# Popular Science Monthly/Volume 74/March 1909/The World's Annual Metal Crop

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* THE WORLD'S ANNUAL METAL CROP
By THEO. F. VAN WAGENEN, E.M.
ZACATECAS, MEXICO
SOME one has characterized the present as the "age of metals." There are at least fifty-nine of these useful substances known to the chemist of to-day, yet if the average well-educated man was asked to name them, it is doubtful if he could enumerate more than a score. In that far distant period called by the archeologists the "dawn of history" (say 8,000 to 10,000 years ago), only four appear to have been recognized, viz., copper, tin, gold and silver. Sometime later, iron, lead and mercury were added to the list. These seven constituted the metallic stock in trade of the ancients, and of the moderns for the first thousand years of the Christian era. In the opinion of most historians, copper, as the metal that is found most abundantly in the native or pure state, was the first to attract the attention of primitive man, and it is likely that tin was recognized very soon thereafter, for the latter, though far from abundant, and never existing naturally in the metallic state, yet occurs under conditions where it would be easily noted by its weight as a substance very different from ordinary stone, and in a chemical combination from which it can be smelted by the simplest of fire processes. Moreover, the greatest tin-producing district in the world lies in a part of the globe that has been inhabited from most ancient times. Both copper and tin are alone too soft to be utilized as weapons or tools, and humanity at a very early period in the progress of civilization learned to produce, by combining the two, that most serviceable alloy we know as "bronze," which can be forged and tempered to a keen edge and point, and which is so resistant to the attacks of air and water that great numbers of the implements made by the ancient smiths are preserved in the museums of the present day. Gold and silver were doubtless recognized as separate entities at a very early date, and their rarity and beauty set them apart at once as suitable measures of the value of other things. It is thought that iron, though the most abundant of all the common metals, did not come into general use until 1500 or 1000 B.C. for a long time lead was regarded as another form of tin. It does not occur in a metallic condition in nature, only one of its ores (cerrusite) is easily smelted, and most of them are associated with ores of antimony, arsenic and zinc, from which it is separable only with considerable skill. Mercury, on the other hand, comes from its ore with much ease, but it was a puzzle ​to the ancients, who called it "liquid or live silver" (whence our modern name, quicksilver), and they found but little use for it. Zinc was also one of the mysteries of the olden times. The Greeks and Romans knew of it as a troublesome impurity, often associated with lead ores, and in some way the very desirable alloy now called "brass," which is composed of tin and zinc, was discovered and produced by them to a limited extent, but the metal zinc remained unknown*
Through medieval times practically no progress was made in a knowledge of the metals. The science of chemistry was unknown, but its precursor, alchemy, flourished. The alchemists recognized many of the natural substances that are now known as ores of the metals, but were unable, except by accident, to decompose them. However, about the year 1450, antimony and bismuth became articles of commerce, and in 1520 pure zinc was produced, though it did not come on the market in any quantity until 1743. In 1694 arsenic was isolated and recognized. Thus, up to a little-more than 200 years ago, the world knew of but eleven of the metals, and of these, arsenic and antimony are not now regarded as such, being classed as semi-metals.
Chemistry, as a science, began to arise during the eighteenth century, as a result mainly of the perfection of the laboratory balance to a point where delicate operations in weighing could be carried on. In this period the list of the metals was doubled by the discovery of cobalt and platinum in 1735-6, of nickel in 1751, of manganese in 1774, of tungsten and molybdenum in 1781, of titanium, uranium and zirconium in 1789, and of chromium and yttrium in 1792. All of these except zirconium and yttrium are now fairly familiar names to us, but none of them were produced in any quantity, or put to any commercial use as metals, for a long time after their discovery. Platinum for a century was merely a curiosity. Certain compounds of cobalt and of uranium found considerable use in the ceramic arts, and of chromium and manganese in the laboratory as reagents, in the crude chemical research of the day. But with the opening of the ninteenth century, and the advance of chemistry to the condition of an exact science, the metal elements began to come to light. Cerium, iridium, osmium, palladium, rhodium and tantalum became known in 1804; in 1807 potassium and sodium were recognized; in 1808 barium, calcium, magnesium and strontium, and in 1817 cadmium and lithium. Between 1828-1830 aluminum, glucium, thorium and vanadium were added to the list, and in 1839 lanthanum. Then came didymium, erbium, terbium, columbium and ruthenium in the five years between 1842 and 1846. In the sixties cæsium, indium, rubidium and thallium were discovered; in the seventies gallium: in the eighties germanium, and since then the chemists have added gadolineum, scandium, samarium, thulium, ytterbium, and finally radium.
