The total per capita output of cement in 1876 was 16 pounds. In 1913 it was $50 pounds, equivalent to nearly four of the bags in which we are accustomed to see Port land cement transported.
 It is only since the beginning of the present century that the production of sulphur in the United States has had any significant influence on the trade, but the domestic product has now vir- tually supplanted Sicilian sulphur in the markets in this country. In 1876 the per capita production of sulphur in the United States was 140 grains, or less than one-third of an ounce. In 1913 it was 50,000 grains, or IA pounds. The production of pyrite, used in the manufacture of sulphuric acid, had in- creased from ounce per capita in 1876