When we consider how largely the discovery and exploration of America was due to the search for mines, that the precious metals might be found to replenish the depleted treasuries of European monarchs; and when we note that, as a result of this search, the world’s annual production of gold and silver had increased in the three hundred years following the discovery from $5,508,000, in 1500, to $48,995,000 at the beginning of the nineteenth century, we view with surprise the little progress made during this period in the art of mining.
At the beginning of the present century, we find in use the same general methods that were followed in the time of Columbus. The very first operation—the search for veins—was oftentimes conducted after the manner of the Middle Ages; for in Pryce’s “Mineralogia Cornubiensis,” which seems to have been one of the leading works on mining of the last century, there occurs, among other methods, a lengthy treatise on “How to Discover Mines by the Sole Virtue of the Hazel-tree.” Powder, although it had been invented for centuries, had been so little employed in mining that it was considered merely as a last resort. In a description of mining methods, another work says: “The soft vein is generally dug with the spade and turned out into wooden trays; but the hard veins are knocked out with a gad and a hammer. If the ore is so hard as to be incapable of breaking it in this manner, they usually soften it with fire. But a still more expeditious method is the working with gunpowder. A small quantity of powder does great things this way.”
In 1800 the coal miner was working by the naked light of the tallow dip. Cast-iron rails had been introduced but a few years, and rails of wrought iron, which could be bent to follow the curves of the drifts, were unheard of. The cars were pushed along the levels by boys. Water power, where it could be obtained and applied by means of the overshot wheel, was in general use for pumping, hoisting, and ventilating. But from many a mine the ore was raised by women, who pulled the bucket up “by walking away with the end of the rope” which passed from them over a sheave and thence down the shaft. In places the ore was still carried up the steep inclines to the surface on the backs of women and girls. Ventilation, when not secured by natural means, was obtained by bellows operated by men or mechanically. A mine which had been worked to a depth of one thousand feet was extraordinary. Though steam power, applied in the form of what was known as the atmospheric engine, a device utilizing for suction the vacuum formed by the condensation of steam in a chamber, had been used for years in draining mines, the steam engine, as invented by Watt, had been introduced for hoisting in only a few places. The power was applied to turn a long crank arm, which rotated the drum.
At the beginning of the century the mines of Cornwall, which were the greatest producers in Great Britain, were turning out about 5,000,000 pounds of tin and 10,000,000 pounds of copper a year, while the whole United Kingdom was furnishing only 170,000 tons of iron. South America was the greatest producer of gold and silver, wonderfully rich mines of the latter having been found in Peru and Chile. Humboldt places the production of the whole South American continent for the year 1800 at 691,625 pounds of silver and 9900 pounds of gold.
The United States at that time had practically no mining within its borders. Some small mines of iron, lead, and copper, which had been opened to supply the demands created by the Revolution, were producing spasmodically; but even as late as 1821, William Keating, in an address before the American Philosophical Society, said, “Upon the whole we think we may be warranted in saying that there are as yet no mines in activity in the United States. Coal, in most places, is taken from the surface, or dug from the foot of a hill. The lead mines of Missouri are rich and abundant, but the mining is a mere pilfering of the richest spots.”
In 1801 the Cornish pumping system was introduced. A long rod, extending from the surface to the bottom of the shaft, operates simultaneously a series of pumps placed, one above the other, at intervals of about two hundred and fifty feet. The lowest one lifts the water from the pump and delivers it into a tank from which the next one draws its supply, and this in turn forces it up to a higher tank. With this improved means of drainage mines began to be sunk deeper, a depth of three thousand feet having been reached with this method of pumping. The manufacture of iron pumps, which had begun to replace wooden ones toward the end of the eighteenth century, decreased the amount of repairs necessary on the pumps, and aided in making possible better arrangement of underground work.
It was at about this time, the beginning of the present century, that the method of opening ground by shafts, levels, and raises, which we refer to as “blocking out ore,” began to be more generally adopted, displacing the former mode of following down the ore by a series of irregular, isolated excavations. With it came overhead stoping, in which, after the shaft has been sunk, the level driven and timbered, and a raise made, the miner begins breaking down the ore from over his head, allowing it to run down into chutes. From these it is drawn out into cars pushed along the tracks in the level. The waste is allowed to accumulate on top of the stulls, or timbers, forming the top of the level above referred to, and serves as a platform upon which the miner stands in breaking down more ore.