​The most of these are as yet merely names to the general public, and some are certain to remain no more than chemical curiosities for years to come. There are good reasons to believe, moreover, that the list is still incomplete. But of the fifty-nine now known, eleven, aluminum, copper, gold, iron, lead, nickel, mercury, platinum, silver, tin and zinc, are, as metals, among the staple articles of commerce, which are being produced in large and ever increasing quantities, as the demand grows; while another list of six (manganese, tungsten, molybdenum, titanium, chromium and vanadium) are market staples in the form of alloys with iron, being largely used in the production of certain brands of steel. These are known in the trade as the ferro-metals. Again, there are six more (bismuth, arsenic, cobalt, uranium, thorium and cadmium) that are regularly produced, but not in the metallic state, for use mainly in the ceramic and electrical arts. Finally are iridium, osmium and palladium which find employment to a small but steadily increasing extent among makers of delicate instruments and tools of precision; tantalum, of which the electricians are now making incandescent light filaments, and magnesium, which for a number of years has been used by the photographers in the production of flash light. Thus nearly half of the total list may be said to be already among the indispensables of civilization, and already several of the remainder are under consideration by scientists, engineers and inventors—notably potassium, sodium and calcium—on account of the qualities they possess. Lithium, the featherweight of the metallic family, which will float in water, and has only one fifth the weight of aluminum, may before long be commandeered by the aeronauts, if a way can be found to protect it from the corroding action of air and water, while rubidium, that is as soft as fresh putty or wax at ordinary temperatures, zirconium, that possesses many of the qualities of thorium, and ruthenium, that is extremely infusible, are all certain to fill a want in the arts before long. In fact, each of the remaining known metals appears to possess some inherent and exclusive quality that will sooner or later be needed in our complex civilization. The most of those that are not yet exploited occur apparently in very small quantities in the crust of the earth, as, for instance, the last discovered, radium, which is so rare that but a few grains can be obtained from many tons of its ore. Yet it is one of the surprising facts of recent years that as soon as one of these rare metals is proved to be of real use to humanity, new sources of supply have quickly been found. We know little as yet as to the capacity of the wonderful storehouse we live upon. Nature seems to have provided a substance for every conceivable want of mankind, and beyond question, some of these substances that appear now to be useless are merely in reserve for wants not yet developed, while others that apparently are so scarce as to be ​of no practicable use, even if they had desirable properties, have only to be searched for, to be found in sufficient quantity for our needs.
Returning to the eleven well-known true metals, viz., aluminum, copper, gold, iron, lead, mercury, nickel, platinum, silver, tin and zinc, wonderful progress has been made during recent years in the matter of their production. Few of us appreciate the extent to which we are absolutely dependent on some of these substances which, a generation ago, were so rare. It is quite impossible now to conceive of a metal-less civilization, or one in which they were so costly as to be practically unavailable for the ordinary affairs and circumstances of life. In the home, the office, the factory and the club they confront us everywhere. Upon the person of a day laborer ordinarily clothed, half of the list will usually be found, while in the home of the average well-to-do citizen every one, except perhaps platinum, will exist in more or less abundance. It will be both interesting and instructive to note just what amounts of these metals have been taken from the crust of the globe during recent years, for the benefit of our modern civilization.
