MINERALS OF THE UNITED STATES — PEHRSON 177 



the growth of mineral production from 1880 to 1944. During this 

 period the annual output rose from less than one-half billion dollars 

 to eight and one-half billion, a sixteenfold increase. During the first 

 two decades of this period there was a relatively slow rise in produc- 

 tion, but with the turn of the century a rapid advance set in which 

 was further stimulated by World War I and the succeeding boom 

 period. Since 1900 mineral production in the United States has ex- 

 ceeded that of the entire world prior to that time. This period ter- 

 minated with the collapse in the latter part of 1929 following which 

 there was a precipitous decline to 1932 and a substantial recovery 

 thereafter which was carried to an all-time record production in 1944 

 by the war. It will be noted that since 1915 the production of mineral 

 fuels has achieved outstanding significance, this being due largely to 

 the rapid rise in petroleum production and the accompanying growth 

 of automotive transportation. Metals have ranked second in im- 

 portance in recent years, with the nonmetals other than fuels holding 

 third place. The importance of metals in war is clearly indicated by 

 the peaks experienced in both war periods. 



Aside from these direct contributions to the national income, the 

 mineral industries have employed hundreds of thousands of workers. 

 In 1900 it is estimated that 500,000 persons were gainfully employed 

 only in the extraction of minerals. By 1923 employment had reached 

 a peak of 1,080,000, following which there was a decline to about 

 660,000 in 1943. Increasing mechanization and other improvements 

 in mineral technology have greatly increased the output per worker 

 so that compared with 1923 it was possible in 1944 to obtain a third 

 more output measured quantitatively, with a third less workers. The 

 processing of minerals and the services required by the mineral indus- 

 tries give employment to several hundred thousand more workers. 



Figure 2 compares the growth of the physical volume of mineral 

 production with that of agricultural and industrial production and 

 population from 1900 to 1944. It will be noted that prior to 1940 

 mineral output and industrial production were closely correlated and 

 increasing faster than the growth in population. Expansion in agri- 

 cultural production, on the other hand, more nearly approximated 

 the population trend. Since 1940 there has been great disparity be- 

 tween the mineral and industrial trend lines. This is due to several 

 factors, among which are the greater use of imported minerals, which 

 is reflected in the industrial indexes, but not in the mineral indexes 

 used in constructing the chart, and in part by the fact that the mineral 

 index does not include certain commodities such as aluminum and 

 magnesium, production of which has increased greatly during the war. 