The invention of the safety lamp, in 1815, is probably the most important event of the early part of the century. Previous to this the miners fired the gas in the “rooms” with their candles, which were raised toward the roof with the aid of a long pole, the miners lying flat on the floor of the level to escape the blaze, and sometimes putting on wet jackets to avoid being scorched. As first invented by Davy, the safety lamp consisted merely of a cylinder of wire gauze surrounding the flame, much as the flame is surrounded by a glass globe in the modern lantern, except that the diameter of the cylinder did not exceed two inches. This was based upon the theory that the gas set on fire by the light would burn inside the gauze without heating it hot enough to ignite the gas outside. The principle was correct, and the lamp worked satisfactorily when carefully used under proper conditions. It was soon found, however, that in a strong air current, or if swung at a more rapid speed than six feet per second in an explosive mixture, the surrounding gas would be ignited. As a man walking naturally on the surface moves at a rate of between five and six feet per second, it will be easily seen that even were the speed considerably diminished underground,—and any one who has tried to follow a mine foreman through mine workings knows the speed slackening is slight,—a very slight swing of the arm would bring the rate of movement of the lantern up to the danger point. Another and a very unexpected factor in causing explosions with the new lamp also developed; and that was the great carelessness of the men who used it. Armed with this device, and deluded by the quietly burning flame, the miner would seat himself upon a pile of coal, draw forth his pipe and fill it, and deliberately open the gauze to light it. As a consequence, for a time after the introduction of the safety-lamp, the number of accidents from explosions increased. This latter difficulty, the recklessness of the miners, was presently overcome by having the lamps locked, and by depriving the men of all matches before admitting them to the mine. An improved lamp, introduced by Clanny, wherein the lower part of the cylinder was replaced by glass, partially protected the flame from strong air currents, and also gave a better light. Later, Müseler added an interior sheet iron chimney, which divides the air current so that the hot air does not strike directly against the gauze, and the lamp as thus improved is very largely used, especially in Europe.
In 1831 the safety fuse was invented, a train of powder having been used before this for firing the charges. The same year a patent was granted to Moses Shaw of New York for an electrical device to fire several charges at once. It was at about this time, too, that the man-engine was invented in Germany. Some miner, noticing the slow and steady up and down motion of the long rods which operated the pumps in the Cornish system, had conceived the idea of nailing steps on to them at intervals, and riding up and down. As mines grew deeper and the time and labor required for the men to get down to their work increased, a special engine, utilizing an improvement of this device, was employed for raising and lowering men. This “man-engine” consisted of two parallel beams, moving slowly up and down the shaft with a reciprocating motion, the length of the stroke being about twelve feet. Upon these beams small platforms were nailed at distances equal to the length of the stroke. The miner wishing to descend stepped upon the top platform of one beam as it started on its down stroke. At the end of this stroke he found himself twelve feet down the shaft, on a level with the second platform of the other beam, which had in the mean time been coming up, and he stepped across on to this, which now began its down stroke. Thus by constantly stepping from one rod to the other at the completion of each down stroke, he was conveyed to the bottom. By reversing the process he was raised to the surface.
In general, mining progress was slow up to the middle of the century. The production of the baser metals, here and abroad, increased gradually with the demands of the mechanic arts, but it was not until the middle of the century that this factor, joined with the improved methods of transportation, and of metallurgy, gave to mining that impetus which, though through alternate recurring waves of prosperity and stagnation, carried it forward until the annual expenditure for technical skill, machinery, and supplies used in the industry is estimated to-day at one thousand million dollars.
The first mining excitement in the United States occurred in 1829, following the discovery of gold in the South; but these fields soon declined in importance without resulting in any improvements to mining methods and machinery.
The next mining fever resulted from the inauguration of work upon the copper properties at Keweenaw Point, Mich., in 1845. This caused the first mining-stock speculation in this country, and it is interesting to note that the century closes with a repetition of this same fever, founded upon almost the same ground. Yet the conditions have changed wonderfully. Upon the then barren peninsula, whitened with the tents of speculators and geologists, has grown up a multitude of towns, filled with thousands of people whose labors are performed at a depth of nearly a mile under ground. Thousands more transport the ore to the mills, separate the copper from the rock, and cut timber for the mines; while yet other thousands prepare food and clothing and shelter for all these. During 1898, the copper mines about Lake Superior produced nearly 160,000,000 pounds of copper, and paid in dividends $6,490,000.