Aluminum
This metal began to appear on the market as a costly curiosity, in 1888, just twenty years ago, commanding a price of $5 per pound, and the total world's output for that year did not exceed 50 tons. By the end of the century, however, the annual production had increased to nearly 5,000 tons, while the price had fallen to $1.50 per pound. Since then there has been a steady increase of output until during 1906 it amounted to about 20,000 tons, while the price had fallen to 35 cents, causing the metal to be available in so many ways and forms that the civilized world would now find very great difficulty in getting along without it. But, remarkable as has been this growth, it is as nothing to what may be expected in the near future. For aluminum is the most abundant of all the metals, existing in such enormous quantity in the crust of the earth, and in deposits so accessible and so easily mined, that it is certain to become, before another century has passed, and as soon as its metallurgy has been perfected, the rival and supplanter of iron. Every clay bank and slate quarry is a high-grade mine of the metal, only we have not yet learned how to extract it cheaply from these ores. Innumerable other rocks and formations contain it in various quantities. A well-known geologist has recently calculated that 8.13 per cent, of the earth's crust is aluminum, against 4.71 per cent, for iron, and less than one tenth of one per cent, for copper. Bulk for bulk, aluminum has one third the weight of iron. In tensile strength it is almost the equivalent of cast iron, though far inferior in that respect to steel. Yet the metallurgists are rapidly learning how to increase its strength by alloying ​with it other metals, and when it can be produced at a price not more than two or three times that of iron, it will certainly replace it very extensively. For it is far more ductile and malleable, it melts at half the temperature, and so may be cut or forged into bars, sheets and tubes at much less cost; it is practically unalterable in the air or water, while iron and steel disappear in rust in a very few years, unless very carefully protected by paint or grease or cement. As yet there is but one ore from which the metal can be produced with reasonable economy, the mineral known as bauxite, which has been found at only a few places, and in masses of comparatively small extent. The rate at which the demand for the metal is now growing will result in their exhaustion in a few years. The great metallurgical problem of the day, therefore, is to devise a means for the extraction of aluminum cheaply from its most abundant ore, ordinary clay. This problem is perhaps on the verge of solution. In another decade we are almost certain to see the metal a staple on the markets of the world at not to exceed five to ten cents per pound. When that day arrives a revolution will have occurred in the industries that it is difficult now to apprehend.
Copper
Accurate statistics of the world's output of copper do not go back much further than the year 1879, when the amount was 170,199 tons. But fairly close approximations have been made for many previous years, and from these it appears that in 1856 the production throughout the world was about 47,300 tons. In 1906 it amounted to 786,794tons. This is a marvelous increase in the case of a metal that is yet used as a coin by more than half the population of the globe. That the annual product now should be nearly seventeen times what it was about half a century ago, while at the same time the price should be less, explains why civilized nations have abandoned its use as a coin and for ornamentation, and indicates that modern man has acquired! much greater facility than his immediate ancestors in extracting it from its ores, which are by no means abundant, nor easy to work. Those of us who have reached middle age can easily remember when a copper kettle was almost a family heirloom, to be kept under lock and key when not in actual use, and whose burnished sides and interior were the pride of the housewife. Nor in those days did we refer disrespectfully to pennies and cents as "chicken feed."
Gold and Silver
The story of the two money metals is much the same as that of copper. A half century ago we used to talk of their production in terms of Troy ounces. During the eighties the kilogram (2.2 lbs.) began to be used as a more convenient unit, and now that has become ​entirely too small for silver, while many statisticians are using the 2,000-lb. ton for both metals. A ton of gold would make a little cube measuring about 14$^1$⁄$_2$ inches along its edges, and of silver, one of 17$^1$⁄$_4$ inches. Measure these off on your desk ruler and it will become apparent into what small packages nature can pack her valuables if she has a mind to, for the golden cube will represent $603,861.22, while that of silver, at the price of 55 cents per ounce, will be worth $16,041.30. Now, in 1850, just before California and Australia began to produce the former metal in quantity, the world's annual crop of gold was about 60 tons, which could all be stacked away in a small bank vault, having a floor space four feet square and a height of six and one half feet—a mere closet. But in 1906 the crop amounted to 675 tons, more than ten times as much, and to accommodate it would require a vault of the same height, but with a floor space of twelve by fifteen feet—quite a good-sized room. As to silver, in the fifty-six years that have elapsed since 1850, the world's annual production has grown from about 975 to 6,360 tons. Carefully piled up in cubes this mass of the white metal would nearly fill up a room 100 feet long, 20 feet wide and 10 feet high.
