CHELSEA 
 
 CURTIS 
 
 FRAS E R
 
 OF CALIF. LWRARY. LOfl 
 
 
 '
 
 SECRETS OF THE 
 EARTH 
 
 BY 
 
 CHELSEA CURTIS FRASER 
 
 Author of "The Young Citizen's Own Book," 
 "Boys' Boole of Sea Fights," etc. 
 
 "Look," said God, 
 
 And with fingers slow, 
 
 Drew away the mantle rock. 
 
 Man followed, groping, 
 
 To touch the flesh of his true mother; 
 
 And standing in great valleys, 
 
 He saw the ages passing. 
 
 JAST LOXLEY LEWIS 
 
 NEW YORK 
 
 THOMAS Y. CROWELL COMPANY 
 
 PUBLISHERS
 
 COPYBIQHT, 1921, 
 
 BT THOMAS Y. CROWELL COMPANY 
 
 Printed in U. S. A.
 
 TO 
 
 A STURDY LITTLE ROCK 
 BEARING FINE ORE 
 
 2129787
 
 PREFACE 
 
 WE all have that human characteristic of 
 loving to delve into secrets, especially 
 such rare, soul-stirring secrets as are 
 hidden in the great treasure-chest of the world 
 beneath our feet. At first those treasures were 
 shrouded in ignorance or superstition, but as the 
 years have gone by and merged into centuries, 
 pick and shovel, dynamite and ingenuity, have 
 tapped into these valuable and wonderful stores, 
 and the world has prospered as a result. But in 
 all these ages, geologists and miners have merely 
 dug out small pockets of the vast mineral wealth 
 which apparently exists for future generations 
 to garner, study, and utilize. Geology as a 
 science is still comparatively young, still in 
 knickerbockers, but rapidly becoming a lusty 
 youngster whose power the coming races will 
 enthrone. 
 
 In preparing this volume, it has been the 
 author's purpose to present, not a technical 
 treatise on geology, but rather certain phases 
 of the subject and its related industries, which 
 are of most interest to young readers. Every 
 care has been taken to give only reliable informa- 
 tion; and in order to add spice some actual inci- 
 dents and anecdotes have been judiciously used.
 
 It is hoped that this small contribution to 
 popular geology will awaken for its readers a 
 new and abiding respect for the wonders be- 
 neath us; and that it will result in a further 
 reading on the subject, indeed if not some per- 
 sonal investigations and the thrilling touch of 
 hand against rock itself. While addressed to 
 young readers, there is also the hope that older 
 people, even those who are already deep in the 
 study of this captivating science, may find the 
 contents helpful as supplementary reading. 
 
 C. C. F.
 
 CONTENTS 
 
 CHAPTER PAGE 
 
 I THE STORY OF COAL 1 
 
 II SOME BY-PRODUCTS OF COAL ... 19 
 
 III OIL, THE NEW INDUSTRIAL GIANT . . 27 
 
 IV IRON ORE, THE WORLD'S RICHEST MINERAL 48 
 V WHERE COPPER Is KING .... 69 
 
 VI THE WONDERS OF GOLD 85 
 
 VII THE STORY OF SILVER 106 
 
 VIII DIAMOND, THE KING OF GEMS . . . 118 
 
 IX LEAD, FATHER OF BULLETS .... 140 
 
 X GRAPHITE, BACKBONE OF PENCILS . . 150 
 
 XI LIMESTONE, EVERY MAN'S FRIEND . . 164 
 
 XII LITTLE GRAINS OF SAND 173 
 
 XIII LITTLE LUMPS OF CLAY .... 188 
 
 XIV "THE SALT OF THE EARTH" . . . .199 
 XV SOME RARE MINERALS . 217
 
 Secrets of the Earth 
 
 THE STORY OF COAL 
 
 COAL has come to be one of our commonest 
 and most useful products. Yet, a com- 
 paratively few years ago it lay neglected 
 in the earth. What, then, is it and how is it 
 obtained ? 
 
 Geology tells us that during the Carbonif- 
 erous Period plants of all kinds grew rank and 
 luxuriant, covering practically the whole world, 
 because of the same sort of moist, warm air on 
 which to thrive. Ferns grew, not knee-high as 
 now, but into great soft-bodied trees which 
 would fill a good-sized room. The graceful, 
 feathery staghorn moss then straggled all over 
 the swampy world, with stems as thick as your 
 body, and sent up big branches as high as fifty 
 feet. Then there were the horsetails, which 
 grew into great forests, and which were festooned 
 so thickly with creeping plants that you could 
 
 1
 
 2 SECRETS OF THE EARTH 
 
 not have forced your way through, even with an 
 axe, in years. 
 
 In fact, all vegetable life was big and fat 
 and juicy and lazy and stupid in those days. 
 The plants were of a very low form of life, lack- 
 ing "backbone" to make them lasting. Hardly 
 any of them had flowers. Some were so ugly 
 and shapeless that you could not have told leaf 
 from stem, or stem from branch. Parts just 
 ran together, like a mass of spilled jelly. No 
 matter where you stood, whether in what is now 
 Iceland, or what is now Africa, you would have 
 thought yourself in a vast hothouse. The air 
 was almost suffocating, and filled always with 
 the odor of great beds of decaying vegetable 
 matter. You could not see more than a few hun- 
 dred rods because of the mist of steam always 
 hanging over everything. 
 
 From time to time the folding of the earth's 
 crust created hollow places in its surface hol- 
 low places filled with layers of these decaying 
 giant plants. And water rushed in and filled 
 these depressions, carrying much sand and clay 
 upon the dead and dying vegetable matter. This 
 dampness and immense weight hastened greatly 
 the natural decay of the woody plants. 
 
 When wood decays, a substance in it called 
 carbon mixes with the oxygen of the air, a pro- 
 cess very similar to burning dry wood by touch-
 
 THE STORY OF COAL 3 
 
 ing a match to it. In either case, the carbon is 
 freed from the plant, and what remains of the 
 former woody fiber ashes composed of salts of 
 potash and silica and lime unite with other 
 earthen chemicals to form new bodies. 
 
 In the case of coal formation, the water and 
 earth covering over the decaying plants kept in 
 much of the carbon, just as covering over a 
 piece of dry wood when we burn it does the 
 same, leaving the remains black and large (like 
 charcoal) and not reducing it far enough to 
 bring it to white, loose ashes. 
 
 This is the way coal was made. Some of the 
 layers, or strata, are fifty or sixty feet thick, 
 while others are no thicker than cardboard. On 
 top of each layer is a stratum of sandstone or 
 dark-gray shale, which was made by the sand 
 and mud washed in by the water when the plants 
 were on top of the earth. These shaly rocks 
 split easily, and in them man has found many 
 interesting fossil impressions of the ferns which 
 later turned into coal. How strange that a little 
 thing this way, in changing into something else, 
 should leave behind its everlasting former por- 
 trait the picture to tell what it looked like, 
 where it came from, and what it eventually 
 changed into! May we be careful of our own 
 growth and every-day actions so that the im- 
 pression we leave behind us on our fellow beings
 
 4 SECRETS OF THE EARTH 
 
 will speak as loudly as the fern of having lived 
 to make the world better and more comfortable ! 
 
 After the coal seams were formed in the 
 earth, what should occur from time to time but 
 heavy wrinklings of the earth's crust. These 
 contortions brought some of the coal seams to 
 the top of the ground. The savages were the 
 first to discover that the strange, black lumps of 
 rock would burn and give forth a delightful heat ; 
 but the white man was the first really to make 
 much use of coal. When a vein of coal cropped 
 out on a white man's farm, he broke some of it 
 up with a maul, shoveled it into his wheelbarrow, 
 and trundled it home. After a while hundreds 
 of people wanted coal, then thousands, and now 
 millions depend upon it almost entirely for their 
 fuel and comfort in cold weather. 
 
 The truth of the matter is, coal to-day is easily 
 the "big chief" of all the underground tribe of 
 minerals. Coal's importance to the whole world 
 far eclipses any other product of this great rocky 
 crust on which we live. In peace, in industry, 
 in war, the nation which has the greatest abun- 
 dance of coal is the strongest and best off. We 
 had a strong lesson of this during the late World 
 War, when Germany's forcible possession of the 
 great coal-fields in northern France came very 
 near to bringing triumph to the kaiser's invaders. 
 We know it right here in America at the present
 
 THE STORY OF COAL 5 
 
 time when, because of miners' strikes and a short- 
 age of cars, many homes are cold and cheerless, 
 and great industries are shut down, causing much 
 want and suffering. 
 
 Yes, 75 per cent of the total weight of minerals 
 taken out of the earth is coal. Geologists tell 
 us that at the present rate of consumption, the 
 supply of the world's coal, which is easily obtain- 
 able, will be gone in 200 years. This might make 
 us shudder, but for the cheering thought that 
 none of us will be alive then, and that the fertile 
 brains of those to succeed us will undoubtedly 
 scheme out some new form of fuel equally as 
 good or better. 
 
 This mineral, used as a fuel, was first men- 
 tioned by Theophrastus about 300 B. C., so we 
 may guess that coal was dug up previous even 
 to that early date. Excavations in England 
 brought forth flint axes and mauls embedded in 
 layers of coal, which would indicate that work- 
 men of the Stone Age might have known of 
 its heating properties and used them. And the 
 fact that coal clinkers or cinders have been found 
 in old Roman walls, together with Roman tools 
 for breaking up rock, goes to prove that coal 
 was used for warmth prior to the Saxon inva- 
 sion. 
 
 The first charter granting permission to dig 
 and gather coal was issued to the freemen of
 
 6 SECRETS OF THE EARTH 
 
 Newcastle, England, in 1239, who were to take 
 out coal in those fields. The real history of coal 
 as an important mineral product may be said 
 to have begun at this time. In America, the 
 first discovery of coal was made at Ottawa, Illi- 
 nois, but the first mine was not opened until 
 1751, at Richmond, Virginia. In 1792, coal was 
 found by Nicho Allen, near Wilkes-Barre, 
 Pennsylvania. 
 
 In regard to the latter discovery, it is said that 
 Allen encamped one night, and built his fire 
 upon some small black stones that lay scattered 
 about in profusion. Having cooked his supper, 
 he went to sleep. He was awakened in the 
 middle of the night by intense heat, and found 
 himself lying in a circle of flames. His fire had 
 ignited the "stones" under the brands, and these 
 had fired those immediately around until he had 
 been encompassed. It was with difficulty that 
 he escaped. He told his story far and wide, and 
 afterwards a company was organized to mine 
 and ship the "black stones" to Philadelphia. 
 
 Colonel Shoemaker, a worthy colonial gentle- 
 man, was at the head of the enterprise. Upon 
 his recommendation most of the first consign- 
 ment of 100 tons was sold to the city for use 
 in the pumping works. The Philadelphia engi- 
 neers did not understand how to burn it, and 
 after several unsatisfactory attempts, broke it
 
 THE STORY OF COAL 7 
 
 up and threw it about the yards for gravel. A 
 feeling of indignation against Colonel Shoe- 
 maker arose, and he was denounced as a rascal 
 for having sold the city rocks instead of fuel ! 
 
 In 1814, two ark loads of large lumps of coal 
 (twenty-one lumps to a ton) were sold at the 
 falls of Schuylkill. A whole morning was wasted 
 in futile attempts to burn this, and at noon, the 
 employer and his workmen, discouraged at their 
 ill luck, shut up the furnace and went to dinner. 
 On their return they were astonished to find a 
 roaring fire, the furnace doors red-hot and the 
 furnace itself in danger of melting down. From 
 that day dates the successful use of anthracite 
 (hard) coal in America. 
 
 Now there are many hard and soft coal (bitu- 
 minous) mines in operation over the face of the 
 globe. In some places the coal layers are hori- 
 zontal, and crop out wherever they pass through 
 a hill. In other places they cannot be seen, but 
 are very close to the surface, and very little dig- 
 ging is necessary to uncover them. As a rule, 
 however, the coal seams run diagonally through 
 the earth's crust, outcropping at the surface and 
 slanting downward, and this requires deep shafts 
 and radiating tunnels for the working of them. 
 
 Suppose you are invited to visit one of these 
 deep-shaft mines? You will go up to the mine 
 bravely enough, but when you look down into the
 
 8 SECRETS OF THE EARTH 
 
 great black well of the shaft, which may be as 
 deep as a big city skyscraper, your heart begins 
 to jump in a way to make you feel weak. But 
 the cage, or elevator, soon comes up, and you 
 get in with a bunch of miners and go down, 
 down, down, down, into that Styx-like maw, past 
 one "level" or tunnel, then another, and another, 
 all marked by a ghostly looking oil or electric 
 light, until you come to a stop. 
 
 "Lower level; all out!" calls the grimy lift- 
 boy; and together with the few who are left in 
 the cage, you step forth into a dimly lighted 
 passage. The air is so damp and cold that you 
 gather your coat a little closer about you. You 
 notice a group of miners standing near, some of 
 whom are already crowding into the lift for its 
 return journey. Their day's work, their shift, 
 is over. The fresh-faced, clean- jacketed men 
 who came down with you are to take their places. 
 The new miners start off down the level, gayly 
 laughing and joking; the old miners are more 
 quiet, and look very tired. How dirty they are! 
 It is hard for you to tell whether they are whites 
 or Negroes. Their hands, faces, overalls, are all 
 black with coal dust. On the cap of each is 
 mounted a small lamp, surrounded by a screen, 
 which throws a faint gleam of light around him, 
 showing him where the black walls are, and 
 causing the hard ebony diamonds in the latter
 
 THE STORY OF COAL 9 
 
 to glisten and sparkle brightly. The screen about 
 the lamp protects the flame from direct contact 
 with the inflammable gases, which are frequently 
 found in mines, and goes far to avert the danger 
 of an explosion. Such explosions have often 
 thrown down enough rock to block up a passage 
 and imprison the men behind. 
 
 The dust-covered glasses of the few electric 
 lights about you shut out most of the light, but 
 you notice that the roof is low, and that all along 
 the sides the tunnel is supported by heavy posts 
 across the tops of which are strong timbers to 
 keep the roof from caving in. At your feet, the 
 earth is muddy and damp. In this ooze two shin- 
 ing lines of silver, on top of ties, show where 
 tracks are laid. These run off in the distance 
 till they look no larger than fine threads and 
 are swallowed up in the noisome gloom. 
 
 From out of this pit of blackness there comes 
 a distant hollow rumbling sound, as if Pluto 
 and all his black imps are back in there in some 
 underground chamber, having a merry bowling 
 match with the roundest rocks they can find. 
 Closer and closer these sounds roll. Finally you 
 see a blaze of red light shatter the distant black- 
 ness, the rolling noises grow into a roaring medley 
 made by a rattling of chains, a clattering of 
 couplings, and the rough shouts of men, and 
 a queer-looking little locomotive pants up to the
 
 10 SECRETS OF THE EARTH 
 
 shaft with a line of dirty, box-like open cars, 
 which are loaded with shining lumps of coal. 
 
 In a few minutes the cars have been emptied, 
 and you are invited to jump on one of them and 
 go back into the diggings. By this time your 
 timidity has vanished; you rather enjoy the situ- 
 ation. So you respond with alacrity, and spring 
 on the last car just as it rumbles past you. You 
 would like to talk with the miner hanging on 
 close to you, but the clatter and rattle is too 
 great for words. 
 
 The little locomotive pulling this train is not 
 operated by steam like those in the outside world. 
 Steam would mean a fire-box, and a fire-box 
 would mean the possible escape of a tiny spark 
 which in one instant might ignite the mine gases 
 with terrible results. So a safer power is utilized 
 in this case, a pneumatic engine does the pull- 
 ing. The air supply which revolves the sturdy 
 little driving wheels is gained from large tanks 
 carried just above them, where a pressure of 600 
 pounds per square inch is confined in each. When 
 the air becomes exhausted from these tanks, all 
 the engineer has to do is to stop at any one of 
 the numerous refilling stations along his course, 
 and recharge them. This is done by using a 
 nozzle connected to a high-pressure tube coming 
 from a main supply pipe. 
 
 Formerly the only safe way of getting the
 
 coal out of the interior of mines to the shaft was 
 by single little cars pulled by a mule. Boys 
 operated these cars, which traveled very slowly, 
 as might be expected. In Europe, mules are 
 still used to a great extent. Many of these 
 animals have never seen daylight, and con- 
 sequently are practically blind. They are born 
 in the mines where they work, are stabled there, 
 and never know what sunlight looks like. 
 
 All along the tunnel down which your little 
 train is whizzing, you pass openings of various 
 shapes and extents. Into some of them sort 
 of cross-streets leading back into distant dig- 
 gings tracks lead off from your line. But most 
 of the openings are merely big chambers like the 
 interior of a low barn, and have been formed by 
 the miners scooping out the coal they once con- 
 tained. Above these pockets is a vast amount 
 of earth and rock, sometimes hundreds of feet 
 in thickness. There is always danger that the 
 roofs will cave in, so where the rooms are large, 
 the men leave supporting pillars of coal. 
 
 Presently the little train you are on comes to 
 a stop before one of these chambers. With the 
 clatter of wheels gone, you are now able to ask 
 questions of the engineer, and you are greatly 
 surprised to find that you are more than a quarter 
 of a mile under the "sod," and have traveled 
 fully three miles since you left the shaft. In-
 
 12 SECRETS OF THE EARTH 
 
 voluntarily you glance hastily upward, as if to 
 assure yourself that hills and houses and trees 
 are not really tumbling down upon you, and then 
 your look goes downward and you begin to 
 wonder if there is surely enough earth under 
 your feet to keep from cracking and letting you 
 through into the boiling liquids of the world's 
 middle. 
 
 But your attention is soon back to realities. 
 The engineer is talking to you. He is telling you 
 how miners used to get out coal in this mine, and 
 how they do it now. Shorn of his quaint phrases 
 and ungrammatical speech, the facts of his state- 
 ments are about as follows : 
 
 Not many years ago the miner used to do all 
 the digging with his muscles; now machines do 
 most of it for him. In those days he often had 
 to work in places so small that he would have 
 to lie on his side, often in water, and peck away 
 with his pickaxe all day long, week in and week 
 out. So hard was the floor on which he lay that 
 big callouses formed on his hips, elbows and other 
 exposed parts, callouses as hard as the toughest 
 rawhide. But for them he never could have 
 stood the brutal cuts and chafings of his rough 
 bed. 
 
 As soon as he could hew out a proper opening 
 for the purpose, this miner of the past would 
 drill a hole into the seam by hand, push in a car-
 
 THE STORY OF COAL 13 
 
 tridge of powder, thrust in a slender fuse, light 
 it, and run for dear life. Sometimes he was 
 caught by the fall of coal and slate; if not, he 
 would return and have his helper shovel the ton 
 or two of coal that he had dislodged into the 
 empty mule-car near by. 
 
 Nowadays in this and most other large mines, 
 where cutting must be done, it is all accomplished 
 by means of a small machine. The miner puts 
 this mechanical cutter on the floor against the 
 wall of coal, and turns on the air or electricity, 
 according to which power operates it. A buzzing 
 is the answer, as the sharp steel chisel cuts rapidly 
 into the coal, fairly eating it up. Soon there is 
 a deep gully cut all along the side of the chamber. 
 
 The machine cutter now goes to another room 
 that needs his attention, while new men come in 
 and bore deep holes into the coal rock along the 
 gully made by their predecessor. The drills 
 are pneumatic, very powerful, and work ten 
 times as fast as the old hand tools. Late in the 
 day, other miners come in, insert sticks of dyna- 
 mite in these holes, and then connect the det- 
 onator of each stick with electric wires which lead 
 to a switch out in the tunnel, out of direct line 
 with the mouth of the chamber. A simple closing 
 of the switch then discharges each load, as fast 
 as desired. 
 
 The jar which accompanies these explosions is
 
 14 SECRETS OF THE EARTH 
 
 something terrific. It comes not only from the 
 shock of heavy charges of the terrible explosive 
 itself, but from the concussion of great blocks 
 of coal thrown in all directions through the air. 
 Woe to the human being who might chance to 
 be in that chamber, or in front of its open portal! 
 Down below the whole ground trembles percep- 
 tibly in the neighborhood; and up above, under 
 the blue vault of the heavens, passers-by would 
 feel the shake. 
 
 Before you leave your mine you learn that 
 mining coal is mighty dangerous work; that 
 hardly a day passes in which some poor chap is 
 not carried out with a broken leg or broken back 
 as a result of a sudden fall of slate upon him. 
 Any blow of a pickaxe, or twist of a drill, may 
 break into an underground vein of water which 
 will burst out and flood the mine. The wooden 
 props which support the roof may break at any 
 moment and let tons of rock down upon any one 
 unfortunate enough to be underneath. 
 
 Then there are the dreaded poisonous gases. 
 The coal, as has been said before, was made while 
 under water. Therefore the gas which was 
 formed in the decaying leaves and wood could 
 not escape. It is always leaking out from coal, 
 and no miner knows what instant his tools may 
 break into a natural pocket that is highly charged 
 with the vile stuff.
 
 THE STORY OF COAL 15 
 
 One kind of gas is called "choke-damp," be- 
 cause it chokes or suffocates any one who 
 breathes it. There is also "white-damp," the gas 
 which you see burning with a pretty blue flame 
 over a hot coal fire. But worst of all is "fire- 
 damp." If you stir up the water in a swamp, 
 you will see bubbles of this gas arise to the sur- 
 face. While harmless in a swamp, it is quite the 
 opposite in a mine. For when it unites with a 
 certain amount of mine air it becomes explosive 
 as soon as the slightest fire meets it. Even coal 
 dust sometimes explodes when the air is full of 
 it and a heavy blast of powder sets it into violent 
 commotion. 
 
 The only way to make a mine at all safe from 
 dangerous gases is to keep it full of fresh, pure 
 air. There is no wind to blow through the cham- 
 bers and passages, so air has to be forced in. 
 One way is to keep a large fire at the bottom of 
 the air shaft. This causes hot air to rise from the 
 fire, creating a vacuum or sucking force in the 
 lower part of the shaft. The vacuum is so strong 
 that fresh air from outside is pulled in, and this 
 is gradually distributed through the workings of 
 the mine. But the best system yet found is that 
 used in most large public buildings a great fan 
 at the shaft entrances, which draws in fresh air 
 constantly and also forces it along the various 
 tunnels.
 
 When the coal reaches the surface, either by 
 tunnel or by shaft, you will find it passing rap- 
 idly through a series of operations which render 
 it fit for the market. These processes are carried 
 on in a great structure called a "breaker." The 
 breaker is usually erected close to the main shaft 
 of the mine, and railway tracks run right into it, 
 so that the cars can be loaded as fast as possible. 
 
 This building is a place of dust and noise, of 
 rambling sheds, inclined tramways and chutes; 
 a monstrous, grimy structure not at all pleasing 
 to look at, but very interesting to study within. 
 
 The loaded mine cars reach the breaker at a 
 point high in the air. As fast as they arrive they 
 are tilted so that they dump their cargo into the 
 chutes provided for it. As the coal goes rattling 
 down the incline it is carried beneath massive 
 steel rollers which smash up the large lumps 
 into much smaller ones. Then it goes on to a 
 succession of screens with meshes of various 
 sizes. By this process it is sifted and sorted with 
 mechanical precision, until it finally reaches the 
 bottom, where each grade falls into the bin in- 
 tended for it. As fast as the big steam railway 
 cars run under these bins, the bottoms of the 
 latter are swung open, and the coal pours into 
 them and is carried far and wide over the country 
 to keep us warm, to cook our food, to keep our 
 factories and great industries humming.
 
 THE STORY OF COAL 17 
 
 But it is not enough merely to sort the coal 
 into sizes. It must also be cleaned as well, for few 
 mines are free from slate and other impurities, 
 which, if left untouched, would reduce the quality 
 and value of the coal. The best cleaning is done 
 by mixing the coal with running water. As the 
 slate is heavier than the coal, it sinks; thus the 
 coal is easily separated from it. 
 
 As the coal passes through the breaker and 
 over the screens it is watched by keen-eyed, deft- 
 fingered boys, who pick out and throw aside 
 whatever large pieces of stone or slate they dis- 
 cover. These lads are called "breaker boys." 
 They are taking the first steps in the life of a 
 miner, and in every mining town there are num- 
 bers of such little fellows busily engaged, and 
 helping to earn the living for the household. 
 
 The fathers of these boys are usually for- 
 eigners, and miners themselves. As they are 
 poor, and begin work at an early age, they have 
 little opportunity to obtain a good education. 
 But our Government does all it can to improve 
 their working and living conditions. To this end 
 the Bureau of Mines is constantly sending out 
 helpful reading matter to the miners, and some- 
 times lecturers, telling them how to prevent ac- 
 cidents in the mines, how to take better care of 
 their health, and how night-schools will give them 
 better educations if they will only attend them.
 
 18 SECRETS OF THE EARTH 
 
 Their wives, too, receive from the Bureau bul- 
 letins which acquaint them with the importance 
 of keeping their homes clean and sanitary, their 
 children healthy, and their cooking wholesome.
 
 II 
 
 SOME BY-PRODUCTS OF COAL 
 
 THE value of coal can by no means be 
 measured by its heating capacity. Impor- 
 tant as it is to the world as a fuel, it is un- 
 doubtedly just as useful to us for the many by- 
 products which chemists have pried from its 
 black interior. 
 
 Three of the most valuable of these by-prod- 
 ucts are coke, gas, and coal-tar. From the latter 
 alone a countless host of useful compounds have 
 been worked out, and hardly a week goes by that 
 does not witness new additions to the fold. Some 
 are important therapeutic agents ; others are del- 
 icate flavors for foods, or fragrant perfumes; a 
 small number are helpful to the photographer, 
 who takes your picture ; a few belong to the class 
 of powerful explosives in which dynamite is in- 
 cluded; many are good substitutes for widely 
 used natural products, such as rubber, camphor, 
 and the like ; finally, there is a vast array of color- 
 ing compounds which meet all possible needs in 
 the dyeing or staining of textiles, leather, wood, 
 straw, feathers, hair, etc. 
 As we think of this we do not have to day- 
 
 19
 
 dream very much in order to bring vividly before 
 our mind the days far, far back, when this old 
 world was much younger, and strange objects 
 grew upon it and ran over its changing face. We 
 see before us the great-great-grandfather of this 
 wonderful thing, Coal: the luxuriant tropical 
 vegetation of the Carboniferous Period ; the slow 
 transformation of that rank growth, buried be- 
 neath water, sand, and mud; the elapse of cen- 
 turies, and the presence of peat, the change into 
 lignite, and finally the new garb of coal. The 
 scene switches swiftly. We seen now the dark 
 bowels of the earth, hear the thud of the miner's 
 pick, the dull report of a blasting charge, the 
 return to sunlight, the entrance into the glowing 
 coke oven; the quick tragedy of disintegration, 
 as gas and tar and ammonia pour forth and leave 
 behind an incandescent mass of coke ; the separa- 
 tion of oxygen, hydrogen, and nitrogen ; the start 
 of the humble, homely coal-tar on its career of 
 kaleidoscopic brilliancy I 
 
 Most people think of coal-tar as a material for 
 roofing, for lining Bessemer converters in making 
 steel, for producing electric arc-lamp carbons, 
 for preserving timber, for keeping boat joints 
 from leaking, and, in recent years, for laying 
 the dust on modern highways. But, as we have 
 shown, it is far more useful than in just those 
 ways. To be more explicit, we may say that
 
 BY-PRODUCTS OF COAL 21 
 
 this material has furnished by separation no less 
 than 190 substances of a definite composition. 
 
 The ingredients are secured from the coal-tar 
 by what is known as "fractional distillation." The 
 tar-distiller starts with as much as forty tons of 
 tar at a time, which he puts into a huge cylindrical 
 steel retort. As the heat below gets in its work, 
 the vapors pass through a long coil of iron tub- 
 ing, or condenser, which ends in a suitable re- 
 ceptacle for imprisoning them. The distillation 
 is interrupted at certain points, and the con- 
 densed fractions are removed. There are five 
 primary ones, as follows: 
 
 Tar water (containing ammonia). Light oil. 
 Carbolic oil. Creosote oil. Anthracene oil. Re- 
 sidual pitch. 
 
 These compounds form the bottom of the coal- 
 tar chemical industry of to-day. 
 
 The average amounts of the products derived 
 from the distillation of 1,000 pounds of bitu- 
 minous coal are as follows : 
 
 Pounds 
 
 Coke 700 
 
 Tar 50 
 
 Gas-water, 9 to 11 gallons. 
 
 Gas, 300 cubic meters 170.4 
 
 Benzene in the gas 9.38 
 
 Benzene in the tar 5 
 
 Total benzene 9.88 
 
 Toluene in the gas 3.12
 
 22 SECRETS OF THE EARTH 
 
 Toluene in the tar 4 
 
 Total toluene 3-52 
 
 Total benzene and toluene 13.4 
 
 Napthalene 3.0 
 
 Anthracene 2 
 
 Phenol 7 
 
 Coke plants are usually so equipped that when 
 the gas which issues from the ovens in such 
 abundance is passed through the "scrubbers" 
 most of the hydrocarbons, benzene and toluene, 
 present as vapor, are recovered in the liquid 
 form. But in the manufacture of illuminating 
 gas, they are allowed to remain in the form of 
 vapor, in order to increase the luminous power. 
 
 A given quantity of coal will generally pro- 
 duce a little less than 72 per cent of coke, about 
 22 per cent of gas, 6 per cent of coal-tar, and 
 0.36 per cent of tar useful for dyes. 
 
 A very large part of the Pennsylvania coal 
 product is converted into coke for use in the steel 
 mills and manufactories where it is needed. The 
 coke furnaces thus become a feature of the coal 
 industry, and they have grown to immense pro- 
 portions because of the demand of the steel trade, 
 although of late years there has been an increas- 
 ing demand from households for it. It is gen- 
 erally used by citizens for starting coal fires, but 
 some make a compound fuel of it by mixing it 
 with anthracite in home furnaces.
 
 BY-PRODUCTS OF COAL 23 
 
 So complete are the appliances used in the 
 manufacture of coke that virtually all the work 
 can be carried on by machinery. First the coal 
 is put into great furnaces, direct from the car in 
 which it is received from the mine. Here it is 
 subjected to just enough heat to char it deeply. 
 During this roasting process gas escapes from it, 
 and is caught in a hood and conveyed subse- 
 quently to huge gas tanks from which it is dis- 
 tributed through underground pipes to con- 
 sumers, who may use it for either lighting or 
 cooking. 
 
 As soon as the coke is properly charred it is 
 drawn from the furnaces by a long mechanical 
 arm, operated by an engine on a car, which rakes 
 the light, porous pieces into a trough. The latter 
 has running through it an endless belt which 
 carries moving buckets or scoops. The buckets 
 convey the coke into waiting railroad cars, ready 
 for shipment. 
 
 Acetylene gas is another product owing itself 
 partly to coal. This gas is generated when cal- 
 cium carbide is put into water. Calcium carbide 
 is a hard, porous, grayish material, produced by 
 fusing pulverized coke and air-slaked lime in an 
 electric furnace. One ton of carbide makes 11,- 
 000 cubic feet of acetylene gas. This is as power- 
 ful in illumination as twenty-five times that 
 amount in ordinary coal gas.
 
 24 SECRETS OF THE EARTH 
 
 Acetylene gas is a comparatively modern il- 
 luminant and heating agent, having come into 
 use only within the last decade. It gives a white, 
 brilliant light, fully as strong as electricity, and 
 is much more economical to maintain. But it 
 has the drawback of requiring more attention, 
 and it is also more dangerous to have around, for 
 the gas sometimes explodes with great force if 
 the lamp is not properly adjusted. On account 
 of these defects, it is not as popular as formerly 
 with vehicle owners and householders, who gen- 
 erally prefer electricity. Where electricity can- 
 not be had, however, acetylene gas is still widely 
 used for illuminating purposes. 
 
 Another of the important uses of this gas is in 
 the way of heating. Its remarkable properties 
 in this respect are in every-day use in the indus- 
 tries all over the manufacturing world. Great 
 bars of steel that formerly resisted being severed 
 by the hacksaw, are now literally melted in two 
 with acetylene gas almost as neatly as you could 
 halve a potato with a'butcher knife, and in a very 
 short time. Railways cut their rails with it when 
 making repairs and installations. Structural iron 
 workers use it in cutting great steel girders 
 when building modern skyscrapers and bridges. 
 Broken metal castings are mended, cracks being 
 melted together so nicely that you cannot find 
 them afterwards.
 
 BY-PRODUCTS OF COAL 25 
 
 Did you ever stop to think where the pretty 
 dyes came from the brilliant reds, greens, yel- 
 lows, blues, browns, etc. with which your neck- 
 ties, shirts, caps, and hats are colored? Or where 
 the Easter-egg dyes come from, with which you 
 decorate Mrs. Hen's belongings early each 
 spring? Or where those colors originated in Sister 
 Sue's gay little parasol? Or from what source 
 came that rich mahogany shade on mother's birch- 
 wood sewing stand that you gave her last Christ- 
 mas? From coal-tar taken from coal. To be 
 more explicit, from the compounds of phenol, 
 anthracene, and toluene, which have been 
 extracted from coal-tar. 
 
 It was not so many years ago that cochineal 
 and madder furnished the reds, logwood the 
 black, and indigo the blues, for almost all fabrics, 
 which had these colors or their combinations in 
 them. But that was before chemists had begun 
 to dream that the coal they burned in their grates 
 possessed better color values. First, an experi- 
 menter discovered how to make coal-gas, and as 
 soon as the process began to be generally used it 
 was noticed that a brownish, pungent-odored 
 syrup flowed away as a troublesome by-product. 
 After a time this was named coal-tar by the 
 scientists, who began to pick it to pieces. Mar- 
 velous substances were extracted, one after 
 another, in quick succession, until, as we have
 
 26 SECRETS OF THE EARTH 
 
 already said, the number reached into the hun- 
 dreds, many of which can be converted into 
 beautiful dyes. 
 
 Before the World War, Germany made most 
 of the dyes of the world, the other countries hav- 
 ing given little study to the business and there- 
 fore knowing little about it, as all their colors 
 were obtained from Germany. But when hos- 
 tilities opened up a breach, there was nothing for 
 the others to do but try their hand at the job if 
 they were to continue having good coloring 
 agents at reasonable cost. 
 
 At first their attempts were clumsy and marked 
 with poor success. Black stockings bought in the 
 stores were gray stockings after the first wash- 
 ing. Shirts with pretty pink and green stripes 
 faded into a nondescript tint in the washtub. In 
 other words, the colors were not well "set" ; they 
 lacked permanency. 
 
 But the new American dye manufacturers, 
 with their customary versatility and ingenious- 
 ness, soon solved the problem, and dyes just as 
 good or better than the former European prod- 
 uct soon began to appear. At the present time 
 America, within the space of four years, has 
 become the leading dye-producing country out- 
 side of Germany, and that nation has undoubt- 
 edly forever lost its exclusive prestige in this line 
 of endeavor.
 
 Ill 
 
 OIL, THE NEW INDUSTRIAL GIANT 
 
 THREE famous statesmen have recently 
 paid their tribute to the importance of oil. 
 Said Admiral Fisher, chief of the British 
 Navy: "The oil-engine will revolutionize com- 
 merce, and alter the whole art of war at sea." 
 
 Earl Curzon, British Foreign Secretary, 
 stated: "In the recent World War the Allies 
 floated to victory on a sea of oil." 
 
 Franklin K. Lane, formerly Secretary of the 
 Interior, said in a report to President Wilson: 
 "It draws railroad trains and drives street cars. 
 It pumps water, lifts heavy loads, has taken the 
 place of millions of horses, and within twenty 
 years has become a farming, industrial, business, 
 and social necessity. The naval and merchant 
 ships of this country and all Europe are being 
 fitted out to use it. The airplane could never 
 have amounted to anything without it. There 
 has been no such magician as this drop of mineral 
 oil since the day of Aladdin." 
 
 Indeed oil has become, from a mere lubricating 
 and lamp-burning commodity twenty years ago, 
 the biggest and most important industrial giant 
 
 27
 
 28 SECRETS OF THE EARTH 
 
 of the age. It has risen like a meteor in the sky, 
 with a sudden, swift, dazzling jump until today 
 it has the record for producing the bulk of our 
 mechanical energy, and of having made more 
 poor men rich in a short time than all the gold 
 and diamond mines that ever existed. All of the 
 big nations of the earth are doing their level best 
 to get control of as many oil lands as possible, 
 realizing that the nation possessing the greatest 
 amount of crude oil will be the future giant in 
 both industrial and fighting strength. In other 
 words, oil is to modern nations what water is to 
 the sailor, what muscle is to the wrestler. It is 
 just about as near to being indispensable as any- 
 thing you can find. 
 
