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diff --git a/10251-h/10251-h.htm b/10251-h/10251-h.htm new file mode 100644 index 0000000..59ec3eb --- /dev/null +++ b/10251-h/10251-h.htm @@ -0,0 +1,4156 @@ +<!DOCTYPE html + PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" + "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII" /> +<title>Town Geology</title> +</head> +<body> +<h2> +<a href="#startoftext">Town Geology, by Charles Kingsley</a> +</h2> +<pre> +The Project Gutenberg eBook, Town Geology, by Charles Kingsley + + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + + + + + +Title: Town Geology + +Author: Charles Kingsley + +Release Date: November 24, 2003 [eBook #10251] + +Language: English + +Chatacter set encoding: US-ASCII + + +***START OF THE PROJECT GUTENBERG EBOOK TOWN GEOLOGY*** +</pre> +<p><a name="startoftext"></a>Transcribed by David Price, email ccx074@coventry.ac.uk</p> +<div class="GutenbergBlankLines3"><br /><br /><br /></div> +<h1>TOWN GEOLOGY</h1> +<div class="GutenbergBlankLines3"><br /><br /><br /></div> +<h2>PREFACE</h2> +<div class="GutenbergBlankLines2"><br /><br /></div> +<p>This little book, including the greater part of this Preface, has +shaped itself out of lectures given to the young men of the city of +Chester. But it does not deal, in its present form, with the geology +of the neighbourhood of Chester only. I have tried so to recast +it, that any townsman, at least in the manufacturing districts of England +and Scotland, may learn from it to judge, roughly perhaps, but on the +whole accurately, of the rocks and soils of his own neighbourhood. +He will find, it is true, in these pages, little or nothing about those +“Old Red Sandstones,” so interesting to a Scotchman; and +he will have to bear in mind, if he belong to the coal districts of +Scotland, that the “stones in the wall” there belong to +much older rocks than those “New Red Sandstones” of which +this book treats; and that the coal measures of Scotland, with the volcanic +rocks which have disturbed them, are often very different in appearance +to the English coal measures. But he will soon learn to distinguish +the relative age of rocks by the fossils found in them, which he can +now, happily, study in many local museums; and he may be certain, for +the rest, that all rocks and soils whatsoever which he may meet have +been laid down by the agents, and according to the laws, which I have +tried to set forth in this book; and these only require, for the learning +of them, the exercise of his own observation and common sense. +I have not tried to make this a handbook of geological facts. +Such a guide (and none better) the young man will find in Sir Charles +Lyell’s “Student’s Elements of Geology.” +I have tried rather to teach the method of geology, than its facts; +to furnish the student with a key to all geology, rough indeed and rudimentary, +but sure and sound enough, I trust, to help him to unlock most geological +problems which he may meet, in any quarter of the globe. But young +men must remember always, that neither this book, nor all the books +in the world, will make them geologists. No amount of book learning +will make a man a scientific man; nothing but patient observation, and +quiet and fair thought over what he has observed. He must go out +for himself, see for himself, compare and judge for himself, in the +field, the quarry, the cutting. He must study rocks, ores, fossils, +in the nearest museum; and thus store his head, not with words, but +with facts. He must verify—as far as he can—what he +reads in books, by his own observation; and be slow to believe anything, +even on the highest scientific authority, till he has either seen it, +or something like enough to it to make it seem to him probable, or at +least possible. So, and so only, will he become a scientific man, +and a good geologist; and acquire that habit of mind by which alone +he can judge fairly and wisely of facts of any kind whatsoever.</p> +<p>I say—facts of any kind whatsoever. If any of my readers +should be inclined to say to themselves: Geology may be a very pleasant +study, but I have no special fancy for it. I had rather learn +something of botany, astronomy, chemistry, or what not—I shall +answer: By all means. Learn any branch of Natural Science you +will. It matters little to me which you learn, provided you learn +one at least. But bear in mind, and settle it in your hearts, +that you will learn no branch of science soundly, so as to master it, +and be able to make use of it, unless you acquire that habit and method +of mind which I am trying to teach you in this book. I have tried +to teach it you by geology, because geology is, perhaps, the simplest +and the easiest of all physical sciences. It appeals more than +any to mere common sense. It requires fewer difficult experiments, +and expensive apparatus. It requires less previous knowledge of +other sciences, whether pure or mixed; at least in its rudimentary stages. +It is more free from long and puzzling Greek and Latin words. +It is specially, the poor man’s science. But if you do not +like it, study something else. Only study that as you must study +geology; proceeding from the known to the unknown by observation and +experiment.