This district is the only one in the United States where the man-engine has been used; but as the shafts were sunk deeper and deeper, it was found that even this method was not sufficiently rapid, and the men are now lowered into the mines by cages or skips. A “cage” is simply the miners’ name for the ordinary elevator when used underground, and has developed from the bucket in use at the beginning of the century. A “skip” is a car especially designed for use on an incline. The roadway upon which the skip runs is so planned, at the top of the shaft, that the rear wheels run upon a track raised above the one over which the front wheels pass, so that the rear end is elevated and the skip is dumped automatically. At the De Beers diamond mines in South Africa are two of these skips which hold nearly five tons of rock each. At the bottom of the shaft are chutes containing the rock, and when the skip is in position a man pulls a lever, allowing the ore to run into it. Another pull closes the chute, a button is touched which rings a bell in the engine-room, and the skip starts up the shaft. At the top it dumps itself and returns to be filled again. In the mean time the other skip has been filled and is going up while the first is coming down. With these two skips, making ninety-two trips an hour, over four thousand tons of rock have been hoisted in less than twelve hours, from a depth of 1250 feet.
To handle these enormous quantities tremendous hoisting engines are used. At the Calumet and Hecla mines is a pair of quadruple expansion engines which will lift cages, carrying six tons of ore, a mile in a minute and a half. The “Modoc” hoist, built for the Anaconda Mining Company of Butte, Montana, is the largest hoist in the world. It is a double compound beam engine, and is designed to be used in sinking to a depth of 6000 feet. This machine weighs four hundred tons, and has seven separate subordinate engines for use in operating it. Think of it! An engine so ponderous that smaller engines are necessary to apply the clutches that set the reels in motion; other engines set the brakes, and another reverses the action, if need be. All these are controlled by levers operated from the engineer’s platform, the “runner” having one foot and seven hand levers to handle. Besides these there are two indicator discs, directly in front, requiring constant attention, for these show the exact position of the cage in the shaft. Yet such wonderful skill have the runners in the control of these veritable flying machines that they instantly interpret the complicated signals, and drop the cage with such exactness that the car of ore is run from the track in the level to the track on the cage, almost without a jar.
Nor is the hoist the only large machine necessary in the equipment of the modern mining plant, for in sinking to great depths vast quantities of water have to be removed. The Chapin Mining Company, at Iron Mountain, Mich., have one of the largest pumping engines in the world. This engine is located on the surface, driving the pumps after the Cornish style, though it would be difficult to see much of the pump of 1801 in this magnificent machine. With a ten-foot stroke it conveys the power to the pumps through a walking beam weighing a hundred tons. In an hour it will raise nearly 200,000 gallons of water from a depth of a quarter of a mile.
Imagine the miner of 1800 “softening by fire” sufficient ore to supply a modern hoist. For the mines which now turn out 2000 tons a day can by no means be counted on one’s fingers, and 2000 tons means more than a foot deep over a whole city block. Before the middle of the century the use of powder and drill had largely increased, and in 1845 an attempt was made to aid the man behind the drill with a machine which swung a hammer by steam power. In 1805 a machine was invented using compressed air in a cylinder, and this was gradually improved until it became a success in 1861, in the Mont Cenis tunnel. As finally employed, the power drill is practically a small engine, the drill being attached to the piston rod and moved rapidly back and forth by compressed air or steam. The machine has three functions: to strike the blow, turn the drill, and advance it, as the hole is driven deeper and deeper.
Soon after the machine drill became a success dynamite was invented, and these two have been the greatest factors in bringing about that rapid development and production which is the most pronounced attribute of modern mining. Dynamite alone has doubled the amount of ore which can be extracted from a face in a given time. Le Neve Foster, in his work on mining, gives the rate of advance in driving a tunnel by fire setting at two fathoms per month. Compare with this the Niagara Falls tunnel, driven with power drills and high explosives, 342 feet in four weeks.
It is probably to the power drill more than to anything else that we are indebted for the development of the air compressor; the exhaust from a steam drill and the heat emitted from the pipes being very disagreeable under ground. As early as 1800 a Welsh engineer had attempted to run a blast by means of a water power a mile and a half distant, but it was not until 1865 that machines were operated to any extent by compressed air. The great difficulty had been the loss of efficiency, owing to the clearance spaces and the heating of the air. In driving the Mont Cenis tunnel but 16 per cent of the power developed was available, and up to 1880 the efficiency was extremely low; but to-day as high as 80 per cent is obtained. The air compressor is simply a force pump with ingenious devices to overcome the loss of energy. For ordinary use the air is compressed to a pressure of from 60 to 80 pounds per square inch. This is done in a single cylinder for low pressures, but for high pressures two cylinders are used. From the compressor the air is conducted to a reservoir, from which it is piped to the machine which it is to run.