Iron
In iron, the metal which is at the basis of the civilization of the day, the record is, if possible, even more remarkable. Reasonably accurate statistics of the world's production do not go back of the year 1865, when it amounted to 10,009,632 tons. In 1906 the output was 64,983,481 tons, showing an increase of nearly 650 per cent, in the forty years. Such figures are not easily grasped by the mind, but let us make the effort. Metallic iron weighs seven and a half times as much as an equal bulk of water. A cubic foot of water will weigh in round figures 62 pounds, and consequently one of iron will tip the beam at 465 pounds. This means that a ton of metal will contain a little more than four and a quarter cubic feet, and that a cube of it measuring about nineteen and a half inches along its edges will weigh a ton. Hence, the output of the year 1906, if put in the form of a solid cube, would contain 279,429,000 cubic feet, and would measure along its edges nearly 650 feet. A city block in New York measures, say, 250 by 500 feet, and its area is about 125,000 square feet, or roughly, three acres. Ten such blocks would be completely covered to the depth of 220 feet by the world's output of iron during the year 1906. This would be the equivalent in dimensions of an eighteen story building, completely covering a thirty-acre tract of land in the metropolis of America.
But to gain even a more striking impression of what the metal is to modern man, let us figure up the total production of the iron mines of the world during the last eventful forty years. In round numbers. ​it amounts to over six hundred million tons. Such a mass will measure up nearly twenty-six billion cubic feet. Put this into the form of a pyramid, with a base ten thousand feet square (about twenty-three hundred acres) and its height would be nearly eight hundred feet. Or, cut down the base to dimensions of a five thousand foot square (say sixty acres) and the structure would be nearly two thirds of a mile high. It may not be so difficult then to agree with the iron producers who claim that another half century of such strenuous civilization as the last one will serve to exhaust all the known great iron deposits of the world. Who of the generation that saw the Civil War would have imagined such an expansion of an industry that was then but lightly regarded even by economists? It is indeed high time for the chemists and metallurgists of the day to redouble their efforts to solve the problem of the cheap production of aluminum, for in that direction only does there seem to be an escape from the dilemma of a world unable to procure the common metal it needs, if its civilization is to continue.
Lead
In the case of lead we come down to more ordinary figures, yet none the less surprising when the services the metal gives us, by reason of its peculiar qualities, are considered. Without lead, no paint, no shot or bullets, no flexible piping. These are the three principal uses to which it is put in these days, and more than half of the annual crop of the mines becomes paint, and is employed to protect and improve the appearance of the structures that man raises to live, and to transact his business in. In 1885 the world turned out 391,542 tons of the metal. Lead is a dense and heavy substance, and it only requires a cube measuring a short seventeen inches along its edges to weigh a ton. Even so, the production of the year 1885 would make a mass covering a quarter of an acre of ground, and standing nearly one hundred and ten feet high. But when the year 1906 closed, and its doings were figured out by the statisticians, it was found that the lead mines of the world had turned out in that twelve months nearly three times as much as they had in 1885. To be accurate, the crop amounted to 1,061,533 tons. This mass of metal would make a pyramid with a base one hundred and fifty feet square, and rising nine hundred feet into the air. An increase of 300 per cent, in twenty years indicates an enormous growth in the demand for paint and putty, to say nothing of the consumption in the way of ammunition and piping.