 The World War, which called for new 
 strength in such an emphatic manner, showed us 
 the necessity of oil as nothing else could. Oil 
 drove our submarines, our submarine-chasers, 
 many of our great battleships. Oil also carried 
 our brave dispatch-bearers on their motorcycles, 
 made the long lines of trucks transport our field 
 supplies and troops at break-neck speed across 
 the country to the front-line trenches, whirred 
 the propellers of the fighting airplanes, to say 
 nothing of its use in greasing countless great and 
 small field-guns, and keeping the bearings of 
 railway cars and automobiles in good working 
 order. And those left behind to back up the
 
 OIL, INDUSTRIAL GIANT 29 
 
 fighters used oil just as lavishly and helpfully. 
 For them it helped to operate a myriad of ma- 
 chines in hundreds and hundreds of factories, 
 furnished power for transporting the manufac- 
 tured products from factory to pier, and from 
 pier across the seas. The Red Cross depended 
 upon it for many of their important surgical sup- 
 plies, likewise hospitals sought its healing influ- 
 ences in various by-products. 
 
 This great jump of oil in popularity is due 
 principally to the wide use of gasoline, at this 
 time its chief by-product. 
 
 Figures are tiresome things at best, but it will 
 be interesting to know that since the year of 1878 
 the consumption of petroleum (crude oil) has 
 increased nearly thirty-fold. During the month 
 of June, 1920, the daily average production was 
 1,240,633 barrels, the highest ever attained, and 
 even then there were more calls for oil than could 
 be filled. So great was the demand during the 
 late war that automobiles used for pleasure had 
 to be put under gasoline restrictions in order to 
 provide gasoline for business and war purposes. 
 
 In recent years oil has not only made riches 
 for the capitalist, but also for many with little 
 or no money. There are many cases where needy 
 adventurers, even men with criminal records, 
 became suddenly rich by rushing into the newly 
 opened Texas fields. Land owners all the way
 
 30 SECRETS OF THE EARTH 
 
 from cattle kings down to worthless, shiftless 
 proprietors of a small patch of unfertile dirt, and 
 ignorant half-breed Indians, made millions in 
 almost a night. One man at Ranger, in less than 
 a year, changed from the poorest of the poor to 
 the owner of seven million dollars. Business 
 men and professional oil operators also arose in 
 a few years to dizzy riches. This sounds like the 
 fairy stories of old in its improbabilities, but it 
 only goes to accent the old saying that "truth is 
 stranger than fiction." 
 
 At the present time there are 225,000 oil wells 
 in the world. Many of these produce less than 
 one-quarter of a barrel per day, while the big 
 "gushers" average close to fifty barrels daily. 
 The great bulk of oil wells cost $50,000 to estab- 
 lish, while some run into twice that figure, owing 
 to the hardness of the soil and the depth to which 
 they must be bored in order to make a strike. 
 Then, too, the life of the average well is not long. 
 As a rule, their supply grows less and less as the 
 months roll by. A Texas well which began at 
 1,200 barrels a day less than two years ago, 
 has now fallen off to an insignificant (by com- 
 parison) fifteen barrels a day. 
 
 Two great petroleum corporations control most 
 of the world's oil supply. Of these, the Standard 
 Oil Company, of the United States, possesses 
 about two-thirds of the refined supply, while a
 
 OIL, INDUSTRIAL GIANT 31 
 
 good share of the remainder is produced by the 
 Rothschilds in Europe. Of course there are 
 many smaller concerns getting out petroleum on 
 an independent basis, but their output is small 
 when balanced against the enormous volume of 
 production of the two interests named. 
 
 Probably the greatest developed oil field in the 
 world is that at Baku, a Russian port on the west 
 shore of the Caspian Sea, just south of the Cau- 
 casus Mountains. The contrast between the stu- 
 pendous grandeur of the mountain scenery and 
 the industrial activities of Baku, lying in the val- 
 ley far below, is a most striking one. Hundreds 
 of spidery towers rise up into the air about the 
 town, forming a maze of lattice work very diffi- 
 cult to penetrate with the eyes at a distance. 
 These wells are constantly pouring a wealth of 
 crude oil into immense nearby reservoirs, while 
 tank trains are coming and going all the while. 
 The earth of the town is saturated with the oil, 
 so much so that nothing can be grown ; and white 
 shoes are never worn by the citizens. Even the 
 air itself is heavy with the odor of the dark- 
 brown petroleum, and almost everybody you 
 meet has a greasy, leathery look about him. But 
 they do not seem to mind that, for they are 
 largely oil workers themselves, and are doing 
 their share to produce Baku's annual output of 
 50,000,000 barrels.
 
 32 SECRETS OF THE EARTH 
 
 In the United States are many oil fields, quite 
 widely scattered. These wells producing the 
 highest grade petroleum are situated in Pennsyl- 
 vania, which is the oldest oil field in the world. 
 Pennsylvania crude oil has a high percentage of 
 paraffin in it, which makes it an almost ideal 
 fluid. From it the best oils for lamps are made, 
 also the finest qualities of lubricants for greasing 
 cars, wagons, machinery, automobiles, etc., and 
 the highest grades of gasoline. It is often mixed 
 in refineries with lower grade oils from other 
 fields, so as to bring up the quality of the latter 's 
 products. 
 
 Oil is contained in rocks of considerable 
 porosity, mainly sandstone and shale, which, 
 when containing oil or gas, are usually referred 
 to as "sand." 
 
 In this district the main producing "sand" 
 averages about thirty feet in thickness, and is 
 found from 1,100 to 1,800 feet below the surface. 
 The early colonists learned that there was pe- 
 troleum here, and also in the western part of 
 what is now the State of New York. While they 
 knew of its illuminating qualities, they preferred 
 to go on burning candles or sperm-whale oil, 
 rather than make the long trips back and forth 
 to the oil districts. 
 
 The Indians had discovered the strange fluid 
 long before this. At first they were very much
 
 OIL, INDUSTRIAL GIANT 38 
 
 afraid of it, but later found that by rubbing it 
 over their bodies they shone beautifully, and so 
 determined that it must be some form of "good 
 medicine." They then went to the springs where 
 they had found the oil floating, threw their 
 blankets into the water, and carried the heavy, 
 soggy things back to camp. Here they were 
 wrung out, and their oily contents traded to 
 others. 
 
 It is said that one day, after this practice had 
 been going on for some time, an Indian war party 
 built a fire near one of these oil springs. Here a 
 council was held, during which the majority of 
 the band declared for returning to their village, 
 fearing that the enemy tribe against which they 
 had been advancing was too strong for them. 
 But the old chief was very angry, called his fol- 
 lowers cowards, and finally became so violent at 
 the protests of his son-in-law, Sag-nee-wah, that 
 he picked up one of the blazing fire brands and 
 cast it toward him. Sag-nee-wah saved himself 
 a searing by dodging. The brand flew into the 
 pool near by, ignited the heavy scum of oil, and 
 at once there was a flash, and tongues of fire 
 leaped up all over the surface of the spring. 
 
 None of the savages understood this phenome- 
 non. So they immediately ran from the scene in 
 the greatest fright, going back to their people 
 with the story of the terrible wrath of the Great
 
 84 SECRETS OF THE EARTH 
 
 Spirit, as manifested in the "pool of good medi- 
 cine" where they had been only a few minutes 
 before anointing their bodies for warfare. 
 
 It was not until about ten years after the rush 
 for gold into the California diggings that the 
 first company was organized for securing crude 
 oil in Pennsylvania. These men did some pros- 
 pecting, selected a piece of land that looked 
 promising, paid the owner for it, and then went 
 to work with pick and shovel. Poor dolts, they 
 thought to dig this first oil well as they would 
 have dug for drinking water by making a large 
 hole down into the ground ! You can imagine the 
 result: they came to an underground stream long 
 before they could have reached the oil-bearing 
 strata, and their "well" was truly a well from that 
 moment on, but one of water instead of oil. 
 
 Realizing their folly, the men then drove down 
 several sections of iron pipe till the sand belt was 
 struck in which the oil was contained. Just back 
 of this was a pocket of natural gas, such as is 
 often found below the oil, and when the drill 
 tapped into this, the gas was strong enough to 
 force the oil up into the pipe and out at the top, 
 where it spurted several feet high a mild little 
 "gusher." 
 
 The news of this "strike" traveled fast, and 
 soon people in the East were scraping together 
 all their spare money and rushing into the Perm-
 
 OIL, INDUSTRIAL GIANT 85 
 
 sylvania fields looking for oil lands to buy. A 
 song of the day had this for its refrain 
 
 "Stocks par, stocks up, 
 
 Then on the wane; 
 Everybody's troubled with 
 Oil on the brain." 
 
 A few years later the first real gusher was 
 tapped. The workmen had drilled down close to 
 a thousand feet, and were working away 
 patiently when a furious stream of oil burst forth 
 out of the casing at the top of the ground. They 
 and their tools were drenched with oil in a 
 moment, and the men had to make a hurried 
 jump in order to save their lives. The oil spurted 
 in a thick, dark stream, many feet over the 
 nearby treetops, and came down like a shower of 
 molasses. Hundreds of barrels were lost before 
 means were found for capturing the valuable 
 fluid. That strike made these men all rich. 
 
 An oil field is not necessarily a small district; 
 very often it will extend over a large portion of 
 a whole State, sometimes several adjoining 
 States. When a prospector thinks there is oil in 
 a certain spot, he secures permission of the owner 
 to sink a test well there. If this turns out to suit 
 him he may buy the property, but usually he 
 secures the oil privileges by guaranteeing the 
 owner a royalty, that is, a certain amount of
 
 36 SECRETS OF THE EARTH 
 
 money for each barrel of oil he takes out. We 
 will say he offers a royalty of fifty cents, and 
 sells his product to the refineries for $4.00 a bar- 
 rel. You will readily see that if there is only one 
 well, the owner will soon be well off with his roy- 
 alty, for a hundred barrels a day would bring 
 him nearly twenty thousand dollars a year; and 
 the operator himself of course should make much 
 more. 
 
 When he decides to go ahead, the operator 
 builds his derrick. This is made of four heavy 
 uprights of wood which lean together toward the 
 top, in the form of a pyramid, and are braced by 
 cross-timbers. The tower is from forty to eighty 
 feet high, according to the depth of the well, and 
 stands directly over it. Close by an engine- 
 house is set up. From the engine flywheel a 
 heavy belt runs up to a pulley in the top of the 
 derrick. This pulley turns a shaft to which is 
 connected the drilling mechanism. 
 
 The work goes on day and night till success or 
 failure manifests itself. Imagine yourself an oil- 
 well owner during this time. Just think how 
 your pulse quickens as the sharp-toothed drill 
 bites deeper and deeper into the earth, and the 
 steel casing outside of it is driven down, rat-a- 
 tat-tat, rat-a-tat-tat, into the clay and sand. Will 
 the next stroke bring you that coveted dark fluid? 
 Oh, will it? Or will you have to go on drilling
 
 OIL, INDUSTRIAL GIANT 37 
 
 (how gloomy the thought!) for a long time yet, 
 only to find nothing but water and rock? Rat-a- 
 tat- tat, rat-a-tat-tat ! One moment you are wal- 
 lowing in the richest of dreams, seeing yourself a 
 second John D. Rockefeller; the next, you are as 
 blue as a heron, in the dumps, fearful of failure. 
 Rat-a-tat-tat, rat-a-tat-tat ! 
 
 As the drill keeps nipping away at the soil, the 
 pump sucks out the water and loose bits of rock. 
 This well may be a great gusher, pouring out 
 several thousands of barrels a day. Again, it may 
 evolve itself into a sluggish "pumper" only a 
 well lacking sufficient gas force to throw up the 
 oil, and calling for constant pumping from above 
 in order to make it a paying proposition. There 
 are many of the latter type of wells in various oil 
 fields. Sometimes these can be made to flow mod- 
 erately by exploding a heavy charge of dynamite 
 at the bottom. This breaks up the rock, making 
 a larger opening, and often gives an obstructed 
 gas pocket a vent for heaving the oil upward. 
 
 Since the Pennsylvania field is the oldest it is 
 but natural that many of the wells which at first 
 produced largely should have flowed out. For 
 a long time these dry wells were considered 
 worthless. They were plugged up, according to 
 State law, and left alone. But what surprised 
 the oil men was that very often when a certain 
 well went dry, an adjoining one began to give
 
 88 SECRETS OF THE EARTH 
 
 forth more oil than ever before. Greatly puz- 
 zled, but bent on finding the reason, geologists 
 made the most careful investigations. By put- 
 ting two and two together they came to the con- 
 clusion that the renewed influx of oil into these 
 wells was caused by water entering the oil sand 
 at the old hole, which had not been properly 
 plugged, and driving the oil by back-pressure 
 through the porous rock to the producing well. 
 
 This opened their eyes. Now nearly every 
 well that goes dry is heavily flooded, and new 
 wells are drilled in advance of the flood, one acre 
 apart. These new holes, in about three years, be- 
 gin to be influenced by the subterranean flood 
 water, and produce much more oil as a conse- 
 quence. But as the oil becomes exhausted, water 
 takes its place, and after a while there is more 
 water than oil, and the well is abandoned for 
 good. 
 
 Whence come the great volumes of oil issuing 
 from the many gushers of the California oil 
 fields? How long will they continue to flow, 
 making fortunes for those who have an interest 
 in them? Will the gushers cease spouting tomor- 
 row, or will they continue to furnish man with 
 nature's bountiful supply of petroleum for 
 months, maybe years? 
 
 Geologists, engineers, and oil operators all 
 are more or less befogged when it comes to
 
 OIL, INDUSTRIAL GIANT 39 
 
 furnishing answers to these questions. Some 
 operators, who have had wells gushing without 
 perceptible loss for several years, may claim that 
 their wells are practically inexhaustible, but they 
 are really not so sure as they pretend and have 
 an uneasy, guilty feeling when they say it, too. 
 Although they know that all the gushers of the 
 great California fields seem to be fed by the same 
 steady, gigantic subterranean force, like many 
 small water pipes leading from one large feeder 
 in which a terrific pressure is always present, 
 their experts tell them that the life of any oil 
 field is comparatively short. 
 
 The oil situation in the world really is some- 
 what critical. Our modern inventions and mode 
 of living are using up this wonderful fluid at a 
 tremendous rate. We are told that the world's 
 production of oil will soon be on the decline and 
 in twenty years the supply will be much less 
 than the present demand unless some great new 
 fields are discovered. 
 
 But meanwhile so much oil is flowing out of 
 these California wells that it is the biggest job 
 they ever undertook to find places to store it, 
 and cars in which to ship it. For the huge out- 
 put has not only taxed their resources to the limit, 
 but has called for an expenditure of more than a 
 million dollars to handle it. Great reservoirs of 
 concrete have been built to contain the oil, and a
 
 40 SECRETS OF THE EARTH 
 
 vigilant watch is maintained over these day and 
 night to prevent seepage and contact with fire. 
 
 Fire indeed is one of the greatest perils in the 
 oil fields all over the world. Nobody is permitted 
 near the vats or gushers with a flame of any kind ; 
 smoking is positively prohibited. One tiny match 
 has often set a great gusher into a spouting vol- 
 cano of fire and the blackest sort of smoke clouds, 
 to burn for days and weeks while the men help- 
 lessly tried to extinguish it. Reservoirs, too, 
 have had all their valuable contents destroyed in 
 the same manner, it being practically impossible 
 to put out the flames when once they are started 
 till the last drop of oil is consumed. Everyone 
 who has been in railroad yards has observed the 
 cards on tank cars, warning of keeping away with 
 all fire. 
 
 In the Maricopa oil fields of California is a 
 well called the "Lakeside." This is probably the 
 deepest and heaviest producing gusher ever 
 bored. Its great volume of oil flows up through 
 the ground a distance of 2,225 feet close to 
 half a mile. Usually the velocity of the flow of 
 a well of this type will force sand and rock into 
 the pipe and clog it up, but this has never hap- 
 pened with the Lakeside's 6-inch casing. For 
 many weeks following its tapping this great well 
 projected high into the air thousands of barrels 
 of beautiful crude oil every day. This spouted
 
 Publisher's Photo Service 
 
 SHOOTING AN OIL WELL
 
 OIL, INDUSTRIAL GIANT 41 
 
 higher than the tallest trees, and came down in a 
 vast cascade, flooding the entire country there- 
 about for several miles. It was absolutely be- 
 yond control. For weeks the engineers, braving 
 the blinding deluge, tried their best to get a cap 
 over the pipe and stop the loss, but it would only 
 be torn each time out of their hands by the fierce 
 pressure, as the wind will whisk away a feather. 
 In time, however, man's ingenuity and persever- 
 ance succeeded. The great gusher was capped, 
 and thereafter has been feeding its tremendous 
 supply of oil into a big conducting pipe which 
 connects with a great reservoir over half a mile 
 long. 
 
 Although natural gas is usually found wher- 
 ever oil wells are sunk, and probably does do 
 much in some instances to force up the tapped 
 oil, at the same time there are many reputable 
 geologists and oil engineers who hold to the 
 theory that underground water exerts most of 
 the pressure, and facts seem to give them good 
 grounds for this belief, called the "diatomic 
 theory." These experts point out that the greatest 
 gusher of all the Lakeview, which we have 
 mentioned varies in intensity with the rise and 
 fall of the ocean tides, although the ocean is at a 
 considerable distance, with a mountain range be- 
 tween. And they also point out that which we 
 have previously noticed : the extra impetus given
 
 42 SECRETS OF THE EARTH 
 
 to producing wells by flooding a nearby ex- 
 hausted one. All of which would seem to show 
 that water does have a strong influence over the 
 flow of oil, at least. 
 
 Before crude petroleum can be utilized to any 
 great extent it must be refined, which is a pro- 
 cess of removing from it its grossest impurities. 
 In the beginning of its history it was carried for 
 this purpose in wagons and boats, from the oil 
 fields to Pittsburgh, where the only refinery was 
 situated. Then came the railroads, which re- 
 placed both the wagons and boats as a medium 
 of transportation. The railroads provided spe- 
 cial flat cars to which were fastened great cylin- 
 drical steel tanks that would hold thousands of 
 gallons each. 
 
 There was only one difficulty about sending oil 
 by rail, and that was that it still had to be hauled 
 by team from the oil wells to the railroad station, 
 often a distance of several miles, and this was no 
 easy task. At length some one said to himself, 
 "Why can't we run a pipe direct from the well 
 to the railroad?" It proved a wonderfully good 
 idea; so simple, too! So pumping engines were 
 put in a few miles apart, and almost all the big 
 fields began sending their oil straight to the cars 
 through a feed pipe. 
 
 Before this it had been necessary to build re- 
 fineries as near the oil regions as possible in order
 
 OIL, INDUSTRIAL GIANT 43 
 
 to save expense in transportation; but now they 
 could be built wherever wanted. There are cases 
 where the feed lines travel as much as a hundred 
 miles to reach the nearest refinery. They go over 
 hills and through swamps. They cross rivers, 
 sometimes by means of bridges, sometimes by be- 
 ing anchored to the bed of the stream. They 
 cross deep ravines and gorges not too wide by 
 simply stretching across from ledge to ledge. In 
 salt marshes they are laid in concrete to keep rust 
 from destroying the iron. If these great oil 
 arteries were to be ruined by any means, so that 
 oil had to be carried in the old way, kerosene and 
 gasoline would become much more expensive 
 necessities than they are today. 
 
 At the present time crude oil can be brought at 
 small expense from the fields far west of the 
 Mississippi River to the Atlantic seaboard, re- 
 fined, and distributed throughout that part of 
 the country, or loaded into "tankers" (oil ships) 
 and taken across the ocean. In the early days of 
 this pipe system great trouble was encountered 
 by the pipes getting choked with impurities, shut- 
 ting off the flow or diminishing it. But some 
 ingenious chap invented what he called a "go- 
 devil" to do away with this nuisance. The go- 
 devil is about three feet long, and shaped like a 
 cartridge, but its body is composed of flexible 
 plates which allow it to turn around any bend in
 
 the pipe line. From time to time the go-devils 
 are inserted in the pipe at the wells, and the rush 
 of oil forces them along to the receiving end, by 
 which time they have done their duty of scraping 
 out the pipe line, and can be shipped back and 
 used over and over again. 
 
 If you hold a piece of cold earthenware in the 
 steam of a teakettle water will collect on it. This 
 is distilled water, and is much purer than that in 
 the kettle. Petroleum was at first distilled in a 
 rough way; but now it is done with the utmost 
 care and exactness. The crude oil is pumped into 
 boilers holding six hundred barrels or more. The 
 fires are started beneath, and the oil soon begins 
 to turn into vapor. This vapor passes through 
 coils of pipe, and sometimes long lines of parallel 
 pipes, on which cold water is pumped. This 
 causes the vaporized oil to turn once more into 
 liquid, and this liquid is a crude form of the kero- 
 sene we buy for lamps. 
 
 Kerosene oil is only one of the many useful 
 substances found in petroleum. Some of these 
 are light, like gasoline and benzine; some are 
 heavier, like kerosene and thin lubricants; while 
 paraffin and tar are heaviest of all. In the sepa- 
 ration of these by-products, there are also gases, 
 which pass off first and are used to provide fuel 
 for the furnaces. Nothing is lost. Every atom 
 of the crude oil goes into something valuable for
 
 OIL, INDUSTRIAL GIANT 45 
 
 making our lives easier and more comfortable. 
 One by one come the other substances, according 
 to weight or specific gravity. The still man keeps 
 close watch. When the color of the distillate 
 changes he turns the cock of that tank shut and 
 opens another. This process is called "fractional 
 distillation," and the various products are known 
 as "fractions." No two kinds of petroleum and 
 no two oil wells are just alike in their chemical 
 properties, so it needs a highly skilled still man to 
 manage the cocks. 
 
 After its distillation kerosene oil is still unfit 
 for good illuminating purposes. It has both a 
 disagreeable smell and a way of smoking the 
 lamp chimney. So it is treated with sulphuric 
 acid and caustic soda, which carry away the re- 
 maining impurities. 
 
 Then it is given three tests. These are to make 
 sure that the oil is light enough to absorb freely 
 through the wick; that it is of the right con- 
 sistency to produce a vapor that will flash into 
 fire when a certain amount of heat has been ap- 
 plied; and that it will not burn too easily on the 
 surface when heat is applied to it, as this would 
 make it unsafe. 
 
 We do not burn oil in our lamps, as we are in 
 the habit of saying. What we really do is to heat 
 the oil until it gives off gas, and then we burn the 
 gas. The chimney is merely a helper in regulat-
 
 46 SECRETS OF THE EARTH 
 
 ing combustion. The hot air rises in the chimney, 
 the cold air rushes in underneath to take its 
 place, and this brings the necessary oxygen to 
 the flame for making it burn brightly and stead- 
 ily. The more air we let in from below, the 
 brighter the light, up to a certain point. Burners 
 and chimneys are all carefully thought out by 
 the manufacturers, and made so that they will 
 give the best results possible. In a close, stuffy 
 room no lamp will give a clear light, because 
 there is not oxygen enough for its flame. 
 
 In a wax candle we light the wick, its heat 
 melts the wax, the wax runs up the wick in the 
 form of oil, the oil is reduced to gas, and the 
 flame feeds upon the gas just as with kerosene 
 oil. Wax alone will melt, but it will not take fire. 
 Ignition of practically all substances requires the 
 formation of gas first. 
 
 The by-products of petroleum are many and 
 important. Omitting such well-known sub- 
 stances as kerosene and gasoline, we have many 
 grades of lubricants for oiling machinery ; tar, as 
 used in dyes; naphtha for dissolving the resins 
 used in varnishes; benzine for cleansing clothes, 
 printers' types, and almost everything else; par- 
 affin for candles and fruit sealing, for covering 
 match heads, and for making waxed paper with 
 which to do up our lunches when a picnic is in 
 prospect. Even printers' ink and waterproof
 
 OIL, INDUSTRIAL GIANT 47 
 
 roofing-paper both owe their existence to petro- 
 leum. In medicine, vaseline is one of the greatest 
 standbys. It can be mixed with drugs without 
 changing their character, and it never becomes 
 rancid. For this reason it is used largely as the 
 principal part of salves and ointments. It also 
 has a certain medicinal or healing value on its 
 own account.
 
 IV 
 
 IRON ORE, THE WORLD'S RICHEST 
 MINERAL 
 
 FROM iron ore is made steel, man's richest 
 metal, industry's greatest asset except coal. 
 From steel the modern world makes its 
 wonderful tools, constructs its great bridges, 
 tunnels, and buildings; builds its famous rail- 
 ways, shapes its powerful steamships and war 
 implements. From plowshare to pen, from 
 super-dreadnaught to watch spring, steel reaches 
 over countless products of the manufacturing 
 realm with deep mothering interest. "They are 
 mine," she says proudly; "all mine! Are they 
 not beautiful children wonderfully smart chil- 
 dren?" 
 
 Would you like to know the size of the Amer- 
 ican steel industry alone ? Then reflect that even 
 before the great World War broke out, in the 
 slack and uncertain days of 1914, it employed 
 more people than live in all the four States of 
 Nevada, Arizona, New Mexico and Wyoming. 
 More money is invested in the industry than the 
 national wealth of Switzerland. 
 
 Think of an ore train so long that it would 
 48
 
 IRON ORE 49 
 
 take a fortnight to pass a certain point, going all 
 the time at freight-train speed! Think of ore 
 ships moving one behind another and stretching 
 from Detroit, Michigan, to Erie, Pennsylvania! 
 Think of a row of blast furnaces (for making ore 
 into steel) reaching from New York City twenty 
 miles past Philadelphia! Picture a column of! 
 rolling mills and puddling furnaces stretching 
 from New York to Indianapolis! Imagine a 
 stream of ten tons of liquid iron flowing out of 
 great crucibles and becoming pig metal every 
 second of the year ! 
 
 This will give you a faint idea of the vastness 
 of the steel industry. But for American steel 
 we might be little better than savages to-day. 
 Without American steel probably German sub- 
 marines would be ruling the seas at this time, 
 and German hordes tramping ironshod over 
 British, French, Italian and American lands. 
 Steel is king! The nation possessing great 
 wealth of iron ore not only has in her mines a 
 university of great civilizing and progressive in- 
 fluences, but she also has the most formidable 
 weapon she can possess with which to protect 
 herself from enemy invasion. 
 
 There is a wide distance between the primitive 
 miner of iron ore, his own crude furnace and 
 molding appliances, and the present gigantic and 
 systematic methods employed by specialists in
 
 50 SECRETS OF THE EARTH 
 
 the production of iron and steel. The United 
 States Steel Corporation, a group of many rich 
 men combining a working capital of more than 
 two billions of dollars, controls most of the steel 
 industry of this country. These men not only 
 own the greatest share of the iron mines, but also 
 the multitude of blast furnaces, rolling mills, and 
 other enterprises connected with the smelting and 
 production of iron and steel in various forms and 
 qualities. Finished products are made where 
 there is a large demand for them. These include 
 such things as railway rails, structural steel, 
 armor-plate, automobile-plate, and tubing. Less 
 used products they leave to the smaller industries 
 to manufacture. 
 
 Leaving aside European interests, it was not 
 so very long ago that Pennsylvania was the 
 source of all our steel. Now great steel mills are 
 operated in all sections of the country north, 
 south, east and west. With the great ore deposits 
 of the Lake Superior region at their very doors, 
 the mills of the United States Steel Corporation 
 at South Chicago and Gary, Indiana, are working 
 day and night. At Birmingham, Alabama, other 
 mills are transforming the ore of the surround- 
 ing mountains into rails and structural steel, 
 while out at Irondale, Washington, a new era in 
 the industries of the Pacific coast was opened a 
 year or so ago when the plant of the Western
 
 IRON ORE 51 
 
 Steel Corporation began to turn out pig iron and 
 steel ingots. 
 
 The story of modern iron-ore mines naturally 
 begins at Hibbing, Minnesota, the iron-ore capi- 
 tal of the world, and the richest village on the 
 planet. Most of the streets in Hibbing start at 
 one man-made precipice and end at another; for 
 not content to be the proud possessor of the big- 
 gest iron mine in existence, this enterprising little 
 metropolis has gathered several other good-sized 
 mines around her, as a hen gathers in her brood. 
 In 1910 the population of the iron town was less 
 than 9,000, and yet it had a street-lighting system 
 as ornamental and efficient as that of such large 
 cities as Cleveland, Minneapolis, and Detroit, and 
 far more beautiful than that of the nation's cap- 
 ital, Washington. 
 
 The streets are well paved, and everybody 
 seems to have an automobile, even the miners ; so 
 that street-cars would be about as necessary as a 
 fifth wheel on a wagon. Going up to Hibbing 
 from Duluth you get the idea that the ore capital 
 risks money lavishly, as in the parlor cars and 
 day coaches alike appear signs which warn 
 against playing cards for money in railroad 
 trains. 
 
 Hibbing's great mine is the Hull Rust, which 
 is a hole in the ground rivalling the immense Gal- 
 liard Cut at Panama. This mine is a vast ter-
 
 52 SECRETS OF THE EARTH 
 
 raced amphitheater cut out of rolling ground, and 
 covers an expanse of two miles in length by a 
 half mile in width. Could you dump the huge 
 Gatun Dam of Panama fame into it, there would 
 still be a yawning chasm unfilled. A ten-story 
 office building set down into its deepest trench 
 would leave the flag-pole of the building barely 
 reaching to the line of the original surface. 
 
 Ordinarily we think of mining as an occupa- 
 tion for human moles that burrow in the ground 
 and bring out hard ores from cavernous depths. 
 But when nature laid down the Lake Superior 
 ore ranges she spread her precious layer close to 
 the surface, so that for the most part burrowing 
 and blasting was quite unnecessary. This is par- 
 ticularly the situation in the Mesaba Range, the 
 richest stretch of iron-bearing ore ever discovered. 
 The work is done by stripping off the surface de- 
 posits and useless vegetable mold, until the iron 
 ore is uncovered, whereupon it is removed by 
 steam-shovels to waiting cars. This becomes 
 quarrying rather than mining, in the strict sense 
 of the word, but though it may lack some of the 
 picturesque features of mining operations deep 
 in the earth, it is much more convenient com- 
 mercially, and makes the cost of the product far 
 less than if it were garnered through shafts and 
 tunnels where the light of day never penetrates. 
 
 The ore bodies are first thoroughly explored
 
 IRON ORE 53 
 
 by churn- and diamond-drilling, surface and ore 
 contours are sketched on maps by the engineers, 
 and complete plans made for stripping and min- 
 ing before excavation really begins. Then things 
 begin to hum. It is somewhat uncanny to see a 
 whole batterjr of huge steam-shovels biting into 
 the soft, red-brown stuff that looks more like 
 some sort of sand than iron-ore. These shovels 
 are operated from heavy cars which travel slowly 
 along tracks built on "shelves" or "benches" 
 which are left, terrace-like, around the sides of 
 the great bowl where operations are carried on. 
 
 When one of these large scoops buries itself 
 in the earthen matter it usually shovels out a hole 
 twenty-five feet deep and fifty feet wide. Just 
 think of that ! In such a trench a whole company 
 of soldiers could conceal themselves. This is 
 "making the dirt fly" in deadly earnest 1 
 
 In stripping operations, that is, working off 
 undesired soil to expose the iron-ore, the steam- 
 shovels dump enough of the scrapings ahead of 
 them to form a roadbed for their own tracks, as 
 they advance. When there is a surplus of such 
 foreign earth it is generally dropped to one side, 
 out of the way ; but sometimes, owing to a rise on 
 that side and an accumulation of too much dump- 
 ings, the piles slide down in true avalanche 
 fashion and partially bury the cars or knock them 
 from the tracks.
 
 54 SECRETS OF THE EARTH 
 
 As a rule very little dynamite is used in this 
 form of mining, the big shovels doing practically 
 all of the loosening work as well as the loading. 
 Strange little trains, pulled by diminutive steam 
 locomotives, are a part of each shovel outfit. In 
 each train there are all the way from five to a 
 dozen flat-cars, each of which holds from five to 
 thirty yards of dirt. The first car is usually the 
 steam-shovel itself, which empties its load of 
 iron ore on the nearest flat-car. Often a locomo- 
 tive is required at each end of the train when the 
 cargo becomes heavy, or the grade is steep. 
 
 Day and night the work goes on two tons to 
 the shovelful, five shovelfuls to the minute, and 
 five minutes to the carload. A whole ore train is 
 loaded in less time than a child with a toy shovel 
 could fill his little red express wagon. Not long 
 ago a big 300-ton steam-shovel loaded 7,689 tons 
 of ore in a single day. 
 
 The railroads reaching from the mines down to 
 Duluth, Superior and Two Harbors, where most 
 of the ore goes for lake shipment, are of the best 
 construction, like the main lines of our biggest 
 eastern roads. The long ore trains crawl through 
 the hills and vales that Proctor Knott declared, 
 in his celebrated speech in Congress, would not, 
 except for the pine bushes, "produce vegetation 
 enough in ten years to fatten a grasshopper," but 
 where to-day farmers are growing splendid crops
 
 IRON ORE 55 
 
 of potatoes and wheat. Where gold and silver 
 were located on the map Knott made famous, we 
 now find the richest iron mines in the world 
 mines that beggar the bonanzas of California. 
 
 The haul from Hibbing to Duluth is eighty 
 odd miles. Just before the trains reach Duluth 
 they come to Proctor, the biggest ore yard in the 
 universe. Here they are weighed on a scale 
 unique in its convenience and accuracy. A sec- 
 tion of the tracks are on this scale, the trains 
 pass over it without stopping, and as it leaves the 
 weight of every loaded car is automatically regis- 
 tered. 
 
 From Proctor the trains run down to the huge 
 unloading piers at Duluth. These piers are vast 
 platforms built out over the lake, nearly half a 
 mile long, and wide enough to accommodate two 
 tracks which are elevated to the approximate 
 height of a two-story building. Beneath the 
 tracks is a series of large pockets, holding some 
 two or three hundred tons of ore each. The ore 
 is dropped mechanically into these pockets, and 
 the train returns to Hibbing for a new cargo. 
 
 Even while the trains are dropping their bur- 
 den special ore-ships are alongside. From the ore 
 pockets on the piers long funnels reach down to 
 the hatches of these vessels, and the ore goes 
 flowing down till the pockets are emptied or the 
 ships supplied.
 
 56 SECRETS OF THE EARTH 
 
 These ore-ships are a picture in themselves. 
 They remind us of the exclamations of an old 
 Cape Cod salt who beheld one of them for the 
 first time: "Now clap your eyes on that! D'ye 
 call that a ship? Bless your mizzen-scuppers, 
 why a loggy lighter with a city store on one end 
 and a match-factory on t'other would look more 
 like a ship than that! It's so long, how'd the 
 skipper and chief engineer ever get acquainted? 
 And you say the skipper bunks in the skys'l 
 fo'c'stle for'd, while the cook and ship's boy has 
 the quarterdeck? Well, I wouldn't ship on such 
 a bloody drogher for all the gold in the world !" 
 
 In a general way the big freighters do fit the 
 old sailor's sketchy description. Some of them 
 are more than 600 feet long, and only 60 feet 
 beam. A big sort of house at one end, occupied 
 by officers and crew, and a great stretch of flat 
 decking in between, surely make them look like 
 uncanny monsters of the deep, in their dull, dark 
 dresses of paint. More than thirteen thousand 
 tons of ore have been carried on one of the largest 
 of these ships. The cost of operating them on 
 trips is often as much as three hundred dollars 
 a day. 
 
 When the big ore carriers arrive at the lower 
 lake ports Lorain, Cleveland, Ashtabula, Con- 
 neaut, Erie, and Buffalo they are quickly un- 
 loaded at huge piers. Gravity may load a
 
 IRON ORE 57 
 
 ship, but it has never yet unloaded one, and so 
 machinery does the work entirely. The Hulett 
 unloader, one of the chief mechanical agents used, 
 reminds you of the glorified walking-beam of an 
 old side-wheel steamer, with one of the two beams 
 left off. At the lower end it has a wonderful set 
 of claws, and above them an "ankle" of startling 
 agility. These great claws open and shut by 
 electricity, and take up seventeen tons of ore 
 with as much ease as you might close your hand 
 on a nice, juicy, red apple. The operator is sta- 
 tioned inside the leg just above the claws, so as 
 it swings back and forth, up and down, he goes 
 with it from hour to hour, getting all the sensa- 
 tions of riding a roller-coaster, and good pay for 
 his experience. Once it took a week, with a regi- 
 ment of men to unload a small ore-ship. Now, 
 in half a day, a corporal's guard can empty the 
 biggest ore-carrier that ever cut the waves. 
 