One of the advantages of air-driven machines under ground is that the exhaust furnishes fresh air to the miners and cools the atmosphere. The result has been that in metal mines, where there are no noxious gases escaping from the ground, the exhaust from the air-drills, together with the natural air currents, has supplied sufficient ventilation. In the coal mines, however, it has been necessary to employ other means. After it was found that, even with the safety-lamp, gas would be exploded if a large amount of it had accumulated, more attention was paid to ventilation. Levels and shafts were divided to produce a natural current; the size of the drifts was carefully figured in order to regulate it; doors were put in to compel it to follow the faces; devices were adopted to split it, a part going to one room, the remainder to a second; and boxes were built to carry one current across another. Early in the century hand fans run by a wheel and pinion had been employed for forcing the air down the shaft, but it was soon found that the circulation produced in this way was inferior to the result of eduction. Large furnaces were then constructed at the bottom of the upcast shafts, in order to cause a strong upward current. Again, huge air pumps, run by machinery, were tried for exhausting the air. By 1850 exhaust fans were coming into use, and these, occasionally replaced by blowers, also used for exhausting, are now generally employed. The Guibal, which has been the most prominent of the fans, has been made as large as forty-six feet in diameter. The Capell, which is an improved form of the Guibal, has six curved veins, or blades, and is made from eight feet to fifteen feet in diameter. It is driven quite rapidly, making from one hundred and eighty to three hundred revolutions, and having a capacity of from one hundred thousand to three hundred thousand cubic feet of air, per minute. The result of this thorough ventilation is that the gas is removed from the mine almost as rapidly as it enters, and often the safety-lamp is no longer needed by the common miner. Nevertheless, it has by no means become useless, since as an indicator of the presence of gas it is invaluable. The action of the different lamps in the presence of gas varies, but in general the size of the flame increases in direct proportion to the increase in the amount of gas mixed with the air. Each morning, before the men go to work, the fire boss takes his safety-lamp and makes the round of the mine. When he goes into a room he watches the flame, and if it burns up to the point which indicates that it would not be safe to enter with a naked light, he makes a mark on the wall which serves as a danger line beyond which the men do not go.
Another machine, which, like the fan, has been developed by the demands of the coal mines, is the coal-cutting machine. Probably the lot of no man was as hard as that of the coal-digger at the beginning of the century. After he had performed the dangerous task of exploding the accumulated gases, he was often forced to work all day lying in the most constrained attitude. Applied in this manner, his power was largely wasted, and much useless dust and small coal was produced. The first effort at relief was a machine which imitated the miner, striking a blow with a pick worked by a lever, and making as high as seventy blows a minute. These have been generally replaced by quite another type of machine, one which depends on the action of either a rotary bar, a rotary wheel, or a chain cutter. These machines are operated by either air or electricity. The Jeffrey rotary bar cutter will undercut a block of coal thirty-nine inches by fifty-four inches in six minutes. The chain-cutter is an endless chain carrying cutting knives and traveling horizontally. It is claimed that these machines will effect a saving of about ten cents a ton in the cost of mining.
When in 1848 the finding of gold in California was reported, followed in 1851 by the discovery of the Australian fields, large numbers of men were attracted to the placer mines, who later, as the placers became exhausted, turned their attention to vein mining. Nor did hydraulic mining itself fail to progress. When the placers were first discovered, the miner, standing in the shallow stream, washed the gravel, a panful at a time, and secured from fifteen to twenty-five dollars a day. As the placers became poorer he built sluices, and, shoveling in his gravel, turned the stream in to wash off the light rock, while the heavy gold was caught in the interstices between the blocks with which he had paved the bottom. If the ground became clayey, he brought part of the water through a hose and used it to break up the lumps in his sluice box. Then as he gradually removed the gravel and the banks about him became higher, he turned his hose toward the bank and brought more water from a higher level, until, to quote Bowie, “a forty-inch wrought-iron pipe has been substituted for canvas hose and a stovepipe, and an inch stream replaced by a river of water discharged through a nine-inch nozzle under a four-hundred-foot pressure.” By this means, at North Bloomfield, Cal., nearly a million yards of gravel, containing but two and nine tenths cents per cubic yard, was moved in a single season, and at a profit.