Mercury
Mercury is the one degenerate in the family of the metals. Between 1850 and 1860 it was tremendously in demand by the miners ​of Australia and California, who were gathering their golden harvest with its aid, and in the two succeeding decades the silver miner also impressed it extensively into his service. But as the various great precious-metal mining districts of the world became connected with fuel and labor centers by rail, the smelting industry arose and gradually supplanted most of the amalgamation process in which quicksilver was the prime factor, and so the demand for it slowly declined. The largest recorded yield occurred in the year 1877, when the output amounted to 5,308 tons. In 1906 the world's production was only 3,964 tons. For many years now the silver miner has given up its use almost altogether, but the Alaskan placer miner must still have it, and there is yet a considerable consumption in those gold districts of Africa and Australia, where smelters do not exist, and even in our own west, at isolated or very low grade mines. At present the principal demand is for the manufacture of mirrors, and certain scientific instruments like thermometers and barometers. There is good reason to believe that there yet remains, undiscovered, in Asia, Africa and South America, one or more great gold placer regions. When these come to light the market for mercury will revive, and remain active until the new fields are exhausted. There is no lack of its ores in the crust of the earth. The metal has been produced in Spain for at least three millenniums; the California deposits are far from being exhausted, though they have been worked more energetically in the last fifty or sixty years than the Spanish deposits since their discovery, and the great mines of Huancavelica in Peru have hardly been touched. So when the demand again arises, mother earth is prepared to meet the drafts of her children, as usual.
Nickel
Fifty years ago this metal was practically unknown, except to the scientist. Its successful production as an article of commerce began in the United States about 1863, when it was detected in some copper ore coming from the Lancaster Gap Mine in Pennsylvania. For the next ten years, practically the entire world's output came from this mine. At its best, however, the yield never exceeded 100 tons per year, the metal commanding a price of $2.50 to $3 per pound, which of course severely restricted its use. In 1867 one of its ores was found in comparative abundance in the island of New Caledonia, a French possession, lying to the northeast of Australia, and commercial production from there began about 1874. In 1880 the metal was discovered in copper ores coming from Sudbury district, Canada, on the north shore of Lake Huron, and by 1886, a production began which has since steadily increased until at the present time two thirds of the annual world's crop of the metal comes from the later locality. ​Finally, there is a small amount produced annually in Sweden and Norway. The total world's output in 1906 was in the vicinity of 19,000 tons. The largest use to which it is now put is in the manufacture of an alloy with iron which is particularly hard and tough, and hence suitable for armor plate. After that comes nickel coinage and plating. The metal has excellent qualifications for these latter purposes. It will not corrode or blacken under ordinary atmospheric conditions, it takes a high polish, and its soft white luster, with a faint tinge of yellow in it, is exceptionally pleasing to the eye. The modern world has a genuine need of nickel, and so the production will increase, but it is never likely to become as common a metal in the arts as copper or lead or zinc.
Platinum
The heaviest of all the metals is also the rarest of those that have become staple articles of commerce. It required nearly seventy-five years after its discovery for mankind to find uses for it. Then its extreme resistance to heat, and to the action of acids, commended it to the chemist, and later to the electrician. It began to come into the market in small quantities in 1824, from the region where it was first found—the western foothills of the Andes in the republic of Colombia. Almost simultaneously it was found in the Ural Mountains of Russia. The Colombian region has never been exploited or worked regularly, owing to the unsettled political conditions of the country, and it is figured that up to date not over 25 tons altogether of South American origin have been produced, practically all of which was gathered by natives in a desultory way. The Russian field has been operated regularly since its discovery, but with little enterprise or judgment or science. The metal has also been found in small quantities associated with gold in the auriferous gravel deposits of the Pacific coast of our own country. But up to the end of 1907 not more than 160 tons altogether of platinum had been produced throughout the world since its discovery, in spite of its rapidly increasing price, for it is now worth, weight for weight, about 25 per cent, more than gold. It is a real commercial misfortune that the two localities where it exists in such comparative abundance, and from which it could be produced in quantity, are under the control of nationalities so backward in social conditions and general civilization, that capital and engineering talent hesitate to take the risks involved in the illiberal laws and disturbed conditions that prevail. The metal occurs in nature generally in the pure or native state, and in the condition of grains, nuggets and dust disseminated throughout deposits of gravel, from which it is very easily recovered by methods similar to those employed in operating gold-bearing placer mines.