</p> +<p>But here some of my readers may ask, as they have a perfect right +to ask, why I wish young men to learn Natural Science at all? +What good will the right understanding of geology, or of astronomy, +or of chemistry, or of the plants or animals which they meet—what +good, I say, will that do them?</p> +<p>In the first place, they need, I presume, occupation after their +hours of work. If any of them answer: “We do not want occupation, +we want amusement. Work is very dull, and we want something which +will excite our fancy, imagination, sense of humour. We want poetry, +fiction, even a good laugh or a game of play”—I shall most +fully agree with them. There is often no better medicine for a +hard-worked body and mind than a good laugh; and the man who can play +most heartily when he has a chance of playing is generally the man who +can work most heartily when he must work. But there is certainly +nothing in the study of physical science to interfere with genial hilarity; +though, indeed, some solemn persons have been wont to reprove the members +of the British Association, and specially that Red Lion Club, where +all the philosophers are expected to lash their tails and roar, of being +somewhat too fond of mere and sheer fun, after the abstruse papers of +the day are read and discussed. And as for harmless amusement, +and still more for the free exercise of the fancy and the imagination, +I know few studies to compare with Natural History; with the search +for the most beautiful and curious productions of Nature amid her loveliest +scenery, and in her freshest atmosphere. I have known again and +again working men who in the midst of smoky cities have kept their bodies, +their minds, and their hearts healthy and pure by going out into the +country at odd hours, and making collections of fossils, plants, insects, +birds, or some other objects of natural history; and I doubt not that +such will be the case with some of my readers.</p> +<p>Another argument, and a very strong one, in favour of studying some +branch of Natural Science just now is this—that without it you +can hardly keep pace with the thought of the world around you.</p> +<p>Over and above the solid gain of a scientific habit of mind, of which +I shall speak presently, the gain of mere facts, the increased knowledge +of this planet on which we live, is very valuable just now; valuable +certainly to all who do not wish their children and their younger brothers +to know more about the universe than they do.</p> +<p>Natural Science is now occupying a more and more important place +in education. Oxford, Cambridge, the London University, the public +schools, one after another, are taking up the subject in earnest; so +are the middle-class schools; so I trust will all primary schools throughout +the country; and I hope that my children, at least, if not I myself, +will see the day, when ignorance of the primary laws and facts of science +will be looked on as a defect, only second to ignorance of the primary +laws of religion and morality.</p> +<p>I speak strongly, but deliberately. It does seem to me strange, +to use the mildest word, that people whose destiny it is to live, even +for a few short years, on this planet which we call the earth, and who +do not at all intend to live on it as hermits, shutting themselves up +in cells, and looking on death as an escape and a deliverance, but intend +to live as comfortably and wholesomely as they can, they and their children +after them—it seems strange, I say, that such people should in +general be so careless about the constitution of this same planet, and +of the laws and facts on which depend, not merely their comfort and +their wealth, but their health and their very lives, and the health +and the lives of their children and descendants.</p> +<p>I know some will say, at least to themselves: “What need for +us to study science? There are plenty to do that already; and +we shall be sure sooner or later to profit by their discoveries; and +meanwhile it is not science which is needed to make mankind thrive, +but simple common sense.”</p> +<p>I should reply, that to expect to profit by other men’s discoveries +when you do not pay for them—to let others labour in the hope +of entering into their labours, is not a very noble or generous state +of mind—comparable somewhat, I should say, to that of the fatting +ox, who willingly allows the farmer to house him, till for him, feed +him, provided only he himself may lounge in his stall, and eat, and +<i>not</i> be thankful. There is one difference in the two cases, +but only one—that while the farmer can repay himself by eating +the ox, the scientific man cannot repay himself by eating you; and so +never gets paid, in most cases, at all.