( Originally Published 1918 )
Lesser minerals. There are several other minerals which are of considerable significance in the economic life of the country but which have not been deemed worthy of separate treatment, either because their advent is too recent for them to have had as yet a very profound influence upon the development of our industrial life or because their importance is one with narrow rather than wide limits. Such minerals are copper, lead, zinc, aluminum, clay products, building stone, cement, lime, phosphate rock, salt, mineral waters, slate, and others. In this chapter we shall briefly touch upon some of the most significant of these.
Copper. This is a metal second only in importance to iron for the industrial development of the country ; but that is due chiefly to the fact that it is indispensable where electricity is employed, for, despite much investigation, no satisfactory substitute has appeared. Consequently, although it is a metal that has long been known, the rise of the copper industry on the large scale is rather modern. The metal is widely distributed over the earth, being encountered at times in a pure state, but ordinarily in the form of ores. It is alloyed very commonly with tin and zinc, these alloys forming bronze and brass respectively. Since it can be hammered out without being softened by heat, it afforded to savage man what was, very likely, his first chance to use metal ; in any case, it is one of the very oldest metals known and has been used in tool-making and in the arts generally since remote antiquity.
Indian use of copper. Along with other uncivilized peoples the American Indians had discovered the utility of copper ; it was the one metal which they had learned to put to practical use. They had even learned to harden copper so as to be able to make implements from it. It was mined in a rude way in the Lake Superior region, the masses of almost pure copper being dug out and raised upon a sort of staging until they could be removed from the shallow shafts. It has been iron and steel that have driven out the copper industry as civilization has advanced ; but the Indian, as we have seen, had not arrived at a knowledge of iron.
Not much early copper-mining. Inasmuch as copper deposits are scattered widely over this country, even on the eastern slopes made in colonial times ; in general, however, the comparatively few attempts to work the deposits were abandoned as unremunerative. Copper was found in Massachusetts as early as 1648, and was smelted by imported Swedish workmen ; and in 1709 a company was organized to work a copper deposit in Connecticut. The so-called Schuyler mine, in New Jersey, discovered in '1 719, was prominent as a producer prior to the Revolution. But our output of the metal long remained small ; as late as 1830 we produced not over 5o tons a year, and by 1845 this had risen only to about 100 tons. If these figures be compared with the present yield of over 800,000 tons, some idea can be had of the newness of the industry.
The Michigan deposits. For a long time the Upper Michigan deposits were the great source of our copper ; this is a great native copper region, following without a break the axis of the Keweenaw Peninsula for a distance of seventy miles, with a width of from three to six miles. The Lake Superior region came into prominence shortly before the middle of the last century, largely in consequence of the " copper fever " —a sort of popular furor of 1845 or thereabouts. Stories of the great masses of pure copper to be found in this region had unsettled the judgment of many people, and the shores of the copper peninsula soon teemed with prospectors and speculators. Hundreds of copper-mining companies were formed ; but in 1847 the bubble burst, and only about a half-dozen of the strongest companies were able to withstand the collapse. The yield of copper had risen from something like 100 tons in 1845 to 65o in 1850, largely in consequence of the opening of the Lake Superior district ; but this was only a of the region came later on.
Montana discoveries. Then, toward the close of the last century, came the Montana discoveries, chiefly in the Butte district, and Montana soon came to surpass Michigan ; but in 1910 Arizona took the lead. Here, by contrast with Michigan and Montana conditions, the metal comes from a number of different parts of the state. We now lead the world in copper-production.
Lead. Lead is seldom found in a pure state, but usually as galena, or sulphide of lead ; it is often a by-product of silver production. It has been known since early times, and widely, since deposits are common about the earth. They are common in this country, but although the Indians were familiar enough with galena, there is no evidence to show that they had found out how to reduce the ore to metal.
Revolution the colonists discovered lead and made attempts to work the deposits. In the eastern parts of the country the results were poor. Lead-mining in Missouri (now our leading state in that industry) began as early as 1720 ; it is estimated that in 1819 there were forty-five mines in Missouri. At the present time the states following Missouri are
Idaho, Utah, and Colorado. The figures for lead production, in short tons, run from 1500,in 1825, to over 500,000 at the present time.
Zinc. Zinc occurs along with other metals, such as lead and copper. The crude metal is called spelter. Spelter production is a new industry in this country ; for although zinc was known to exist in colonial New Hampshire and elsewhere, little was mined, and its systematic and profitable production dates back only a few years. It started in an experimental way in 1858, but statistics of production before 1873 are not available.
Thus, as compared with the other metal industries of the country, the zinc industry is of late development. The 7000 tons of 1873 have risen to 124,000 tons in 1900 and to 585,000 tons at the present time. These figures do not take account of the zinc-white derived directly from the ore. The largest use of zinc is in galvanizing iron, but, as is the case with lead, much is used in the manufacture of white paint. The balance is employed in brass making, sheet-zinc making, etc. Many of our states have zinc-bearing ores, but Missouri is far in the lead in spelter production.