Tin
The story of tin is particularly interesting because it illustrates (perhaps better than that of any other metal) the interdependence of the elements of modern civilization. In 1862, which is about as far back as accurate statistics of its production go, the world's annual output was roughly 22,000 tons, of which about half came from Cornwall, and the balance in small and scattered amounts from Germany, Austria, South America, Mexico and the East Indies. In 1906 the crop amounted to nearly 109,000 tons, showing an advance of almost 500 per cent, in 45 years. When we investigate the uses to which the metal is put, we find that previous to our Civil War about all the need the world had for tin was for the manufacture of cooking and kitchen utensils, and for roofing. Now, however, nine tenths of the demand is caused by the canned food industries, and those connected with the distribution of mineral oils. Tin roofs are completely out of fashion, and aluminum is rapidly becoming the favorite kitchen metal. But the tin can, made of plated sheet iron, is the vehicle in which kerosene has traveled to every part of the inhabited globe, and which has made it possible for the fisherman, the stockman, the farmer and the horticulturist to deliver their products in a fresh and edible condition wherever there are people who want them. It is an interesting fact that quite three quarters of the annual crop of tin now comes from the East Indies, and is gathered by Chinamen and Malays. The region is probably the most ancient mining district in the world. Tin has been coming from there in small quantities for at least 5,000 years, ever since the beginning of the bronze age of the archeologists, and the world is only now beginning to appreciate the extent and value of the field. More than fifty per cent, of this old world product finds its market in the United States, where it is converted into millions of cans of all kinds, from the familiar five-gallon receptacle in which the Standard Oil people pack their product, down to the diminutive sardine can of the picnicker. When these are filled and sealed they start on their travels, and in a few brief months—or years at the outside—the neat vessels are scattered throughout the world from the equator to the poles, over the plains and deserts and through the mountains. Vast numbers of the larger sizes are doing duty as water pails everywhere, while the remainder become vagrants and strays in the refuse piles that everywhere mark the paths or dwelling places of man. Thus the metal, gathered with toil and danger by the patient and stolid oriental, is by the strenuous and impatient occidental put to a use which almost immediately insures its dissimination to and dissipation in every corner of the known world. Without tin, our present-day civilization would almost come to a standstill, and certainly the exploration of the yet unknown parts of the planet would ​be seriously delayed. The metal is almost as resistant as gold to the action of air and water, and to the attacks of those acids which exist in foods of all kinds, and which in a few weeks would destroy iron, and convert copper, lead or zinc into poisons, and kindly nature has segregated it in the crust of the earth in places where it may be collected at moderate cost, and utilized in activities that have become quite of the nature of indispensables to the further progress of humanity.
Zinc
This metal, which a thousand years ago was a puzzle to the metallurgists, and a nuisance to the lead miner, has become, during the last quarter of a century, one of the most useful and necessary products of the mine. The demand has increased so enormously that producers have at times had the greatest difficulty in meeting it. We have no reliable statistics of the world's output previous to 1883, when it amounted to 310,000 tons. Its principal use up to that date was for the production of brass, an indispensable alloy in the manufacture of bearings and fittings for all kinds of machinery. Previous to the present mechanical age its only use was in ornamentation. Now many other employments have been found for the metal. In the condition of an oxide it is consumed very extensively by the paint manufacturers. In the form of an electrically deposited coating on sheet iron it is in great demand by the building trade for cornice work, etc., under the name of galvanized iron, and is exported in enormous quantities to all new parts of the world for use as roofing and siding in those temporary structures reared for protection against the weather in lands where lumber is not available at reasonable cost. With the development of the electrical industries it has become a necessity in many forms of batteries, and during the last dozen years or so hundreds of tons have been consumed annually in the recovery of gold from certain of its ores by means of what is known as the cyanide process. These new uses, as well as the steady increase in the demand for brass in the ever-growing machinery trade, have caused its production to grow with such rapidity that in 1906 the crop amounted to 774,525 tons, a gain of 250 per cent, in twenty-four years. Zinc is not reckoned as one of the heavy metals, nor yet is it a light one, its specific gravity being a little less than that of iron. Yet if the product of last year was melted and cast into a pyramid with a base of an acre, the apex would stand at an altitude of about 250 feet. This is a fairly good record for a metal that in 1850 was practically unused except in the form of brass. By itself, it is a beautiful substance, almost as soft as lead, very malleable, and with a rich blue-white luster that is the delight of the artist.