As the banks became poorer, the miners turned their attention to the river beds. In New Zealand, in the early days, they worked the banks as far down into the river as they could reach with a spoon dredge. Then a dredge was made resembling a ladder of buckets, continually revolving, and operated by wheels driven by the current. When the river got low the current became too weak, and a steam engine was substituted. Then a revolving screen was put on to separate the large rocks from the fine sand, and gradually the modern dipper dredge has been evolved, with its pumps, screen, distributors, and tables and sluices, handling 2000 yards of gravel a day at a cost of three cents a yard.
In 1859 the Comstock lode in Nevada was discovered, and it is to this district that we owe the “square set” method of timbering, so largely in vogue in wide veins to-day. Some of the “bonanzas,” that is, pockets of rich ore, were of enormous size. For example, one found in the “Gould and Curry” was 400 feet long, 80 feet wide, and 400 feet deep. As the walls were not sufficiently solid to stand unsupported, and a single stick of timber was too short to reach across, splicing was tried. It was soon found that this weakened the timber too much, and the method of square “setting” was invented. This consists in framing timbers together in rectangular sets, having a square base of four pieces, usually six feet long, placed horizontally as sills. Into these are framed posts, surmounted by a cap of four additional timbers which become the base for the next set. The timbers are usually twelve inches square, and cost on the Comstock about $10 a set. From 1870 to 1891 there is said to have been used up on the Comstock 200,000 acres of forest, valued at $45,000,000.
The amount of timber which is consumed under ground in a single year must be enormous. Mr. C. W. Goodale estimates that in Butte alone, in 1895, 37,500,000 feet, equal to 3750 carloads, were used in the mines. As the timber decays in from five to fifteen years, and has to be replaced, efforts are constantly directed toward decreasing the large expense which is thus continually recurring. In shafts and levels for permanent use iron is an economical substitute. Wherever possible, new methods of mining are being introduced. Thus in the Lake Superior iron regions, the mine development is planned along lines almost unheard of ten years ago. In the first place the gravel which overlies the ore is stripped off, even if it is fifty feet thick. This is done with steam shovels, which load the gravel upon cars. These are then pulled away by one locomotive while a second places new “empties” in position to be filled. One shovel will load from 150 to 175 cars a day; that is, will take from 3500 to 4500 tons of dirt from the sides of the pit and put it upon the cars. This method obviates the use of timber for holding up the surface.
After the overlying gravel is removed, should the conditions be favorable, the ore is taken out with a shovel. If this cannot be done, some method depending on rock-filling is adopted. At the Auburn mine, after stripping and driving the levels, raises are made to the surface at intervals of about fifty feet, the ore broken down around them, starting at the surface, and dropped down through them. This leaves openings in the shape of inverted cones, having their bases at the surface. Additional raises are then made halfway between the others, and the remaining material extracted.
At the Fayal mine they take out rooms twenty-four feet wide by three hundred feet long, with a twenty-four-foot pillar between them. These rooms are carried up from the first level to the surface, and filled with gravel which is run in from above. Then the pillars are mined by “slicing and caving;” that is, by running drifts along the sides of the pillar and caving the ore down from the roof. After removing this ore another drift is run, the roof caved, and another slice taken off. It is claimed the saving in timber by using this method amounts to ten cents on each ton of ore mined.
All of these, and many other inventions, have constantly tended to decrease mining costs. Yet the industry is carried on to-day in so many out-of-the-way places, and under such varying conditions, that the cost per ton of the ore mined vacillates between wide extremes. As an example of what can be accomplished, working on a large scale, and where supplies are easily and quickly obtained, the Atlantic mine, in Michigan, may be mentioned. This mine produced, in 1898, 370,000 tons of ore, at a cost of sixty-six cents per ton.
With all these wonderful advances in mine mechanics, engineering, ventilation, and lighting, have come the foundation and development of mining schools, the rise of technical societies, and a general governmental recognition of the importance of the industry. It is not so very far back in the preceding century that we find among the statutes of England the following: “Stealing ore out of mines is no larceny, except only those of black lead, the stealing ore out of which is felony without benefit of clergy.” It would be interesting to know the name of the gentleman who owned the black-lead mine, for, in modern parlance, he certainly “had a pull.” By 1833 mining legislation had so far progressed in England that laws were enacted regulating the employment of children under ground. In this country, in 1830, a state geological survey was inaugurated by Massachusetts, and this institution has since been copied by many States. The majority of the States where mining is carried on have passed laws tending to increase the safety of men working under ground.
