CHAPTER XLII

  _In the Service of the King_

  Very early the next morning the boys, who had caught the Doctor'senthusiasm, began again their task of digging through the "out crop"coal, which began now to grow softer and more workable, while the coalitself grew steadily better in quality.

  But about noon, when they had pushed their little shaft about a dozenfeet into the hill, the Doctor ordered a cessation of the digging.

  "We must put in some supports for our roof," he said, "or we shallpresently be caught in a cave in."

  "How are we to do it?" asked Jack.

  "Well, I am not a mining engineer," answered the Doctor, "but I've seenenough of the work to know how to protect a little shaft like this,anyhow. The engineers, when they come, will of course tear out all thatwe do, because they must drive a big shaft into the hill, while all wewant to do is to push a little gallery three or four feet wide farenough in to find the best of the coal. But even in doing that we mustsecurely support the roof of our mine. So we'll cut some timber and putit in place. Jack, I wish you would choose the trees to be cut."

  "All right!" said Jack. "What dimensions are required?"

  "First of all," answered the Doctor, "we want from six to ten pieces ofoak, say four feet six inches long and fully twelve inches in diameter.They will serve for roof timbers, and will be enough to carry us thirtyor forty feet further. Then for perpendicular supports--one at each endof each timber--we shall need just twice as many perfectly straightoaken sticks eight or nine inches in diameter."

  "But why do you want big sticks to go crossways and comparatively littleones for the perpendicular supports?" asked Ed. "The perpendiculartimbers must after all bear the weight."

  "Oh, that's simple enough," said Tom, whose perceptive faculties werealways alert. "You see a stick set up on end, if it is perfectlystraight and set true, will bear vastly more weight than a stick oftwice or three times its thickness, if laid crossways. In fact astraight eight-inch stick nine feet long, if set on end will supportnearly as much as another stick nine feet thick--if there were anysticks that thick--laid lengthwise."

  "That's it," said the Doctor. "We want heavy timbers across the top,supported by stout eight- or nine-inch sticks set endwise under them.Now, Jack, select the best trees and we'll all get to work as soon asdinner is over. We'll get the dinner ready while you choose the timberto be cut."

  The cutting of the timber was a small task to expert young woodchoppers; but it was a very difficult task for the six boys to bring thetimbers to the mine and set them in place. True, only two frames had tobe set up for the present, but the cross pieces, short as they were,were enormously heavy, and it required all the ingenuity as well as allthe strength the boys could command, to get these two frames up, eachconsisting of one cross piece under the roof and two uprights supportingit.

  When night came only one of the two frames was in place, and it wasobvious, as Jack said, that "another half day must be wasted on suchwork" before they could begin mining again. But that evening the Doctordug two bushels of coal out of the farthest end of the shaft, built aspecial fire, placed the coal on it, and carefully covered it withearth.

  "What are you doing, Doctor?" asked his crony, Tom.

  "I'm making a coke oven, Tom," he replied. "I want to see how our coalwill coke."

  "But I don't understand about coke," answered Tom. "Why is it that whenyou burn most of the substance out of coal it will make a hotter firethan with all its combustible materials in it?"

  "That isn't quite the case, Tom," answered the Doctor. "What we do inmaking coke is chiefly to expel the gas from the coal and to roast outthe sulphur, which seriously interferes with the making of sufficientheat to smelt iron. Some coal gets burnt up in the process; some makesan indifferent and nearly worthless coke; while some makes a coke thatwould melt the heart of a miser. Now, as I told you the other night, Iam convinced as a geologist, that a little further in our mine we shallcome to coal so free from sulphur that we can smelt iron with it withoutmaking coke of it at all. But it is always preferable to make coke ofit, and so I'm trying to see what sort of coke our coal will make. Ofcourse we haven't come to the real coal yet, but I can tell a good dealby what we have now. We'll let my little coke oven roast all night andin the morning I'll know a great deal more than I do now. But if youhave any question in your mind as to the gas making capacity of thiscoal, I'll remove it at once."

  With that he went to the camp fire, seized a blazing brand and appliedit to the little mound of earth under which he had buried his coal.Instantly the whole outside of the mound was aflame.