 This ore is stored in huge bins, from which it 
 is transported by train to the blast furnaces. 
 
 The modern blast furnace is a tremendous and 
 spectacular institution, tremendous in size and 
 output; spectacular in its appearance when in 
 operation, especially at night when the vividness 
 and weirdness of its saffron-green cupola flames, 
 shooting erratically into the dark heavens, cause 
 exclamations of awe and wonderment from those 
 who see them for the first time.
 
 58 SECRETS OF THE EARTH 
 
 At the top the blast furnace takes in iron-ore, 
 coke, and limestone. Without the two last- 
 named products, good pig iron would not result. 
 The furnace is a large circular, silo-shaped affair, 
 about ninety feet high, which is kept going day 
 and night, Sundays and Christmas alike, year in 
 and year out. The coke, limestone, and ore, are 
 soon melted, as a veritable inferno of heat exists 
 down near the bottom of the furnace, caused by a 
 tremendous blast of air driven into the fire by 
 huge engines. The blast causes all the oxygen 
 in the air to unite with the carbon, and to leave 
 through the gaspipes leading from the furnace. 
 
 The pure ore and the limestone melt together 
 under the fire, while the foreign matter in the ore 
 unites at once with the molten coke. Being lighter 
 than liquid iron these newly wedded substances 
 rise to the top of the bubbling caldron like oil 
 rises to the top of water or cream to the top of 
 milk. 
 
 There are two holes in the lower part of the 
 furnace. Out of the upper one of these, when 
 tapped, conies the waste matter, now liquid slag, 
 which soon hardens and is shipped away to be 
 made into prosaic cement. 
 
 When the iron, now as liquid as milk, is drawn 
 off through the lower hole, it is plain molten iron. 
 At some furnaces it is run into large cavities in 
 sand, called "sows," and then conducted to
 
 Underwood and Underwood 
 
 IRON MINERS AT WORK
 
 IRON ORE 59 
 
 smaller ones, called "pigs," where it is allowed 
 to cool and harden. The iron is then in the form 
 of grayish-brown slabs about the size of two 
 bricks placed end to end, and is termed "pig 
 iron." At other furnaces the molten iron is 
 drawn off into metallic molds instead of sand 
 ones; and at still other furnaces it is "machine 
 cast," drawn off into ladles, transferred to molds 
 mounted on an endless belt, and cooled by water 
 through which the belt runs. 
 
 In some cases the furnace and steel mill are 
 in the same plant, and the pig iron is delivered 
 in its molten condition directly to the steel-maker, 
 and he reduces it to steel before it has a chance to 
 
 
 
 harden. But though it may never become "pig" 
 it is known as "pig" just the same. 
 
 Up to this point all things made of steel have 
 a common history. Pig iron is the common de- 
 nominator of every fraction of the steel industry. 
 The 200-ton casting for a powerful electric 
 dynamo, the tiny second-hand for the highest 
 grade watch, the powerful 16-inch gun that 
 weighs as much as a locomotive, and the micro- 
 scopic screw with threads that elude the human 
 vision, all come the same road. The ore that 
 was bought of the land-owner in the Lake Su- 
 perior iron region for the paltry sum of 25 cents 
 a ton, now, in the form of fine watchsprings, is 
 worth $7,000,000.
 
 60 SECRETS OF THE EARTH 
 
 But once out of the blast furnace, pig iron 
 comes to the parting of the ways. Some of it 
 will go to the puddling furnace and become 
 wrought iron (such as blacksmiths use) ; some 
 will take the cupola route and become cast iron 
 (iron poured in molds according to foundry 
 method) ; much more will go into the Bessemer 
 converter and become soft, malleable steel; but 
 still more will take the path that leads to the 
 open-hearth furnace. A little, comparatively 
 speaking, remains behind. It finds its way into 
 a crucible furnace or an electric furnace, and be- 
 comes the tool steel of the industrial world, the 
 refined, tough, hard steel that goes into the mak- 
 ing of knives, saws, bits, drills, cutters, reamers, 
 taps, dies, and the like. 
 
 In making wrought iron used generally in 
 the manufacture of chains, pipe, bolts, wagon 
 rods, nuts, and the like close to 600 pounds of 
 pig iron is heated until it reaches the consistency 
 of dough. Slag soon begins to form, and being 
 lighter and more fusible than the pure iron, floats 
 to the top, and the greater portion is poured off. 
 At this stage, the iron begins to form into small 
 pasty globules, about the size of a pea, each 
 globule surrounded by a thin covering of fluid 
 slag. 
 
 Stripped to the waist, with arms and muscles 
 like those of a prizefighter, the puddler stirs or
 
 IRON ORE 61 
 
 "puddles" the iron for nearly an hour and a half. 
 He takes a bar of iron, known as a rabbling-iron, 
 which in itself would make a staggering load for 
 most men, puts one end through the furnace door, 
 and turns the pigs over and over until they are 
 melted, stirring the mass so as to expose all parts 
 of it to the action of the intense overhead flame 
 until the impurities are largely eliminated. The 
 iron is then formed into two or three pasty balls, 
 as a woman might knead dough and divide it for 
 loaves. These balls are not touched by the hands, 
 however. The work is done with more discretion 
 than that, the rabbling-iron being utilized. They 
 are taken out of the furnace glowing with heat 
 and dripping with slag, and conveyed by tongs 
 to the "squeezer," where most of the remaining 
 slag is pressed out. 
 
 It is a strange thing about iron that, before 
 it is converted into steel, it cannot be "tempered" 
 or made harder. Compared to steel, iron is 
 always soft and quite pliable. But once put 
 through the converting process, and becoming 
 steel, treating it later with heat will give it almost 
 any degree of softness or hardness. For instance, 
 if you have a piece of soft steel and wish to make 
 it harder, you would heat it to a cherry red and 
 plunge it quickly into water. This renders the 
 steel as hard as such metal can be made. If too 
 hard for the purpose in view, the temper is
 
 62 SECRETS OF THE EARTH 
 
 "drawn," that is, the hardness is reduced. To do 
 this it is only necessary to subject the steel again 
 to heat for a very limited length of time, or until 
 the proper color shows on it, signifying the de- 
 gree of hardness desired. It is then withdrawn, 
 and cooled naturally. 
 
 Cast iron is different from steel in hardness 
 and color. It can stand almost as much squeez- 
 ing together as the best steel, but it is compara- 
 tively weak in resisting a pulling or straining 
 force. A sharp blow will easily crack or shatter it. 
 
 In making cast iron the cupola furnace is 
 usually used, but not always. A bed of coke is 
 laid down, then a layer of iron, then another layer 
 of coke, and so on. It is then fired, the iron melts 
 and runs out, and is poured into molds. Air- 
 brake parts for railways, radiators, car brackets, 
 and pipe fittings, are examples of its use. 
 
 The story of Bessemer steel is one of the fas- 
 cinating chronicles of the industrial world. It has 
 to do with two men working in different countries, 
 each without knowledge of what the other was 
 doing, reaching the same conclusion about the 
 same time. Both were granted American patents ; 
 but upon application for renewal, the Patent 
 Office held Kelly to be the inventor. The world, 
 in spite of this, gives the credit to his contem- 
 porary, Bessemer, and the method is known as 
 the Bessemer process accordingly.
 
 IRON ORE 63 
 
 Kelly was a maker of old-fashioned cooking- 
 pots and kettles. It is related that one day he 
 was sitting in front of his furnace and observed 
 a point of incandescence where there was no 
 charcoal, only the metal and the air. This led 
 him to believe that air alone would burn out the 
 impurities from molten iron. So he experi- 
 mented along this line, and produced a tilting 
 converter. When his engineer tried this out he 
 blew such a tremendous blast through the first 
 eharge that iron and all went up as sparks, to 
 Kelly's chagrin and the onlookers' amusement. 
 He finally succeeded in getting the amount of air 
 regulated, and soon afterward poured out the 
 finest tempered steel. People were so surprised 
 that they said the next thing Kelly would be do- 
 ing would be to burn ice! Since his crude old 
 converter was first used, billions of dollars' worth 
 of Bessemer steel has flowed out of the world's 
 converters. 
 
 To go into a great building where there is a 
 battery of Bessemer converters is to see more 
 heat than Dante ever pictured in his "Inferno." 
 A converter is like a huge egg of steel swung on 
 trunnions at its middle. The shell is lined with 
 fire-brick, which is the greatest resistant of heat 
 that can be found. Were it not for this unmelt- 
 able lining, the steel shell would collapse into 
 liquid as the white-hot metal enters.
 
 64 SECRETS OF THE EARTH 
 
 Into the open top of this gigantic egg some 
 twenty tons of molten pig iron are poured. And 
 then, through more than two hundred little holes 
 in the bottom, powerful engines pump in as many 
 streams of cold air. As the oxygen-laden air 
 sweeps up through the molten iron, it comes in 
 contact with molten carbon and silicon which 
 constitute the impurities and carries them 
 away through the open top of the converter, up 
 through a gaping hole in the roof of the build- 
 ing, up into the outside atmosphere. 
 
 Millions of red and white sparks fill the air, as 
 if some demon within the fiery fluid were spitting 
 out his spite in a last cataclysm of terrible rage. 
 A thousand boilers, with safety-valves hissing 
 under tremendous pressure, have the voice of a 
 soothing nightwind in comparison. First the 
 flame that pours out is violet ; then it merges be- 
 witchingly into orange, becomes a ghostly and 
 then a dazzling white, and burns finally into a 
 faint blue, which is a sign that all the impurities 
 are gone. 
 
 Then the blast ceases, the carbon that is neces- 
 sary to replace the needed portions burnt out is 
 added, the great brick and steel egg swings back 
 to position, the carbon is mixed with the fervent 
 fluid, and then the egg tips over on its side, and 
 out of its top flows the liquid steel, Bessemer steel 
 now, into a great ladle.
 
 IRON ORE 65 
 
 When the converter is swung back again into 
 an upright position, a man with colored glasses, 
 to protect his eyes, walks out over the converter 
 and peers down into its white-hot depths to see 
 if the heat from the last charge has melted away 
 any of the fire-brick lining. If it has, he hurls 
 balls of fire-clay in putty form down into the 
 burned-out holes to stop them up, or sets a crew 
 of workmen to re-lining the damaged places 
 after the converter has cooled. 
 
 The whole operation of conversion takes about 
 twenty minutes a ton of steel a minute. Bes- 
 semer steel is used for structural beams and 
 girders, for railroad rails, wire, and pipe. 
 
 In 1900 there was twice as much steel produced 
 in the United States by the Bessemer process as 
 by the open-hearth method. But with the rapid 
 exhaustion of ores having the proper amounts of 
 phosphorus for converter practice, the open- 
 hearth process largely replaced the other. The 
 open-hearth system successfully handles ores 
 having any amount of phosphorus in them. 
 
 An open-hearth furnace looks a good deal like 
 an ordinary bake-oven; but when you look in 
 through the water-cooled door a vast difference 
 appears. Instead of pans of fat loaves of bread, 
 there is an imposing pool of fiery liquid as bright 
 as the filament of a strong tungsten lamp, so 
 dazzling that it can be looked at with safety only.
 
 66 SECRETS OF THE EARTH 
 
 through colored glasses. Tinted here and there 
 with streaks of soft blue and dainty pink, it looks 
 for all the world like melted stick-candy. 
 
 In preparing a battery of open-hearth furnaces 
 for a charge, finely-ground dolomite is shoveled 
 in first. This melts like glass, and fills up all 
 cracks and crannies caused by the intense heat of 
 the preceding charge. Then a little train rolls 
 up before the battery, and an electric crane 
 dumps box after box of scrap metal from the cars 
 into the furnaces. 
 
 Off some distance is a great steel tank lined 
 with fire-brick and full of liquid pig metal. This 
 tank is called a mixer. In it hundreds of tons of 
 the flowing, glowing iron are mixed. It is then 
 drawn off in a giant ladle, like water from a 
 spigot, is carried across to the furnace by an elec- 
 tric crane, and poured into it. Every now and 
 then, as the process goes on, a laborer puts a 
 shovelful of limestone into the mixture. 
 
 When the scrap has melted, and the contents 
 of the caldron are cooked enough; when the im- 
 purities have been driven off by the limestone and 
 tolled away, the fiery broth is "seasoned," as it 
 were, with the proper amount of carbon, spiegel, 
 ferro-manganese, tungsten, ferro-silicon, vana- 
 dium, or whatever is necessary to give the de- 
 sired quality to the resulting steel. 
 
 Then comes the tapping of the furnace. An
 
 IRON ORE . 67 
 
 electric crane lifts a great ladle into position, a 
 workman jams a crowbar through a clay-plugged 
 hole at the base, and out flows the frenzied stream 
 into the ladle. The slag rises to the top and over- 
 flows, congealing on the outside of the big dipper. 
 Then the crane picks up the ladle, swings it over 
 to the pouring platform, and a clay plug in the 
 ladle's bottom is also punched out, permitting the 
 purified liquid to run swiftly out into molds. It 
 then becomes steel ingots. 
 
 Great care has to be taken in handling these 
 ladles. Should there be a few drops of moisture 
 clinging to the inside of them when the hot metal 
 is poured in, a great explosion may occur and 
 cause horrible burns, if not death, to the work- 
 men. And the "tappers" and others who manip- 
 ulate the dippers, filling and emptying them of 
 their glowing burdens, must use the utmost skill 
 and caution at all times to prevent an accidental 
 spill. Their job is always one of playing tag 
 with the Grim Reaper of life. Hardly a week 
 goes by that some poor fellow is not caught, 
 touched, and eternally retired. 
 
 There are two other important types of steel 
 furnaces the crucible furnace and the electric 
 furnace. 
 
 In a crucible furnace the metal is placed in 
 graphite-clay pots, covers are put on, and the pots 
 subjected to great heat. Silica is gradually ab-
 
 68 SECRETS OF THE EARTH 
 
 sorbed out of the clay in the pots, and is trans- 
 formed into silicon by coming into contact with 
 the carbon in the steel. The silicon in its turn 
 absorbs the oxygen, which quiets the frothing 
 and foaming contents of the kettle, and they are 
 then ready to be poured into the waiting molds. 
 
 The electric furnace operates in much the same 
 way. But its heat is so pure that there is no 
 necessity of putting the steel in covered pots to 
 keep out the gases and other impurities. An 
 electric arc, established between huge electrodes 
 and the surface of the slag, produces the heat in 
 such a furnace. By varying the materials used in 
 the formation of the slag, any impurity can be 
 coaxed off, leaving the glowing steel as pure as 
 crystal. The alloys are mixed in, and the steel is 
 thus made fit for any kind of use intended. 
 
 When properly mixed, the molten liquid is 
 poured into ingot molds, where it hardens. It is 
 then ready to be sold to the steel manufacturers 
 of the world, to be worked up into all those 
 numerous and valuable things of commerce and 
 industry that constitute the last word in fine steel.
 
 WHERE COPPER IS KING 
 
 COPPER is a metal which has been known 
 from the earliest times, and is frequently 
 spoken of in the Bible. We find it stated 
 there that Tubal Cain was the first worker of 
 brass, of which copper is the principal part. 
 Palestine indeed abounded in copper. King 
 David used immense quantities of it in building 
 'his famous temple. All sorts of vessels and 
 weapons of copper were made in the temple and 
 tabernacle. 
 
 As the ores of copper are usually in beautiful 
 colors, it is not to be wondered at that they at- 
 tracted early attention. In ancient times, how- 
 ever, it seems that copper was not employed so 
 much by itself as it was as an alloy with other 
 metals, such as silver, zinc and tin. When alloyed 
 with tin it formed what is known as bronze. This 
 compound was very popular for coins, medals and 
 statues, and is still used for tablets and statues 
 to a considerable extent. The famous Statue of 
 Liberty, in New York Harbor, is made of 
 bronze. 
 
 In America, the Mound Builders and In- 
 69
 
 70 SECRETS OF THE EARTH 
 
 dians used native copper in a pure state long be- 
 fore the white man made his appearance, and for 
 a long time they jealously guarded the secret of 
 the location of the lodes from which they obtained 
 their supplies of ore. Wonderful examples of 
 savage copper work, in the shape of spear points, 
 arrowheads and knives, have been unearthed in 
 some localities. These show that the Indians 
 possessed the secret of tempering the reddish 
 metal, a feat that modern metallurgists have in 
 vain tried to equal. 
 
 Although copper is found to-day in many parts 
 of the earth, being one of the most generally dis- 
 tributed metals, the United States produces well 
 over half of the world's supply. The region 
 around Butte, Montana, is exceedingly rich in the 
 mineral and the southern half of Arizona is now 
 literally sprinkled with phosphorous copper 
 mines. The Calumet and Hecla mines, formerly 
 the most bountiful in the country, have now been 
 surpassed and Michigan has dropped to third 
 place among the copper-producing states. 
 
 The free metal is not often found in large 
 quantities, though a specimen weighing 2,020 
 pounds was found in Brazil. The Academy of 
 Sciences at Petrograd has on exhibition an 
 enormous nugget of copper which was found in 
 Kamtschatka, and there is another specimen in 
 Canada which measures fifteen feet around,
 
 WHERE COPPER IS KING 71 
 
 It may seem strange to you to learn that so 
 hard a substance as copper is soluble in water. 
 But it is so. The water flowing from copper 
 mines always contains copper in a dissolved 
 state. This was first noticed when the celebrated 
 copper spring at Wicklow County, Ireland, was 
 discovered, about the middle of the eighteenth 
 century. The discovery was due to a miner who, 
 having left an iron shovel in the water of the 
 mine, found it later heavily coated with copper. 
 This principle has since furnished miners with a 
 simple test when prospecting. A drop of nitric 
 acid is placed upon the specimen to be tested and 
 allowed to remain a few minutes, whereupon the 
 blade of a knife is drawn across the spot where 
 the acid was applied. If the specimen contains 
 copper, a plainly visible amount will be found 
 clinging to the blade when the knife is raised. 
 
 Copper is largely employed in the arts as a 
 sheeting for the bottoms and trimmings of ships, 
 for all kinds of utensils subjected to dampness 
 (copper will not rust) ; for telephone, telegraph 
 and electric wires; for tubing and many other 
 articles too numerous to mention. Alloyed with 
 zinc it forms brass; alloyed with tin it produces 
 gun-metal, bronze, bell-metal and speculum- 
 metal. It is used in gold quartz mills in the form 
 of a plate amalgamated with mercury, to hold the 
 particles of gold as they pass over it.
 
 72 SECRETS OF THE EARTH 
 
 Oxide of copper is employed in glass factories 
 to give those pretty red and green colors to the 
 ware which you have admired. As a sulphate, 
 copper yields the well-known blue vitriol, which 
 is used largely by the dyer and calico printer and 
 in the making of galvanic batteries. Lastly, cop- 
 per perhaps is more familiar to us all in its use in 
 the mints of all civilized countries for coining the 
 smaller forms of legal tender with us, the cent; 
 with Great Britain, the penny; and for similar 
 small coins in other countries. 
 
 But we can get a better idea of the value and 
 importance of copper if we take a trip of inspec- 
 tion to one of the world's most famous copper 
 mines, the Calumet and Hecla mine in the Upper 
 Peninsula of Michigan. 
 
 In every direction you will see, towering above 
 the surrounding buildings, tall, elevator-like 
 structures, from one side of each of which may be 
 seen a great incline running down into the mine 
 near it. On the other side of these buildings, or 
 tipples, are high frames supporting a series of 
 wheels, through which run long cables. These 
 extend across the street into an engine-house. 
 Here power is furnished for pulling up and pay- 
 ing back the little cars, called "skips," in which 
 rock is brought to the surface. Another form of 
 car, termed a "cage," is used for transporting the 
 miners up and down the shaft.
 
 Underwood and Undersvood 
 
 INSPECTING A VEIN OF COPPER ORE
 
 WHERE COPPER IS KING 73 
 
 If you visit the interior of one of the mines, you 
 would find Shaft No. 5 a most interesting one to 
 enter. This is on the conglomerate lode, is one of 
 the richest mine entrances, and has the great 
 depth of 8,100 feet almost two miles! That is 
 going down into the earth a considerable dis- 
 tance, especially if it is your first time down. In 
 fact, there is only one mine deeper, and that is 
 the Tamarack, which is not far distant. The 
 Tamarack has a depth of 9,000 feet. 
 
 Shaft No. 5 runs down at an angle of about 37 
 degrees, following the incline of the copper vein 
 clear along. The cage which carries the men 
 is a box-like car with seats rising one above the 
 other, similar to stair steps, or much like seats in 
 a theater. If the seats did not set at a strong 
 pitch in this fashion, the men would slide off in 
 going up and down. On each side of the car is 
 a strong railing, and a powerful headlight at the 
 end. Beneath are wheels running upon the track 
 of the incline. A strong wire cable is attached 
 to the car, and as the engine above drives this 
 cable around a drum, like an endless belt, the 
 cage must go with it. When he wishes to stop, 
 the operator in the cage lets go of the cable with 
 his clutch, and applies the brakes. 
 
 As you glide swiftly down into the dark maw 
 of the earth, a damp, cool breeze strikes your face. 
 The headlight casts flickering, will-o'-the-wisp
 
 74 SECRETS OF THE EARTH 
 
 shadows along the walls. Big timbers rush sud- 
 denly out at you from in front, and instinctively 
 you dodge; but by that time they have whisked 
 by you and new ones are appearing. These are 
 the sturdy props, set in the shaft by man, to keep 
 the walls of the tunnel from caving in. 
 
 As you go deeper the air grows cooler, and the 
 size of the timbers increases. Most of them are 
 now more than two feet in diameter, and if you 
 were not going so fast you would see, probably 
 with a quaking heart, that some of them are bent 
 from the enormous pressure of rock above. In- 
 deed, your headlight does illuminate one old- 
 timer long enough for you to note that it is badly 
 splintered. Your companions look at it casually, 
 and calmly remark that before another twenty- 
 four hours the "proppers" will probably have it 
 replaced. Devoutly you pray that it doesn't give 
 away until you repass on your outward trip, at 
 least! 
 
 It is not long before the pressure of air on your 
 ears becomes uncomfortable. Soon it is so ter- 
 rific that your ears begin to ache. 
 
 The miner next to you notes your trouble, with 
 a sympathetic grin. "Ears kickin' up a fuss, eh ?" 
 he roars out so that you can hear him above the 
 din and racket of pounding cage wheels on the 
 clattering track. "Jest open yer mouth, sonny, 
 an' give a good swaller. That'll cure it, sure !"
 
 WHERE COPPER IS KING 75 
 
 You take this advice, and to your surprise and 
 delight the pain disappears. 
 
 As the cage bowls along you observe every 
 little way a sort of landing, where the shaft is 
 wider, and where a beacon light dimly burns in a 
 fight with the blackness all about. These are 
 called "levels." They are the stations from which 
 miners have been landed and taken on when they 
 worked in the vicinity, also from which the copper 
 ore they have loosened has been loaded for its trip 
 up to the world of sunlight. 
 
 At the Forty-ninth Level is a pump, used for 
 keeping the mine free of water. You have a good 
 chance to look about you here, because the cage 
 stops for a few moments to let off some of your 
 companions. Before you go on you note that you 
 are feeling much warmer. A look at the ther- 
 mometer surprises you. It shows 94 degrees 
 good, strong summer heat! You are told that 
 this is due to the efficient working of the venti- 
 lating machinery of the mine, and not to the fact 
 that you are getting closer all the time to the 
 boiling fires of the earth's center, and you heave 
 a sigh of relief at the explanation. 
 
 Really the truth of the assertion is soon after- 
 ward made manifest; for as the cage drops on 
 down and reaches the Seventy-fourth Level, you 
 find the temperature 75 degrees. This is just a 
 little too cool to be thoroughly comfortable, but
 
 76 SECRETS OF THE EARTH 
 
 you are advised the ventilators cannot entirely 
 overcome the cold air here owing to the near 
 presence of considerable water. Everything is 
 wet and slimy. 
 
 At the Eightieth Level your car stops and 
 your guide steps off with you. The walls and 
 footing are comparatively dry, and you are given 
 an excellent opportunity for observing the 
 method of mining. Here in the "drifts," or 
 transverse tunnels, lie tracks 'connecting with 
 the shaft tracks, and on them the tram-cars run 
 forward with their loads of ore as fast as they 
 are loaded. The propping is of the very stoutest 
 character. Not only are the timbers large and 
 tough, but they are planted closer together than 
 in the levels higher up, so that greater resistance 
 can be maintained against the greater weight of 
 earthen matter, whose pressure is something tre- 
 mendous. Three months is the limit of life for 
 these huge props. Then they must be renewed. 
 
 From the drift the "stopeing" is done. This 
 consists in taking out the rock in 80-foot sections 
 between levels. For instance, the miners in the 
 Eightieth Level work upward toward the 
 Seventy-ninth Level, allowing the ore to fall 
 back to the Eightieth to be loaded into the tram 
 cars, hauled by a small pneumatic locomotive to 
 the shaft, dumped there into the first empty skip, 
 and sent to the surface. When the work is done
 
 WHERE COPPER IS KING 77 
 
 there will be but one big hole from the Eightieth 
 to the Seventy-ninth Level, and so on down until, 
 when the entire vein has been worked out, there 
 will be just one great cellar under the shell of 
 the earth, supported here and there by pillars of 
 rock and wood. 
 
 The work of loosening the copper ore is done 
 in much the same manner as in coal mining. That 
 is, automatic drills, looking a lot like gatling 
 guns, are used in making holes in the rock 
 around the ore-bearing sections. At the end of 
 his shift the miner inserts sticks of dynamite in 
 these holes, and when the men have all gone out 
 of harm's way, the charges are exploded by elec- 
 tricity. There is a terrific din, which will cause 
 your ears to ring for hours afterward, as the 
 shots go off, one following closely upon the heels 
 of another, and the rock goes tumbling down in 
 a great sloughing pile. 
 
 In the next shift, the trammers clean up this 
 loose rock and send it to the shaft. As the skip 
 load of ore goes up to the surface, it runs straight 
 into the tipple at the mine mouth. With the ex- 
 ception of the large pieces of rock, it is dumped 
 automatically into a bin, below which stand the 
 ore cars. The large chunks are carried into the 
 crusher, where heavy steel rollers squeeze them 
 into many small fragments, as you might crush 
 a lump of baked mud in your mother's clothes-
 
 78 SECRETS OF THE EARTH 
 
 wringer. The pieces then fall through the bin, 
 which has a swinging bottom, as fast as cars ap- 
 pear below to receive them. 
 
 The ore is then brought to a stamp mill, where 
 the crushing process is carried much further. 
 Gradually powerful little trip-hammers break up 
 the pieces. Each time they are projected onto a 
 screen of diminishing sized mesh, until all the 
 rock is as fine as ordinary sand. 
 
 Then comes the separation work. Remember 
 that it is not the ordinary rock itself which is 
 wanted, but the smallest part of it the pure 
 copper ore. Up to this point it has been neces- 
 sary to dig, handle and convey a dozen pounds of 
 common, worthless rock, in order to secure the 
 pound of pure copper that it contained. Now the 
 wheat is to be separated from its chaff, as it were. 
 
 At first it might strike you as a very simple, 
 even crude, method for so big an undertaking. 
 But it is efficient, nevertheless; and simplicity is 
 always desirable where good results are not lost 
 by its adoption. Specific gravity is the agency 
 used in this case. Since, as with gold, the free 
 copper is considerably heavier than the rock in 
 which it is found, the valuable metallic sand will 
 fall to the bottom, when cast in flowing water, 
 and the rock sand go drifting onward. This pro- 
 cess of settling is further assisted by shooting a 
 powerful jet of water up into the air. The mixed
 
 WHERE COPPER IS KING 79 
 
 sands fall down into this jet; the rock waste is 
 carried away by the supporting spray; while the 
 copper sands, for the most part, descend straight. 
 A light rubber ball dancing at the apex of a 
 fountain jet a spectacle most people have 
 seen is a good illustration of the rock sand part 
 of this action. 
 
 But this does not take out all of the copper 
 particles. So the separation process is con- 
 tinued. At last the sand reaches a sort of large 
 table having a distinct slope to it. Thin strips of 
 wood run up and down this, to keep in the water 
 and sand which flow over the table while it shakes 
 back and forth very gently and regularly. What- 
 ever copper grains are in the mixture settle in 
 the troughs, while the rock sands are carried over 
 with the rush of water. 
 
 Smelting is the last step in preparing the ore 
 for the market. It is put into a furnace and 
 melted, whereupon the foreign substances rise 
 to the surface in a kind of scum, and are scooped 
 off. Oxygen is then blown into the molten mass 
 to drive out the remaining impurities, but the 
 oxygen itself must be gotten rid of. This is done 
 by inserting a stick of wood down into the molten 
 copper. The oxygen promptly burns itself up, 
 and the copper is then drawn off in a pure state 
 and poured into molds for ingots. 
 
 It was in the early days of this famous copper
 
 80 SECRETS OF THE EARTH 
 
 region that the great conglomerate vein now 
 owned by the Calumet and Hecla interests was 
 uncovered. In those days the finding by hunters 
 and woodsmen of old copper pits dug by the 
 ancient miners was of frequent occurrence. But 
 nobody knew that these had been opened up for 
 the purpose of obtaining copper. Nobody knew 
 that there was such a thing anywhere around as 
 copper. The secret had died with the ancient 
 miners. 
 
 The story goes that one day a man out hunt- 
 ing wild hogs, which were very plentiful then, 
 routed out a big bristly fellow which made fast 
 time through the timber, somehow managing to 
 evade the two shots the hunter sent after him. 
 But a hog is too short-legged and heavy-bodied 
 to run very fast, and the hunter kept this one in 
 sight till he vanished into one of the strange pits 
 which marked the neighborhood. 
 
 This was surely a huge mistake on the part of 
 Mr. Piggy, so far as his welfare was considered. 
 But for the welfare of the world at large it was 
 one of the most fortunate things that ever hap- 
 pened. When the hunter came to the brink of 
 the hollow, the animal was frantically trying to 
 scramble up the farther side, making the dirt fly 
 with his sharp-pointed little hoofs. He presented 
 a capital mark during his slow headway. Having 
 rammed home another charge in his gun, the man
 
 WHERE COPPER IS KING 81 
 
 took careful aim and this time brought the hog 
 to earth. 
 
 As he came up to get his trophy, the hunter 
 noticed something bright shining on the ground 
 where the animal's hoofs had scraped off the thin, 
 overlying earthy deposits. Looking closer, he 
 found several other salmon-colored pieces of 
 rock like the first. He did not know copper 
 when he saw it, but was sufficiently interested 
 in the luster of the pretty bits of rock to 
 chip off some pieces with his hunting-axe, and 
 later on showed them to a friend who was better 
 posted in geology than himself. This friend, 
 greatly excited, told him that the bits of rock 
 contained superb specimens of copper, and wished 
 to be led to the old pit. There more investigation 
 showed the rocky ground to be fairly studded 
 with ore containing the rich, pure copper. The 
 vein thus uncovered by an accident was the so- 
 called conglomerate vein which has been such a 
 bonanza to the Calumet and Hecla company 
 ever since. 
 
 When, in bygone ages, the rock of this section 
 had become molten, so intense was the heat from 
 below that such materials as gravel, sand and 
 rock, had been mixed with the pure molten copper 
 until all became a batter-like mass which cooled in 
 the form of a gigantic wedge or layer known to 
 geologists and miners as a "conglomerate" vein.
 
 82 SECRETS OF THE EARTH 
 
 From the surface this vein runs at a strong 
 angle down into the crust of the earth, as a far- 
 leaning post might do. Just how deep it goes 
 nobody knows, and probably never will know. 
 Shafts have followed it, however, very nearly two 
 miles down, and still the rich ore is there in large 
 quantities. 
 
 The Calumet and Hecla Mining Company was 
 organized fifty years ago, and began work on 
 two separate mines along the conglomerate vein. 
 One of these was called the Calumet ; the other, 
 the Hecla. Each mine consisted of numerous 
 shafts, so extensive was the layer. Later, as the 
 result of further exploration in the surrounding 
 country, other mines were opened up by the 
 organization. These were the Ahmeek, the Al- 
 louez, the Tamarack, the Centennial, the Isle 
 Royale, the Superior, the Laurium, and the La 
 Salle. A few years ago the Osceola mine, which 
 had belonged to another copper company, was 
 also taken over. 
 
 During all these years many another mine, too, 
 has been opened up by the C. and H. people, only 
 to be abandoned because copper was not found 
 in paying quantities after diamond drill had un- 
 covered deceiving amounts of the ore. So there 
 have been some "downs" sprinkled in with the 
 "ups," which Dame Fortune has handed out to 
 this big mining corporation, but the "downs"
 
 WHERE COPPER IS KING 83 
 
 have been of such small dimensions as compared 
 with the tape-busting "ups," that the business 
 has been a huge success from the very first. To 
 the two big conglomerate mines, the Calumet 
 and the Hecla, is due the chief credit for this 
 success, 
 
 But it is not the mere taking out of the copper- 
 bearing rock in which the Calumet and Hecla 
 company is interested. It practically owns the 
 two large counties, Houghton and Keweenaw, 
 where its mines are situated. And the township 
 of Calumet is really its own property, every inch, 
 except for one or two small lots. Houses, stores, 
 churches, schools and other buildings, are erected 
 in this township only because the C. and H. com- 
 pany says they may be. 
 
 The taxes on this real estate are paid by the 
 mining concern. It furnishes water, electric 
 light, fire protection, police protection, and all 
 other public conveniences, to all the various vil- 
 lages of the township. The company has built 
 churches, schools, libraries, theaters, hospitals, 
 and other public edifices. 
 
 Nor have amusements been forgotten. Excel- 
 lent baseball grounds and grandstands may be 
 found. Here play teams representing various 
 departments of the big copper industry, all of 
 which belong to a league. In the winter months 
 a hockey league is maintained in the same way,
 
 84 SECRETS OF THE EARTH 
 
 and skiing courses are laid out and kept in 
 the pink of condition. A brass band, famous 
 wherever it is heard, is another gift of the H. and 
 C. people to their employes. 
 
 There is still another secret of this company's 
 success, one which touches the employe even 
 more directly. When you think of a mining 
 camp your mind instinctively pictures a bunk- 
 house and the narrow streets and dirty, shambling 
 buildings of the mining settlements of the coal 
 fields. In the copper country you never see such 
 unsightly shacks. Instead you behold row upon 
 row of neat frame houses, each with its own lot 
 of 60-feet frontage, everything neat and orderly. 
 These houses are rented to employes at a low 
 rate, the rental including sewage system, free 
 water and free garbage collection. Coal is sold 
 to the tenant at cost price. Each back yard is 
 large enough for a pretty little vegetable garden, 
 and seldom will you find a home, as you pass 
 along, which does not raise enough vegetables 
 to supply the family table throughout the sea- 
 son with fresh, wholesome foods. 
 
 This company has produced close to $400,000,- 
 000 worth of copper since its organization, and 
 paid dividends of more than $125,000,000 on its 
 early $25 shares. And this is only one of several 
 sections in America where copper is king.
 
 VI 
 
 GOLD has long been esteemed as the most 
 precious of metals. From the earliest 
 period of the world's history it has been 
 used by man as his chief medium of exchange 
 for buying and selling; also for personal adorn- 
 ment in the way of jewelry. Although the 
 quantity of gold found, compared with other 
 metals, is very small, yet gold leads them all for 
 being well scattered over the universe. It is 
 found in nearly all hilly and mountainous 
 countries. 
 
 In its pure state gold has a deep yellow color 
 and a high metallic lustre. It is nearly as soft as 
 lead, and can be easily beaten out cold into sheets 
 so thin that you can see light through them. And 
 it can be drawn out so fine that a mere grain 
 will make 500 feet of wire, wire as dainty as the 
 finest spider's gauze. If you were to put it in 
 a fire you would be astonished to find that, 
 although so soft a metal, it will take 2,016 de- 
 grees Fahrenheit to melt it. While most of the 
 common acids will eat into such hard metals as 
 iron and steel, they have no effect whatever on 
 
 85
 
 86 SECRETS OF THE EARTH 
 
 gold. But chlorine and nitro-imiriatic acid will 
 corrode and dissolve it, forming what is called 
 chloride of gold, which is very soft and putty-like 
 and can be dissolved in ordinary water. 
 