</p> +<p>But as for mankind thriving by common sense: they have not thriven +by common sense, because they have not used their common sense according +to that regulated method which is called science. In no age, in +no country, as yet, have the majority of mankind been guided, I will +not say by the love of God, and by the fear of God, but even by sense +and reason. Not sense and reason, but nonsense and unreason, prejudice +and fancy, greed and haste, have led them to such results as were to +be expected—to superstitions, persecutions, wars, famines, pestilence, +hereditary diseases, poverty, waste—waste incalculable, and now +too often irremediable—waste of life, of labour, of capital, of +raw material, of soil, of manure, of every bounty which God has bestowed +on man, till, as in the eastern Mediterranean, whole countries, some +of the finest in the world, seem ruined for ever: and all because men +will not learn nor obey those physical laws of the universe, which (whether +we be conscious of them or not) are all around us, like walls of iron +and of adamant—say rather, like some vast machine, ruthless though +beneficent, among the wheels of which if we entangle ourselves in our +rash ignorance, they will not stop to set us free, but crush us, as +they have crushed whole nations and whole races ere now, to powder. +Very terrible, though very calm, is outraged Nature.</p> +<div class="GutenbergBlankLines1"><br /></div> +<p>Though the mills of God grind slowly,<br /> Yet +they grind exceeding small;<br />Though He sit, and wait with patience,<br /> With +exactness grinds He all.</p> +<div class="GutenbergBlankLines1"><br /></div> +<p>It is, I believe, one of the most hopeful among the many hopeful +signs of the times, that the civilised nations of Europe and America +are awakening slowly but surely to this truth. The civilised world +is learning, thank God, more and more of the importance of physical +science; year by year, thank God, it is learning to live more and more +according to those laws of physical science, which are, as the great +Lord Bacon said of old, none other than “Vox Dei in rebus revelata”—the +Word of God revealed in facts; and it is gaining by so doing, year by +year, more and more of health and wealth; of peaceful and comfortable, +even of graceful and elevating, means of life for fresh millions.</p> +<p>If you want to know what the study of physical science has done for +man, look, as a single instance, at the science of Sanatory Reform; +the science which does not merely try to cure disease, and shut the +stable-door after the horse is stolen, but tries to prevent disease; +and, thank God! is succeeding beyond our highest expectations. +Or look at the actual fresh amount of employment, of subsistence, which +science has, during the last century, given to men; and judge for yourselves +whether the study of it be not one worthy of those who wish to help +themselves, and, in so doing, to help their fellow-men. Let me +quote to you a passage from an essay urging the institution of schools +of physical science for artisans, which says all I wish to say and more:</p> +<p>“The discoveries of Voltaic electricity, electromagnetism, +and magnetic electricity, by Volta, Œrsted, and Faraday, led to +the invention of electric telegraphy by Wheatstone and others, and to +the great manufactures of telegraph cables and telegraph wire, and of +the materials required for them. The value of the cargo of the +Great Eastern alone in the recent Bombay telegraph expedition was calculated +at three millions of pounds sterling. It also led to the employment +of thousands of operators to transmit the telegraphic messages, and +to a great increase of our commerce in nearly all its branches by the +more rapid means of communication. The discovery of Voltaic electricity +further led to the invention of electro-plating, and to the employment +of a large number of persons in that business. The numerous experimental +researches on specific heat, latent heat, the tension of vapours, the +properties of water, the mechanical effect of heat, etc., resulted in +the development of steam-engines, and railways, and the almost endless +employments depending upon their construction and use. About a +quarter of a million of persons are employed on railways alone in Great +Britain. The various original investigations on the chemical effects +of light led to the invention of photography, and have given employment +to thousands of persons who practise that process, or manufacture and +prepare the various material and articles required in it. The +discovery of chlorine by Scheele led to the invention of the modern +processes of bleaching, and to various improvements in the dyeing of +the textile fabrics, and has given employment to a very large number +of our Lancashire operatives. The discovery of chlorine has also +contributed to the employment of thousands of printers, by enabling +Esparto grass to be bleached and formed into paper for the use of our +daily press. The numerous experimental investigations in relation +to