most of the coal is coked, as it is better for blast-furnace use in this form, giving greater heat and containing less sulphur or other injurious substances than coal. Owing to the smaller bulk and cost of transporting ore, most of the iron and steel industries are situated in the vicinity of the coal supply, as in Pennsylvania, Ohio, Alabama, etc.
Petroleum or coal-oil is closely allied to coal in its origin and distribution and must be classed with it as a most important product, not only for industrial uses, but also because of the contributions it has made to the comforts of living. In its production the United States ranks first, being closely followed by Russia; together these two countries furnish over 90 per cent of the world’s supply of petroleum. Enormous economies have been effected in its production and distribution, which is done by piping the crude oil underground to the refineries. For illuminating purposes it is the cheapest form of artificial light; as a fuel it is supplanting coal, where the latter is dear or its cost of carriage high, as on ocean steamers. Finally, the construction of light and convenient gasoline motors has given it great importance as a source of motive power. Natural gas is closely related to petroleum, but the supply has been so reduced by rapid and reckless use that it has but a limited economic outlook and is of local significance only.
Of all the metals iron must be considered the most useful for man, far surpassing the so-called precious metals in economic importance. Its great value is so evident that its production and use have often been taken as a criterion of the material progress of a community. Iron is the only metal that can be welded, and is accordingly of great significance, whether in making strong machinery, as the shafts of ocean steamships or the framework of a twenty-story building, or, in the form of steel, the most delicate surgical instruments or watch springs. Judged by the test
of iron ore production the United States ranks high, for it turns out about four-fifths of the world’s supply; all of this is used for domestic consumption, in its own blast furnaces, though much of it is afterwards exported in the form of pig iron or structural iron or steel. Though iron is universally distributed throughout creation, it must occur in large beds or deposits before it can be profitably mined. “The most favorable situation of an iron ore for profitable extraction is near good coking coal for smelting and limestone for a flux, as in the Birmingham district of Alabama; and in such a situation even low-grade ores can be worked profitably. Unless this is the case, iron ore cannot be extensively mined excepting under conditions of great abundance and economical methods of transportation, as in the Lake Superior district, where thick and remarkably uniform beds of good ore occur in such a position that water transportation to the market is possible. Where these conditions do not exist, iron-mining is feasible only on a small scale for the local market. Thus, in the Rocky Mountains there are almost inexhaustible supplies of iron, often of a high grade, which are at present of no value whatsoever.”[1]
The most wonderful iron-mining region in the United States and probably in the world lies in the northern part of Michigan and Minnesota, where five ranges or lines of hills contain immense deposits. These lie so near the surface that they can be dug out of open pits at a cost of from 10 to 50 cents a ton, against $1 a ton in a shaft or underground mine. Three-quarters of the iron ore produced in the United States is mined in this district. Its proximity to the lake ports makes possible its transportation to the iron and steel manufacturing centers at very low rates. Machinery has been applied on an immense scale to the work of mining, loading and unloading the ore. Steam
shovels scoop up the ore from the open pit, filling cars at the rate of almost one a minute; the work of loading this into the ore ships at the ports is equally expeditious, only about two hours being required to load an ore ship of 6,000 tons, while the work of unloading is performed for the most part by an endless chain of buckets and traveling cranes. By these means an ultra-intensive exploitation of these magnificent deposits is taking place and it is a question whether they will not soon be exhausted. “But the Americans,” writes Professor Leroy-Beaulieu, a friendly but keen critic of our industrial development, “relying on the constant good-will of nature, are confident that they will discover either new and productive ranges in this district, or rich deposits in other districts.”
The precious metals have received more than their fair share of attention, for the industrial progress of the world is much less dependent upon their presence in large and easily obtained quantities than it is upon the more common metals. Nevertheless they are of importance both in the arts and especially because of their use as money. In their production the United States stands second, being surpassed in the output of gold by the Transvaal in Africa and in that of silver by Mexico. The production of these metals has always in the world’s history proceeded spasmodically, and a speculative spirit has usually been present. More recently, however, scientific geological knowledge and improved metallurgical methods are removing the industry of gold and silver mining from a gambling venture to a legitimate industry. The practical problem at present confronting American gold-mining companies is to reduce expenses, some of the principal bearings having for some years shown signs of exhaustion, as for instance in the Cripple Creek district of Colorado. There is always a chance however that new gold fields may be discovered to make good the exhaustion of the old. In the case of silver, on the other hand, the metal is found in
such abundance that the present rate of production seems almost indefinitely assured; a slight increase of the price or improvements in the art of extracting the metal will at any time bring enlarged supplies on the market. Africa, Australia, and the United States produce almost all the world’s supply of gold, Colorado being the leading state in the last-named country. Mexico and the United States together produce over two-thirds of the world’s silver, the leading rank in this country being held by Montana.
Among the other metals copper is by far the most important. In primitive civilizations, before the art of smelting iron had been discovered, copper was indispensable as it was so easily malleable; in Homeric times, for instance, armor, utensils, money, etc., were made of copper or alloys of copper (bronze and brass). After an eclipse of some centuries copper has again risen to the front rank by reason of its qualities as a conductor of electricity. The new use of electricity to transmit power and the development of electrical industries has greatly increased the demand for this metal and has caused a great expansion in its production. Here again the United States holds first rank, contributing over half of the world’s copper supply. As in the case of iron the northern peninsula of Michigan is the most important center of copper production, with Montana a close second and Arizona contributing most of the remainder. Like petroleum, copper production is controlled by a small number of operators, five mining companies alone furnishing one-half of the American supply. It is far from being monopolized, however, as petroleum is, for new and rich supplies lie just on the margin of profitable working and will always be brought into the market whenever the price is artificially raised. One reason for American pre-eminence, aside from the rich stores of the metal, lies in the progress made in the art of refining it by the electrolytic process, considerable foreign ore being brought here to be treated by this method.
Nature has not blessed the United States so abundantly with the minor metals, lead, zinc, and aluminum, while almost all the tin used here has to be imported.