 Did you ever suspect that your ring was not 
 solid gold? That your stickpin, your watchcase, 
 that five-dollar goldpiece in your purse, were not 
 the simon-pure, sure-enough yellow metal ? That 
 nobody, prince or pauper, wears jewelry made 
 of gold and nothing else ? 
 
 There is a very good reason why it should 
 not be pure. Generally speaking, all manu- 
 factured articles of so-called gold, whether money 
 or jewelry, are alloyed; that is, other metals are 
 mixed in with the gold. This is no humbug on 
 the buyers and users ; it is a good thing and per- 
 fectly lawful, provided the quantity of pure gold 
 in each piece of jewelry is plainly marked upon it 
 so that you know what you are getting. 
 
 You see, gold in itself is altogether too soft a 
 metal to stand the constant handling given coins, 
 and the wear coming upon jewelry. Very soon 
 the outlines and engravings would be obliterated, 
 and all form, beauty, and character, lost. In the 
 case of money it would even give rogues a good 
 chance to scrape gold off of coins, or "sweat" it 
 off with acids, and still be able to dispose of them 
 at face value. 
 
 So the mints and goldsmiths put harder metals
 
 WONDERS OF GOLD 87 
 
 with gold in order to make money and jewelry 
 wear longer. Copper and silver are the alloys 
 commonly used. These blend nicely with the 
 lustre of the gold, and if used sparingly do not 
 change it materially while giving it much longer 
 life. The goldpieces of the United States con- 
 tain about eleven parts gold to one of copper. 
 Jewelry is marked by "carats" (K), a carat be- 
 ing an old-time weight equal to l-24th of a 
 troy ounce. Pure gold is spoken of as being 
 "twenty-four carats fine"; therefore, if you have 
 a ring marked "14 K" you know that fourteen 
 parts of it are gold, and ten parts alloy. Jewelry 
 of a light yellow color denotes silver alloy, which 
 is the most durable. If the yellow is quite deep 
 you may confidently believe that copper has 
 been used. 
 
 Not only is gold extensively employed in coin- 
 age and ornaments of dress, as well as plate, but 
 we find it widely used in the arts for gilding and 
 plating, as it imparts to materials often the most 
 worthless the semblance of its own unrivaled 
 richness and splendor. 
 
 Just when or where gold was first discovered 
 and made use of will probably never be known, 
 but we do know that it was familiar in the time of 
 King Solomon, who used it lavishly in his temple; 
 and even before this, when the Lord requested 
 Moses to employ it generously in constructing
 
 the famous ark of the covenant. "And thou shalt 
 overlay it with pure gold, within and without 
 shalt thou overlay it, and shalt make upon it a 
 crown of gold round about. And thou shalt cast 
 four rings of gold for it, and put them in the 
 four corners thereof; and two rings shall be in 
 the one side of it, and two rings in the other side 
 of it." 
 
 There is an old account of a province visited 
 by De Soto in his expedition of 1538-40, which 
 was located in the section now known as North 
 Carolina. At the time of the Spanish invasion 
 the country was ruled by a beautiful Indian 
 queen called Xualla. Here De Soto found 
 trinkets and ornaments of gold, and tomahawks 
 formed from an alloy of gold and copper, and 
 his adventurers were wild with the thought that 
 a great gold lode itself must be near. But they 
 searched in vain, and finally went away disap- 
 pointed. The Indians kept their secret. The 
 white men did not know that less than fifteen 
 miles from them, on the Carolina side of the Sa- 
 vannah River, lay one of the richest gold 
 deposits in the world. In 1820, however, Ameri- 
 cans found this and began to mine it. Within 
 ten years the annual output was close to half a 
 million dollars. At Charlotte a United States 
 mint was established, to coin the gold conven- 
 iently.
 
 WONDERS OF GOLD 89 
 
 Closely following this, gold mining was opened 
 up in Virginia, then in Georgia, Alabama and 
 Tennessee. Georgia has been the greatest pro- 
 ducer of any of the Southern States. These 
 mines supplied most of the gold in the United 
 States up to the time of the great discovery of 
 the yellow metal in California, in 1849. The 
 credit for this discovery goes to James W. Mar- 
 shall, who "struck it" rich enough to excite him- 
 self into widely publishing the news, causing a 
 grand stampede of adventurers into the State 
 from all quarters of the country. 
 
 But there were really others who first found 
 gold in California. Its existence was known to 
 both Indians and Mexicans long before Marshall 
 could lisp his own name. According to Spanish 
 records and maps, gold had been taken out of 
 Arizona and California by Spanish-Mexican 
 miners as early as 1748, a good hundred years 
 before the "discovery" in California. But it is 
 safe to believe that the native red men had used 
 the metal before this. Shortly after the organiza- 
 tion of the Catholic missions in Lower California, 
 the Indians who were sent into the upper country 
 to persuade other natives to submit to the guard- 
 ianship of the priests spoke of the "shining sands" 
 in the streams which they crossed in their journey. 
 Some even returned wearing crudely beaten 
 bracelets made of the rich yellow material. How-
 
 90 SECRETS OF THE EARTH 
 
 ever, the whites they met suffered the "shining 
 sands" to remain where nature had placed them, 
 because the priests declared the search for gold to 
 be evil in the sight of God. 
 
 As we have said, a man by the name of James 
 Marshall was the first to awaken wide interest 
 in the gold in California. Marshall was engaged 
 by one Captain Sutter to build a sawmill at Co- 
 loma, on the American River. Marshall hired 
 Peter L. Wimmer and his wife, Elizabeth Jane, 
 to go with him, to assist in the work. They ar- 
 rived at their wild destination in the year 1847, 
 and at once proceeded to erect a little shack in 
 which to live. As soon as this was done the men, 
 with ten Indians who had accompanied them, be- 
 gan to put up the sawmill. 
 
 The work progressed slowly, as the Indians 
 were poor carpenters. But during the month of 
 December, the dam and headgate had been com- 
 pleted. Water was turned on at night, so as to 
 wash out the sand and gravel which had been dug 
 up by the men during the day. Every morning 
 Marshall inspected the millrace, to see how well 
 the washing had cleaned it out. On these occa- 
 sions he often noticed tiny shining specks in the 
 bottom, but being unfamiliar with the appear- 
 ance of gold, paid no heed to them. 
 
 On the morning of the 19th of January, 1848, 
 both Marshall and Wimmer were walking lei-
 
 WONDERS OF GOLD 91 
 
 surely along the tailrace of the mill, when all at 
 once the former stooped over and picked up a bit 
 of glinting substance that lay on a flat rock in 
 the now dry bed of the race. Over and over he 
 turned the object in his hands. The more he in- 
 spected it the more he was struck with its close 
 resemblance in outline to the "bear" which had 
 adorned the State flag he had lately helped to 
 raise as an emblem of California's independence. 
 While he admired the deep lustre of the speci- 
 men, he would never have picked it up except for 
 this remarkable resemblance it bore to that 
 "bear." 
 
 Handing it to Wimmer, he said, "What do you 
 think of that, Pete?" 
 
 Peter took it, juggled it a moment, squinted 
 closely at it, then exclaimed, "Jim, I'll bet a 
 cooky that's a chunk of solid gold. I'd gladly 
 let you pay me off in that metal!" 
 
 Jennie Wimmer, the housekeeper, had pre- 
 pared to make a kettle of soft soap that day. The 
 two men had fixed her kettle of lye over the fire 
 before they left the cabin. 
 
 Now Marshall spoke up. "Pete," said he, "we 
 will send this lump to Jennie, and let her boil it 
 in her soap-kettle all day. If it doesn't tarnish 
 it must surely be gold." 
 
 Wimmer then called his young son, and the 
 boy started home with the message and the shin-
 
 02 SECRETS OF THE EARTH 
 
 ing thing clutched in his fist. On the way he saw 
 a saucy squirrel. Before he thought he had made 
 a missile of his possession, but though he missed 
 his mark he very luckily struck the trunk of the 
 tree to which the squirrel had been clinging, and 
 was able to find it again. Afraid to risk another 
 shot, he went on to his mother with the yellow 
 "stone." 
 
 No inquiry was made about the specimen until 
 the next morning at breakfast. Then the men 
 began to joke Mrs. Wimmer about it. What 
 kind of soap had the "bear" made? Would it do 
 away with the necessity of grease in soap-mak- 
 ing? If so, there was plenty more of the stuff out 
 there in the sand and gravel! 
 
 Even Jennie had forgotten the lump in her 
 kettle for the moment. She now went to it, 
 poured the soft-soap into a hewed trough made 
 to receive it, and at the bottom found the lump - 
 a beautiful, lustrous thing, polished bright by the 
 action of the lye. Quickly she returned to the 
 cabin with it, throwing it on the table before the 
 two men. "There is your nugget !" she cried. "I 
 knew it was pure gold the moment I saw it. Now 
 you can see it for yourself!" 
 
 Other small nuggets were collected by Mar- 
 shall and Wimmer. Four or five days later, the 
 former took them to Fort Sutter, where he was 
 called to report progress to Captain Sutter him-
 
 93 
 
 self. Here convincing tests of the nuggets were 
 made with nitric acid, and Captain Sutter accom- 
 panied him back to the mill on his return. 
 Everybody was greatly excited. Marshall gave 
 his first nugget to Mrs. Wimmer, saying that she 
 could have it to make a ring. Instead of complet- 
 ing the sawmill, every one went to gathering in 
 the precious gold. Yellow grains of rock were 
 to be preferred many times over to yellow grains 
 of wood. Let sawdust take care of itself! But 
 a little later the mill was finished and sawed the 
 lumber to make cabins and "rockers." 
 
 Today none of that little group who were first 
 in the field are alive. James W. Marshall died 
 in 1885, alone, in his cabin at Kelsey's Diggings, 
 Eldorado County, with not enough money to pay 
 his funeral expenses. Like the others of his lit- 
 tle company he had found much gold, but he 
 could not keep it. 
 
 News of the finding of large quantities of gold 
 in the Coloma district spread abroad like wild- 
 fire. In nearly every city and town of the North 
 and South, and even the East, men left their 
 work and hied excitedly westward in groups or 
 singly. By the spring of 1849 more than thirty 
 thousand brave, adventurous fellows had gath- 
 ered at Independence, Missouri; Leavenworth, 
 Kansas; St. Joseph, Missouri; and Council 
 Bluffs, Iowa, ready to face the dangers and trials
 
 94 SECRETS OF THE EARTH 
 
 of the long trip across the plains and mountains, 
 where lurked the fiercest of wild animals and the 
 most treacherous of Indians. In long caravans 
 of canvas-canopied wagons they moved, many 
 with their wives and children. Finally they ar- 
 rived but numbers were missing, pathetic 
 mounds of earth all along the weary trail mark- 
 ing the last resting-places of women, children 
 and men. 
 
 The quartz rock which contains the gold is 
 found in narrow veins which fill up what were 
 once open cracks in the older rocks. This quartz 
 vein is so much harder than the other rocks that 
 the wind and the rain and the frost cannot eat or 
 break it away. As the soft rocks on each side of 
 it are worn away the gold quartz is robbed of 
 support; it falls down, and is left in lumps on 
 the hillside. When the winter and spring floods 
 come the pieces of quartz are carried down by 
 the rushing waters into the bed of the nearest 
 mountain stream. There the current knocks 
 them against coarser rocks and boulders until 
 they are smashed to atoms. The small, heavy 
 particles of gold drop to the bottom, and the rest 
 of the rock bits, being lighter, are carried away 
 to some large river. 
 
 A great many grains of gold, however, take 
 another course. These cling to the ground and 
 are not carried into streams by the rains and
 
 WONDERS OF GOLD 95 
 
 floods, for the very good reason that they lodge 
 in crevices of rocky slopes which protect them 
 until loose gravel, sand and earth, are plastered 
 over them by the settling waters. As the years 
 go by the accumulation of dirt on top of them in- 
 creases, and they become well buried. 
 
 You will see by this that the streams offer a 
 chance to get gold with the least exertion, as it is 
 already exposed, or at least very nearly so. It is 
 for this reason that the miners who first rushed 
 into the California gold fields sought out likely 
 streams and looked for what they wanted 
 in the gravel and sand of their beds. This type 
 of mining, which had no real digging to it, they 
 called "placer mining." Each miner had a pan 
 of tin or iron which he filled about half -full of 
 the gravel, or "pay dirt," as he called it. Then 
 holding it under water, he shook off the stones 
 and mud over the side of the pan, leaving grains 
 of gold mixed with black sand at the bottom. 
 This black sand was iron pyrite. By skilfully 
 dipping the pan under the water, and giving it a 
 whirling motion, and a tilt now and then, prac- 
 tically all of the black sand was coaxed over the 
 edge of the pan, leaving small particles of free 
 gold in the bottom. 
 
 You might find it interesting to try out this 
 method of placer mining in a make-believe way, 
 then you will have a very vivid idea of just how
 
 96 SECRETS OF THE EARTH 
 
 the miner does it. In a dish-pan put some coarse 
 sand, some gravel, a little clay or mud, and a 
 handful of shot varying from the finest bird shot 
 to BB. Hold the pan in both hands under a 
 running faucet and manipulate it constantly with 
 a whirling and tipping motion in the manner pre- 
 viously described. The aim is to get all the soil 
 matter out of the pan without losing any of the 
 shot. The quicker you can do this the better 
 "gold miner" you are. 
 
 Any earth which yields ten cents worth of 
 gold to the pan is known as "pay dirt." Fifteen 
 cents to the pan is good. Twenty cents to the 
 pan is rich. About forty panfuls can be washed 
 out by one man in a day. 
 
 Another contrivance which soon came into use 
 in the California gold fields was the "cradle." 
 This was a long box, sometimes only a hollowed- 
 out log. At the top was a sieve which sifted out 
 the stones. Nailed to the bottom were small 
 cleats of wood, or "riffles," which kept the water 
 from running so fast as to sweep the gold out of 
 the cradle with it. 
 
 This device was placed on rockers, and was 
 also tilted slightly. The miner shoveled the 
 gravel into the top of the cradle, and his partner 
 rocked it. The sieve held back the stones, the 
 water broke up the lumps of earth and gravel, 
 washed them down the cradle, the grains of gold
 
 WONDERS OF GOLD 97 
 
 were stopped by the riffles, and sank to the 
 bottom. 
 
 Placer mining is the simplest of all processes 
 for getting gold out of the ground, but it can only 
 be operated on a paying basis where a supply of 
 water can be had for the sluicing purposes. 
 Even then the profits as a rule are not very large. 
 The early miners were not long in recogniz- 
 ing this fact. At first they thought only of get- 
 ting the free gold, or that which lay in the sand 
 and gravel, but after awhile they got to think- 
 ing that that gold dust must have come from 
 some place where there was probably much more 
 of it, and they began to trace it. Thus they fol- 
 lowed up the streams into the mountains. As 
 they went they made many important discoveries. 
 They found that this gold had come from beds 
 where in ancient times rivers had flowed. There 
 was gold still remaining in these beds, but it was 
 covered quite deeply with layers of gravel, sand, 
 and soil, leaves and moss, making a good deal of 
 digging necessary. 
 
 The men used to placer mining soon began 
 to frown. The digging was very hard. Worse 
 still they often spent days and weeks making a 
 pit, only to find less than ten cents' worth of gold 
 in it. Some of the greenhorns found what they 
 thought were wonderful nuggets, but older 
 miners laughed heartily when they brought the
 
 98 SECRETS OF THE EARTH 
 
 specimens to them, and said they had discovered 
 pyrite, or "fool's gold." 
 
 Finally some miner, tiring of digging, thought 
 that if a powerful stream of water could be di- 
 rected against the great banks of earth, the layers 
 of soil could soon be washed away on a wholesale 
 plan, the muddy flood diverted into sluices, and 
 the gold easily separated and saved. This was 
 done. Great reservoirs were built high up in 
 the mountains, and water was brought down 
 by means of ditches, pipes or flumes, to the 
 scene of mining operations. The ditches and 
 flumes poured the waters directly out upon the 
 banks, like a stream; but the pipes had a large 
 hose fastened to them, such as a fireman uses, 
 with a nozzle at the other end, from which a 
 swirling, gushing stream could be thrown any- 
 where within reach by the miner handling the 
 hose. This is called "hydraulic mining," and 
 usually brings far better returns than placer 
 mining. 
 
 After a few years large companies had been 
 organized for mining gold in California on a sys- 
 tematic basis. These men employed skilled geol- 
 ogists and mining engineers to help them, and 
 bought the best equipment they could get for 
 working. They determined to sink deep holes 
 or shafts down into the hillsides, wherever tests 
 showed a good gold vein existed, and from each
 
 WONDERS OF GOLD 99 
 
 shaft run off horizontal tunnels or levels, so that 
 the gold in the white quartz rock could be reached 
 with pick and shovel. The placer miners laughed 
 at them, and called their shafts "coyote holes"; 
 but in time the placers failed, and then that class 
 of men changed their tune, especially when they 
 saw the great quantities of gold that were being 
 taken out of the regular mines. Today prac- 
 tically all gold comes from the white quartz veins 
 of this sort of mine, and is garnered a good deal 
 the same way as coal and copper. 
 
 A vein of gold is the most uncertain thing in 
 the world. You may find it quite thick where 
 you first strike it, then as you begin to go down 
 into it, it may run thinner and thinner until it is 
 a mere thread, and finally plays out entirely. On 
 the other hand it may be very thin where first un- 
 covered, and then surprise you by growing wider 
 and richer as you follow it down. Often in a 
 comparatively narrow streak, great bulges or 
 swellings called "lodes" will occur here and 
 there, like balls on a spindling chair leg. Such 
 lodes are pockets of the finest treasure, and every 
 miner dreams of the moment he may run into 
 one as he laboriously picks away. 
 
 As a rule all gold mines produce paying 
 amounts of silver also. The silver is found in 
 the quartz occasionally, and of course is always 
 saved.
 
 100 SECRETS OF THE EARTH 
 
 When the broken rock of the gold mine is 
 raised to the mouth of the shaft, it is sent in cars 
 to a stamping mill. Here the ore is fed into a 
 great steel box called a "mortar." Immense 
 hammers, often weighing a thousand pounds 
 each, drop down upon the ore, one after another, 
 until it is fine enough to go through a wire screen 
 in the front of the mortar. You may well im- 
 agine that when several hundred of these ham- 
 mers as happens in large mills are pounding 
 away with all their might, a stamping mill is a 
 pretty noisy place. 
 
 The ore, crushed to a fine powder, now runs 
 over sloping tables covered with copper. Stick- 
 ing to the top of the table is a film of quicksilver. 
 This holds fast all the gold grains, and unites 
 them in a mass, which is scraped off from time to 
 time. Later the golden plaster is subjected to 
 enough heat to drive the quicksilver from it. 
 
 Another method of separating the rock from 
 the pure gold is by the cyanide process. Cyanide 
 is mixed with water to form a strong solution, 
 and into this the crushed gold ore is thrown. The 
 cyanide element in the water causes the gold to 
 dissolve and the false rock to sink to the bottom. 
 The water with the liquid gold is then run into 
 boxes filled with zinc shavings. The gold par- 
 ticles cling to the shavings like a burr to a dog's 
 tail, giving them a sort of gold plate. The shav-
 
 WONDERS OF GOLD 101 
 
 ings are finally placed in a furnace, which causes 
 the zinc to melt first and run off, leaving the gold 
 free. 
 
 When news of the discovery of gold in Cali- 
 fornia reached Australia, it was not believed at 
 first, but when a vessel arrived at Sydney from 
 those gold fields, with 1,200 ounces of gold on 
 board, the whole island went wild. In July, 
 1849, a British barque sailed from Australia with 
 168 passengers, of whom was one E. H. Har- 
 graves, a keen observer of rocks and soils. As 
 soon as this ship arrived at San Francisco, all 
 hands except the crew made for the gold fields. 
 Mr. Hargraves had not been working long be- 
 fore he noticed that the geological structure was 
 very much like that of New South Wales, where 
 he had passed more than eighteen years. He told 
 his companions he believed there might be gold 
 in Australia, too. He was laughed at, but he 
 did not give up his idea. 
 
 In January, 1851, he landed back in Sydney, 
 bent upon testing out his faith. A month later 
 he set out on horseback for the point where he 
 intended to make his first explorations. Finally 
 he stopped at a wayside hotel which was operated 
 by a Mrs. Lister. She was a refined, bright 
 woman, driven into the occupation by misfor- 
 tune. Mr., Hargraves asked her if she knew 
 where he could get a guide, and told her of his
 
 102 SECRETS OF THE EARTH 
 
 enterprise. She was quite enthusiastic with the 
 plan, and promised to send her young son with 
 him as guide, saying the latter knew the country 
 thereabouts like a book. 
 
 Fifteen miles from Guyong, Mr. Hargraves 
 washed his first pan of dirt. Sure enough, he 
 found gold more than he had in California ! He 
 was greatly excited. He tried a second pan. 
 More gold yet ! His excitement grew. A third 
 pan what would that bring? The 'third pan 
 was washed. In the bottom were many glitter- 
 ing particles of yellow. The gentleman turned 
 to his young companion, and cried: "Lad, this 
 is a remarkable day in the history of New South 
 Wales. I shall be a baronet, you shall be 
 knighted, and my old horse there shall be stuffed, 
 put in a glass case and sent to the British 
 Museum!" 
 
 It turned out in part that way. While the 
 horse was never stuffed, nor the boy guide 
 knighted, Mr. Hargraves himself was knighted, 
 and given a pension for life. 
 
 With his discovery the California gold fever 
 waned and transferred its great heat into Aus- 
 tralia, where in a short time every miner with suf- 
 ficient money to pay his passage was headed. 
 There were not nearly enough ships to carry 
 them. And they came from all countries. One year 
 later, 105,000 miners were encamped at three
 
 WONDERS OF GOLD 108 
 
 gold centers: Ballarat, Bendigo, and Castle- 
 maine. In five short years Melbourne rose from 
 a town to be the foremost city in the Southern 
 Hemisphere. Reports of panning $100 to $200 
 per day, and of finding nuggets worth thousands 
 of dollars, upset even the most sober-minded. 
 Farms, shops, ships, were deserted. It was 
 shearing time, but there were no shearers; it 
 looked as if when harvest time came there would 
 be no one to gather in the crops. 
 
 In Queensland, in 1886, the famous Mount 
 Morgan mine was opened. This wonderful mine 
 proved to be literally a mountain sandwiched 
 with gold. At once it began paying dividends 
 of $2,000,000 a year, and to-day it is still produc- 
 ing that much in gold, but added to this immense 
 profit is another one now derived from great de- 
 posits of copper which have been unearthed by 
 the company in the same mine. 
 
 But in all the history of gold excitements, the 
 Klondike craze, awakened in the year 1896 in 
 Alaska, is probably without a peer. For years 
 the great movement kept up, and Alaska was 
 opened to the outside world. Like most great 
 booms, however, it was short-lived. Now the gold 
 mined in the Klondike region is a negligible 
 quantity. 
 
 In Alaska the greatest difficulty in min- 
 ing is the cold. Not only do the miners have
 
 104 SECRETS OF THE EARTH 
 
 to be bundled in heavy furs, but the ground is 
 frozen so hard the year around that they cannot 
 scoop up gravel, or make a hole down into it, until 
 it is first thawed out by building fires upon it or 
 by using pipes filled with scalding steam. The 
 steam is projected through a sharp nozzle which 
 is driven gradually down into the softening 
 ground. 
 
 The hills and mountains of Alaska contain un- 
 told and undreamed of wealth. But for the ex- 
 treme weather conditions, it is quite probable that 
 we should have long ago opened up these vast 
 treasure chests of valuable ores and exposed them 
 to the wonder of other nations. One of these 
 days either science or the mere physical bravado 
 of Americans will do the trick. It is bound to be 
 performed. 
 
 When several grains of gold gather together in 
 a mass they form what miners call a "nugget." 
 Nuggets are the great prizes for which the aver- 
 age miner works and looks forward to finding. 
 The largest one known was found in Australia, 
 at Ballarat, in 1858. It weighed 2,159 ounces, 
 and was sold for $42,000. A boy could not carry 
 such a lump of gold without a cart or wheelbar- 
 row. When found this nugget was 190 feet deep, 
 in the white quartz of the earth, was irregular in 
 shape, and much honeycombed by the action of 
 water.
 
 WONDERS OF GOLD 105 
 
 Although America has produced no record- 
 breaking nuggets, she has, nevertheless, given up 
 some that were very close rivals of those found in 
 Australia. A prospector named Martin found 
 one in Arizona weighing 151 pounds. The dis- 
 covery came about in a queer way. Martin and 
 a comrade were encamped in a canyon, when a 
 cloudburst caused the stream to rise so rapidly 
 that they were caught. The comrade was 
 drowned, but Martin escaped, though severely 
 injured. After the torrent had subsided he re- 
 turned to bury his friend, whose body he found 
 lodged under the roots of a tree. In dislodging 
 the body he saw beside it the huge nugget. It 
 surely seemed that Providence had rewarded him 
 for his faithfulness to this friend. 
 
 Twenty-eight States and dependencies of this 
 country produce an output of gold. In 1918 this 
 totaled 3,320,748 fine ounces, with a value of 
 $68,646,700. 
 
 The Rand mines of South Africa, owned and 
 controlled by the British government, have 
 proved the greatest gold "find" of history. In 
 1918 they produced over half of the gold mined 
 in the world. The mines are being worked con- 
 servatively, with no attempt to get as much as 
 possible in the shortest time and thus flood the 
 world's gold market.
 
 VII 
 
 IN Nevada there is a famous silver mine called 
 the "Comstock." Strange as it may seem, 
 Mr. Comstock, for whom the mine was 
 named, was not the discoverer. Nor was this 
 world-renowned silver mine a silver mine at all in 
 the beginning of its fame, but a gold mine of 
 great promise and large output. 
 
 Ten years after the discovery of gold in Cali- 
 fornia, the placers in that country began to 
 become exhausted, and miners began to look else- 
 where for the precious yellow metal. Among 
 these roamers were two Irishmen, Peter O'Riley 
 and Pat McLaughlin. The restless pair finally 
 drifted into what is now the State of Nevada. 
 Here one day a hunter told them that he had seen 
 some gold taken out at the foot of Mount David- 
 son, and they made haste to that locality. But 
 while they found gold, there was a discouraging 
 scarcity of it for some time. Finally they decided 
 to sink a hole for water. When four feet down 
 their picks struck a strange, black-looking dirt, 
 a sort of decomposed ore. 
 
 At first the peculiar earth was given no more 
 106
 
 THE STORY OF SILVER 107 
 
 than a curious inspection by both miners, but 
 after a while McLaughlin determined to test it 
 in a crude fashion. Therefore he put some of the 
 dirt in his rocker and washed it out. The result 
 was astounding. The bottom of the rocker was 
 literally covered with pure gold. In a few min- 
 utes the two Irishmen were working feverishly in 
 the black dirt, as if they had gone daft, and were 
 taking out gold at the rate of $500 a day. 
 
 About this time a miner named Comstock 
 came upon the scene, and claimed the ground as 
 his by right of previous discovery. There was 
 really some foundation for his claim, as he had 
 actually visited the locality before the Irishmen, 
 and had staked out a claim. When O'Riley and 
 McLaughlin became convinced of the truth of 
 Comstock's story, they offered to take him in as 
 a partner, but would concede no more. To this 
 Comstock agreed, when he learned that the others 
 were willing that the property should be named 
 after him. 
 
 As the gold lode was sunk deeper and deeper 
 it began to thin out, so that it no longer yielded 
 one-third yellow metal, and its fame began to 
 tarnish. But it was only a momentary setback. 
 With the thinning of the gold-bearing strata, a 
 rich silver vein was struck, which soon developed 
 into many other equally rich veins of almost pure 
 horn silver. In a short time the Comstock mine
 
 108 SECRETS OF THE EARTH 
 
 was more famous than ever, but now as a silver 
 mine instead of a gold mine. 
 
 Only one mine on earth ever surpassed the 
 Comstock in its output of silver. This was the 
 lode known as the "Veta Grand," near the city of 
 Zacatecas, in Mexico. The Veta Grand mine 
 is also one of the oldest in North America, having 
 been in operation before the days of Cortez. This 
 mine has turned out about a billion dollars' worth 
 of metal, while the Comstock has equalled half 
 that amount, with $100,000,000 in gold added. 
 
 The processes by which nature forms deposits 
 of silver ought to be almost as interesting to the 
 ordinary reader as to the prospector himself. 
 The earth's crust, of course, is lavishly veined 
 with watercourses. This water runs, trickles, and 
 seeps, everywhere through the rocks beneath our 
 feet. As it goes it rubs off or wears away bil- 
 lions of tiny particles of earth and rock along its 
 path, thus forming certain chemical solutions 
 which have in them a portion of the precious 
 metal itself, grains of which have been gathered 
 here and there after the terrific heat and gases 
 below have projected them upward through fis- 
 sures and have crystallized them at the surface. 
 
 These countless underground streams, flowing 
 hither and thither, through this crevice and 
 pocket, and into that fissure and seam, always 
 are leaving behind them some of their sediment.
 
 THE STORY OF SILVER 109 
 
 Slowly the pockets fill up with the silver particles, 
 which become a solid mass mixed with other min- 
 eral matter, or as miners call it, a "lode." To 
 accomplish this it has taken centuries. Thus cran- 
 nies in the rock in every direction, if at all reach- 
 able by water, may in time become filled with 
 the precious metal, as if a myriad of invisible 
 hands were fetching the treasure from all sides 
 and hiding away a bonanza to enrich some future 
 lucky prospector. 
 
 In the Comstock mine great and unusual 
 dangers were met in getting out the ore. The 
 vein of quartz which bore it was fifty or sixty 
 feet wide. Some of this was very soft, some very 
 hard. Pillars held up the tunnel roof all right in 
 the hard sections, but the soft rock persisted in 
 continually falling in until the walls were literally 
 covered with heavy posts standing side by side 
 on end, across which was a close lathing of similar 
 timbers to support the fickle roof, all bolted se- 
 curely together. In other places great hollow 
 pillars were formed by laying squared timbers in 
 a square formation, one upon the other, rail-fence 
 fashion. 
 
 Water also bothered the miners tremendously 
 for a time. The surrounding earth seemed full 
 of small streams. Seldom was a new pocket cut 
 into, or a tunnel lengthened, than water gushed 
 out with more or less force. Some of these out-
 
 110 SECRETS OF THE EARTH 
 
 lets could be plugged up again, but others could 
 not, and the latter made the diggings very muddy 
 and wet in spite of the pumps which were con- 
 stantly sucking out the inflowing water through 
 long pipes. Then there were the "water pockets" 
 which a pick sometimes encountered. These 
 large reservoirs of water in the walls would rush 
 out with a roar, and for the time being would 
 flood that portion of the mine and drown the 
 unlucky miner who was slow in running away. 
 These water pockets often contained strong min- 
 erals, such as sulphur, which hurt the miners' 
 eyes and lungs when the waters were first freed, 
 and many a poor chap had to be carried out of 
 the mine by his comrades for medical attention. 
 
 In addition, much of this inflowing water was 
 very hot, so hot as to scald the skin when it 
 struck, especially in the deeper workings of the 
 mine. Miners here worked stripped to the skin, 
 and though ice was sent down to them, they could 
 stand it for only short periods, and other shifts 
 took their places. 
 
 Finally a mining engineer named Sutro 
 planned to remedy the water nuisance by driving 
 a big four-mile-long tunnel through the heart of 
 the mountain, letting out the hot water and the 
 foul air. The mine owners quickly raised the 
 money for this huge undertaking, and the tunnel 
 was put through as designed. It was a fine sue-
 
 THE STORY OF SILVER 111 
 
 cess. Out went the hot water as fast as it came 
 in; and in came bushels and bushels of clean, 
 fresii air. From the very beginning the Corn- 
 stock mine was so ready to originate and follow 
 improved mining methods that it was called the 
 mining school of the world. To-day, however, it 
 is a poor producer, and seems practically played 
 out. 
 
 Silver is one of the oldest known metals. 
 Along with gold it was familiar to the ancients, 
 and much esteemed by them not only as a 
 medium of exchange but as a decorative sub- 
 stance. The Hebrews called it Keseph, mean- 
 ing "to be pale." The Greeks knew it as argyroa, 
 signifying "shining." 
 
 The ceiling of the pavilion of the Peacock 
 Hall in Delhi was originally covered with silver 
 filigree work, but in 1799 the Mahrattas, after 
 the capture of the city, took the silver down and 
 melted it. The value of this mass was then 
 estimated at one million dollars. The silver of 
 course came from the early mines of India. 
 
 From time immemorial the mines of Peru have 
 been fabulously rich in silver products. Silver 
 was really the cause of the barbarous acts of the 
 Spaniards in their conquest of that country, the 
 reason for their murdering the people and plun- 
 dering the tombs of the Inca kings, the royal 
 repositories and ancient temples, all gorgeously
 
 112 SECRETS OF THE EARTH 
 
 ornamented and stored with silver. From the 
 Temple of Cusco the despoilers are said to have 
 secured more than eleven million dollars' worth 
 of the precious metal. 
 
 But in spite of the comparatively large silver 
 production of Peru, our own United States 
 exceeded it by more than six times during the 
 last few years, leading all other countries. Mexico 
 was a close second, with Canada, Turkey, and 
 Peru in order. In 1918 the United States pro- 
 duced 67,810,100 fine ounces, and Mexico fol- 
 lowed closely with an output of 62,517,000 
 ounces. While decreasing the output of gold, the 
 World War demands greatly increased the pro- 
 duction of silver over previous years, as silver 
 sold at a higher price and consequently became 
 more profitable to mine, and there was an 
 enormous need of it for paying off soldiers and 
 meeting other national expenses. Nearly all 
 countries find more or less silver within their 
 domain, and about half the States of our nation 
 have mines in operation. Utah and Montana are 
 the leading producers. 
 
 Silver in this country is almost entirely mined 
 as a by-product of copper, lead, or gold itself. 
 Were it not for the other minerals found with 
 silver it would not pay to mine it, but since there 
 is always more or less silver in copper and lead 
 ores it is easily obtainable. Though it is rarely
 
 THE STORY OF SILVER 113 
 
 found in pure chunks, nuggets have been dis- 
 covered which weighed several hundred pounds. 
 Silver is also found in sea water, and small quan- 
 tities in the form of chloride have been detected in 
 volcanic dust. 
 
 As a product of the sea, we might say that for 
 several years mining under the most unfavorable 
 conditions was carried on at Silver Islet, a 
 storm-beaten ledge situated about one mile from 
 the mainland of Lake Superior, not far from 
 Thunder Cape on the Canadian side. The ore 
 when first discovered appeared as shining streaks 
 of white, from three to ten feet under water, and 
 proved to be worth an average of $1,500 a ton. 
 It was of the kind known as "packing ore," and 
 was sufficiently rich to be packed in barrels and 
 smelted (purified) without further treatment. 
 The workings, which extended 1,000 feet under 
 water, were protected at great expense and risk 
 of life by a system of breakwaters, cribs, and 
 coffer-dams, ballasted with rock and clay. On 
 many occasions the furious storms of Lake Su- 
 perior have utterly wrecked the works, but they 
 have been patiently rebuilt each time. 
 
 Silver in its native state is a white, lustrous 
 metal which melts at a temperature of 961 de- 
 grees Fahrenheit. Of all metals it is the best 
 conductor of electricity. It is ductile, and capa- 
 ble of taking a high polish. It is also extremely
 
 malleable, being so tough that it can be drawn 
 out into the very finest of wire without breaking. 
 
 If you should take a thin film of silver and 
 hold it up to the light you would find that the 
 light would come through it, but would be blue 
 instead of white. If you should melt a lump of 
 silver it would immediately absorb twenty-two 
 times its volume in oxygen from the air, then 
 discharge this again as fast as it grew cold and 
 solid again. If you should drop this melted mass 
 into water, cooling it suddenly, the oxygen would 
 become imprisoned before it could escape freely. 
 The oxygen gas would then struggle until it burst 
 through the hardening crust, forcing up a part of 
 the fused silver into tiny little bubbles all over 
 the surface a phenomenon known as "spitting." 
 