coal-gas have been the means of extending the use of that substance, +and of increasing the employment of workmen and others connected with +its manufacture. The discovery of the alkaline metals by Davy, +of cyanide of potassium, of nickel, phosphorus, the common acids, and +a multitude of other substances, has led to the employment of a whole +army of workmen in the conversion of those substances into articles +of utility. The foregoing examples might be greatly enlarged upon, +and a great many others might be selected from the sciences of physics +and chemistry: but those mentioned will suffice. There is not +a force of Nature, nor scarcely a material substance that we employ, +which has not been the subject of several, and in some cases of numerous, +original experimental researches, many of which have resulted, in a +greater or less degree, in increasing the employment for workmen and +others.” <a name="citation1"></a><a href="#footnote1">{1}</a></p> +<p>“All this may be very true. But of what practical use +will physical science be to me?”</p> +<p>Let me ask in return: Are none of you going to emigrate? If +you have courage and wisdom, emigrate you will, some of you, instead +of stopping here to scramble over each other’s backs for the scraps, +like black-beetles in a kitchen. And if you emigrate, you will +soon find out, if you have eyes and common sense, that the vegetable +wealth of the world is no more exhausted than its mineral wealth. +Exhausted? Not half of it—I believe not a tenth of it—is +yet known. Could I show you the wealth which I have seen in a +single Tropic island, not sixty miles square—precious timbers, +gums, fruits, what not, enough to give employment and wealth to thousands +and tens of thousands, wasting for want of being known and worked—then +you would see what a man who emigrates may do, by a little sound knowledge +of botany alone.</p> +<p>And if not. Suppose that any one of you, learning a little +sound Natural History, should abide here in Britain to your life’s +end, and observe nothing but the hedgerow plants, he would find that +there is much more to be seen in those mere hedgerow plants than he +fancies now. The microscope will reveal to him in the tissues +of any wood, of any seed, wonders which will first amuse him, then puzzle +him, and at last (I hope) awe him, as he perceives that smallness of +size interferes in no way with perfection of development, and that “Nature,” +as has been well said, “is greatest in that which is least.” +And more. Suppose that he went further still. Suppose that +he extended his researches somewhat to those minuter vegetable forms, +the mosses, fungi, lichens; suppose that he went a little further still, +and tried what the microscope would show him in any stagnant pool, whether +fresh water or salt, of Desmidiæ, Diatoms, and all those wondrous +atomies which seem as yet to defy our classification into plants or +animals. Suppose he learnt something of this, but nothing of aught +else. Would he have gained no solid wisdom? He would be +a stupider man than I have a right to believe any of my readers to be, +if he had not gained thereby somewhat of the most valuable of treasures—namely, +that inductive habit of mind, that power of judging fairly of facts, +without which no good or lasting work will be done, whether in physical +science, in social science, in politics, in philosophy, in philology, +or in history.</p> +<p>But more: let me urge you to study Natural Science, on grounds which +may be to you new and unexpected—on social, I had almost said +on political, grounds.</p> +<p>We all know, and I trust we all love, the names of Liberty, Equality, +and Brotherhood. We feel, I trust, that these words are too beautiful +not to represent true and just ideas; and that therefore they will come +true, and be fulfilled, somewhen, somewhere, somehow. It may be +in a shape very different from that which you, or I, or any man expects; +but still they will be fulfilled.</p> +<p>But if they are to come true, it is we, the individual men, who must +help them to come true for the whole world, by practising them ourselves, +when and where we can. And I tell you—that in becoming scientific +men, in studying science and acquiring the scientific habit of mind, +you will find yourselves enjoying a freedom, an equality, a brotherhood, +such as you will not find elsewhere just now.</p> +<p>Freedom: what do we want freedom for? For this, at least; that +we may be each and all able to think what we choose; and to say what +we choose also, provided we do not say it rudely or violently, so as +to provoke a breach of the peace. That last was Mr. Buckle’s +definition of freedom of speech. That was the only limit to it +which he would allow; and I think that that is Mr. John Stuart Mill’s +limit also. It is mine. And I think we have that kind of +freedom in these islands as perfectly as any men are likely to have +it on this earth.</p> +<p>But what I complain of is, that when men have got the freedom, three +out of four of them will not use it. What?