Aluminum. This metal also is a newcomer, having reached prominence only two or three decades ago, It is very widely distributed in nature, forming about one thirteenth of the earth's crust ; in some rock there is from 20 to 30 per cent of aluminum. The metal has, of course, always been present, but unlike the rest which we have mentioned, it was not discovered until recently and so has no long history. It possesses, however, certain very valuable properties — lightness together with strength, ductility, and electrical conductivity. Were it not for the expense of extraction it would be far more common than it is, but with greater ease in working it, under electrical processes, production is rapidly increasing. In 1883 we produced 83 pounds of aluminum ; in 1915 we produced 99,000,000 pounds. When its price, as compared with that of iron and copper, is sufficiently reduced, aluminum will doubtless be used extensively as a substitute for them, for it has the necessary qualities ; and the price of copper, at least, is now not so far from that of the newer metal. One of the main superiorities of aluminum is its lightness ; the need for a strong, light metal for use in automobiles, and especially in the manufacture of aeroplanes and other flying machines has raised a considerable demand for aluminum. This metal alloys with others rather easily, and it strongly resists the influence of water and vegetable acids ; it is therefore especially adapted to the construction of kitchen utensils and surgical goods. It is now used for many seemingly inconsistent purposes, such as machine bearings, fancy articles, jewelry, and (a utility as yet only in its beginnings) the decoration of interiors — it supplants wood, for example, in modern business offices.
Clay products. Clay formed an obvious material for the manipulation of early man, and he formed it into many sorts of utensils, as well as into bricks for house construction, which were at first merely sundried (adobe). Probably by accident he early discovered the possibility of baking and so of hardening the clay, and then the way was open to hard brick and pottery. In the course of time the several varieties of clay were discovered, and wares were manufactured that ranged from the coarsest brick to the most delicate porcelain.
Value of the clay industries. Clay beds are, of course, well-nigh universal ; they are so, in particular, in this country. They differ much in grade of product, being fit for, say, brick, tile, or pottery. The American Indian was a great pottery-maker, but in a rude way, for he did not know of the potter's wheel. In early colonial days there were small potteries in all the colonies. And the first manufactory of white ware was in Burlington, New jersey, but the pottery industry was not firmly established here until after the Revolution. At present the annual value of our clay products is between $150,000,000 and $250,000,000; for many years the brick and tile products have constituted about four fifths of the value of all clay products, the other fifth being pottery. In money value the clay products stand, among the nonmetallic minerals, next to coal and petroleum. Bricks and tiles are of the most consistent utility in structural work ; the clay industry goes up and down with building operations. Ohio and Pennsylvania figure most prominently in both general branches of the clay industry.
Stone. An important natural resource of the United States is the variety and abundance of its stone — stone adapted to building and to other important purposes. The principal stone quarried are limestone, granite, marble, basalt and related rocks, and sand-stone - limestone representing over 40 per cent of the total value of the annual output and granite about 25 per cent. The leading states in production are Pennsylvania, Vermont, New York, Ohio, and Indiana.
Development of the stone industry. Despite severe competition with artificial-stone products the stone industry as a whole has advanced as the country has developed. The use of cement has damaged the production of the lower grade of stones—foundation stones, for example —but it has not much affected the higher grades used in building and still less those employed in monumental and ornamental work. In fact, the use of concrete and the extensive building of roads and railroads has stimulated the crushed-stone industry to such an extent as to more than offset the decline in other kinds. Sandstone production alone shows a consistent decrease. It advanced considerably with the building of numbers of railroad bridges and other structures, from 1897 to 1903, but since the latter date its use for building purposes has suffered from competition with cement as well as limestone, and it is not well adapted for use in the crushed form.
Cement. There are three principal types of hydraulic cements — natural, Portland, and puzzolan. The first is sometimes called Roman cement, and is obtained by treating a certain type of lime-stone. This cement was first used in England in 1796. In the United States " cement rock " was discovered in New York State during the building of the Erie Canal in 1818, and cement made from it was used in building the locks and walls of the canal.
Portland cement is a more complicated product named from some resemblance shown by it to a sort of limestone found on Portland Isle, Dorsetshire, England. Puzzolan cement when made into mortar has the property of hardening under water; it has been used in Italy since very early times. The annual value of these three varieties of cement is, for the United States, upwards of $100,000,000, most of which is to be credited to the Portland variety. The use of this material is rapidly increasing, extending even to the " pouring " of a house in molds.
Summary. It is apparent that our country leads the world in the production of most min-
erals. There are only a few in which we are deficient or wholly lacking, the most important being platinum, nickel, and tin. Our minerals are genuine natural resources, for they were placed here by the forces of nature and cannot be imported into the ground, propagated, or otherwise manipulated by man except as he may dig them up and use them. It may be said that this country possesses not alone a rich soil but also a rich subsoil.