 Silver forms ideal alloys with many metals. 
 That consisting of nine parts of silver to one part 
 of copper is the standard alloy used by the United 
 States for making its silver coins, its dollars, half- 
 dollars, quarter-dollars, and dimes. A similar 
 alloy is also used by our government for stamp- 
 ing out silver medals of honor, such as given to 
 its heroes in time of peace and war. When Uncle 
 Sam wants silver for any reason, he sends out 
 circulars describing the quantity and quality to 
 various silver mine owners or brokers, asking for 
 bids. The one whose price is lowest gets the 
 order. When the silver is received it is carefully
 
 tested, or assayed, by the government experts, to 
 see that it is up to the requirements. It is then 
 refined, mixed with the right amount of copper 
 to harden it, melted, and poured in molds, 
 coming out as bars of shining white metal. 
 
 The bars are run through steel rollers which 
 flatten them till they are converted into long 
 ribbons of silver just the right thickness for the 
 coin to be made. This wide ribbon is sawed into 
 strips of the width of the coin, following which 
 the strips go under a punch which cuts them into 
 many plain discs. A stamping machine, with 
 engraved steel die below and above, imprints the 
 design on both sides of the coins at one operation, 
 as they fall under it automatically. Still another 
 machine cuts a little bevel off the sharp edges, and 
 another one cuts in the little creases (called 
 "milling") around the outside. A big revolving 
 "drum," containing sawdust, receives the coins, 
 and tumbles them over and over and upon each 
 other for a long time. Finally they come out 
 smooth and beautifully white and lustrous, and 
 are carefully counted by girls, registered, put 
 into packages, and stored in strong vaults till the 
 banks of the country call for them. 
 
 Great quantities of silver are used in the arts 
 and industries of the world. For making jewelry 
 and silverware it is perhaps the most widely em- 
 ployed. Its greatest fault in either of these uses
 
 116 SECRETS OF THE EARTH 
 
 is its disposition to tarnish. No matter how pure 
 it may be, silver likes to unite with sulphur, and 
 it will always do so if there is a bit of it around. 
 The sulphur some of which is contained in the 
 yolk of so simple a thing as a hen's egg has a 
 tendency to turn the silver a bluish, smutty 
 black, and it is so prevalent in town and city life, 
 in the form of sulphureted hydrogen in the air, 
 that practically every silver owner meets more or 
 less of it, and has to scrub away with some kind 
 of fine grit on a cloth in order to keep the precious 
 metal nice and bright. 
 
 On the back of many silver articles, especially 
 tableware, you will see the words, "Triple plate," 
 or "Quadruple plate." This means that the 
 article is not solid silver, but contains a core of 
 some other metal upon which three or four films 
 (or "plates") of pure silver have been placed. 
 This is the best substitute for solid silver; it looks 
 just as well, in fact just the same, and if the 
 plating is heavy it may never wear through dur- 
 ing a person's lifetime. The plating is done by 
 an electrical process. Two metal rods are laid 
 across the open top of a jar containing a solution 
 of silver cyanide, potassium cyanide, and water. 
 From one end of a rod dangles the article to be 
 plated, hanging in the bath. From the other end 
 hangs a piece of silver plate. The rods are con- 
 nected with opposite poles of a battery. The
 
 THE STORY OF SILVER 117 
 
 electrical current passes through them, releases 
 the silver from the silver cyanide, and this is 
 deposited on the spoon, or whatever the subject 
 may be. The cyanide that has lost its silver then 
 begins to draw from the silver plate, to replace 
 it. This giving and taking process is continued 
 until the operator considers the plate on the 
 spoon heavy enough. He arrives at this decision 
 not by guesswork entirely, because he took the 
 weight of the core spoon before he placed it in 
 the jar or bath, and having determined the weight 
 of silver he wished deposited upon it, he simply 
 adds the two weights, and the sum is what the 
 finished spoon must weigh. So from time to time 
 he tosses it on a scale till the desired balance has 
 been attained. 
 
 Silver is used extensively in photography for 
 making dry-plates, films, and sensitized paper. 
 Compounded it is used to give a yellow color to 
 stained glass, to form silver nitrate and be cast 
 into sticks to be used as a caustic in medicine, to 
 act as the basis of many indelible inks, to give 
 foundation to some black hair dyes. Silver sul- 
 phide, formed by tarnish, is the groundwork of 
 the so-called "oxidized" finish so popular upon 
 many articles of art. This tarnish may be 
 removed by a weak solution of potassium cyanide, 
 which, however, is a deadly poison and must be 
 handled with extreme caution.
 
 VIII 
 DIAMOND, THE KING OF GEMS 
 
 T"1ROM the remotest ages there has been a 
 rl romance and fascination surrounding the 
 diamond which is far greater than that 
 belonging to any other form of personal adorn- 
 ment or belonging. At times other precious 
 stones have been valued more highly, but they 
 have never been regarded with the same strong 
 feeling which has attached to the "king of gems." 
 'Because of their rarity, diamonds were the exclu- 
 sive property of the proudest and most puissant 
 of princes, and the ornament of the most sacred 
 shrines. Their possession inspired respect of the 
 multitudes, and did much to enhance the power of 
 their owners. 
 
 The skin-clad barbarian, idly searching 
 through gravel banks along streams for sharp 
 stones from which to make his arrow and spear 
 points, was irresistibly attracted by the glit- 
 tering pebbles which cast back the sun's rays in 
 scintillating flashes, as his brown toes turned 
 them rollingly over. Such a prize he would keep, 
 unless some stronger warrior took it from him 
 by force, or at least until the tribal chief seized it 
 
 118
 
 DIAMOND, KING OF GEMS 119 
 
 as his right. Other pebbles might have brighter 
 color, might possess more interesting configura- 
 tions; but none had that bewitching, mysterious 
 play of shimmering, beautiful light effects given 
 off by the various sides and sharp edges of the 
 wonderful diamond pebbles. 
 
 As men became more civilized their admira- 
 tion for the diamond grew rather than 
 diminished. Its brilliant radiance held them 
 spellbound, and created in every beholder, 
 humble or rich, a keen desire for possession. 
 There seemed always a strange sort of per- 
 sonality about it, as of a living thing rather than 
 an inanimate object. Its moods seemed ever to 
 change, like those of a human being's eyes ; it sent 
 out to its beholder as many different messages, 
 inspired as many different fanciful thoughts in 
 him, as he viewed it from this angle and that, as 
 a living soul. This very weird quality wove 
 around it a strange, remarkable shroud of mys- 
 tery, awoke superstitions in man's breast that he 
 never dreamed had lain there, and gave rise to 
 stories and traditions of the most entrancing and 
 fanciful kind. The most remarkable story of all 
 that diamonds had been found in meteorites, or 
 "falling stars" was a true one. Present-day 
 scientists say that a meteor is a ball of liquid car- 
 bon and iron, which striking the cool earth would 
 possibly crystallize into diamonds.
 
 120 SECRETS OF THE EARTH 
 
 Rulers became so mad to possess the diamonds 
 that they made rigid laws that finders of them 
 should not keep them, but must turn them over 
 to the throne. To keep peace with pagan gods, 
 these ugly creatures were often adorned with the 
 finest of the gems thus brought in, and the altars 
 of the rulers themselves were lavishly set with 
 others. The smaller stones might be the subject 
 of barter, but the large and brilliant gems were 
 for the monarch and his heirs to use, if he saw 
 fit, as embellishments to religious shrines. 
 
 Out of the Orient, where diamonds were first 
 commonly known, came wondrous stories of the 
 beauty and splendor of the great gems owned by 
 potentates of those Eastern lands, and the 
 Western nations listened and were amazed. 
 Thus grew up a sentiment which has endured 
 even into this century, when discoveries of 
 diamonds in many lands have made the King of 
 Gems a possible possession for everyone with suf- 
 ficient money to purchase one. The diamond is 
 still looked upon as the most imposing of the 
 many articles by which wealth can be represented, 
 and the owner of a fine brilliant is accorded 
 something of the honor, even in democratic 
 countries, that has long been the heritage of 
 monarchs and queens. 
 
 The diamond is a thing of paradoxes. 
 Although known from the most ancient times, it
 

 
 DIAMOND, KING OF GEMS 121 
 
 is the newest of gems in its present form, for its 
 full beauty was never brought out until modern 
 cutting and polishing methods were applied, the 
 greatest advance in these finishing arts having 
 been made right here in our own country, the 
 result of special machinery. As another in- 
 stance of its paradoxical qualities, although the 
 diamond is always the symbol of wealth and 
 opulence, the diamond finders themselves have 
 never ceased to be, as a rule, the very poorest of 
 the poor. Again, should a stone have the 
 slightest tinge of color something that makes 
 other gems worth so much its value is at once 
 lowered; the whiter it is the more precious. 
 Lastly, though the old world has known the 
 diamond all its history, it remained for the new 
 world to create a market for the glittering 
 baubles. To-day most of the diamonds produced 
 by the world are sold in the two Americas, and 
 the great majority of these go to the United 
 States, where the gems are more commonly worn 
 than anywhere else on the earth. 
 
 You have no doubt heard the phrase, "Dia- 
 mond cut diamond," when reference is made to 
 two antagonistic forces of about equal strength. 
 This saying grew out of the fact that a diamond 
 is the hardest substance known, and that it can 
 only be cut with its own kind or its own kind of 
 grit. Of all precious minerals it is the only one
 
 122 SECRETS OF THE EARTH 
 
 composed of a single chemical element. This 
 element in the diamond is crystallized carbon. 
 It is found in all colors of the rainbow, and more. 
 Often it takes on a sooty blackness, like coal, but 
 these colored specimens have little value. It is 
 closely related to both coal and graphite, but of 
 course has undergone an entirely different chem- 
 ical fusion in the furnace of the earth at some 
 time in the dim, dim past. 
 
 In formation, a diamond closely resembles 
 wood, in that it has a grain and splits easily 
 along the plane of such grain. Just as a wood- 
 worker carefully determines the direction of the 
 grain in his lumber before beginning to cut it, so 
 do lapidarists (gem cutters) note the diamond 
 grain before attempting to work it up. A small 
 groove is sunk in the stone parallel with the grain, 
 a thin steel blade is inserted, struck a quick, sharp 
 blow, and the diamond pops apart. In this way 
 expert lapidarists used to separate stones, 
 remove defective parts with the least loss of ma- 
 terial, and get them in proper size for cutting 
 and polishing. 
 
 But within the last few years a better method 
 has been found. Now most lapidarists saw the 
 stones apart, and this scheme is particularly ad- 
 vantageous when the gems have to be cut across 
 the grain. The sawing is done by a thin 
 revolving disc, much like a common circular saw,
 
 123 
 
 but having no teeth. The disc is made of an 
 amalgam of copper and bronze, and has a very 
 thin edge which readily cuts through the diamond 
 when diamond dust and olive oil are fed 
 beneath it during the process. 
 
 Diamond cutting requires great skill, judg- 
 ment, and patience. The sides, or "facets," must 
 all be of perfectly equal size, uniformly situated 
 about the stone, and they must be perfectly flat 
 and of the same angle. In this process the stone 
 is securely fastened in a mechanic's "dop" or 
 holder, which is pressed against a steel wheel 
 covered with diamond-dust paste. The wheel 
 revolves at a speed of 2,500 revolutions per 
 minute. The first facet to be ground is the large 
 horizontal one at the top center of the stone, 
 called the "table." Next the eight large facets 
 around the girdle of the stone are ground, each 
 facet requiring the removal of the gem from the 
 dop and its replacement with cement in a new 
 position. Then the eight small facets around 
 the table are formed. Finally eight intermediate 
 ones are ground, which cut the large girdle facets 
 into sixteen small ones. This completes the top 
 of the stone, and gives it thirty-two facets and 
 one table. The underside is cut in much the same 
 manner, producing twenty-four facets and one 
 culet. 
 
 As each surface is cut it is polished until abso-
 
 124 SECRETS OF THE EARTH 
 
 lutely flawless, without the semblance of a scratch 
 under even the strongest magnifying glass, the 
 finest diamond dust and olive oil being used in 
 this procedure. As the cutting and polishing is 
 all done by eye, the artisan must have great keen- 
 ness and accuracy of vision, as well as skill of 
 hand and knowledge of his work. The perfec- 
 tion and wonderful delicacy of diamond cutting 
 can perhaps be better understood when it is stated 
 that a skilled lapidarist can cut diamonds so tiny 
 that 250 of them will weigh but one carat, each 
 stone being a complete, full-cut brilliant I 
 
 In almost every country of the world diamonds 
 have been found. Yet only three localities 
 produce enough to be called really productive 
 South Africa, Brazil and India- and these 
 supply the bulk of the diamonds which are sold 
 in the open markets, the Kimberley fields of 
 South Africa standing ahead of all others in 
 quality and quantity of output. 
 
 India is the first country in which diamonds 
 are known to have been mined. There is no 
 doubt that long before that many diamonds lying 
 loose were picked up along the water-courses of 
 that motherland of civilization. But the men of 
 those prehistoric times did not search deeply into 
 natural affairs; they regarded the diamonds as 
 the tokens of the Thunder-god, left where his 
 bolts had struck deep into the earth. It remained
 
 DIAMOND, KING OF GEMS 125 
 
 for the lure of gold to entice men to the drifts 
 where a rich harvest was awaiting them. 
 
 It has been observed that in almost every land 
 where diamonds are found in dirt washed up by 
 rivers, gold is also found, which goes to show 
 that both have been washed down into the valleys 
 from the mountain-sides. As soon as the ancient 
 Aryans, searching for gold, began to wash the 
 gravelly sands, they found the sharp, white crys- 
 tals that had hitherto only been discovered by 
 chance. And the princes, jealous of their pres- 
 tige, soon sent watchers to the mines to claim all 
 the larger stones, and to levy tribute upon the 
 yield of smaller gems. An occasional gem of 
 large size was smuggled away by the finder, to 
 be secretly sold to other princes in whose terri- 
 tory no diamond mines were to be found, and 
 these nobles began to blossom out also in the 
 finest of gems. In the constant wars that waged 
 among the leaders of the country, the victor 
 cherished as his richest spoil the treasured dia- 
 monds of the vanquished; and in this way the 
 gems were even more widely distributed. 
 
 Egypt knew the diamond as a graving tool, 
 and possibly also as a gem, while the roving 
 Phoenecians traded extensively in the stone, like- 
 wise in the white sapphire and zircon, which are 
 like it in whiteness but neither so hard nor so 
 brilliant.
 
 126 SECRETS OF THE EARTH 
 
 When the Greeks spread out in a conquering 
 flood over the western part of Asia, they took as 
 their most treasured spoil the diamonds of con- 
 quered kings, and the writers of that period, 
 whose books have come down to us, told mar- 
 vellous stories of the jewels of the East. Rome 
 followed Greece as a world power, and developed 
 commerce so that all sorts of precious stones were 
 known and worn by the sybaritic patricians of the 
 great empire. Rubies, emeralds, and other 
 precious stones glittered in the scarlet and purple 
 robes of the rulers but outshining, outdazzling 
 them all were the diamonds themselves. 
 
 So coveted were the diamonds, even at this 
 early period, that unscrupulous persons began to 
 try to counterfeit them, to try to create sub- 
 stances which would look like diamonds and find 
 a sale as such. These imitations were made 
 chiefly of a sort of paste by the Mediterranean 
 traders, but were never very successful, as a 
 diamond is one of the most difficult gems to 
 counterfeit, owing to its whiteness and great 
 hardness. Of late years Americans and Euro- 
 peans have been far more fortunate in creating 
 artificial diamonds; indeed, have done so with 
 such consummate skill that no one can detect the 
 natural from the man-made stone. These fine 
 imitations, however, are not sold on the market, 
 as they are too small to be of value. They are
 
 DIAMOND, KING OF GEMS 127 
 
 made by dissolving carbon in melted iron and 
 cooling it suddenly, which crystallizes the carbon 
 into tiny diamonds. They sell at a very low price 
 compared to genuine diamonds, which at this 
 time are quoted at from $90 to $200 per carat, 
 depending on quality. 
 
 As the thin and scattered diamond-grounds of 
 India began to give forth smaller supplies of 
 diamonds, a new impetus was given the trade by 
 the discovery of these gems in Brazil. Gold 
 miners there had unearthed stray gems as early 
 as 1670, but it was not until 1725 that their real 
 nature was known, when a trader purchased some 
 of them from two Portuguese miners. Immedi- 
 ately there was a rush of prospectors and miners 
 to the district, and a town, since known as Dia- 
 mantina, sprang up. Gold was forgotten ; every 
 man hastened to wash the river beds in quest of 
 the glinting white gems. Closely following the 
 adventurers came the law. The Portuguese 
 crown declared its sovereignty over all diamond- 
 bearing beds, and no one was allowed to mine 
 without paying heavy taxes ; even then the largest 
 and best stones were confiscated by the crown. 
 This brought the quest in disrepute, and soon the 
 fields were scarcely worked except by the 
 throne's own slaves and hirelings. 
 
 Native Indians and escaped slaves, along with 
 lawless white men, scattered into new districts
 
 128 SECRETS OF THE EARTH 
 
 and prospected. In many instances they were 
 lucky, and before they were detected and again 
 overridden by the law, succeeded in selling many 
 good stones. Whenever one of these lawless 
 miners was caught, he was made a slaveworker 
 in the mines of the Portuguese government. To 
 get these slaves to work harder, the one who 
 found an unusually large diamond was prom- 
 ised his freedom. In this way the government 
 obtained better service than could be gotten 
 through use of the overseer's lash, and secured 
 many fine specimens of stones. Good to relate, 
 the agreement with the men was kept, and every 
 fortunate finder was sent away rejoicing in his 
 freedom. 
 
 Finally Brazil became an independent nation, 
 and then the government mining was largely 
 abandoned, and everyone was given a chance to 
 find and record a mine of his own, and to work 
 it in his own interests, as in the United States 
 mining system. But men found that so much 
 rock and earth had to be handled in order to find 
 even a few diamonds that the game was more 
 often a losing one than a winning one. 
 
 As the lust for gems has had much to do with 
 the wars and conquests of the past, so the dis- 
 covery of the greatest diamond fields of all time 
 those of South Africa has wrought a new 
 empire there. But for the finding of diamonds
 
 DIAMOND, KING OF GEMS 129 
 
 there, we have strong grounds for belief that the 
 semi-desert would still be devoted to a pastoral 
 grazing ground of the Boers. As it is now, cities 
 have sprung up, immense fortunes have been 
 made, and the way has been carved through war 
 and commerce for a new union of states. 
 
 No one knows just when the first diamonds 
 were discovered in South Africa. The first acci- 
 dent that led to the world's attention being 
 attracted was one in which a Boer woman living 
 near Hopetown, on the Orange River, picked up 
 a glittering diamond among the pebbles where 
 her little son was playing along the shore. She 
 did not know its value, but was attracted by its 
 brilliance, and showed it to a neighbor. This 
 man Van Niekirk by name recognized the 
 stone as a diamond, and bought it for a small 
 sum. He in turn sold it to an Irishman, who 
 showed it to Dr. Guibon Atherstone, a noted 
 mineralogist at Grahamtown. The scientist at 
 once pronounced it a very fine specimen of dia- 
 mond, of more than 20-carat weight. He induced 
 the owner to put it in the Paris exhibition, where 
 it attracted widespread comment. Later, Sir 
 Philip Wodehouse, governor of Cape Colony, 
 bought the gem for $2,500, and continued its 
 public display to attract people into the new 
 country. 
 
 In 1867 the rush of miners began, and soon
 
 they were busily searching along every water- 
 course for the precious stones. The Boers them- 
 selves did not join in the quest, and went on about 
 their staid grazing duties as before, calmly smok- 
 ing their pipes and blinking contentedly at the 
 energetic actions of the newcomers. As a sharper 
 instance of this calm indifference of the Dutch- 
 men to the excitement going on all about them, it 
 is related that a Boer who was building a chimney 
 plastered it with pebbly mud from a swale 
 near by. Later when his attention was called to 
 the fact that a number of glittering diamonds 
 were among these embedded pebbles, he merely 
 nodded gravely, and said, without the least sign 
 of flurry, "Yaw; they won't hurt; I will leave 
 them!" 
 
 At first the miners had poor success, but when, 
 in 1869, a native picked up a stone weighing 
 eighty carats, which has since been named "The 
 Star of South Africa," news of the find was 
 spread broadcast, and renewed interest taken. 
 Where previously there had been one hundred 
 miners in the Vaal River field in May, August 
 found more than two thousand. By the follow- 
 ing April there were five thousand prospectors, 
 and more coming in every day. 
 
 It was a hard journey from the coast, either by 
 wagon or on foot, and the adventurers found the 
 cost of living a burden from the outset, with
 
 DIAMOND, KING OF GEMS 131 
 
 supplies difficult to secure. But they kept arriv- 
 ing. Voluntary associations were formed to pre- 
 serve the law and to impose mining licenses, and 
 rules were laid down for the marking and work- 
 ing of claims. Each claim was thirty feet square, 
 and anyone was free to take possession of a claim 
 which had not been worked for three days. The 
 Boers sought to levy taxes, but this effort was 
 resisted, and the territory annexed to Cape 
 Colony to circumvent it. Washing methods were 
 rough, and many small stones were lost. 
 
 Finally, disappointed in the Vaal River dig- 
 gings, the prospectors spread out over the coun- 
 try in quest of more productive fields. One of 
 these chanced upon the gem-plastered chimney 
 of Farmer Van Wyk, previously mentioned. 
 Struck with the possibilities of the locality, he 
 went to work and was soon taking out diamonds 
 in a fashion to attract many others to claims in 
 the same locality. More and more miners 
 swarmed in. Soon the famous De Beers mines 
 were opened up, also the noted Kimberley mines. 
 A peculiar snuff-colored earth was found here, 
 and all through this, well scattered, were the 
 precious stones, ranging in size from pin heads 
 to crystals the size of a pea. The greatest 
 treasure-house of the world had been found at 
 last, although few, if any, of the miners then 
 suspected it.
 
 132 SECRETS OF THE EARTH 
 
 A typical mining town, rough and full of bad 
 men, grew up among the mines. Shafts went 
 deeper and deeper, and the individual miners 
 found that the work was getting so costly that it 
 no longer paid well. Negro laborers became 
 adept thieves and robbed their employers, only to 
 lose their ill-gotten treasure to the rogues of the 
 town. Crime was common. The strictest laws 
 could not entirely keep it down. No man's mind 
 was at ease; if he did not find diamonds he was 
 worried; if he found them he was troubled with 
 the greater and more gnawing fear of having 
 them stolen from him, perhaps losing his own 
 life in the operation from a cowardly knife 
 thrust from behind. 
 
 When the yellow ground was exhausted, and a 
 stratum of blue-clay rock was met, most of the 
 miners concluded that the bonanza times were 
 over, and sold out. The era of consolidation had 
 begun. Men with money combined their capital, 
 combined their claims, combined their intellects, 
 and continued the mining operations on the huge 
 and efficient scale that such power makes pos- 
 sible. Machines were brought in for the digging, 
 expert engineers were engaged to work out the 
 mining problems that arose, miners were hired. 
 Thus the De Beers and the Kimberley mines 
 became the greatest producing diamond mines in 
 the world, and are such today. The syndicate
 
 DIAMOND, KING OF GEMS 133 
 
 which controls them and other paying mines abso- 
 lutely fixes the price of diamonds for the universe 
 from its London office. When we buy a diamond 
 ring or stickpin, or anything else containing a 
 diamond, we pay the price set down by this 
 monopolistic ring of men for that class of 
 diamond. 
 
 The great diamond mines of South Africa asre 
 more orless circular in shape, the formation being 
 like a huge cup of rock filled with the blue 
 ground in which the diamonds are found. As 
 the walls of rock are almost vertical, the taking 
 out of the blue earth has left cavernous pits, with 
 walls straight up and down for hundreds of feet. 
 
 It is necessary to elevate the diamond dirt to 
 the ground level, then deposit it in the open field, 
 where it is allowed to "weather" from six months 
 to a year before being broken up and washed. 
 The gravel from the washings is passed over 
 greased boards which catch and hold every 
 diamond, no matter how small. They are then 
 extracted and sent away to the lapidary works to 
 be cut and polished. 
 
 Greatest of all diamonds ever found was the 
 "Cullinan." This dazzling wonder was taken 
 from the Premier Mine, South Africa, on Jan- 
 uary 25, 1905. It measured 4 by 2^ by 2 inches 
 in the rough, and weighed over 1 1/3 pounds 
 avoirdupois 3,024% carats, Its primal value
 
 134 SECRETS OF THE EARTH 
 
 defied estimation, so different was it from all 
 other stones. 
 
 The "Cullinan" was found by the superinten- 
 dent of the mine, Mr. F. Wells. He describes 
 the discovery thus: "I had a gang of natives 
 working. We had gone down about five feet 
 
 from the surface We were just about 
 
 to knock off for the day when I saw something 
 white and sparkling lying on a slope of the blue 
 dirt. The rays of the setting sun caught it, and 
 it flashed like a small bonfire that might be 
 blazing fiercely. Almost overcome, I rushed to 
 the spot. The earth was already loose about the 
 stone ; my knife blade finished the work, and in a 
 few moments it was in my trembling hands. I 
 was dazed. I dashed headlong to the office and 
 showed it to Mr. McHardy and Mr. Cullinan. 
 
 They, too, were amazed The next day 
 
 word was sent out that the biggest diamond ever 
 known had been found." 
 
 Mr. Wells was awarded $10,000 for this find. 
 
 No person, no government, could afford to pur- 
 chase this wonderful gem. What, then, was to 
 be done with it? 
 
 General Botha, premier of the colony, hit 
 upon a happy solution. He suggested that the 
 Transvaal buy the company's interest in the gem, 
 and present it to their king, Edward VII. 
 Sealed in an ordinary tin box, the great diamond
 
 DIAMOND, KING OF GEMS 135 
 
 was sent by registered mail, and received no more 
 care in the handling than might some simple 
 token from a shepherd lad to his lassie. It was 
 presented to the king on the sixty-sixth anni- 
 versary of his birth, as a testimonial of gratitude 
 for the grant of autonomy bestowed upon the 
 Transvaal colony by the English government. 
 King Edward assured the donors that the 
 precious gem would ever be "preserved among 
 the historic jewels which form the heirlooms of 
 the crown." As is often the case with large dia- 
 monds there were in this certain imperfections 
 and the jewel was cut into several brilliants. 
 The largest of these, known as "The Star of 
 South Africa," is itself the greatest and most 
 lustrous diamond in the world. It is 530 1/5 
 carats in size and several of the smaller pieces of 
 the "Cullinan" are over 150 carats. 
 
 Another famous diamond is the "Koh-i-nur." 
 This is the most ancient noted gem in the history 
 of the world older than the rising of the Star 
 of Bethlehem, or the Tables of the Law as old 
 as Egypt's pyramids. Its history is a record of 
 war and bloodshed, from the first trace that can 
 be found of it in India, an heirloom of the Rajahs 
 of Malwa, until its acquisition by the British 
 crown, in 1849. During this time it passed to 
 the Moguls of Delhi, to the Persian conqueror, 
 Nadir Shah, to Afghan princes, to the "Lion of
 
 136 SECRETS OF THE EARTH 
 
 the Punjab." All through its devious course it 
 gleams through a crimson mist of terrible sacri- 
 fice. One prince after another was imprisoned, 
 tortured in cases to blindness; but not for this 
 would they surrender the coveted jewel, and only 
 stern death itself wrenched it from them. 
 
 Once in its history the "Koh-i-nur" was cap- 
 tured by stratagem; twice was it a gift of ran- 
 som. The story of its tragic travels from owner 
 to owner is too long to tell here, but we will cite 
 its experience with the fierce Persian, Nadir 
 Shah. Nadir descended upon Delhi for conquest, 
 and carried back with him booty that reached into 
 the hundreds of millions. Chief amongst all this 
 treasure was the great diamond, called by Nadir 
 "Koh-i-nur," meaning "Mound of Light." Nadir 
 had come within a hair of missing this prize. 
 
 When he appeared triumphant before the 
 court at Delhi, where Mohammed sat on the Pea- 
 cock Throne, surrounded by such splendor and 
 luxury as to outrank the rivalry of such things 
 for ages back, the defeated ruler gave him un- 
 heard of quantities of jewels as his trophy; but 
 the particular gem the "Koh-i-nur" which 
 Nadir coveted, was not among them. Mohammed 
 stoutly denied knowing where it was when ap- 
 proached by the angry victor; but just then a 
 traitor from the harem told Nadir that it was 
 hidden in the folds of Mohammed's turban.
 
 DIAMOND, KING OF GEMS 137 
 
 Before his departure for Persia, Nadir re- 
 stored Mohammed to the Mogul throne. Upon 
 this occasion he craftily invited his royal captive 
 to exchange turbans with him in token of their 
 everlasting friendship. Helpless and speechless, 
 Mohammed could do nothing else than obey this 
 courtesy. So away went the clever Persian, 
 carrying with him both the ruler's turban and the 
 rare diamond it contained. 
 
 The "Koh-i-nur" is a brilliant diamond of 
 grayish tinge, weighing 102% carats. It has 
 been recut from its distinctive Oriental shape, 
 having thereby lost over 80 carats and much of 
 its intrinsic historic value. In 1911 it was taken 
 from England to India, its original source, and 
 blazed paramount at the crowning of an 
 emperor of India at the Delhi Durbar. 
 
 Still another famous diamond is the "Great 
 Mogul," the chief treasure of the Moguls of 
 India for generations. This was found about 
 1650, and became the property of the diamond 
 merchant, Mir Jumla, who presented it to Shah 
 Jehan in an effort to curry favor with the new 
 court. It was partially cut, and weighed 787% 
 carats. The Venetian cutter, to whom Shah 
 Jehan entrusted it, was very unskillful, and in 
 cutting it wasted so much that when he was done 
 it weighed only 280 carats. The diamond was 
 then in the form of a dome-shaped rosette, like an
 
 138 SECRETS OF THE EARTH 
 
 egg cut in half. It was of fine texture, of beauti- 
 ful color and brilliancy, flashing soft, rosy lights 
 rather than fiery red ones. 
 
 What wonder that the natives fell on their 
 faces and worshipped it, believing it to be the 
 spirit of their deity! One of Shah Jehan's four 
 sons also worshipped the gem, to such an extent 
 that he kept his father in prison seven years in 
 order to get possession of it and the kingdom. 
 Shah Jehan was so incensed that he threatened 
 to grind the great diamond to bits, but his daugh- 
 ter prevented this, and it finally went to the cruel 
 son at his father's death. 
 
 The diamond was last seen in the court of 
 Aurang-zeb, about 1665. No further record of 
 it can be found. In some unaccountable manner 
 it vanished, as a lump of ice melts away in the 
 hot sun, leaving no trace. 
 
 The "Rtegent" diamond, in the Louvre, in 
 Paris, weighs 136 carats, and is valued at 
 $2,500,000. It is a splendid brilliant, discovered 
 in India, in 1701, by a slave in the mines. In 
 order to escape with his prize, the slave made a 
 deep wound in his leg, and inserted the diamond, 
 bandaging the injury in an innocent manner. 
 Subsequently he sold the stone to a merchant of 
 Jamchund for 1,000 pounds. This man later 
 disposed of it to a Mr. Pitt for $96,000. The 
 latter had it cut and polished, the operation
 
 DIAMOND, KING OF GEMS 139 
 
 requiring two years and costing $23,500. So 
 imbued with fear did Mr. Pitt become, that he 
 would some day be murdered and robbed of his 
 treasure, that he sold it for $675,000 to the 
 Regent of France, for the boy-king-to-be, 
 Louis XV. Sixty years later it was conspicuous 
 in the new crown of especial splendor made for 
 the coronation of Louis XVI. During the 
 French Revolution the Tuileries was plundered, 
 the crown jewels stolen; but the "Regent" 
 diamond, too well known to be disposed of with- 
 out detection, was found cast aside by the 
 cunning thieves. 
 
 This famous gem was prominent next in the 
 sword hilt of Napoleon, at his marriage to 
 Josephine; and again at his marriage to Marie 
 Louise, where it reposed in his gorgeous head- 
 gear. 
 
 Among the most valuable diamonds of recent 
 times are the "Victoria" and the "De Beers." 
 The former weighs 180 carats, and was purchased 
 by the Nizam of Hyderabad. The "De Beers" 
 weighs 225 carats, and is still in possession of the 
 mine owners.
 
 IX 
 LEAD, FATHER OF BULLETS 
 
 WHEN you attach a lead fish-sinker to 
 your line, do you ever stop to think how 
 that lead came to be? how it was 
 found? how it was put into the hands of man, 
 ready for his skill to work upon? When you drop 
 a BB shot into your airgun, or a "twenty- two" 
 cartridge into your little "real" rifle, do you ever 
 stop to think what the world would do if there 
 were no lead from which to make such projec- 
 tiles? What would those famous old woodsmen 
 and Indian-fighters, Kit Carson and Daniel 
 Boone, have done without the lead from which 
 to mould their round balls which proved so deadly 
 to animal and redskin? What would modern 
 hunters do? What would soldiers and sailors at 
 war do? 
 
 Without lead many of our every-day comforts 
 and conveniences would be either a thing of the 
 past or would be sadly altered. For instance, 
 lead is much used for water-pipes, especially 
 where bends are to be made on the premises. It 
 is used for making chambers to contain sulphuric 
 acid and other acids which would eat through 
 
 140
 
 LEAD 141 
 
 almost any other material. It is used for making 
 many kinds of toys, especially miniature train 
 wheels, tiny soldiers, roly-polys, come-backs, 
 swinging pollies, boat anchors and keels. It is 
 also used extensively for making paper-weights, 
 and for cores of gear-wheels in modern clocks. 
 The soles of divers' boots are composed of it. 
 
 This is not all. You will find that when molten 
 lead is heated at a moderate temperature, with 
 constant stirring, a substance called litharge may 
 be obtained from it. Litharge is a valuable fluid 
 much used in manufacturing arts; it is used in 
 the manufacture of flint glass, in glazing earthen- 
 ware, as a paint, and for drying oils. Minium, 
 another by-product of lead, has been known ever 
 since the time of Pliny, and is a scarlet crystal- 
 line granular powder; it finds extensive use in 
 the arts as a pigment, in the manufacture of flint- 
 glass, as a cement for making steam-tight or gas- 
 tight joints, and in the manufacture of secondary 
 batteries. White-lead, still another form, is a 
 white, heavy powder, and is extensively used as 
 a pigment or as a body for building on other 
 colors; and boat-builders also use it for making 
 water-tight joints. Lead acetate, another by- 
 product, finds wide use in medicine, in the indus- 
 trial arts, in refining sugar, and in chemical 
 analysis. Lead sulphate, yet another form, is 
 often used as a substitute for white-lead.
 
 142 SECRETS OF THE EARTH 
 
 Without lead for their storage batteries, sub- 
 marines could not operate when they were sub- 
 merged ; so it is extremely doubtful if we should 
 have such a thing as an under-sea boat in that 
 event, for what good would a submarine be if it 
 could not propel itself under water? Similar use 
 of lead will be found in the storage batteries of 
 present-day automobiles those which run by 
 electricity, and those which start by the same 
 medium. Commercial solders are composed 
 largely of lead. 
 
 Lead is one of the oldest known of metals, and 
 is, next to gold, the heaviest. It will be found 
 mentioned in the Book of Numbers as a part of 
 the spoils taken from the Midianites. It is also 
 referred to in the Book of Job. 
 
 Lead constitutes a greater percentage of the 
 rock in which it is found than any other known 
 metal. Hence it is comparatively cheap to mine, 
 particularly because galena, in which it is found, 
 usually contains a little silver, zinc, arsenic, and 
 antimony, and sometimes copper and even gold. 
 Most lead mines produce enough zinc, especially, 
 to make the latter metal a considerable source of 
 revenue to the owners. 
 
 Lead ore, or galena, is found in enormous 
 quantities in many parts of the world. Along 
 the Atlantic border of the United States there 
 are numerous localities in which it is found in
 
 LEAD 143 
 
 veins which cut through the Archean and Paleo- 
 zoic rocks. These deposits have not been worked, 
 however, for many years. 
 
 The ore bodies of the Mississippi Valley, where 
 most of the mineral is mined, are among the 
 finest in the world. One of the most productive 
 fields is in southeastern Missouri. The ore is 
 mixed in limestone through a thickness of about 
 200 feet. The mines of La Motte, Doe Run, and 
 Bonne Terre are among the best of the district. 
 