—someone will +answer—Do you suppose that I will not say what I choose, and that +I dare not speak my own mind to any man? Doubtless. But +are you sure first, that you think what you choose, or only what someone +else chooses for you? Are you sure that you make up your own mind +before you speak, or let someone else make it up for you? Your +speech may be free enough, my good friend; and Heaven forbid that it +should be anything else: but are your thoughts free likewise? +Are you sure that, though you may hate bigotry in others, you are not +somewhat of a bigot yourself? That you do not look at only one +side of a question, and that the one which pleases you? That you +do not take up your opinions at second hand, from some book or some +newspaper, which after all only reflects your own feelings, your own +opinions? You should ask yourselves that question, seriously and +often: “Are my thoughts really free?” No one values +more highly than I do the advantage of a free press. But you must +remember always that a newspaper editor, however honest or able, is +no more infallible than the Pope; that he may, just as you may, only +see one side of a question, while any question is sure to have two sides, +or perhaps three or four; and if you only see the side which suits you, +day after day, month after month, you must needs become bigoted to it. +Your thoughts must needs run in one groove. They cannot (as Mr. +Matthew Arnold would say) “play freely round” a question; +and look it all over, boldly, patiently, rationally, charitably.</p> +<p>And I tell you that if you, or I, or any man, want to let our thoughts +play freely round questions, and so escape from the tendency to become +bigoted and narrow-minded which there is in every human being, then +we must acquire something of that inductive habit of mind which the +study of Natural Science gives. It is, after all, as Professor +Huxley says, only common sense well regulated. But then it is +well regulated; and how precious it is, if you can but get it. +The art of seeing, the art of knowing what you see; the art of comparing, +of perceiving true likenesses and true differences, and so of classifying +and arranging what you see: the art of connecting facts together in +your own mind in chains of cause and effect, and that accurately, patiently, +calmly, without prejudice, vanity, or temper—this is what is wanted +for true freedom of mind. But accuracy, patience, freedom from +prejudice, carelessness for all except the truth, whatever the truth +may be—are not these the virtues of a truly free spirit? +Then, as I said just now, I know no study so able to give that free +habit of mind as the Study of Natural Science.</p> +<p>Equality, too: whatever equality may or may not be just, or possible; +this at least, is just, and I hope possible; that every man, every child, +of every rank, should have an equal chance of education; an equal chance +of developing all that is in him by nature; an equal chance of acquiring +a fair knowledge of those facts of the universe which specially concern +him; and of having his reason trained to judge of them. I say, +whatever equal rights men may or may not have, they have this right. +Let every boy, every girl, have an equal and sound education. +If I had my way, I would give the same education to the child of the +collier and to the child of a peer. I would see that they were +taught the same things, and by the same method. Let them all begin +alike, say I. They will be handicapped heavily enough as they +go on in life, without our handicapping them in their first race. +Whatever stable they come out of, whatever promise they show, let them +all train alike, and start fair, and let the best colt win.</p> +<p>Well: but there is a branch of education in which, even now, the +poor man can compete fairly against the rich; and that is, Natural Science. +In the first place, the rich, blind to their own interest, have neglected +it hitherto in their schools; so that they have not the start of the +poor man on that subject which they have on many. In the next +place, Natural Science is a subject which a man cannot learn by paying +for teachers. He must teach it himself, by patient observation, +by patient common sense. And if the poor man is not the rich man’s +equal in those qualities, it must be his own fault, not his purse’s. +Many shops have I seen about the world, in which fools could buy articles +more or less helpful to them; but never saw I yet an observation-shop, +nor a common-sense shop either. And if any man says, “We +must buy books:” I answer, a poor man now can obtain better scientific +books than a duke or a prince could sixty years ago, simply because +then the books did not exist. When I was a boy I would have given +much, or rather my father would have given much, if I could have got +hold of such scientific books as are to be found now in any first-class +elementary school. And if more expensive books are needed; if +a microscope or apparatus is needed; can you not get them by the co-operative +method, which has worked so well in other matters? Can you not +form yourselves into a Natural Science club, for buying such things +and lending them round among your members; and for discussion also, +the reading of scientific papers of your own writing, the comparing +of your observations, general mutual help and mutual instructions? +Such societies are becoming numerous now, and gladly should I see one +in every town. For in science, as in most matters, “As iron +sharpeneth iron, so a man sharpeneth the countenance of his friend.”