Dr. F. H. Hatch—The World's Copper Supplies. 39 
The vital question is whether production will be able to meet 
such heavy demands as are here foreshadowed in view of the 
approaching exhaustion of some of the existing sources of supply. 
While the number of companies contributing to the world’s 
production is well over three hundred, about half the total is derived 
from a score of mines only. Many of these big producers are in 
America. The United States contributes from its mines in Arizona, 
Montana, Michigan, Alaska, Nevada, New Mexico, and California 
over 60 per cent of the world’s production; and there are big 
producers in Canada (Sudbury), Mexico (Cananea, Nacozari, Boleo), 
Chile (Chuquicamata), Peru (Cerro de Pasco), and Venezuela 
(Aroa). Japan also has some great mines (Ashio, Besshi, Hitachi, 
and Kosaka), and the Rio Tinto in Spain, the Mansfeld in Germany, 
and the Bogoslovsk, Dzansoul, Kyshtim, Sissert, and Spassky mines 
in Russia should be noted in this connexion. Although existing 
reserves may be large enough for the immediate future, it is quite 
certain that some of these large mines cannot have a very long life, 
and their shutting down would appreciably affect production unless 
fresh discoveries enable their places to be filled. 
The copper recovered from the ore mined throughout the world 
probably does not exceed 45 lb. to the long ton or two percent. Exact 
figures are forthcoming for ups Cinna States : in 1906 the average 
yield for all ores treated was 2°5 per cent; in 1903 it had fallen to 
1°67 per cent, and by 1914 to 1°6 per cent; in 1916 it was 1-7 per cent.t 
There is, consequently, not the margin ‘for increasing the available 
reserves by lowering the grade of the ore mined, such as obtains in 
iron-ore mining; and any increase in the supply of copper, or, indeed, 
the maintenance of the present rate of production, must depend in 
the long run either on the discovery of new deposits, or on the 
improvement of the treatment methods. During the last decade the 
world has been searched for new occurrences of copper-ore, and it is 
certain that the efforts of capitalists and mining engineers will not 
be relaxed in that direction. Metallurgists also will perfect the 
existing methods of extraction or find new ones whereby the yield 
will be increased. B.S. Butler states? that from 5 to 30 per cent 
of the copper content of the ore at present treated is lost, and if this 
be so there is room for improvement in this direction. 
The United States, by its refineries on the Atlantic seaboard, 
controls a large proportion of the South American and Canadian 
output of the metal. Acting in conjunction with the large home 
production, the effect of this control has been to place the copper 
market of the world (which for the greater part of the nineteenth 
century was centred in Great Britain) practically in the hands of 
the United States. It may be that in view of an increasing con- 
sumption the copper magnates who control this market will use 
their power to limit supplies and drive up the price of copper. These 
1 The Mineral Resources of the United States, 1916, p. 642. 
2 The Strategy of Minerals, New York, 1919, p, 155. 