 The argentiferous lead ores of the Rocky 
 Mountain States are found in carboniferous lime- 
 stone, and yield both hard and soft ores which 
 contain cerussite and silver chloride. In the 
 deeper workings the oxidized ores give way to 
 unchanged sulphides, which are now of immense 
 importance. 
 
 Lead-silver mines are operated at several 
 localities in Colorado, Idaho, and Utah. And 
 large quantities of lead in crude form are 
 imported into the United States from Mexico 
 and British Columbia. Western smelters do the 
 refining. 
 
 Usually there is not the slightest indication, on 
 the surface, of the valuable lead ore which may 
 lie under it. Therefore, most of the mines have 
 been found by sinking down holes into the rock 
 and taking tests of the mineral pierced by the 
 drill as it comes up in fine powdered form. The
 
 144 SECRETS OF THE EARTH 
 
 ordinary well-type of drill is used, such as already 
 described in an earlier chapter. When it is found 
 that there is a sufficient quantity of lead ore, or 
 its attendant ores, to make the mine pay, shafts 
 are sunk to the levels of the ore bodies. Tunnels 
 called "drifts" are driven off from the shaft, so 
 that the veins can be reached fully and con- 
 veniently. 
 
 The lead vein has been formed in a great crack 
 in the rocks. These cracks go down from the 
 surface of the earth, right through all the rocks, 
 till, if you could follow far enough you would 
 probably come to a place where the internal fires 
 are so hot that everything lead ore and sur- 
 rounding rocks are in a state of boiling liquid, 
 just like lead when you melt it yourself. 
 
 The vein has been formed by water running up 
 and down this crack. Whenever the water found 
 a hole or crevice in the rock it began to fill it up. 
 The water which trickled down through the rocks 
 dissolved a small part of the rock that it had run 
 over. When the water got into a pocket and 
 stayed there, it slowly evaporated, and the rocky 
 sediment of limestone or other rock gradually 
 filled it up, forming in some mysterious manner 
 a compound of lead. This lead-laden water 
 doubtless was forced up, through fissures in the 
 earth, by the fierce gases of the furnace below, 
 where the lead really was first mixed with the
 
 LEAD 145 
 
 water. The zinc, silver, antimony, and other 
 metals found with lead, owe their origin to a 
 similar ejectment, and then slow evaporation of 
 nature. 
 
 You must have noticed that when syrup is left 
 uncovered, the water in it "dries up," and after 
 a while you can see the grains of sugar left in the 
 saucer, or on the top of a jar of jam. In the same 
 way, if a solution containing lead or any other 
 metal becomes cooler, the water cannot hold as 
 much of the metal dissolved in it as it did when 
 it was warm, so the metal crystallizes along the 
 rocky sides of the seam, bit by bit, closing up the 
 passage till it is all filled. 
 
 Some veins have been traced through the hills 
 for miles and miles, continuing to furnish the 
 richest kind of lead ore. Then, as suddenly as 
 you come to the end of a groundmole's hole, the 
 vein will come to an end. Perhaps near by a new 
 vein will appear. Or perhaps the one vein will 
 divide itself into three or four smaller ones. 
 Much the same order of things will meet your eye 
 if you will go to a dried-up mud puddle and look 
 at the cracks in its sun-baked bed. 
 
 The rocky walls on either side of the lead vein 
 are called the "hanger" and "ledger" walls, the 
 former being the one under which the slanting 
 mine shaft is dug, and the latter being the one on 
 the opposite side. Between these walls the whole
 
 146 SECRETS OF THE EARTH 
 
 space of the one-time crack is filled solid with the 
 galena or lead-bearing ore. All of this valuable 
 core is taken out by the miners, leaving only 
 sufficient rock for propping up the roof. 
 
 In sinking the shaft, first a series of slanting 
 holes, which converge like the spokes of a wheel, 
 are bored into the earth. These holes are then 
 charged with dynamite, and exploded at the 
 same instant. This blows out the core of rock 
 they are surrounding, forming a large hole. The 
 hole is then made more square by boring holes 
 around it in four corners and dynamiting these 
 sections. The process is repeated time after time, 
 as fast as the loose earth and rock can be 
 removed, till the mine is a real mine, tracks are 
 laid, and cars begin to run back and forth 
 carrying out the valuable ore. 
 
 In most lead mines, when your eyes become 
 accustomed to the darkness, you can see the lead 
 ore shining along the walls quite brightly. In 
 some of them little caves of beautiful white 
 calcite crystals contrasting strangely with the 
 dusky ore can be found. A common occur- 
 rence is to see curious things hanging from the 
 roof and sides of the passages which look like 
 milk-white icicles. These are called "stalactites." 
 They grow, particle by particle, just like icicles, 
 and usually have a drop of water at the end of 
 each stem; but they are hollow in the middle, and
 
 LEAD 147 
 
 are formed from limestone which has separated 
 itself from the mine water trickling through the 
 walls here and there. In places the limestone 
 water drips to the floor in sufficient quantities to 
 form similar white spearlike points. The latter 
 are called "stalagmites." All caves of limestone 
 rock are made picturesque with these two types 
 of excretion. 
 
 Occasionally pockets are found near the 
 surface which contain pure galena. These are 
 more or less in the shape of semi-spheres, some- 
 times hundreds of feet across. Here mining is 
 easy and a real bonanza. Unfortunately 
 few places are found where lead is obtained so 
 readily. 
 
 Lead ore, after being brought to the surface, is 
 crushed to the fineness of sand, and sent to the 
 "jigs," where it is mixed with water in the huge 
 frames of that name, and subjected to a steady 
 shaking motion by means of machinery. This 
 jigging movement carries away the lighter and 
 worthless rock, called "gangue." It also sepa- 
 rates the zinc and lead ores from one another, 
 and each is collected in troughs or chutes, and 
 carried to bins until needed. 
 
 Some of the very fine material cannot be 
 separated by the jigs, and passes to concentrat- 
 ing tables. Here, mixed with water, it passes 
 over boards which shake the material in such a
 
 148 SECRETS OF THE EARTH 
 
 way as to separate not only the valuable ore from 
 the gangue, but the zinc from the lead ore as 
 well. These products are then sent to the bins 
 with those from the jigs. 
 
 In smelting, there are three processes used. 
 These are the roasting and reaction, the roasting 
 and carbon-reduction, and the iron precipitation 
 process. All produce a crude lead which requires 
 refining later in order to yield a product fit to 
 sell and use. We will not attempt to describe 
 these processes here, as they are too technical to 
 be of general interest. But we will say a few 
 words in regard to the refining. 
 
 After smelting, the lead is still too impure to 
 use successfully, owing to the presence in it of 
 copper, arsenic, antimony, zinc, iron, bismuth, 
 tin, sulphur, and possibly gold and silver. If 
 there is not enough of the last two precious 
 metals to make special treatment necessary, it is 
 refined by blowing steam through the molten 
 metal, which is contained in a kettle, or by slowly 
 melting it in an open furnace which shakes back 
 and forth during the operation. The impurities 
 collect on the surface in a scum. The scum is 
 skimmed off, leaving the metal well refined. It 
 is then cast into "pigs" for market, each pig 
 weighing from 80 to 110 pounds. 
 
 Out of a total world production of lead in 
 1913, of 1,270,458 short tons, the United States
 
 LEAD 149 
 
 contributed 411,878 tons, considerably more than 
 any one other country. About one-third of the 
 world's lead is made into pipe, one-fifth goes into 
 shot, and the rest into sheet lead, alloys, and other 
 products.
 
 X 
 
 GRAPHITE, BACKBONE OF PENCILS 
 
 IT may surprise you to know that what you 
 have always thought to be lead in your 
 so-called "lead pencil" is not lead at all, but 
 is made of graphite, or plumbago. This sub- 
 stance is considerably lighter than lead, as you 
 can readily find out for yourself by splitting 
 apart the wood of a pencil, freeing the "lead," 
 and weighing the latter, then comparing it with 
 a bit of real lead of about the same quantity. As 
 a matter of fact, just balancing first one and then 
 the other in the hand will quickly show you that 
 lead is much heavier, size for size, than graphite. 
 Graphite has a specific gravity of 2.2; lead 
 reaches as much as 11.4, being more than five 
 times heavier. 
 
 Why, then, if lead pencils are not made of lead 
 at all, are they known by that name? There is 
 only one explanation for this. When graphite 
 was first discovered and used, it was not given 
 the name of graphite, but was called black-lead, 
 or plumbago. 
 
 Two of the features about lead which did more 
 to fool the early geologists than anything else 
 
 150
 
 GRAPHITE 151 
 
 were the close resemblance in color, and the mark- 
 ing powers, of this mineral as compared with the 
 same points in the newly discovered black-lead. 
 While it was noticed that there was some dif- 
 ference in structure, and that the lead would not 
 mark as blackly as the plumbago, it was still 
 thought they were both of one family. And while 
 geologists, as well as many other people, know 
 differently now, the old name had gotten such a 
 grip on the fancy of pencil users that to this day 
 they still cling stoutly to the old name of "lead 
 pencil"; and pencil manufacturers have thought 
 to humor them enough to make no attempt to tag 
 their product under its right title, although it is 
 true that manufacturers using graphite in other 
 forms for the public have long sold their com- 
 pounds under their true names, and citizens thus 
 accept them and speak of them. How strange 
 that a customer will go in a store and ask the clerk 
 to show him some "lead pencils," then stop his 
 automobile in front of the first garage, and ask 
 the attendant to sell him a can of "graphite lubri- 
 cant" when in each case he refers to the same 
 identical substance in connection with the pencil 
 and lubricant ! But people all over the world get 
 into some queer habits sometimes from very 
 simple causes, as we see. 
 
 While the uses of graphite do not have as wide 
 a range as some other minerals which Mother
 
 152 SECRETS OF THE EARTH 
 
 Nature has secreted in the earth, these uses are 
 very important. Chiefest among them is that of 
 the pencil, of course. Just pause for a moment 
 and think what you would do, what your father 
 would $o, what your teacher would do, what 
 newspaper men would do, what clerks and book- 
 keepers would do, what lawyers would do, what 
 railway conductors would do, what postoffice 
 forces would do, what armies and navies would 
 do, what the mayor and governor and President 
 would do if there was no such thing as graphite 
 for pencil cores ! There is a strong probability at 
 best that the world would not do half the business 
 it does to-day, for never has a satisfactory sub- 
 stitute been found for graphite as a pencil center. 
 Yet few pencils, if any, contain a core of pure 
 graphite. This mineral, in a pure state, is far too 
 soft to wear well in a pencil, or to make fine 
 enough marks to be suitable for general notes or 
 drawings. Pure graphite in a pencil would 
 crumble away in sharpening, almost melt away 
 in marking, and would create broad lines which 
 would smut with the least touch of the hand or 
 any other object. For this reason, and to make 
 pencils of varying degrees of hardness and fine- 
 ness, which will render them suitable to the wide 
 range of uses to which the world now applies 
 them, pencil manufacturers mix the fine graphite 
 powder with different amounts of carbon (coal)
 
 GRAPHITE 153 
 
 grit. The latter stiffens the graphite core, makes 
 its wearing qualities far greater, reduces the 
 smutting fault to a comparative nothing, and 
 gives the writer or artist just the kind of a record, 
 in tone and fineness of line, that he wants. 
 
 You probably have noticed, when writing or 
 drawing with a pencil, that sometimes it will, if 
 a "hard" pencil, scratch the paper a little rather 
 than leave a gray mark. This is a. defect in the 
 mixture in making the compound of the core, 
 and is caused by too much carbon at that par- 
 ticular point, a large grain of carbon which in 
 some manner has escaped the powdering process. 
 As a rule only inferior brands of pencils, selling 
 at a low price, will be found with unbalanced mix- 
 tures of this kind. 
 
 The proportion of graphite in a pencil in 
 other words, its "hardness" or "softness" is des- 
 ignated by manufacturers by symbols printed 
 on the pencils. "B" stands for soft, "H" for 
 hard. "BB" is very soft, or very little carbon. 
 "HH," or "2n," is double-hard, "mm," or "3n," 
 is triple-hard; and so on up to "HHHHH/' or 
 "5H," which is about as hard as pencils are made, 
 the kind used for the finest of mechanical draw- 
 ings and similar work. 
 
 Graphite also finds extensive use as a lubri- 
 cant. Mixed with various oils and greases, it 
 gives these a heavier and far more slippery body
 
 154 SECRETS OF THE EARTH 
 
 than they naturally possess themselves. In this 
 form we find it employed in lessening friction be- 
 tween the gears of automobiles, printing-presses, 
 and similar large machines, as well as in smaller 
 ones, such as bicycles, carts, phonographs and 
 mechanical window displays. Compounded with 
 turpentine it makes stove blacking; with oils, it 
 forms a splendid waterproof paint. Used dry 
 with foundry sand it makes an ideal casting me- 
 dium. Mixed with clay by a fusing action, it 
 makes the best of refractory crucibles, crucibles 
 which will not melt under the greatest heat man 
 can create from the materials nature has given 
 him and taught him to use. 
 
 Graphite varies a little in color, running from 
 a dark steel-gray to a smutty black, according 
 to the locality of its supply. It crystallizes in the 
 hexagonal form, and may occur in foliated shape 
 also. Its greasy feeling, softness and the black 
 streak generally running through it, make it 
 easily distinguished. It is nearly pure carbon, 
 with only one or two per cent of impurities. 
 
 When you have looked at your pencil, you 
 know that it was made in some factory; but did 
 you ever stop to think that the graphite ("lead") 
 is a vegetable, product like the wood ? The graph- 
 ite was first a gas which chemists call carbon 
 dioxide. It is formed by combining two parts 
 of oxygen with one part of carbon.
 
 GRAPHITE 155 
 
 We are all busy manufacturing this gas in our 
 bodies, and breathing it out as fast as it collects. 
 The fire in the grate is turning the coal into the 
 same kind of gas, and sending it up the chimney. 
 This gas was present very early in the history of 
 the world. It probably came out of the sun, 
 along with the rest of the material from which 
 the earth was made. 
 
 We are all so accustomed to seeing plants and 
 trees growing in the ground that we think all the 
 food for them comes from the dirt. Really only 
 one fiftieth part of the substance of a plant con- 
 sists of mineral matter absorbed from the 
 ground; the other forty-nine fiftieths consist of 
 carbon, nitrogen and water taken from the air. 
 
 At the time when the coal of the world was 
 formed, the globe was a very different place from 
 what it is to-day. There was a great deal more 
 carbonic acid gas in the air than there is now. 
 Carbonic acid gas, although it feeds plants, 
 poisons all the other living things, humans, 
 animals, fishes, reptiles, birds and insects. If 
 you were to shut up the doors and windows of 
 your room, seal up all the crevices, and block up 
 the chimney, so no pure air from outside could 
 get in, you would soon begin to feel very stupid 
 and sleepy. Later you would be assailed with 
 a dull headache, your eyes would grow heavier 
 and heavier, your senses would whirl round and
 
 150 SECRETS OF THE EARTH 
 
 round, and before long you would probably fall 
 into a stupor from which you might never awake, 
 because you would be poisoned by the deadly gas 
 which,we are all breathing forth out of our bodies. 
 
 Scientists say that in the Carboniferous Period 
 the earth was one great steaming greenhouse. 
 We now find the remains of tropical vegetation 
 all over the world. Even at those coldest of cold 
 points the North and South Poles the fossils 
 of soft plants, which now grow only in hot 
 countries like Africa and South America, are 
 found in great quantities. This goes to prove 
 that in those prehistoric days, millions of years 
 before man or woman came, everything every- 
 where was the same hot, misty place, all the year 
 round, without any perceptible difference. It 
 was the age of perpetual oven-like heat. The 
 whole land was, moreover, soaking with water; 
 for we find that it rained every day, and poured 
 down fifty times harder than rains we are used 
 to. From almost any place you might choose to 
 stand, you would find some body of water within 
 range of your vision a stream, a pond, a lake, 
 or a swamp. 
 
 Steam was constantly rising up into the air 
 from the wet earth, and being condensed into 
 clouds which girdled the universe in a great white 
 chain of billowy links, twenty miles high. These 
 clouds kept the heat of the earth from escaping
 
 GRAPHITE 157 
 
 into space, and at the same time stored up most 
 of the dry heat which came from the sun. This 
 did much to keep the earth the hot, moist place 
 it was in the beginning, and to create a suffocat- 
 ing amount of carbonic acid gas, which caused 
 the great plants to thrive in magnificent abun- 
 dance, but prohibited other forms of life from 
 existing. In other words, the whole world was 
 one vast greenhouse. If you would know how 
 such an atmosphere affects human health, visit 
 a few greenhouses and note the pale faces of the 
 attendants and their listless step. 
 
 During this time in the world's history, when 
 huge masses of vegetable matter covered the 
 whole country, the surface of the earth was con- 
 stantly sinking. A land on which was growing 
 some great forest thousands of miles across, 
 would gradually sink down lower and lower, 
 until the rivers all around it would spill into it, 
 instead of running into the sea as before, and a 
 great lake would result. At other times the ocean 
 itself would flood into a tract of land that had 
 sunken below its bed, and a larger ocean would 
 result. 
 
 If the covered land consisted of trees and 
 plants, the force of waters would soon knock 
 them down, lap over them, and form them into 
 a tangled mass of mud and vegetable fibre at 
 the bottom of the new lake or new ocean-way, as
 
 158 SECRETS OF THE EARTH 
 
 the case might be. The violent and frequent rains 
 of that time would not be long in gnawing away 
 the sides of mountains and hills, as well as the 
 banks of streams. So the rivers after a rain 
 would be thick with mud, and at times would flow 
 like treacle, bringing down enough sand and 
 gravel to fill up the vast lake in which the old 
 forest of huge plants had been drowned. Float- 
 ing masses of vegetation often became water- 
 logged and sank to the bottom. 
 
 Long before the lake had been filled up with 
 this mud and decaying plant life, other plants 
 took foothold in the muck and began to take 
 their place. There were giant horse-tails, mosses 
 with brilliant green fringe as long as your arm, 
 jungle plants with leaves as large as a big kite; 
 and all kinds of rank water weeds would struggle 
 up through the morass and intertwine on the 
 surface like a net. Then as the lake became shal- 
 lower and shallower, scale trees and monkey- 
 puzzle trees and tropical ferns would spring up 
 out of the marsh, and their dead stalks and leaves 
 would later help to fill up the remainder of the 
 lake until at last a new forest had grown up 
 right on top of the old one. 
 
 This great heap of mud and sand and growing 
 trees, piled up and growing on the sinking crust 
 of the world, would make it very much heavier 
 at this place, and aid in causing the land to sink
 
 GRAPHITE 159 
 
 down into the earth again. This would of course 
 create a new hollow, which would quickly fill up 
 with water from nearby higher bodies. The in- 
 rushing new waters would kill the new forest. 
 Its trees would fall as a tangled mass to the bot- 
 tom; and so, on and on, the story would be re- 
 peated. These plants turned into coal. 
 
 Coal, the source of graphite, may truthfully 
 be said to be bottled sunshine. The sunbeams 
 gave the growing plants their strength and 
 energy to break up the little particles of car- 
 bonic acid gas, digest the carbon, and build it 
 into their own bodies, and set the oxygen free. 
 As you sit before the grate warming yourself on 
 a cold winter's day, you are really enjoying the 
 sunshine of millions of years ago, preserved for 
 you by little green plant cells which lived and 
 died in that far-away past, that you in time of 
 need might have comfort in the form of fuel, 
 and graphite for pencils and other things. 
 
 If a tree falls on the ground and dies, nearly 
 all its substance is broken up into gases, and 
 escapes into the air; but if the tree falls into 
 water, the water preserves it, and it may last 
 for hundreds of years. The first thing to protect 
 our coal was the water into which the tree trunks 
 fell. The second thing was a layer of clay or 
 mud-rock which formed itself over them. This 
 layer is not always on top of the coal ; there may
 
 be one or two layers of sandstone between. The 
 layer of clay stuff, which is called "shale," acts 
 in the same way as the air-tight lid of a fruit jar 
 in which a housekeeper is putting up some fruit. 
 It keeps out the air, and prevents the carbonic 
 acid gas, which has formed by the decomposition 
 of vegetable matter, from escaping. The objects 
 thus bottled up are kept from further going to 
 pieces, and remain in the same state in which 
 they were when the "lid" was sealed down over 
 them, until finally, by the action of the weight 
 of rocks piled on top of them, and the heat com- 
 ing up from the center of the earth, the plant 
 trunks are squeezed and baked and boiled into 
 cakes of coal, or graphite. 
 
 Very frequently we find the roots of the coal 
 plants and trees growing in a layer of clay or 
 sandstone; then we have a seam of coal formed 
 from the remains of the vegetation resting di- 
 rectly on the stumps of the old trees. Above 
 these we find a bed of sandstone, then another of 
 shale, then a higher bed of clay. In the latter 
 are the roots of trees of another generation of 
 forests, with a layer of coal on top of them ; and 
 'so on until in some places as many as fifty seams 
 of coal have been formed, one above the other, 
 and sandwiched in between layers of sandstone 
 and clay. 
 
 While graphite, like coal, is composed chiefly
 
 GRAPHITE 161 
 
 of carbon, a product of this buried plant life, it is 
 a very much rarer mineral. It is found only in 
 those spots where molten rock has squeezed 
 through cracks above or below the seams of coal, 
 which has caused the coal to go through a sort 
 of baking process that has changed it into the 
 softer, greasy-feeling substance we call graphite, 
 plumbago, and black-lead. Thus, strange though 
 it may seem at first thought, we now see that the 
 wood casing of a pencil and the pencil's "lead" 
 come in reality from the same identical thing a 
 tree. 
 
 Although it is found in many different parts 
 of the world, graphite seldom occurs alone in 
 large deposits, but is usually mixed with other 
 minerals. It requires special treatment after 
 mining in order to separate it from the rock and 
 other earthen matter in which it lies embedded. 
 The substances with which it is found are lime- 
 stone, gneiss, or schist, and especially minerals of 
 the pre-Cambrian age. It has also been found 
 in small quantities in meteorites, or heavenly 
 bodies which have been thrown to the ground 
 from out of the skies. 
 
 There are two forms of graphite which we 
 recognize. One of these is the crystalline or true 
 graphite; the other is the amorphous or pul- 
 verulent form. 
 
 The vein-like deposits of crystalline graphite
 
 162 SECRETS OF THE EARTH 
 
 have undoubtedly been formed in fractures, prob- 
 ably at considerable depth. Various theories 
 have been advanced by geologists to explain this 
 composition; in the case of the veins in Ceylon, 
 Weinschenk believes that the graphite came 
 originally from volcanic eruptions and was due 
 to a reaction between carbon dioxide and cyan- 
 ogen compounds. Crystalline graphite is used 
 largely in the manufacture of crucibles and lu- 
 bricants. 
 
 Many amorphous graphite deposits were once 
 coal beds which have been converted into graphite 
 by the creeping in of igneous rock, as in Sonora, 
 Mexico, and at Turret, Colorado, both of which 
 places possess valuable mines of this kind of 
 plumbago. It is used chiefly in pencils, paints 
 and boiler compounds. 
 
 In 1898 a way was found at Niagara Falls for 
 making artificial graphite from coke. That very 
 year 200,000 pounds of carbon rods, were 
 graphitized in the electric furnaces, and scientists 
 were enthusiastic at the success of the experi- 
 ment. By 1912 the production jhad risen to 
 12,896,347 pounds. It is said that the artificial 
 kind of graphite is just as good as the natural 
 mineral as an electricity conductor, for use as a 
 lubricant, and for making "leads" for pencils. 
 
 Even though the production of graphite in 
 the United States has been increasing almost
 
 GRAPHITE 163 
 
 every year, we do not turn out half enough to 
 meet the domestic demand, and so our manu- 
 facturers have to import considerable quantities 
 from other countries in order to get enough for 
 all of their purposes. Our country produced, in 
 1913, 4,445 short tons of natural graphite, and 
 manufactured 6,817 short tons. Close to 30,000 
 short tons were imported.
 
 XI 
 LIMESTONE, EVERY MAN'S FRIEND 
 
 ONE of the most common stones, and one 
 of the most useful, is limestone. It is used 
 in nearly every nook and cranny of the 
 civilized world in one form or another. And it is 
 found in nearly all parts of the country, also. 
 When the Lord made this valuable stone, so 
 necessary to the well-being of every person, he 
 took all pains to see that it should be planted in 
 everybody's backyard, so to speak, where it 
 would be easy to reach. 
 
 In its very simplest form, limestone is a rock 
 formed by the combination of calcium or mag- 
 nesium with oxygen or carbon. Magnesium and 
 calcium are both metals that closely resemble tin 
 or zinc in appearance. 
 
 We all know that oxygen is the part of the air 
 that keeps up our life when we breathe it into 
 our lungs. We likewise know that while this 
 oxygen is in our bodies it undergoes a chemical 
 change, so that when we expel it out of our lungs 
 into the air again it is no longer pure oxygen, but 
 has become a deadly gas called carbon dioxide. 
 The coming together of pure oxygen, and this 
 
 164
 
 LIMESTONE 165 
 
 carbon dioxide from decaying vegetable life, 
 forms a combination which, meeting either cal- 
 cium or magnesium, makes the many different 
 kinds of limestone known to us. Each of the 
 metals produces its own peculiar kind of stone, 
 and each kind of stone has its numei ous uses. 
 
 In certain forms of crystallization, the com- 
 binations mentioned make a clear stone which is 
 so transparent that it resembles glass. This 
 peculiar substance, however, is found only in a 
 few places. Elsewhere there are other substances 
 or impurities which produce a great variety of 
 colors, and add special characteristics to the looks 
 and texture of the limestone, just as people's 
 faces and forms and dispositions vary according 
 to their heritage and environment. 
 
 Like all things else, limestone had once to be 
 made. One kind was built under water by 
 myriads of tiny animals which extracted the rock- 
 forming materials from the salty seawater in 
 which they lived, and deposited them in fantastic 
 forests of coral. Another kind was formed by 
 accumulations of shells of different kinds. Still 
 other kinds were shaped by nature out of the 
 materials left by the seas when they evaporated, 
 or changed their beds owing to a new wrinkling 
 of the earth's crust somewhere not far distant. 
 
 By these different methods have been de- 
 veloped many kinds of rock, and all limestones,
 
 166 SECRETS OF THE EARTH 
 
 varying all the way from the most delicately 
 colored onyx, and the whitest marble, through 
 many classes of the ordinary limestone, down to 
 the slimy or muddy matter closely resembling 
 ordinary earth. From the different classes and 
 qualities of stone are prepared not only many 
 necessary articles, but the finest gems of art, 
 as well. 
 
 Thus the beautiful marbles which* when hewn 
 and shaped by man's hand, produce the greatest 
 examples of statuary in the world, are in reality 
 nothing but limestone. The famous Colosseum 
 of ancient Rome the largest theater the universe 
 has ever known and the more modern Cathedral 
 of St. Peter in the same city, were built of 
 travertine, a form of limestone, and are the most 
 magnificent specimens of limestone architecture 
 ever raised to the heavens from which all things 
 animate and inanimate have come. In our own 
 time, and own country, striking examples of the 
 beautiful and impressive structures built from 
 limestone are the National Capitol and Wash- 
 ington's Monument, at Washington, and St. 
 Patrick's and St. John's Cathedrals, in New 
 (York City. 
 
 In addition to its architectural uses, limestone 
 plays a most important part in the commercial 
 and industrial life of the world of to-day, more so 
 than in the past. One of its most valuable ap-
 
 LIMESTONE 167 
 
 plications in this connection is in the refining of 
 metals, where it is used as a "flux," or means of 
 making iron and similar substances melt easier, 
 and in collecting or separating certain impurities 
 from the molten mass. It would be impossible to 
 make iron or steel without limestone, especially 
 of the quality and on the large scale with which 
 they are now produced. Millions of tons of lime- 
 stone are used annually in the steel industry 
 alone. 
 
 Limestone is burned in kilns to produce lime. 
 The intense heat drives out the carbon dioxide 
 from the hard rock, leaving only the metallic 
 substance and the oxygen. In this form it is 
 known as "quicklime," which is used in the mak- 
 ing of mortars and plasters, and for the treat- 
 ment of soils as an enriching agent. 
 
 You cannot have failed to hear a good deal 
 about a substance called "concrete" ; in fact, every 
 city boy sees concrete every day of his life, walks 
 upon it to and from school, perhaps sits on a con- 
 crete bench at recess, perhaps crosses a concrete 
 bridge with a letter which he mails for his mother 
 in a concrete postoffice, after the day's studies are 
 over and he has left the concrete schoolhouse. 
 Great skyscraper office buildings and warehouses 
 are made of concrete. Even huge ships, with 
 concrete hulls, decks and cabins, are now plough- 
 ing their way back and forth across the oceans.
 
 168 SECRETS OF THE EARTH 
 
 The truth is, concrete is a substance known to 
 everyone, and is one of the most essential con- 
 structive materials known to modern civilization. 
 But while thousands mix and mould it, and count- 
 less millions admire it in a finished state, only a 
 comparatively few know that without limestone 
 there would be no cement worthy of the name to 
 bind together the water, sand, and gravel, which 
 give strength and body to the compounded con- 
 crete. For this last purpose the use of limestone 
 has reached gigantic proportions. 
 
 At this time the subject of transportation is 
 one of the greatest importance. The late war 
 left the railroads in a sad state of repair, with 
 little good rolling stock; therefore, manufac- 
 turers and shippers all over the land have been 
 trying to keep their goods moving out to dealers 
 and consumers by the use of automobile trucks. 
 Of course this state of affairs immediately called 
 almost every shipper's attention to the condi- 
 tion of the roads, and everything that could be 
 done to improve them was done, so that the trucks 
 could make better time. Every decent road in 
 the country was well sprinkled with farmers 
 coming into town with farm produce, with city 
 buyers chugging out to call on the stay-at-home 
 farmers, and with town and city automobiles 
 making inter-city trips to dispose of homemade 
 articles. "We want good roads !" "Give us good
 
 LIMESTONE 169 
 
 roads!" became the cry of the drivers, the pro- 
 ducers, the consumers. People even moved their 
 household goods from city to city, as much as a 
 hundred miles, by truck, and these persons and 
 the moving-van owners also cried for good roads. 
 
 How did they get them ? By the counties and 
 State raising funds to buy limestone. Lime- 
 stone became at once the most important single 
 substance for making bad roads good and good 
 roads better. Now you will see it on roads almost 
 everywhere. On some roads it is laid raw, being 
 crushed into small pieces and evenly distributed 
 over an earthen bed, usually clay. On other 
 roads it is sometimes more finely crushed, and 
 mixed with tar or some similar binder to give it 
 a solid body. Even the railroads often call for 
 it as something fine for ballasting up their tracks. 
 
 On the farms especially those of the central 
 and eastern States millions of pounds of lime, 
 either as finely ground limestone or as burned 
 lime, are needed to "sweeten" the soil and make 
 possible the better production of important foods 
 for man and beast. In other words, crops grow 
 much more thriftily and with more appealing 
 taste because of this homely limestone. 
 
 But its usefulness does not stop here. We 
 could go on and on for some time, naming its 
 valuable uses, and not speak of one twice, were 
 we so minded. It is enough to finish, however,
 
 170 SECRETS OF THE EARTH 
 
 with a reference to its importance in chemical 
 manufacture. In this industry it is used to pro- 
 duce such well-known and highly desirable 
 chemicals as caustic-soda soda-ash, salicylic acid, 
 baking soda, and a variety of kindred compounds. 
 Would you believe it ? even the refreshing glass 
 of soda-water, the tart bottle of pop or ginger 
 ale, and many other sparkling drinks which you 
 may have tried, owe their very popular existence 
 to the gas derived from limestone! Strange 
 though it may seem, the sugar with which they 
 are sweetened required a certain proportion of 
 lime in its preparation. 
 
 The story of the progress of limestone, from 
 the quarry where it is won from massive beds or 
 ledges, to its ultimate use, is very interesting. 
 The methods of getting it out differ, according 
 to the use that is to be made of the stone. For 
 the gigantic building blocks and slabs the most 
 painstaking care is required to prevent the shat- 
 tering or cracking of the desired pieces, one check 
 in any one of which would mean the ruination of 
 that particular segment, and the loss of hours of 
 laborious toil. In this case the top or useless 
 earth and stone, called "the stripping," is re- 
 moved until the solid, usable rock is reached. 
 This is cut off in blocks or slabs by different 
 means. Sometimes the sections are marked out 
 by holes drilled close together. Steel wedges
 
 LIMESTONE 171 
 
 driven in these will often break loose the whole 
 block; but if this fails or does not look feasible, 
 light charges of blasting powder are inserted in 
 the holes and exploded. 
 
 In some quarries heavy machines are now used 
 for freeing the blocks from the quarry walls. 
 These are so powerful and well handled that they 
 actually chisel, with a greater ease than you could 
 cut out a square of wood from a soft pine board, 
 the great blocks of limestone from the parent 
 ledge. Derricks operated by steam or electricity 
 swing the huge blocks upon flat cars standing on 
 nearby tracks which run down into the pit and 
 along just below the serried walls. The cars 
 transport them to the stone-cutting establish- 
 ments all over the land. Here, by means of spe- 
 cial machinery, with water as a lubricant, the 
 great pieces are sawed, chiseled, and planed into 
 the desired shapes and sizes. If they are to ap- 
 pear in an ornamental way, artisans wielding 
 sturdy little pneumatic chisels sculpture them 
 into the most elaborate and beautiful figures. 
 
 But for the greater use of limestone this care 
 in quarrying is not required, for the reason that 
 the stone must ultimately be broken up into small 
 fragments. Consequently, the quarrymen in- 
 variably adopt the faster method of coaxing the 
 blocks from their holdings, which is to force them 
 loose with charges of dynamite. The holes are
 
 172 SECRETS OF THE EARTH 
 
 not bored so close together, nor so deep, for small 
 blocks; and lighter charges are used, sometimes 
 only a few pounds. But when great piles of stone 
 are to be secured, long, rows of holes are drilled 
 back of the "face" or wall of the quarry, and 
 loaded with tons of explosive. All of the holes 
 are fired together, and a successful shot brings 
 down a veritable avalanche of broken rock. 
 
 Another method, popular in some parts of 
 the country, is to dig tunnels under great masses 
 of limestone, and pack the ends of the tunnels 
 with hundreds of kegs of powder and some dyna- 
 mite. Such a blast actually lifts the mountain or 
 hill if it is of ordinary size, and shatters the rock 
 in a chaotic storm. 
 
 So we see that explosives are required for 
 tearing the broken limestone from the heart of 
 the hillside or mountain-side; and somewhere far 
 back in the history of the steel rail, the carving 
 knife, the toothsome bonbon, the sparkling soda, 
 there was a terrific thud of confined explosive as 
 these familiar friends of ours began their life of 
 usefulness to mankind.
 
 XII 
 LITTLE GRAINS OF SAND 
 
 YES, just little grains of sand. Very com- 
 mon, very ordinary, very old friends, 
 played with since we were the tiniest of 
 tots, there on the summer seashore where Mother 
 and Daddy took us, and there in the kindergarten 
 where we received our first Qay's schooling. 
 
 It would be farthest from our thoughts, we are 
 sure, ever to connect this homely substance of 
 Mother Earth with valuable and important 
 things which great factories manufacture, and 
 which we and other people all over the world need 
 very much. Yet it is true that were it not for 
 sand we would miss many comforts and con- 
 veniences which we enjoy to-day. It is extremely 
 doubtful if we should have any window glass, 
 glass dishes, cameras, telescopes, opera glasses, 
 magnifying glasses, mirrors, bottles, marbles, 
 lamp chimneys and lamps, and numerous other 
 articles made of glass. Just think what that 
 would mean : Dark houses in the day-time in cold 
 weather and no chance to look out at passing 
 sights ; no photographs of our dear ones or any- 
 body else; no magazines and books with pic- 
 
 173
 
 174 SECRETS OF THE EARTH 
 
 tures; no "movies"; no way even to see an 
 image of ourselves unless we went, like the primi- 
 tive savage, to the clear brook, where a hazy re- 
 flection might meet our gaze; no intimate 
 understanding of insect life and fine structures of 
 all kinds, such as the magnifying glass has given 
 the world. 
 
