The Relative Importance of Mineral Products.—The importance of mineral products is almost incalculable. The discovery of how tc smelt iron ranks with the introduction of speech, fire, tools, domestic animals, agriculture, and the wheel as a great epoch in human progress Nevertheless in 1919, the year covered by the Census of 1920, the mineral wealth produced in the United States was worth only $4,613, 000,000 compared with 20 billion for farm products, and 25 billion as the value added by manufacturing. Indeed, the mineral production that year was less valuable than two great crops, corn ($3,850,000,000) and wheat ($2,000,000,000). Thus, important as minerals are, they cannot compare either with the soil or with human labor as a source of wealth.
Mineral products fall naturally into three classes: (1) fuels, (2) metals, and (3) quarry products which include those like sand and gravel that are dug from pits, and certain minor non-metals that are mined. The accompanying table shows that the fuels are worth twice and the quarry products half as much as the metals. Ordinary stone produced in the United States is worth one and one-half times as much as silver or gold, while sand almost equals lead.
The Distribution of Mineral Industries in the United States.—The distribution of mineral production in the United States is shown in Fig. 72. The fuels cause the enormous concentration in Pennsylvania and West Virginia, and also immediately to the west as far as Illinois. That region produces not only all the anthracite coal and the main part of the bituminous, but also considerable supplies of petroleum and natural gas. Probably no other part of the world is so well supplied with high-grade fuel. A less important concentration of fuel appears in Kansas and Oklahoma, where there is a fair production of coal and a huge production of petroleum.
The metals of the United States show two areas of abundant produc tion: (1) the iron and copper region near Lake Superior, and (2) the Rocky Mountains and Sierras, which produce chiefly copper, lead, and zinc, and the precious metals. A minor area is the lead and zinc region of Missouri. Quarry products, on the other hand, are distributed quite evenly over the country. In a general way their value bears a fairly close relation to the density of population and the activity of business. Quarrying, like agriculture, is a relatively universal occupation, not only in the United States but in almost all well-inhabited countries, except plains with deep soil and tropical regions with a dense cover of vegetation. In the United States, however, its products are worth
only about a thirtieth as much as the agricultural products. I.
The value of the output of minerals per person in various regions varies enormously more than the similar value in agriculture or manu facturing. This is due to great differences in (1) the richness of mines, (2) the depth at which the ore is dug, (3) expenses in draining and ventilating the mines, (4) transportation, and (5) the amount of material that must be removed to get a given product. Thus in 1919 the produc tion of copper per worker in the copper industry was 6i tons in Michi gan, nearly 16 in Idaho, and nearly 19 in Arizona. In Texas, where the oil wells average 27 barrels per day, there is only one worker for each 7100 barrels produced per year, while in Pennsylvania where the wells are old and average only 0.3 barrel per day the annual production per man is 820 barrels. Another noteworthy difference between min ing and agriculture is the extreme localization of each product. Iowa, for example, is a great corn state, but corn furnished only 39 per cent of the value of its farm products in 1919, while animals furnished about 25, wheat 11, and hay 11. In Mississippi, one of the states where the one-crop system is most persistent, 54 per cent of the value of the farm products in 1919 was due to cotton, 18 to corn, and 14 to animals. On the other hand, in Pennsylvania, coal mining employs over 93 per cent of the persons engaged in mining; in Arizona an equal percentage is engaged in mining copper, and in four-fifths of the states over half the mining population is engaged in a single industry. In more than half the states the three leading mineral industries employ more than 90 per cent of all the people engaged in such occupations. This means that in mining regions, as in those devoted to one-crop agriculture, if the main industry suffers there is little else to fall back on.
The Problem of the Mineral Industries.—Every industry has its own problems, which often have a widespread effect. For example, how far can the production of gold be increased without lessening the value of the product? Anything which lowers the cost of producing gold, immediately increases the supply of gold brought to the mints, and raises the gold reserves. This tends to make money cheap, which is the same as making prices high. Thus any marked change in the rate at which gold is produced not only makes trouble in business, but raises a serious problem for the owner of gold mines.