Abroad, carefully prepared codes describe the method of lease or sale of mining rights, and define the rights of owners of ground. In this country the first legislation of this character was in 1807, when the government mineral bearing lands were withdrawn from sale and ordered leased. In 1834 the miners refused to pay the royalty, owing to the large number of illegal entries, and in 1847 the lands were opened to sale. It was not until 1866, after fifteen years of self-government among the miners of the West, that Congress earnestly undertook to regulate the acquisition of mining titles on the public domain. Leagues beyond the towns, miles from the nearest roads, hurrying from the scene of one excitement to another, pushed by the crowd of constantly arriving adventurers, with surveyors unobtainable and courts not accessible, almost without time to measure, and in a region absolutely unlocatable, it had been impossible for the miner of the West to secure a legal title to his land as contemplated by the act of 1847. Accordingly, there had grown up the custom which gave to the discoverer of a lode the right to a certain length of it, and it was this right which was recognized by Congress, and became the basis of the law of 1866.
So far our story has been of progress, but what shall we say of the action of Congress, which, in 1872, abrogated this law and substituted for it the prolific breeder of litigation called the law of the apex? To quote Dr. Raymond: “The leading characteristic differs from all previous mining laws of this or any other country. The old right of discovery, which was the basis of the miner’s title down to 1872, has dwindled under the present law to a nominal importance. It is true that the discovery of the lode within the claim is made a prerequisite to location. But the right to follow the lode in depth beyond the side lines of the claim depends no longer upon having discovered it, but on having included its top, or apex, in the surface survey.” Should the miner be so fortunate as to have a vein which outcrops plainly on the surface, he may stake out the ground without difficulty, so that the vein crosses the end lines. But if his vein does not appear on the surface, and he fails to guess its direction correctly, and finds, on developing, that it does not cross the end lines of his claim, he is suddenly cut off from all extra-lateral rights. Or should he, in laying out his lines along the rough, precipitous mountain-side, fail to make his end lines parallel, he again finds his rights limited. Nor has this law been made clearer by court decisions, but rather it has been complicated.
THE POWER PLANT AT JEROME PARK, N. Y.
(Ingersoll-Sergeant Duplex Corliss Condensing Air Compressor.)
Certainly this is a peculiar condition of affairs. The century which has witnessed an advance from the hazel rod to the diamond drill, from the spade to the steam shovel, from fire softening to dynamite shattering; a century during which a clumsy car pushed over cast-iron rails by a boy has grown to a cable train, and a two-hundred-pound bucket raised by women has developed into a six-ton self-dumping skip hoisted by electricity; a century productive of new devices which tunnel mountains, cross ravines, or sink through quicksands with equal ease; a century which has seen the touch of a button and the turn of a wheel bring power from thirty miles away to light and drain the mine, as well as operate the drills and hoist; such a century closes with a law in force in the greatest mining country in the world which makes litigation one of the expected stages of mine development.
At the beginning of the century the mining engineer advised where to sink, the manner of working, and the method of dealing with the water: to-day he must not only be a mining, civil, and hydraulic expert, but a mechanical and electrical engineer, a chemist, and a lawyer.
The time was when he who leveled forests, built himself a home, and brought the land under cultivation, was regarded as the true pioneer of civilization. In later times the miner fairly divides this honor. Pursuing a hazardous occupation, he has invaded most out-of-the-way and desolate places, creating untold wealth, founding towns and States, and inviting vast and substantial populations. By his industry and enterprise he has not only revealed the seventy-seven non-metallic underground products which in the United States alone, in 1899, had a value approximating $500,000,000, but the twelve metals—precious and useful—whose value in the same year approximated $270,000,000. Around his gold mines—deep and placer—have grown California, Nevada, the Dakotas, Colorado, and even Alaska; while empires have sprung up at the sound of his pick and the introduction of his mighty machinery in Australasia and South Africa. In the development of silver he has contributed wealth, population, and institutions to Colorado, Nevada, Utah, Montana, and Arizona. His iron and copper mines have transformed the barren coasts of the Great Lakes. The quicksilver mines of Southern California brought San José and other towns to wealth and importance. In the history of Ureka and Leadville, Col., we have the romance of both the gold and lead mine. And so, whether the miner unearths the ores, the coals, the wonderful variety of buried materials which nature has provided for the use and comfort of mankind, he so frequently becomes the source of wealth, population, and permanent civic organization as to give him high rank among the “true pioneers of civilization.”