 Common sand consists either of small crystals 
 of quartz, or of the remains of larger crystals, 
 which have been broken up into small particles 
 or grains. If you examine a few grains of sand 
 under the miscroscope you will be surprised to 
 see how transparent and beautiful they are. In 
 the quartz will generally be found a small pro- 
 portion of mica or isinglass, some feldspar, 
 magnetite, and other resistant minerals. Sand is 
 really produced by the wearing effects of rains, 
 and the abrasion or rubbing together of stone 
 against stone, or rock against rock. Gradually 
 the tiny bits of rock are scoured off from the 
 parent quartz, and go to mingle with countless 
 other particles, and become "sand," as we know 
 it. It is blown about by the winds of every day, 
 and carried hither and thither by the streams. 
 Even you and I, when we strike off for a hike, 
 help to distribute it when we get it in our shoes, 
 and travel a mile or so before we deem it neces- 
 sary to shake it out. It is an important part of 
 most soils, and is very abundant on the surfaces
 
 LITTLE GRAINS OF SAND 175 
 
 along the courses of rivers, on the shores of lakes 
 and the sea, and in arid or desert regions. 
 
 Have you ever noticed at the seaside, when you 
 have been walking across the damp sand, that 
 the sand around your foot seemed to dry up 
 strangely when you first put down your foot, 
 and then, as soon as you raised it, became very 
 wet again? 
 
 If you will remember that the sand consists of 
 little crystals of quartz, and that each of these 
 are six-sided columns, with six-sided pyramids 
 at each end, you will be able, probably, to figure 
 out just how the phenomenon occurs. Under- 
 stand that the little grains of sand arrange them- 
 selves automatically in rows, side against side, 
 so that they fit into one another and make a very 
 compact mass. When your foot pressed down 
 the crystals beneath it, these disturbed grains 
 tried to wedge their pointed ends into the long 
 joints between the sides of the grains just be- 
 neath them. The crystals below were forced 
 aside enough to open up tiny spaces between 
 them, and as quick as "scat" the water above ran 
 down into these crevices, leaving the sand above 
 quite dry. Just as soon as the pressure of your 
 foot was removed, the disarranged crystals 
 formed in perfect order again, squeezed out the 
 water from the cracks between, and caused it to 
 seek the upper sand level once more.
 
 176 SECRETS OF THE EARTH 
 
 By reason of this very compact natural ar- 
 rangement of all sand grains, sand makes one 
 of the finest bulwarks for stopping cannon balls 
 and other high-powered shot that has ever been 
 used. Almost all government target ranges have 
 hills of sand behind the targets to prevent farther 
 progress of the missiles, which might otherwise 
 go on and injure people far behind them. In all 
 wars bags filled with sand have proven splendid 
 shields in making hasty entrenchments. Each 
 little grain of the countless millions of sand 
 crystals forms its own peculiarly strong re- 
 sistance to the advance of the bullet, and the 
 consequence is that this resistance is multiplied so 
 fast, as the missile forces its way in, that it soon 
 loses all power to advance another iota, and be- 
 comes "dead." 
 
 A very interesting sight are the sand dunes 
 along the shores of Lake Michigan. Especially 
 at the southern end of the lake do these mounds 
 of clear sand rise up to great heights, appearing 
 like small mountains rather than hills. In spite 
 of the fact that the tides and the vagrant winds 
 are keeping these dunes in an almost constant 
 state of movement, wiry grasses persist in grow- 
 ing in them, and sometimes shrubs and trees have 
 taken root and help to keep them anchored in 
 place. 
 
 Some sands contain the valuable ores, iron,
 
 LITTLE GRAINS OF SAND 177 
 
 gold, and platinum; and other metals are occa- 
 sionally obtained from sand in paying quantities. 
 
 It is usually one of the principal ingredients 
 in making concrete, is used extensively by rail- 
 way locomotives for making the wheels stick bet- 
 ter to the tracks in going up a steep grade, is 
 often thrown on icy walks to help pedestrians, is 
 employed in making mortar for laying bricks, 
 and is widely used all over the world as a filtrat- 
 ing agent for purifying drinking water. Prop- 
 erly mixed with clay, it forms one of the finest 
 soils for the production of crops. 
 
 But of all its numerous uses there is none per- 
 haps quite so important as that applied to the 
 manufacture of glass. Here sand becomes a 
 veritable giant of value to mankind. 
 
 Common as is glass it is safe to say that it adds 
 more to our daily comfort and happiness than 
 the costliest gems which the mines can yield. We 
 have already spoken of what a dreary place this 
 world would be with no window panes to give 
 us light, and none through which to view the out- 
 side universe as it swirled by in never-ending in- 
 terest. And it is quite evident that none of us 
 would wish to go back to the times when people 
 drank out of gourds and horns instead of glass 
 goblets. Nor would we care to use bottles made 
 of skins in place of our convenient present-day 
 glass bottles. In the beautiful stained glass
 
 178 SECRETS OF THE EARTH 
 
 windows of the great cathedrals, and in exquisite 
 vases and costly cut glass tableware, we see 
 something of the artistic possibilities of this very 
 useful substance. 
 
 Glass is not a natural substance, like gold, 
 silver or coal, but is an artificial compound; that 
 is, it is made by putting together several sub- 
 stances. The principal ingredients used are : ( 1 ) 
 sand (or crushed quartz or flint), (2) lime, and 
 (3) sodium carbonate, or potassium carbonate or 
 sodium sulphate. For various kinds of glass, 
 other materials are added, such as manganese, 
 cobalt, copper, zinc, tin, arsenic, saltpeter, etc.; 
 pigments for coloring are also added. 
 
 Cheap grades of glass are made from common 
 sea and river sand; but for the manufacture of 
 better qualities the sand is quarried ; that is, dug 
 out of pits. Thus, ordinary bottles and window 
 glass would be made from sea and river sand, 
 while such fine quality as plate glass and mirror 
 stock, also high-grade tableware, would be 
 formed from the quarried sand. 
 
 Lime is found in nearly all varieties of glass, 
 but lead oxide is substituted in making those 
 kinds which require a brilliant luster and a high 
 degree of transparency, such as flint glass used 
 for lamp chimneys, for cut glassware, and for 
 some of the lenses of optical instruments, and 
 the strass or paste used in imitation diamonds.
 
 LITTLE GRAINS OF SAND 179 
 
 The lime has the effect of softening the glass, so 
 it must be used sparingly. 
 
 In preparing the sand for making glass the 
 manufacturer does everything possible to free it 
 from impurities. In many cases it is stirred in 
 great quantities of water, then burned in the 
 flames of a fire, and finally sifted through copper 
 gauze screening. Iron is the most troublesome 
 impurity; if there is the tiniest bit of it in the 
 sand it cannot be used for making colorless glass. 
 
 In the seventeenth century ground flint-rock 
 was used in the best glass, because it was purer 
 than any sand they could then find; hence the 
 name flint glass. Curiously enough this name is 
 still applied to a variety of glass which is ex- 
 traordinarily soft and has not a bit of flint in it, 
 hard sands taking its place. 
 
 The mixing of the ingredients into what the 
 glassmaker calls the "batch" is a process that 
 often requires the services of an expert chemist, 
 and in the most modern factories it is customary 
 to prepare the batch according to the formulas 
 outlined by this skilled engineer. 
 
 Two types of melting furnace are commonly 
 used the pot furnace and the tank furnace. In 
 the former the ingredients are melted in huge 
 pots made of fire-clay, arranged in a circle around 
 a central fire, at the base of a large chimney. As 
 these pots are very difficult to make, and of un-
 
 180 SECRETS OF THE EARTH 
 
 certain durability, the tank furnace, heated by 
 gas, has come into general use. This type of 
 furnace is provided with a tank in which the in- 
 gredients are melted, and from which the molten 
 mass is drawn. There are usually several of them 
 in operation at one time, and all are worked 
 without interruption, new material being fed into 
 them at one end as the supply of melted glass is 
 drawn out at the opposite end. 
 
 Window glass was formerly made entirely by 
 hand labor, but in recent years machines have 
 been introduced. In the old wav there was a man 
 
 / 
 
 especially trained for each part of the operation. 
 The "gatherer" dipped a long iron blowpipe into 
 the white-hot molten glass. Skillfully twisting 
 this about he formed on the end, as you might 
 twist syrup on a toothpick, a mass of the sub- 
 stance weighing from twenty to forty pounds. 
 This ball of melted glass he spun round and 
 round in an iron mould until it assumed the 
 shape of a great pear. Then he passed it on to 
 the "blower." 
 
 The blower, by a process of clever blowing 
 through the tube, with now and then just the 
 right kind of a circular swing, shaped the mass 
 into the form of a C} r linder, sometimes as long as 
 himself. Allowing it to cool somewhat, he would 
 hold the end of the cylinder in the furnace, blow 
 into the pipe, and then cover the mouthpiece with
 
 LITTLE GRAINS OF SAND 181 
 
 his thumb. The exhaled air, thus imprisoned, 
 and expanding with the heat, would split an 
 opening in the end of the glass cylinder, which 
 the blower would enlarge by revolving the end 
 swiftly in the furnace. As soon as the hole was 
 as large as the diameter of the cylinder, and the 
 mass had cooled to a cherry-red heat, an assistant 
 would detach the glass from the blowpipe, and 
 the cylinder would be cracked lengthwise with a 
 red-hot iron or a diamond on a long handle. 
 
 The opened cylinder, with the split side up, 
 was then placed on a fire-clay table which re- 
 volved in an oven. The heat soon flattened the 
 cylinder into an irregular surface. This the next 
 workman, the "flattener," smoothed out with a 
 tool made of an iron rod, to each end of which 
 a block of wood was fastened. The smoothed 
 sheet was next placed in the coolest part of the 
 furnace, and was afterward removed to the cool- 
 ing stone. When rigid enough to be moved, it 
 was carried to the annealing chamber. 
 
 Annealing is a process of "tempering" the 
 glass, or making it tougher, so that it will not 
 break readily when subjected to sudden changes 
 of temperature. The glass is slowly heated until 
 the melting point approaches; then it is very 
 slowly cooled, this process taking place in a 
 chamber having various compartments of dif- 
 ferent degrees of heat.
 
 182 SECRETS OF THE EARTH 
 
 Plate glass is the most expensive form of 
 window glass, and is made by a special process. 
 The ingredients are melted in huge, open vessels, 
 some of which have a capacity of almost three 
 tons. These tanks rest upon frames behind fire- 
 clay doors. When the melting has reached the 
 required stage the tank is drawn out by a great 
 fork mounted on a truck, and is rolled to the 
 casting table. There it is hoisted by a crane, and 
 the contents poured in a fiery, livid stream upon 
 the metal table. A heavy roller spreads out the 
 mass evenly to the desired thickness, whereupon 
 it is placed in the annealing chamber and left 
 several days. It comes out in the form of rough 
 plate glass, and must be polished before it can 
 be sold and used. Polishing is done by means of 
 grinding machines which rub the surface with 
 sand, emery powder, and rouge, first on one side 
 and then on the other. In this process almost 
 half of the thickness of the plate is worn away, 
 but when it is done it is surely a beautiful sheet 
 of glass, clear, as smooth as smooth can be, and 
 sparkling in its brightness. Its thickness is then 
 from one-fourth to three-eighths of an inch. 
 
 To make glass stronger, for places where it 
 is subjected to jars and strikings, some rein- 
 forcing medium is often employed, which adds 
 greatly to its durability, though affecting to some 
 extent its transparency. One of the most used
 
 LITTLE GRAINS OF SAND 183 
 
 methods is to make the glass up of two sections, 
 with a wire netting cemented between when the 
 glass sheets are soft and "tacky." Such glass 
 may crack in short lengths when exposed to se- 
 vere shocks, but it cannot fall out in chunks like 
 common glass, and it is much employed as a fire 
 protection around elevator shafts, in windows 
 close to machinery, and in basement windows 
 where exposure to blows is always imminent. A 
 more recent method is that of manufacturing the 
 glass with a sheet of transparent celluloid in its 
 center. Such glass is even stronger than the wire 
 screen variety, since practically every atom of 
 the glass is securely attached to the tough, flexible 
 compound of the celluloid, rendering it essentially 
 break-proof. This kind of glass is now much 
 used in automobile curtain lights. 
 
 A large part of the ordinary glassware that 
 you see in the stores and on your neighbor's table 
 is made by pressing into that shape when the 
 glass is in a soft condition. The press consists of 
 an iron mould which contains the design of the 
 object to be made, and a plunger which is worked 
 by a lever. The gatherer sticks his iron rod into 
 the molten glass in the furnace, and brings out a 
 large lump on the end of it. Some of this is cut 
 loose and forced down into the mould by means 
 of the plunger. It rapidly cools, the piece of 
 glassware is removed, and is then put into the
 
 184 SECRETS OF THE EARTH 
 
 annealing furnace. Some articles are made in 
 two parts. In manufacturing a goblet, for in- 
 stance, the bowl is shaped in one press, the stem 
 in another, and the two parts are then softened 
 where they join, and connected. A good deal of 
 the more expensive tableware is made by blow- 
 ing. In many factories machines operated by 
 compressed air take the place of the human 
 blower with his sturdy lungs. 
 
 Cut glass is the most expensive and ornate 
 tableware in use. Often the object is cast in a 
 mould, but as often it is blown. In either case its 
 plain surface is then marked with the chosen de- 
 sign. Then it is held by the workman against a 
 steel wheel with a sharp edge. This wheel whirls 
 at great speed, being kept wet with a small 
 stream of water, mixed with hard sand, which 
 assist greatly in making the cuts smoothly and 
 deeply, without burning. It takes a skilled cut- 
 ter to follow some of the intricate designs found 
 on the costliest pieces; but there are some men 
 who are so expert at the wheel that they can form 
 very beautiful patterns as they work, having no 
 guide except their own artistic conception and 
 unerring hand. 
 
 After the design is cut the article is held 
 against a wheel of sandstone, which also has a 
 sharp edge around it in its middle. This wheel 
 smooths the rough edges of the cuttings, and also
 
 LITTLE GRAINS OF SAND 185 
 
 runs in water. Next a wooden wheel, fed with 
 pumice-stone, gives a smoother finish and final 
 polish to the article, whose newly cut crevices are 
 then cleaned out by means of a delicate brush 
 made of spun glass. How strange that sand, the 
 main ingredient of glass, should be used to grind 
 and cut the manufactured substance, and that fine 
 glass itself should be found the best thing for 
 giving the cuts their final cleaning! 
 
 In making a glass bottle the operator takes a 
 mass of molten glass from the furnace, swabbing 
 it around a long metal blowpipe. In small shops 
 he usually blows through this tube with his 
 mouth, but in large factories most of such work 
 is done by pneumatic machinery. When the mass 
 of liquid glass is blown into a pear-shaped object, 
 it is placed in a red-hot mould the size and shape 
 of the article to be made. Here the blowing is 
 continued until the pressure of the incoming air 
 forces the soft glass into every little crook and 
 cranny of the mould. It is then slowly cooled, 
 and removed from its close-fitting metal jacket, 
 which parts in the middle. Should there -have 
 to be lettering or a design of any kind on the 
 bottle, this is made in the mould and is cast into 
 the glass at the same time the bottle is shaped. 
 
 Glass is colored by the oxides of various 
 metals; that is, molten metals which have had a 
 certain amount of oxygen injected into them
 
 until a distinct color results. In this manner 
 iron produces a pale yellow or a pale green; 
 manganese gives us a pretty pink and an ame- 
 thyst-violet. Copper produces a deep green or 
 deep blue of great richness, but by adding a re- 
 ducing agent a beautiful ruby-red color is im- 
 parted to the glass. 'A still finer ruby glass is 
 formed by using gold in place of copper oxide. 
 A pretty blue is produced by cobalt oxide; a 
 milky white by tin oxide, calcium fluoride, or 
 bone-ash; and many delicate tints are formed 
 by combinations of the various coloring sub- 
 stances. 
 
 The exquisite stained glass windows of many 
 great churches are made up of numerous pieces 
 of different-colored glasses. These have been 
 cut very carefully to match various sections of 
 one large design, and when fitted together by 
 master workmen they produce an effect of out- 
 line and harmony of color that is bewitchingly 
 mellow and beautiful, especially when the sun or 
 bright skies from without reflect a strong light 
 through them. On cheaper ornamental windows 
 the colors are painted on them, and burned into 
 the glass. 
 
 During the World's Columbian Exposition, 
 held at Chicago in 1892, an exhibition of spun 
 glass created wide attention. So fine were these 
 tiny threads of glass that they were woven into
 
 LITTLE GRAINS OF SAXD 187 
 
 cloth from which a dress was made for the Queen 
 Regent of Spain. White silk constituted the 
 warp, and glass the woof. The fabric was woven 
 on a hand loom. Such spun glass is made by 
 melting a glass rod in the flame of a blowpipe, 
 and drawing the melted thread over a wheel 
 which revolves at a high rate of speed. 
 
 The iridescent effect seen in the frost work on 
 Christmas cards is produced by fine flakes of 
 glass. 
 
 Another interesting use of glass may be seen 
 in the collection of "fadeless flowers" at Harvard 
 University. In this rare collection there are 
 some 800 large sprays and clusters, and over 
 2,000 magnified parts of flowers. These were 
 originally real flowers, but by some secret process 
 of a German chemist they have been coated with 
 a very thin layer of silvery glass, which not only 
 holds them up into lifelike position but preserves 
 them against all change in color or substance.
 
 VIII 
 LITTLE LUMPS OF CLAY 
 
 CHILDREN know clay best as the sub- 
 stance from which marbles are made in 
 factories, and from which certain handi- 
 work is modeled in the schoolroom. Brawny 
 workmen know it best as the material from which 
 brick and tile are formed. Mothers know it best 
 as the stuff from which their pretty china table- 
 ware and other articles of household pottery are 
 ushered into the world. Sculptors know it best 
 as the substance from which they model their 
 first statues and statuettes, before casting the 
 beautiful finished forms in plaster of paris and 
 bronze. Farmers know it best as a valuable soil 
 when properly -mixed with other earths. 
 
 Little lumps of clay how plain, how common, 
 how homely ; and yet how very valuable to us all ! 
 
 When clay is dry it is very hard and compact. 
 When moist, its particles stick together, and this 
 makes it possible to mould it into any form 
 desired. If moist clay is subjected to an intense 
 heat it will bake almost as hard as a stone, but 
 will crack easily under a sudden blow. 
 
 Clay is composed of silica and alumina, and 
 188
 
 LITTLE LUMPS OF CLAY 189 
 
 may contain small quantities of iron, calcium, 
 magnesium, potassium, and sodium. Most clay 
 is formed by the decomposition or rotting away 
 of rock containing feldspar. It varies in color 
 from nearly white to gray, dark blue, and red, 
 according to the nature of the ground in which it 
 is found. If it contains iron it usually turns red 
 when burned. This is why we have red brick, 
 red tiling, and red pottery ware. 
 
 Porcelain clay, or kaolin, is usually white or 
 light gray. Potter's clay and pipe clay are simi- 
 lar to kaolin, but not so pure, and are used in 
 making the cheaper grades of pottery. Fire clay 
 will withstand intense heat. It is used for lining 
 furnaces, for smelting iron, and for making fire 
 brick and crucibles. Tripoli and "fuller's earth" 
 are kinds of clay which are easily made into a fine 
 powder ; the former is sometimes used for polish- 
 ing purposes, while the latter is sold on the mar- 
 ket, under fanciful names, as an inflammation 
 reducer in the ills of mankind. Clay is also used 
 in the manufacture of soap, in putting the glazed 
 surface on some kinds of paper, in the manufac- 
 ture of paint, for adulterating food, and for 
 making filters. 
 
 Bricks are one of the most important kind of 
 things made from clay. The story of the brick 
 is an interesting one. It carries us back into the 
 days of the remotest past, when Egypt was the
 
 190 SECRETS OF THE EARTH 
 
 center of what little civilization then existed. 
 According to the Bible, brick making was the 
 principal task of the captive Israelites in Egypt. 
 There was a plentiful supply of clay and sand on 
 the banks of the river Nile, also water in the 
 stream itself with which to mix the substances, 
 and usually an intensely hot sun to bake the 
 bricks. These might have been made of just the 
 water and sand and clay, but even in that day 
 the Egyptians had learned the need of some 
 reinforcing medium to make the bricks stronger ; 
 so for some time they had been using straw 
 mixed in the compound. When the captives 
 clamored for straw, therefore, it was not for mak- 
 ing fires with which to bake bricks, but for laying 
 in the brick mixture and weaving it closer 
 together, in the same way that steel wires and 
 rods are placed in great concrete walls of to-day, 
 and horsehair in plaster. 
 
 The Chinese employed bricks for buildings 
 many centuries before the Christian era. The 
 Romans introduced the industry into Britain and 
 other conquered territories. At the present time 
 bricks exist in England which are stamped with 
 the initials of Roman brickmakers who lived 
 many centuries ago. A well-built brick house 
 will outwear a wooden one many times. The 
 first brick building in America was built in 1633, 
 on Manhattan Island, from material imported
 
 from Holland. At the present time, wherever 
 there is suitable clay, and building is to be done, 
 there springs up a brick-making plant to take 
 care of all needs. 
 
 The first thing necessary in the making of good 
 bricks is a clay free from fossil remains, and one 
 containing little iron or lime. If sand is not 
 already present in the clay in the proportion of 
 one part of sand to two parts of clay, enough 
 sand must be added to secure this relation. The 
 clay and the sand are first mixed into a pliable 
 mass by the addition of water. From this body 
 the bricks may be moulded by hand, or they may 
 be moulded and cut by machinery. Machines 
 which will make over 100,000 bricks a day are 
 now in general use. From the trough in which 
 the sand and clay are mixed the material is 
 forced through tunnel-like openings the size of 
 the brick. This long column of clay emerges 
 from the machine like meat from a mincing ma- 
 chine, and steel wires come down upon it and cut 
 it into proper lengths, as you might clip off 
 sections of a cotton string with scissors, as fast 
 as it could be unwound from a ball. 
 
 The clay bricks thus formed drop down on 
 endless belts which carry them to the drying 
 sheds. After the bricks are dried long enough 
 in the open air to "set" them, they are sent to 
 kilns to be hardened. In these kilns they are piled
 
 192 SECRETS OF THE EARTH 
 
 in hollow squares in such a way that the heat of 
 a big fire in their middle will penetrate them and 
 convert the plastic clay into a stonelike sub- 
 stance. The firing takes from six to ten days. 
 During this period bricks for ordinary building 
 purposes are kept at a cherry-red heat. Others 
 for finer purposes are raised to almost a white 
 heat. 
 
 A harder form of brick is that used for paving 
 purposes, and usually called "vitrified brick." 
 To make these hard enough to withstand the wear 
 of heavy traffic, lime is added to the clay and 
 sand. During the burning process, the lime 
 fuses and renders the bricks extremely firm and 
 durable. "Facing bricks" are those which occupy 
 exposed and prominent positions. They are 
 more elaborately finished, more uniform in color, 
 and are sometimes glazed by a special process in 
 which salt is thrown on the flames, while the 
 article to be enameled receives a coating of the 
 burned salt. 
 
 Tiles and pipes, baked in the same way as 
 bricks, are extensively used for drainage pur- 
 poses. These are usually formed in moulds, the 
 clay being rammed in by a plunger. When fairly 
 dry they are removed from the mould, and later 
 go to the kilns for final burning. 
 
 Another substance which is made of almost the 
 same materials as brick is terra cotta. To make
 
 LITTLE LUMPS OF CLAY 193 
 
 this, fire brick, bits of pottery, partly burned 
 clay, and fine white sand, are ground to powder 
 and mixed very thoroughly. This mixture is 
 moulded, dried, and burned. Until recently all 
 terra cotta was of a yellowish brown color, but 
 now it is made in gray, white, and bronze, as 
 well. Terra cotta is an ornamental form of 
 brick, and goes a long way in beautifying a 
 dwelling or business structure. It is usually 
 used as a veneer, or outside facing, to walls, etc., 
 covering much coarser and cheaper materials. 
 
 One of the fine arts handed down through the 
 centuries is that of making vessels of clay. To 
 this art is applied the name ceramic, derived from 
 a Greek word meaning pottery. Clay containing 
 the right amount of moisture can readily be 
 worked into a plastic state which will admit of 
 its being fashioned into almost any shape desired. 
 When dried the clay becomes hard and firm; 
 when subjected to intense heat it becomes still 
 harder. 
 
 The simplest forms of pottery can be made 
 with a few crude tools. Therefore, primitive 
 peoples have always attained a good degree of 
 skill in making earthen dishes. Some of the 
 finest specimens of the ability of these persons 
 are found in the examples of Indian pottery dis- 
 covered in the pueblos in the southwestern part 
 of the United States. Even the descendants of
 
 194 SECRETS OF THE EARTH 
 
 these peoples produce, by fine skill of the hand, 
 wares of the most exquisite beauty of pattern. 
 
 The first step in the making of pottery starts 
 with the preparation of the material. Clay of 
 various grades is used. Before grinding, any 
 hard substances, such as pebbles and bits of rock, 
 are separated from the clay. During the grind- 
 ing, proportions of fine sand, feldspar, or flint, 
 may be added. The proportions of these ingredi- 
 ents determine the sort of ware to be made. 
 
 Vessels are fashioned in moulds, sometimes by 
 hand, and sometimes with the aid of machinery. 
 The potter takes enough clay for the vessel he is 
 to make, and throws it on the center of a hori- 
 zontal disc called the potters' wheel. Sometimes 
 this is turned by hand, sometimes by foot like a 
 bicycle, and sometimes by steam, or electric 
 power. In either case the speed of the wheel is 
 easily regulated. With moist hands the work- 
 man punches and scrapes at the soft vessel as it 
 whirls round and round before him on the wheel. 
 If a hollow vessel is desired he fashions the clay 
 into a cone, then presses upon the apex with his 
 thumbs, till gradually the revolving lump of clay 
 is brought out magically, right before our own 
 eyes, into the most beautiful, symmetrical speci- 
 men of pottery. The finishing touches are put 
 on with tools of wood and leather ; then the vessel 
 is placed in the drying-room to harden.
 
 LITTLE LUMPS OF CLAY 195 
 
 At the present time revolving moulds, called 
 "jiggers," are used in practically all large manu- 
 factories, and they greatly increase the output. 
 Plates and saucers are made by placing the 
 mould for the upper side of the article on the 
 wheel; then pressing the clay down on it, next 
 laying over the clay the mould which forms the 
 bottom, the moulds being so adjusted that a 
 uniform thickness is secured for each plate. 
 
 Vases and many other hollow vessels of fine 
 ware are now made in moulds of plaster of paris, 
 applied in sections so they can be easily taken 
 apart. This is the casting method. The mould 
 is filled with a thin mixture of water and clay, 
 and allowed to stand until a layer of clay is 
 deposited on the sides, when the mixture is poured 
 out. The porous plaster of paris absorbs the 
 water, leaving the shell of clay. When this has 
 sufficiently hardened the mould is taken apart. 
 The most delicate wares are made by casting. 
 
 If you should mould something in clay, and let 
 it harden in a natural way, you would find that 
 it will again absorb moisture perhaps at a time 
 when that is the last thing you wish it to do ; for 
 moisture causes the vessel to become soft and 
 weak again. So to prevent this reabsorption of 
 moisture the manufacturers heat their products 
 to a high temperature in a great oven called a 
 "segar." A number of these ovens are stacked
 
 196 SECKETS OF THE EARTH 
 
 in a kiln, one above the other. The "firing," as 
 it is called, lasts from thirty-six to forty-two 
 hours, during which the ware is so hot that it 
 looks almost white. Before it is removed from 
 the oven it is allowed to cool slowly by a gradual 
 shutting off of the heat. When it is removed it 
 is called "biscuit." 
 
 This process has hardened the clay vessel to a 
 surprising extent, but the surface is still com- 
 paratively rough, and has many tiny pores in it 
 which do not look well and which would prove 
 unsanitary lodging places for food particles 
 should the dishes be so used. To fill these pores, 
 and at the same time to apply a smooth, glossy 
 surface to the dish, which will make it easier to 
 wash and keep clean, a coating called "glaze" is 
 put on. For glazing various substances are 
 employed, including lead oxide or litharge, pow- 
 dered feldspar, flint, white clay, paris-white, and 
 other substances. The glaze compound is ground 
 to a very fine powder, then mixed with water. At 
 this stage it is known as "slip," and is about the 
 thickness of cream. 
 
 If you were to watch the workman you would 
 see him dip each article in the big tank of slip, 
 then set it aside, next to many others, to dry. 
 Here, in the course of a short time, the water in 
 the slip evaporates, causing the coating to thicken 
 and harden. To hasten this hardening process,
 
 LITTLE LUMPS OF CLAY 197 
 
 and make the finish as glossy as possible, the ware 
 is next put in a firing kiln for the second time in 
 its brief history. At first the kiln is not very hot, 
 but gradually the operator increases the tem- 
 perature. At its highest point he lets it stand a 
 while; then as slowly as before, he begins to 
 decrease the heat, the ware cooling by degrees. 
 Sudden changes in temperature would crack and 
 blister the film. The firing changes the glaze to 
 a beautiful transparent gloss which brings out 
 clearly any figures which may have been placed 
 on the ware proper. 
 
 Some of the very prettiest pottery owes its 
 appeal to its splendid color effects. These colors 
 are not in the clay itself, but are mixed in the 
 glazes. One part of an urn or vase may be dipped 
 in a glaze of one color, and another part of the 
 ware dipped in a glaze of another color. And 
 sometimes the glaze is poured on in an oven, and 
 the flow stopped by heat, which produces the 
 most bewitching shaded effects. 
 
 Designs and decorations are put on with 
 brushes by hand, either before or after glazing. 
 If put on afterward a third firing is necessary, 
 in order to set them and make them lasting. 
 Glazing is usually the finishing operation, and 
 when the ware comes from the glazing kiln it is 
 ready to be packed and sent off to the stores for 
 public use.
 
 198 SECRETS OF THE EARTH 
 
 Pottery making is one of the oldest of arts. 
 Scientific men of to-day who have dug up buried 
 cities in the Old World, have probably learned 
 more about the degree of civilization of the 
 former inhabitants through specimens of ancient 
 pottery than by any other single clue; for there 
 is practically no decay to good earthenware ves- 
 sels. The early Egyptians, Assyrians, and 
 Babylonians were very expert in making pot- 
 tery, as were the Greeks and Romans, who fol- 
 lowed in the art. The Chinese and Japanese are 
 famed for the delicacy of their clay products. 
 Ware from Holland, France, and Great Britain 
 is much prized for its pattern and durability. 
 
 In the United States no attempt was made to 
 manufacture pottery on a large scale until 
 1825. Since then the industry has steadily 
 increased until now the yearly output is close to 
 $35,000,000, and our wares compare well with 
 the best.
 
 XIV 
 
 IF you wish to know what an important thing 
 salt is in the world, you can quickly convince 
 yourself by the very simple test of asking 
 your mother to put no salt in any of the food 
 she cooks for you for a couple of weeks, and also 
 place none on the table for you to use. You 
 really can not understand fully just how taste- 
 less and wretchedly flat your food will seem until 
 you have gone through this experiment, and you 
 will straightway thank your lucky stars that there 
 is such a thing as salt, and make up your mind 
 to appreciate it for its full worth in the future. 
 Of course we do not know exactly, but it is 
 extremely doubtful that we could live long if 
 there were no little grains of salt. Scientists tell 
 us that without salt we would care very little 
 about food, and it would actually have very lit- 
 tle man-building energy in it for us besides. We 
 would soon grow thin, our smooth bodies would 
 become harsh of skin and covered with scurvy, 
 and our faces and limbs would turn a repulsive 
 sallow color. Without salt we could not have the 
 preserved meats and fishes which the markets 
 
 199
 
 200 SECRETS OF THE EARTH 
 
 sell us. It would be missed in the manufacture 
 of soda ash, sodium carbonate, and caustic soda. 
 Soap manufacturers would wonder what to use 
 for hardening their toilet soaps; potters would be 
 in a quandary to find a substitute for glazing 
 their coarser wares; glassmakers would have a 
 merry time to find something as good for im- 
 proving the clearness of some of their glass. 
 Farmers would miss it sorely, because it has 
 proven a first-class fertilizer, attracting and 
 holding moisture, and setting free the inert plant 
 life in the soil. They would also miss it as an 
 essential food-tonic for their cattle. And what 
 a sad fix wild animals would be in without it! 
 for all such yearn for salt as we yearn for drink- 
 ing water, and travel great distances in order to 
 find a salty spring from which to lap, or a "salt 
 lick" upon which to scrub their tongues. 
 
 When cereal and vegetable foods began to be 
 used by people, many centuries ago, salt became 
 a necessity. But in those days it was very diffi- 
 cult to obtain, as everybody thought the salty 
 spots on the surface were the only places to get 
 it, and that these springs were special gifts from 
 the gods. They never dreamed of securing it 
 from the ocean, or digging down into the earth 
 after it, where it lay in some sections in large 
 quantities. So few were the salt springs that the 
 ancient Roman historians tell us the German
 
 I 
 
 Underwood and Underwood 
 
 BLASTING IN A SALT MINE
 
 "SALT OF THE EARTH" 201 
 
 tribes fought fiercely for the possession of them. 
 
 Salt was used by the early Hebrews and other 
 Semitic peoples, and by the Greeks and Romans, 
 in their offerings. By them it was undoubtedly 
 regarded as a symbol of purity and faith. The 
 "covenant of salt," mentioned in the Old 
 Testament, was one which could not be broken, 
 as salt stood for things everlasting. Christ spoke 
 of his disciples as "the salt of the earth" when he 
 referred to their spiritual influence in the world. 
 
 Among the Orientals of the present day, as 
 well as the past, salt used at a meal is representa- 
 tive of friendship and hospitality ; hence the Arab 
 phrases, "there is salt between us," signifying 
 friendship; "to eat of a man's salt," or to par- 
 take of his hospitality; "to sit above the salt," or 
 in the place of distinction. In Persia a man who 
 is said to be "untrue to salt" is accused of dis- 
 loyalty. 
 
 Salt and incense were of vast importance in 
 developing the ancient highways of commerce. 
 The salt of Palmyra and Tadmore built up the 
 extensive trade between the Syrian ports and the 
 Persian Gulf; the great Salt mines of northern 
 India were the center of a wide trade before the 
 time of Alexander the Great; a caravan route 
 united the salt oases of the Libyan desert; and to 
 the present day the traffic in salt forms a large 
 part of the caravan trade of the Sahara. One
 
 202 SECRETS OF THE EARTH 
 
 of Italy's oldest roads, the Via Solaria, is the 
 route by which the salt of Ostia was carried up 
 into the Sabine country. 
 
 Cakes of salt were anciently used as money in 
 parts of Abyssinia and Tibet, and salt taxes 
 existed both in ancient and medieval times. 
 
 Fortunately for the world there are few things 
 more generally found or cheaper, to-day, than 
 salt. The ocean, which occupies approximately 
 three-fourths of the surface of the globe, holds 
 inconceivable quantities of the valuable saline 
 mineral. This has been carried, in part, into the 
 seas by the rivers which empty into them, and 
 the rivers have absorbed it from the salt deposits 
 that exist here and there in the earth's surface. 
 The remainder of the ocean's salt is absorbed 
 from beds of the substance on the oceans' own 
 floors. 
 
 On land, underground and surface deposits of 
 salt alike are found the world over, and some 
 great inland bodies of water are saturated with 
 this simple substance, which they are ready to 
 yield at the demand of the salt-gatherer. There 
 are not many such inland salt lakes, but the three 
 or four which do exist are quite remarkable as 
 compared with ordinary fresh-water bodies. 
 Here in the United States we have one of these 
 in Great Salt Lake, in Utah, which every year 
 is a source of keen interest and wonder to thou-
 
 "SALT OF THE EARTH" 203 
 
 sands of tourists. This remarkable body of 
 water stands at the head of its kind in this coun- 
 try for its great salt density, having more than 
 twelve per cent of pure salinity. So heavy with 
 salt is it that it is almost impossible for a person 
 to swim far; but how easy it is to float! Just 
 stretch yourself out and lie on your back, serene 
 and confident, and you will float like a chip. If 
 you could attach a sail to yourself you could be 
 your own sailboat, and go skidding about with- 
 out the least effort on the part of hand or foot. 
 When you come out and let the sun dry you off, 
 the evaporating water on your body will leave 
 little grains of salt as a memento of your strange 
 experience. No one could sink in Great Salt 
 Lake if he wished to ever and ever so hard. 
 Everybody is safe from drowning. 
 