History seems to indicate very clearly that nations who have ​possessed and developed notable deposits of the metals, have invariably taken a prominent position among their contemporaries, and have reached a higher physical and intellectual plane than those dependent alone upon agriculture or on commerce. Food crops quickly disappear. Fabric crops are worn out in a year or two. Fuel crops burn up about as quickly as they come into the market. There must be an annual harvest of these or trouble ensues. Commerce is the science of the distribution of crops, and is dependent on them for its existence. The various metal crops, however, are of the nature of permanencies. They go into use and not into consumption, and a very considerable part of each year's addition to the world's stock become articles or structures that are capable of earning interest for their owners. Probably in this lies the explanation of the prosperity that invariably results from an active metallic production. These substances can not be eaten up like wheat, they can not be worn out like cotton or wool, they can not be burned up like coal or lumber or tobacco. They remain and accumulate, are perhaps remelted and used yet another time, and even such parts as are apparently lost in the chemical arts, or in plating or ornamentation, are very extensively recovered from time to time. As a nation, we are producing about 35 per cent, of the world's crop of aluminum, 58 per cent, of that of copper, 23 per cent, of the gold, 33 per cent, of the lead, 43 per cent. of the iron, 26 per cent, of the mercury, 30 per cent, of the silver, and 29 per cent, of the zinc. This is a remarkable record for a community that has existed for less than a hundred and fifty years, and it means that not only are we in possession of a part of the globe that has great mineral resources, but that our form of government and the nature of our laws are such as to foster and encourage that individualism that alone permits a people to develop the best that is in them. The metal era has but just begun. The earth beneath us is a storehouse abundantly full of them. Heretofore man has been content to utilize only those things that were on the surface of the planet. We have now begun to call upon the earth for its very heart blood. Heretofore the mason and the woodworker have been almost the sole executors of the will of the architect and the artist, but now the founder and the smith are becoming his main interpreters. Substances that can be liquefied and molded, rolled and hammered and drawn into form, are taking the place of those that with painful and long effort must be chiseled and sawn. Materials that seem to be capable of taking on life, that can be made to pulsate and vibrate, that will transport energy and light and sound and other forms of force, are being substituted for inert stone and brick and mortar, wherever strenuous life exists or is to be protected. In its future evolution ​mankind is bound to reflect this great change in the nature of the materials upon which it impresses its ideals and will.
On the following sheet is given the statistics of the crop of the principal commercial metals for the year 1906.
The Metal Crop of the World during 1906
| | Tons | | Value |
| Aluminum | 20,157 | | $15,319,320 |
| Copper | 786,794 | | 309,996,839 |
| Gold | 675 | | 406,931,323 |
| Iron | 64,983,481 | | 2,323,799,280 |
| Lead | 1,061,533 | | 120,483,995 |
| Mercury | 3,964 | | 4,233,552 |
| Nickel | 18,983 | | 16,879,684 |
| Platinum | 5 | .5 | 3,527,481 |
| Silver | 6,365 | | 123,822,928 |
| Tin | 108,738 | | 86,577,768 |
| Zinc | 774,525 | | 69,428,421 |
| Total | 67,765,220.5 | | $3,481,000,591 |