  "That's the gas," said the Doctor. "You see there's plenty of it, evenin the imperfect coal that we've reached. It will burn out presently andmeantime its heat will help roast my coal into coke."

  After supper the boys again plied the Doctor with questions concerningcoal. Tom began it by saying:

  "You told us the other evening, Doctor, that the value of a bed of coaldepends upon many things besides its location and its accessibility tomarket. What are those things?"

  "Thickness, for one thing," answered the Doctor, "and that is a point inwhich our mine excels. You see coal seams are of every thickness, fromthat of a knife blade to beds 100 feet through. Those last are veryrare, however. In this country the seams vary from knife blade thicknessto about nine or ten feet. Now, in working a coal mine the men, ofcourse, must have room to stand up in the shaft, so that wherever thevein is less than six feet thick a good deal of rock or earth must beremoved so as to give sufficient height to the mine. It costs as muchto remove the rock or earth as to handle a like amount of coal, and thestuff is worthless. So you see it is greatly more profitable to work athick than a thin vein. Indeed there are very few veins under three orfour feet thick that it pays to work at all. Our deposit here appears tobe about nine feet thick, and that means much to us.

  "Another condition of value in a coal mine is a good roof. There aremany rich veins of coal that have only earth or soft shale above them,and they are practically worthless because they are unworkable. Wefortunately have a superb rock roof over our mine."

  "But, Doctor," said Tom, "you told us the other night that coal is atthe basis of modern industrial civilization. Then I suppose that thosenations which have coal must be the foremost ones in industry andconsequently in civilization."

  "Certainly they are," said the Doctor, as the other boys gathered aboutto hear the talk; "and they will be more and more so as time goes on.England has more coal than any other country in Europe and so England isby all odds the foremost industrial nation in Europe, though othernations there have the advantage of buying English coal in an openmarket. Ever since our modern age of industry and machinery setin--that is to say ever since Old King Coal came to his throne--Englandhas grown greater and richer, till now she is by all odds the richestcountry in Europe."

  "Haven't the other countries there any coal?" asked Ed.

  "Yes, but comparatively little. Let me see if I can remember the figuresapproximately. Great Britain's coal fields cover nearly 12,000 squaremiles; France has only 2,000 square miles, Prussia about the same,Belgium has only 500 square miles, Austria less than 2,000; Italy noneat all to speak of, and as for Spain, the Spanish indolence, which putsoff everything till 'to-morrow' has prevented that country from evenfinding out what coal she has. Russia has vast fields and bids fair totake her place ultimately among the great coal producing and industrialnations of the earth. But as yet her coal fields are imperfectlydeveloped and her coal production is only about one-thirty-fifth asgreat as that of Great Britain."

  "What about the United States, Doctor?" asked Tom, who was an aggressivepatriot.

  "Well, we have many times more coal than all Europe combined," answeredthe Doctor. "Great Britain's 12,000 square miles of coal lands sink intoinsignificance in comparison with our 214,000 square miles of measuredcoal fields, our 200,000 or 300,000 square miles in the Rocky Mountainstates, and our totally unguessed-at coal fields
in Oregon andWashington. As four or five hundred thousand and probably more, is totwelve thousand, so is our known coal area to that which has made GreatBritain the greatest industrial nation on earth next to our own. Andsome of the British mines are pretty nearly worked out, while we havescarcely scratched the surface of ours."

  "Then this is likely to become the greatest industrial nation on earth?"said Jack.

  "It is already that," answered the Doctor. "We are selling ourmanufactured goods--even iron and steel products--in England to-day,almost as freely as we are selling our grain and our meat. I tell you,boys, there is nothing in this world that can happen to a man that is sogood as being born an American citizen."

  "Amen!" said Tom. "To employ the dialect of my friends among themountaineers, 'them's my sentiments every time all over and clearthrough.'"

  "All right," said Jack, "now let's get to bed."

  "I suppose there's a lot more you could tell us about coal, Doctor,"said Jim, "if there was time."

  "Of course there is," the Doctor responded; "but you'll learn it allpractically. For we've a great mine here, and you boys will have firstchoice of places in its management."

  With that they all went to bed.