 The Dead Sea, in Asia, is recognized as the 
 most fully impregnated with salts of all the 
 bodies of water on the face of the globe. More 
 than one-fourth of its bulk is salt. But chloride 
 of sodium the chemist's name for common salt 
 is not the dominant salt, chloride of magnesium 
 forming more than sixteen per cent of the salty 
 content. The Caspian Sea, the largest land- 
 locked body of water known, and Lake Balkash, 
 and the Sea of Aral, are other salt lakes of Asia, 
 all notable for their strong saline quality. 
 
 At one time almost all the common salt of
 
 204 SECRETS OF THE EARTH 
 
 commerce was produced by gathering and evap- 
 orating the salty waters of the inland lakes we 
 have named and those of the great oceans. The 
 fact is, considerable quantities of salt are still 
 obtained in this way from San Francisco Bay, 
 Great Salt Lake, and the waters along the sea- 
 board countries of Southern Europe. Since there 
 are about three-eighths of a pound of salt in each 
 gallon of sea water, it has been estimated that, if 
 the Pacific Ocean were to dry up, or be gathered 
 and boiled up in great kettles, it would yield close 
 to 4,419,000 cubic miles of solid salt. If this were 
 spread out one mile deep it would more than 
 cover the entire continent of Europe. 
 
 Salt is obtained in ways that differ as widely 
 as do the localities where it is found. Perhaps 
 the most picturesque and interesting of all the 
 salt-gathering industries is found in our own 
 country. 
 
 Away down in Southern California, in the 
 middle of the Colorado desert, about one hun- 
 dred miles from the ocean and eighty miles from 
 the Mexican boundary line, is the little station 
 of Salton, on the Southern Pacific Railroad. It 
 lies between the San Bernardino and the San 
 Jacinto ranges of mountains. Here the valley 
 sinks to a level more than four hundred feet 
 below the level of the sea, making it the most 
 depressed spot in the United States. Should
 
 "SALT OF THE EARTH" 205 
 
 these mountains and the surrounding country 
 settle a little by a movement of the earth's crust, 
 which may happen any day, the Pacific Ocean 
 will flow over and fill in this strange valley, mak- 
 ing it once more its own, as it undoubtedly at 
 one time was a part of this great body, for it has 
 been comparatively recently cut off from the 
 ocean by the delta of the Colorado River. 
 
 In this remarkable depression, and only a short 
 distance to the south of Salton, is a field of crys- 
 tallized salt more than a thousand acres in extent. 
 When the sun shines on this great crust of white, 
 it scintillates like a world of diamonds, fairly 
 blinding the eyes of those not used to the sight. 
 The field is growing constantly, for all around 
 it numerous salt springs are flowing down from 
 the surrounding hills, draining into the basin, 
 where they rapidly evaporate, leaving fresh 
 deposits of almost pure salt. This film of white 
 covers the entire area like the frosted crust of a 
 gigantic cake, and it is all the way from ten to 
 twenty inches thick. 
 
 The Salton field is worked by a company of 
 men who own the tract and employ a number of 
 laborers to gather the salt for the market in a 
 very unique manner indeed. First the crust is 
 plowed by a heavy steel share which makes a 
 broad and shallow furrow, one following another, 
 leaving high ridges of the plowed-up material
 
 206 SECRETS OF THE EARTH 
 
 between, as a farmer plows his ground. The 
 plow is not pulled by horses, however, but by a 
 sturdy little locomotive, which runs on two tracks 
 at right angles to the furrows, and which pulls 
 the plow along by means of two steel cables 
 running through pulleys just behind the engine. 
 
 As the plowshare cuts into the salt, brine from 
 the springs oozes up into the furrows. Laborers 
 with hoes follow after the plow, work out the 
 earthen particles in the salt by chucking it in the 
 water, and stack up the clean white crystals in 
 conical heaps. These men are Coahuila Indians, 
 the only ones who can be hired to do the trying 
 work, as the temperature is 140 degrees on the 
 average, and furthermore, dark glasses must be 
 worn to protect the eyes against the almost 
 intolerable glare of the white field. The air, 
 laden with impalpable tiny particles of salt, 
 creates an intense, burning thirst which the work- 
 men find it impossible to satisfy with the luke- 
 warm, alkaline water of the artesian well, 900 
 feet deep, their only supply of drinking water. 
 
 When the mounds of salt in the field are well 
 dried out by the hot California sun, broad-tired 
 wagons carry the salt to flat-cars which, in turn, 
 transport it to the mill in Salton. Here it passes 
 through grinders which crush it up into a uniform 
 powder. It is then sifted and sewed up into sacks 
 by Japanese workmen.
 
 "SALT OF THE EARTH" 207 
 
 Out of this field of 1,000 acres of virgin salt, 
 not more than ten acres are worked at this time. 
 Yet from such a small portion about 700 tons 
 can be plowed and shipped every day. As fast 
 as the crust is removed a new one forms. Thus 
 the supply seems practically inexhaustible. 
 
 Under certain atmospheric conditions this salt 
 field displays remarkably perfect examples of the 
 phenomenon known as the mirage. Beautiful 
 flowering fields, crystal-like lakes with wooded 
 shores, and even towering cities and pretty cathe- 
 drals and castles, appear in most deceptive form. 
 
 The greater part of the world's salt, however, 
 is produced from what is known as "rock salt," 
 that is, salt which has been obtained by going 
 down into the earth after it, either by means of 
 wells or mines. The well method is the easier 
 one of the two. Here holes are drilled far down 
 until the salt is struck, much the same as in mak- 
 ing an artesian well. The hole is cased by piping, 
 and water is often pumped in to dissolve the salt 
 just below the pipe end. Once dissolved and in 
 the form of a brine, steam pumps suck it up 
 through the pipe. It is then put in great kettles 
 and evaporated by fires underneath, or it is 
 placed in large vats out in the open air, where 
 the winds and sun dry up the water, in a some- 
 what slower but less expensive manner, and leave 
 the clear salt remaining. Most of the rock-salt
 
 208 SECRETS OF THE EARTH 
 
 in the United States even in Michigan, which is 
 the greatest home producer is secured in this 
 manner. 
 
 England is the chief salt-producing country. 
 Her counties of Cheshire, Staffordshire, and 
 Worcestershire, are noted for their fine saline 
 deposits, especially. Droitwich, in Cheshire, has 
 been celebrated for its "wyches," or salt springs, 
 ever since the Roman occupation, and the word 
 salary (latin, solarium) is due to the fact that 
 salt was once made a part of the Roman soldier's 
 
 Pay- 
 Salt has been made in England from natural 
 
 brine springs for centuries, but the mining of the 
 rock-salt deposits, through which water must 
 flow in order to become salty, is a comparatively 
 modern industry there. The splendid Cheshire 
 beds were discovered in 1670 by men boring for 
 coal, and have been mined ever since. The salt 
 is so hard sometimes that it has to be blasted with 
 gunpowder. It is curious, but coal, oil, and 
 natural gas, are often found close to salt. In 
 China there is a remarkable salt spring from 
 which sufficient natural gas escapes to provide a 
 fuel for evaporating the brine. 
 
 Vast as are the English deposits, those found 
 at Wieliczka, in Galicia, Austria, are a close sec- 
 ond in productiveness, and really superior in the 
 way of extent. The remarkable formation and
 
 "SALT OF THE EARTH" 209 
 
 capaciousness of these workings make them the 
 most famous in the world. 
 
 Just imagine, if you can, a region under your 
 feet where there is a solid mass of salt measuring 
 500 miles in length, 20 miles in breadth, and 1,200 
 feet in thickness! For nearly eight hundred 
 years men have been hacking away at this im- 
 mense bed of salt, and although their labors have 
 left a veritable underground city, they have made 
 only a comparatively wee, wee hole in the 
 enormous bulk of white which constitutes the 
 "ground" in that vicinity. 
 
 In a coal, iron, silver, lead, copper, or mercury 
 mine, you may see many strange and curious 
 sights ; but none can compare with the wonderful 
 sensations you will experience when you visit the 
 underground salt city at Wieliczka. It is one of 
 the "show-places" of Europe, owned by the Aus- 
 trian government, and is often visited by official 
 heads. From the very beginning these salt work- 
 ers seemed of the opinion that it would be just as 
 easy to form a pretty chamber in their mine as an 
 ugly one, while they went about their task of 
 gleaning the milk-white crystals. Anyhow, 
 instead of merely digging for the sake of dig- 
 ging, like miners else\vhere, they formed their 
 chambers and aisles and slopes into the most 
 entrancing architectural effects. And with such 
 an eye-intoxicating, soul-stirring substance as
 
 210 SECRETS OF THE EARTH 
 
 this beautiful snow-like salt to work in, no won- 
 der that, as their labors grew, they became proud 
 and enthusiastic, and that the public at large 
 opened their mouths and stared in delighted 
 wonder. 
 
 Thus day by day, week by week, month 
 by month, year by year, decade by decade, cen- 
 tury by century, from a single pretty chamber 
 this strange mine of Wieliczka has developed 
 into a regular city of beautiful booths and vaults, 
 arcades, amphitheaters, parks, boulevards and 
 winding avenues, arches and bridges and bal- 
 conies and stairways, all embellished with crystal- 
 white statuary, shrubbery, and other forms of 
 decorative art. Young miners have grown old, 
 with frosted hair and beards, in this ambitious 
 work of creation. Aye, they have died in the 
 harness, as white as the crystals about them, while 
 sons and grandsons took up the tasks they had 
 laid down. And all so that you and I may wit- 
 ness what man can do while engaged in a homely 
 commercial enterprise. 
 
 As we go down into this rare underground 
 city, where electric lights and candles cause 
 prismatic hues of sparkling light to radiate from 
 countless tiny facets of salt crystals all about 
 us, we are struck speechless with awe and ad- 
 miration. We go through and pass silent 
 chapels that speak eloquently of angels and
 
 "SALT OF THE EARTH" 211 
 
 heaven and other pure things, then across an 
 altar, into a dazzling ball-room, around graceful 
 pillars, and by richly garnished throne all 
 hewn from the solid salt-rock. Salt staircases 
 lead us from one floor to another, from balcony 
 to street level, from marvel to amazement. 
 Chandeliers of the same sparkling white sub- 
 stance hang from ceilings here and there. What 
 statesman is this, standing in statuesque ermine, 
 just at our right elbow? God's cleanest snows 
 could not be more white than that splendid horse, 
 with alert ears and majestically held head, over 
 by the wall yonder. Let us sit down in this fine 
 salt chair for a little rest, and look around a bit. 
 Everywhere is salt, everywhere is sparkle. But 
 the salt does not seem to be salt. It is too beauti- 
 ful, too throbbing of life, too unusual of shape, 
 to be salt. Surely, we think, it must be the 
 "earth" of which all fairyland is made; and this 
 about us is that fairyland ! 
 
 Altogether the mines have a length close to 
 three miles along the bed, and there are eight 
 levels. In the topmost three are the sights which 
 tourists delight in viewing; the levels below are 
 for "business only." Many of the horses used in 
 transporting the salt to the shaft are born under- 
 ground, and have never seen daylight. These ani- 
 mals are practically blind, but have, by instinct or 
 development, a wonderful sense of location.
 
 212 SECRETS OF THE EARTH 
 
 About a thousand miners work at Wieliczka. 
 They exercise such care in making their excava- 
 tions that accidents are very rare, although in the 
 history of the mines some terrible disasters are 
 recorded which have resulted from fire or the 
 flooding of the mine by a subterranean lake. On 
 account of the whiteness of everything around, 
 the galleries are much better illuminated than the 
 average coal mine. The air, too, is kept very 
 pure by its contact with the salt, so that both men 
 and animals enjoy good health. At the end of 
 the day the miners ascend to the surface in "lifts," 
 or elevators, and when all are up the shafts are 
 closed and locked. 
 
 You would hardly think that salt is a com- 
 modity worth stealing, or that the owners would 
 object if a miner did take away from such a vast 
 storehouse a few meager pinches of it. But in 
 that country salt is a taxable commodity, and it 
 appears that at one time so much of it was smug- 
 gled out in miners' boots and pockets that every 
 man was thereafter searched when leaving work, 
 just as though he were an employe of a gold or 
 diamond mine. The practice is still continued, 
 although in a perfunctory way, as the miners are 
 now too well paid to be tempted to augment their 
 income by theft. 
 
 Near the entrance of this famous mine stands 
 a block of buildings the offices of the manager.
 
 "SALT OF THE EARTH" 213 
 
 Here visitors are first received, provided with a 
 guide, and asked to pull on a pair of overalls to 
 protect their good clothes while exploring the 
 subterranean passages. The outfits worn by 
 Royalty, as may be expected, are of a superior 
 character, and each time they are worn are care- 
 fully labeled with the name of the wearer and 
 the date of the visit. 
 
 You can descend in two ways by a hydraulic 
 cage, or by a staircase hewn out of solid salt. 
 When you begin to get into the real levels of the 
 mine there bursts upon your view a little world 
 of such fantastic ermine beauty that you are quite 
 sure, for a few moments, you are either dreaming 
 or gazing upon the work of genii and fairies. 
 You behold a spacious plain containing a strange 
 little whitewashed city, with houses and roads, all 
 scooped out of one vast mass of salt rock. It is, 
 everywhere, as bright and glittering as crystal, 
 while the blaze of lights continually burning is 
 reflected from the dazzling columns which sup- 
 port the lofty arched vaults of the mine, in a 
 manner most bewitching. These arched ceilings 
 are tinged with all the colors of the rainbow, and 
 sparkle with all the luster and richness of 
 precious stones. Your guide, from time to time, 
 as you go along, manipulates the numerous lights 
 to give you the best effects. For the highest fig- 
 ures, all the electric lamps and candles in the
 
 214 SECRETS OF THE EARTH 
 
 vicinity are lighted. To show the remote corners, 
 fireworks in the form of colored flares and rockets 
 are utilized. 
 
 The first level is 216 feet below the surface. It 
 contains the famous Letow Ballroom, which was 
 excavated over a hundred and fifty years ago. 
 Here many festive gatherings, presided over by 
 the Emperor, have been held. At one end of the 
 room is a colossal Austrian eagle, with transpar- 
 encies painted on slabs of salt. In an alcove at 
 the other end of the apartment stands a throne 
 of green, the crystals of which flash out rays of 
 fweird green and ruby-red. It is on this throne 
 that the Emperor has always sat when he visited 
 the mines. 
 
 Close by is St. Anthony's Chapel. Even older 
 than the Ballroom, this ornate chamber dates 
 back to 1698. It may be considered the religious 
 center of the queer underground city. Legends 
 say that it is the work of a single miner. Be that 
 as it may, one thing is sure: it was an artist as 
 well as an indefatigable worker who conceived 
 and wrought that beautiful interior. The walls 
 and altar are embellished with many fine carv- 
 ings, all executed in salt. The character of these 
 blends in spirituously with the snow-like tone of 
 the whole apartment, giving you a peculiar, sweet 
 sense of rest under the subdued artificial lighting 
 system. Would you believe it? they hold
 
 "SALT OF THE EARTH" 215 
 
 "real" regular services in this Chapel; and on the 
 3d of every July there is a special mass, attended 
 by scores of people, some of whom come long dis- 
 tances. Then there are other shrines and temples. 
 Perhaps the finest of these is Queen's Chapel, 
 which, in addition to its splendid altar of salt, 
 exhibits on one wall a realistic view of Bethle- 
 hem, carved in salt, while overhead hangs an 
 elaborate salt chandelier. 
 
 In the second level you will come upon the 
 Michelowitz Chamber. This is an immense room 
 approximately ninety feet square, with a ceiling 
 118 feet up. The chamber has remarkable 
 acoustic properties. You can utter the lowest 
 whisper, and a friend at the farthest opposite 
 corner will hear your words as though his ear 
 were at your very lips. 
 
 The third level contains a salt railway station. 
 Here the twenty-five miles of mine tracks have 
 their upper terminal. It is as busy a little station 
 as you will find at a good-sized junction town 
 above ground almost anywhere in the country. 
 There are always miners and visitors waiting on 
 the salt platform or in the salt seats in the sta- 
 tion, for a train to come or go. At the same time 
 others will be found in the restaurant-room, par- 
 taking of refreshments and chatting gaily. When 
 you hear the rumble of an approaching train in 
 the tunnel near by, hear its wailing, echoing
 
 216 SECRETS OF THE EARTH 
 
 shriek, and note its twinkling lights coming 
 toward you and growing bigger and bigger like 
 expanding eyeballs of fire, you shrink just a 
 little closer to your guide, then laugh at your 
 foolishness as nearness makes the coming monster 
 take on a familiar, friendly aspect. 
 
 In strong contrast to the "dry" features of the 
 mine, there are sixteen subterranean lakes which 
 lap salty shores within its confines. Of course 
 these bodies are all intensely salty, and while 
 people bathe in them the water is not fit to drink 
 or use for cooking. The larger one of the lakes 
 is navigated by a ferryboat, which is hauled from 
 shore to shore by means of a rope.
 
 XV 
 SOME RARE MINERALS 
 
 THE world's minerals are constantly chang- 
 ing, constantly becoming something else. 
 Therefore from a comparatively few "raw" 
 materials to begin with, the world is able to find 
 these substances in various stages of develop- 
 ment, each stage having its own peculiar value 
 to the peoples who unearth them and make use 
 of them. But that is not all. There are many 
 of these ores which would be absolutely without 
 value when used alone, and their wonderful possi- 
 bilities never would have been known had not 
 man experimented with them in his laboratory, 
 and made scientific investigations, as a result of 
 which he found that by mixing or alloying them 
 with other mediums he could produce something 
 of great usefulness to his fellow-beings. 
 
 For instance, the miners who worked the Corn- 
 stock silver mine (which we have spoken of else- 
 where), in its early days, threw on the "waste 
 dump" the mineral cerusite, a lead carbonate 
 which is now valued at more than a thousand dol- 
 lars a ton. In this and other Colorado metal 
 mines, the early miners, not knowing what they 
 
 217
 
 218 SECRETS OF THE EARTH 
 
 were doing, threw away the valuable tungsten 
 portion of their ores. After the same manner, it 
 was not until quite recently that pitchblende was 
 known to contain those important constituents, 
 uranium and radium, the latter especially valued 
 to-day for its wonderful usefulness in the treat- 
 ment of the malignant diseases which afflict 
 people. 
 
 Altogether there are two values placed upon a 
 mineral scientific and economic. The scientific 
 value depends largely upon the scarceness or 
 rarity of a mineral. The economic value, on the 
 other hand, depends wholly upon the usefulness 
 to mankind of any part of a mineral. All rare 
 minerals have both a scientific and an economical 
 value. Some of the more important of these will 
 be considered in this chapter. 
 
 ALUMINUM 
 
 Some years ago there was a college boy who 
 read about an interesting metal called "alumi- 
 num," which had been discovered in France. A 
 French chemist, by taking common clay which 
 exists in vast quantities almost everywhere, had 
 succeeded in producing by some secret means a 
 wonderful metal with the strength of iron, the 
 toughness of copper, and almost the lightness of 
 pine wood. This aluminum was said to be by 
 far the lightest of all known metals. It was of a
 
 SOME RARE MINERALS 219 
 
 whitish color, with a faint tinge of blue, and 
 looked much like tin. Moisture could not make 
 it rust, however, like tin and iron. The boy read 
 that the new metal had been used in France for 
 making jewelry, and that a rattle made of it had 
 been presented to the baby son of the Emperor 
 of France as a great rarity. 
 
 This college boy, whose name was Hall, 
 thought by day and dreamed by night of this 
 strange aluminum, made from so simple a sub- 
 stance as clay or alumina, as the scientists love 
 to call clay. The papers said the cost of pro- 
 ducing aluminum was $90 a pound. The boy 
 knew this was too costly a process ever to make 
 the metal really useful, for common people could 
 never afford to buy it. So he wondered if some 
 new way could not be found in which to take 
 clay and produce the same result by a cheaper 
 method. 
 
 When this young man graduated, even the 
 pleasure of receiving his diploma could not keep 
 his mind away from aluminum. In fact, an idea 
 came to him, and he obtained the use of the col- 
 lege laboratory, and set to work. For almost a 
 whole year he tried mixing clay with various sub- 
 stances in an effort to produce the desired result. 
 But it was no use there was no aluminum. At 
 length he tried a stone from distant Greenland 
 called "cryolite," which had already been used
 
 220 SECRETS OP THE EARTH 
 
 for making a kind of porcelain. This stone melts 
 very easily. To his unbounded delight he found 
 that the clay and the cryolite fused together in 
 just the manner he wanted, when he passed an 
 electric current through them, the molten clay 
 melting the cryolite, the clay being decomposed 
 by the current. At the negative electrode, the 
 compounded molten aluminum ran down to the 
 bottom of the crucible, and here young Hall was 
 able to draw it off through a tap-hole. The 
 positive electrode was composed of heavy carbon 
 plates or cylinders, and here oxygen was set free. 
 
 Triumph had come at last. This young man, 
 just out of college, had not had his dreams in 
 vain. Dreams and hard work together had per- 
 formed the miracle, just as they will ever per- 
 form miracles in the future for those who apply 
 them properly. A process had been discovered, 
 in this particular instance, for reducing the cost 
 of aluminum production from $90 to 20 cents a 
 pound. What a benefaction to man! 
 
 Only a few months later a Frenchman, who 
 had also been quietly working away at the same 
 problem, made the same discovery. This man 
 Heroult, by name obtained patents in his own 
 country, while young Hall covered the rights in 
 the United States and Canada. 
 
 The clay from which aluminum is made is now 
 called "bauxite," and in this country is found
 
 SOME RARE MINERALS 221 
 
 chiefly in Georgia, Alabama, and Arkansas. 
 Mining it is much more agreeable than coal or 
 iron mining, for all the work is done above 
 ground, as sand or gravel is taken out of the 
 quarries you have seen. 
 
 When bauxite is purified the result is a fine 
 white powder which is pure alumina, consisting 
 of the unformed metal, aluminum, and the gas, 
 oxygen. Aluminum element is found not only in 
 clay, and indeed in most rocks, except sandstone 
 and limestone, but also in several of the precious 
 stones. In fact the oxide of aluminum is known to 
 the chemist as "alumina," to the mineralogist as 
 "corundum," to the jeweler as ruby and sapphire, 
 and to the lapidarist as emery. We may stake 
 a good deal that you never imagined before that 
 the tiny jewel bearing in your watch which makes 
 it run so accurately, the grit in the wheel on 
 which you sharpened your chisel in the manual- 
 training room of your school, the material of 
 which your mother's choicest kitchen metal- 
 ware is made, all came from the simple clay 
 which children in the kindergarten pummel about 
 into various images. 
 
 The uses of aluminum are constantly increas- 
 ing. It is a good conductor of electricity, and 
 sometimes takes the place of copper wire in the 
 construction of electric lines. The top of the 
 famous Washington Monument is covered with a
 
 222 SECRETS OF THE EARTH 
 
 thin sheet of aluminum, which is connected with 
 a lightning rod, to protect the monument from 
 destruction during thunder storms. A single 
 ounce of the metal, put into a ton of steel when 
 the latter is being poured out, will drive away 
 the gases which often make little holes in cast- 
 ings. Mixed with copper it makes a beautiful 
 bronze which has the yellow gleam of gold. 
 When a piece of jewelry which looks like gold 
 is offered to you at too low a price to be real 
 gold, the chances are that it is aluminum bronze, 
 very pretty at first, but very likely to tarnish 
 and lose its luster before long. Aluminum also 
 alloys splendidly with silver. Mixed with a very 
 little bit of the precious metal, the whole mass 
 looks like silver and will deceive most people. 
 
 With so many good qualities and so few bad 
 ones, it is small wonder that aluminum is em- 
 ployed for more purposes than can be counted. 
 Thirty years ago it was an interesting curiosity, 
 but now it is one of the most-worked metals. 
 Automobiles and air-planes owe much of their 
 success and efficiency to it. Engine cases for 
 them, frames, gear cases, fenders, hoods, bodies, 
 all owe their light features to its employment. 
 Travelers, soldiers, and campers, prefer alu- 
 minum dishes to those made of heavier materials. 
 Strange as it may seem this accommodating ma- 
 terial is even used for "wallpaper," threads of
 
 SOME RARE MINERALS 223 
 
 it being combined with silk to give a specially 
 brilliant effect in stage settings. Equally as 
 strange, it can be made into a paint which will 
 protect iron from rust, and woodwork from burn- 
 ing so quickly. 
 
 TUNGSTEN 
 
 You probably know tungsten best for its use 
 in the filaments of modern incandescent electric 
 lamps. When made of this valuable metal, the 
 filaments are twice as durable as the old carbon 
 filaments, give a much superior quality of white 
 light, and consume less than half as much elec- 
 tricity. Thousands of filaments can be made 
 from a single pound of tungsten, so that while 
 we know the metal best in this way, its use 
 therein is really quite limited compared to its 
 other applications. 
 
 For example, tungsten salts are utilized in 
 the arts. Tungstate of sodium is used in photog- 
 raphy. Tungsten is employed for fireproofing 
 theater curtains, cloth, etc. It is also used in 
 dyeing, being a powerful mordant which forms 
 an insoluble compound with any coloring matter, 
 and holds it within the tissues of the fabric. 
 
 But the chief economic use of tungsten is as 
 an alloy with other metals, such as iron, alu- 
 minum, steel, etc. An alloy of aluminum and 
 tungsten, known as "partinium," is used in the
 
 224 SECRETS OF THE EARTH 
 
 construction of airships and automobiles. It was 
 much employed by the Germans in the late war 
 in the construction of the great frameworks of 
 their Zeppelins. 
 
 An alloy of tungsten and its sister metal, 
 molybdenum, is a good substitute for platinum, 
 and for some purposes is said to be better. 
 
 The most important as well as the most gen- 
 eral use of tungsten is as an alloy of steel. This 
 metal is to the steel industry what copper is to 
 the electrical world, and possibly even more. 
 Steel containing 5 to 6 per cent tungsten is 
 very hard and tough, though still workable. By 
 putting 10 per cent in it the steel is rendered so 
 hard that it cannot be worked in a lathe and must 
 therefore be forged or ground to shape. Tung- 
 sten steel is highly magnetic, not easily rusted, 
 and requires no tempering or annealing. A ma- 
 chine equipped with tungsten-steel tools will do 
 more work than five similar machines using car- 
 bon-steel tools. Tungsten-steel drills, by hold- 
 ing their temper when red-hot, can be run at 
 many times greater speed than ordinary drills. 
 For bridge building and the erection of modern 
 sky-scraper city buildings, tungsten-steel has 
 been found to be the most dependable for 
 girders. 
 
 The World War gave a great impetus to the 
 use of tungsten. Steel made of it was used in
 
 SOME RARE MINERALS 225 
 
 the manufacture of high-powered siege and field 
 guns; it was employed in hardening armor- 
 piecing shells, and in producing armor-plate for 
 tanks and war vessels. 
 
 Tungsten is not found as a pure metal. The 
 truth is, if you were to know the metal by sight 
 and feeling ever so well, you would not recognize, 
 in the fine gray powder from which it is made, 
 any connection or relationship. To form the 
 solid metal the powder is reduced with aluminum 
 filings, and also by fusing with charcoal in spe- 
 cial furnaces. The metal thus produced is of a 
 steel-gray color, malleable, but hard enough to 
 scratch glass. It is not easily acted upon by 
 mineral acids, and is stronger than either iron 
 or nickel. It is so ductile that it can be drawn 
 into the finest wire. 
 
 Tungsten is classed as an "acid mineral." The 
 principal basic elements associated with it are 
 calcium, iron, manganese and lead. In the be- 
 ginning, when tungsten minerals were discovered 
 in 1781, they were thought to exist in only a few 
 favored countries, and within a small area; but 
 during recent years they have been found in 
 almost every mining country on the globe. How- 
 ever, no vast deposits have been unearthed any- 
 where. As a rule the deposits are very spare, 
 occurring in small stringers of the pure minerals, 
 or in lodes carrying other metals or minerals.
 
 226 SECRETS OF THE EARTH 
 
 It takes about 3,080 degrees C. to melt tung- 
 sten, which is one of the highest melting points 
 required by any metal. 
 
 PLATINUM 
 
 This metal was first taken to Europe in the 
 year 1735 from Colombia, South America. Be- 
 ing a white metal, resembling silver in appear- 
 ance, it was called platina in Spanish, plata 
 being the Spanish name for silver. It is, how- 
 ever, much heavier than silver, and is with the 
 exception of two extremely rare minerals, iridium 
 and osmium, the heaviest of all substances 
 known. It is fusible with other metals only with 
 great difficulty, and is very resistant to acids. 
 
 These latter properties make the metal in- 
 valuable for the construction of certain kinds of 
 chemical apparatus, such as crucibles, basins, 
 wire and foil. Platinum is of rare occurrence, 
 and owing to the very limited supply, the price 
 is constantly rising. At one time during the 
 late war it went as high as $100 an ounce, but is 
 now somewhat lower, owing to increased supply 
 and a falling off in demand. Formerly the metal 
 was made into coins in Russia, but this soon 
 ceased as the value of it mounted far above that 
 of gold. 
 
 Native platinum is found as grains and small 
 nuggets in the beds of streams. Practically the
 
 SOME RARE MINERALS 227 
 
 whole of the metal used commercially comes from 
 the Ural Mountains. So ductile is this extremely 
 heavy substance that it has been drawn into wire 
 so fine that a mile's length weighs only a single 
 grain! It is largely used in the manufacture of 
 fine jewelry, in making electrical, photographic, 
 dental and surgical supplies, as well as munitions 
 of war. 
 
 RADIUM 
 
 While radium is a metal it is never found or 
 prepared in metallic form. It can be reduced to 
 this condition, but there would be sure to be some 
 loss of the constituents, as the substance oxidizes 
 rapidly, and is soon lost in the air, vanishing like 
 a ghost. As the mineral has such a fabulous 
 value, and is so hard to get even in the smallest 
 quantities, chemists must do everything in their 
 power, you see, to prevent any loss of material. 
 
 For this reason radium is usually prepared 
 either in the form of chloride or as a bromide, 
 which conserves the element so that it will last 
 indefinitely and without any apparent loss. It 
 is very difficult and dangerous to handle because 
 of its wonderful and mysterious penetrating 
 powers, the cause of which no man has yet been 
 able to explain, trained in science though he be. 
 In its pure state, looking much like salt and 
 equally as harmless, it is one of the biggest de-
 
 228 SECRETS OF THE EARTH 
 
 ceivers that ever was. It will quickly destroy 
 the life in seeds. Should you take a tube con- 
 taining it in your bare hand, though it never 
 touched you its intense violet rays would cause 
 ugly and painful sores to appear on the hand. 
 
 Radium gives off a slight light, but its real 
 activity is learned only through the effects it 
 produces. It gives off enough heat to melt its 
 own weight of ice every hour, or to raise its own 
 weight of water from the freezing to the boiling 
 point. When a tube of radium is placed on a 
 surface coated with sulphide of zinc, or some 
 other similar substance, the surface becomes lumi- 
 nous. It discharges electrified bodies, and makes 
 any gas on which it acts a conductor of electricity. 
 If a photographic plate is wrapped in black 
 paper, and an opaque object, such as a penny, 
 is coated with radium and laid upon the paper 
 with the coated side up, a picture of the penny 
 will be made upon the plate. 
 
 Altogether, radium is easily the most wonder- 
 ful and costly metal which old Mother Nature 
 has let us get our fingers on in the pocket of her 
 rugged apron. It is valued at $9,000,000 a 
 pound. A glass tube of this substance, which is 
 no larger around than a straw, and no longer 
 than a pin, is worth $4,000. Very recently the 
 State of New York purchased two and one- 
 quarter grams of radium, in behalf of the State
 
 SOME RARE MINERALS 229 
 
 Institute for Malignant Disease, at a cost of 
 $225,000. The metal is to be used by the Insti- 
 tute in research work and the cure of some of its 
 patients. It took twenty-one cars to carry the 
 625 tons of carnotite ore, from which this small 
 amount of radium was gleaned, from the mines 
 in the Colorado desert. An equal bulk of coal 
 and chemicals was employed in the process of 
 extraction. 
 
 Carnotite occurs with pitchblende in Paradox 
 Valley, Colorado, in amorphous masses. It is 
 a new mineral, named after the French scientist, 
 Carnot, and is mainly confined to the limits of 
 the United States. Its color is a rich yellow or 
 orange. It usually occurs in white or gray sand- 
 stone, and is often found with copper or silver 
 ores. Quite the opposite in looks is pitchblende. 
 This is an ugly black mineral bearing some re- 
 semblance to pitch. It is remarkable in having 
 strong radio-active properties; that is, it is con- 
 stantly emitting invisible rays of light, which 
 make the air a conductor of electricity. For in- 
 stance, if a piece of pitchblende is placed near a 
 charged gold-leaf electroscope, the charge of 
 electricity rapidly escapes, and the gold-leaves 
 fall together. 
 
 It was these peculiar properties of pitchblende 
 which led Professor and Madame Curie, the dis- 
 coverers of radium, to separate from the ore the
 
 230 SECRETS OF THE EARTH 
 
 particular elements radium and polonium to 
 which these special effects of pitchblende are due. 
 This was in 1898, in Paris. The most productive 
 mines of pitchblende are those at Joachimsthal, 
 in Bohemia, although it is also found in some of 
 the Cornish mines. The feldspar quarries of 
 southern Norway produce it in small cubic 
 crystals, embedded in the feldspar. 
 
 But carnotite has become in the last few years 
 the chief ore supply of radium, and the whole 
 world looks to our own Colorado and Utah for 
 most of this valuable mineral. 
 
 The manufacture of radium is a long, tedious 
 chemical process, complicated by many diffi- 
 culties, and requiring special care and skill. 
 Previous to 1912 there were no laboratories for 
 its production in the United States, and the car- 
 notite was sent to Europe. In that year the 
 United States Government established a labora- 
 tory at Denver, and since that time this institu- 
 tion has successfully extracted such radium as 
 we have used, employing new and better pro- 
 cesses than those which had existed heretofore. 
 
 The action of radium upon the tissues of the 
 human body makes it a valuable agent in the 
 treatment of cancer in its first stages, for the re- 
 moval of scars, warts and corns, and in the treat- 
 ment of that form of goiter which causes the eyes 
 to protrude from their sockets. The radium may
 
 SOME RARE MINERALS 231 
 
 be applied directly to the part to be treated, or 
 it may be given internally in diluted solution. 
 But it is safe only in the hands of experts who 
 understand its whims through long experience. 
 
 MERCURY 
 
 "Quicksilver" is the common name for the 
 element mercury. It is a silver- white metal, 13.5 
 times heavier than water; it flows freely, and 
 when spilled is about the most difficult thing to 
 recover you ever saw, evading the touch of every- 
 thing except that on which it lies. It is the only 
 metal which is a liquid at ordinary temperatures. 
 At 37.9 degrees F. below zero it freezes and be- 
 comes solid; at 675 degrees F. it changes to va- 
 por. When heated or cooled it expands or con- 
 tracts quickly and at a very regular rate. For 
 this reason it is especially valuable for making 
 thermometers, and mirrors, in which guises it is 
 probably most familiar to us. 
 
 Mercury is most extensively used for extract- 
 ing gold and silver from ores. But it is also used 
 extensively in the arts. Its compound with 
 chlorine is widely used as a medicine under the 
 name of "calomel." Another compound with 
 chlorine is the well-known and exceedingly 
 poisonous "corrosive sublimate," often used as 
 an antiseptic. "Vermilion," another compound, 
 with sulphur, is used in some red paints. Mer-
 
 232 SECRETS OF THE EARTH 
 
 cury is largely employed also in the manufacture 
 of explosive caps, both for blasting purposes and 
 in the production of cartridges used in small fire- 
 arms as well as large fieldpleces. Dentists use 
 it, electricians value it, barometer manufacturers 
 could not get along without it. And what would 
 the mirror makers ever do without it? 
 
 Mercury occurs native, but only in small 
 quantities. Most of it is taken from the ore cin- 
 nabar, which in a pure state contains 86.2 per 
 cent of mercury and 13.8 per cent of sulphur. 
 The crystals of cinnabar are often transparent 
 with a deep-red color and brilliant luster. The 
 mercury occurs in the ore in the form of little 
 globules of liquid embedded here and there in 
 its surface. 
 
 Mercury is obtained by roasting the ore in a 
 current of air. This heating process drives off 
 the sulphur, which combines with the oxygen of 
 the air to form a gas, thus leaving the mercury 
 free. Spain, Mexico, and the United States pro- 
 duce most of the world's supply. The chief 
 mines of this country are near San Francisco. 
 
 THE END
 
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