</p> +<p>And Brotherhood: well, if you want that; if you want to mix with +men, and men, too, eminently worth mixing with, on the simple ground +that “a man’s a man for a’ that;” if you want +to become the acquaintances, and—if you prove worthy—the +friends, of men who will be glad to teach you all they know, and equally +glad to learn from you anything you can teach them, asking no questions +about you, save, first—Is he an honest student of Nature for her +own sake? And next—Is he a man who will not quarrel, or +otherwise behave in an unbrotherly fashion to his fellow-students?—If +you want a ground of brotherhood with men, not merely in these islands, +but in America, on the Continent—in a word, all over the world—such +as rank, wealth, fashion, or other artificial arrangements of the world +cannot give and cannot take away; if you want to feel yourself as good +as any man in theory, because you are as good as any man in practice, +except those who are better than you in the same line, which is open +to any and every man; if you wish to have the inspiring and ennobling +feeling of being a brother in a great freemasonry which owns no difference +of rank, of creed, or of nationality—the only freemasonry, the +only International League which is likely to make mankind (as we all +hope they will be some day) one—then become men of science. +Join the freemasonry in which Hugh Miller, the poor Cromarty stonemason, +in which Michael Faraday, the poor bookbinder’s boy, became the +companions and friends of the noblest and most learned on earth, looked +up to by them not as equals merely but as teachers and guides, because +philosophers and discoverers.</p> +<p>Do you wish to be great? Then be great with true greatness; +which is,—knowing the facts of nature, and being able to use them. +Do you wish to be strong? Then be strong with true strength; which +is, knowing the facts of nature, and being able to use them. Do +you wish to be wise? Then be wise with true wisdom; which is, +knowing the facts of nature, and being able to use them. Do you +wish to be free? Then be free with true freedom; which is again, +knowing the facts of nature, and being able to use them.</p> +<p>I dare say some of my readers, especially the younger ones, will +demur to that last speech of mine. Well, I hope they will not +be angry with me for saying it. I, at least, shall certainly not +he angry with them. For when I was young I was very much of what +I suspect is their opinion. I used to think one could get perfect +freedom, and social reform, and all that I wanted, by altering the arrangements +of society and legislation; by constitutions, and Acts of Parliament; +by putting society into some sort of freedom-mill, and grinding it all +down, and regenerating it so. And that something can be done by +improved arrangements, something can be done by Acts of Parliament, +I hold still, as every rational man must hold.</p> +<p>But as I grew older, I began to see that if things were to be got +right, the freedom-mill would do very little towards grinding them right, +however well and amazingly it was made. I began to see that what +sort of flour came out at one end of the mill, depended mainly on what +sort of grain you had put in at the other; and I began to see that the +problem was to get good grain, and then good flour would be turned out, +even by a very clumsy old-fashioned sort of mill. And what do +I mean by good grain? Good men, honest men, accurate men, righteous +men, patient men, self-restraining men, fair men, modest men. +Men who are aware of their own vast ignorance compared with the vast +amount that there is to be learned in such a universe as this. +Men who are accustomed to look at both sides of a question; who, instead +of making up their minds in haste like bigots and fanatics, wait like +wise men, for more facts, and more thought about the facts. In +one word, men who had acquired just the habit of mind which the study +of Natural Science can give, and must give; for without it there is +no use studying Natural Science; and the man who has not got that habit +of mind, if he meddles with science, will merely become a quack and +a charlatan, only fit to get his bread as a spirit-rapper, or an inventor +of infallible pills.</p> +<p>And when I saw that, I said to myself—I will train myself, +by Natural Science, to the truly rational, and therefore truly able +and useful, habit of mind; and more, I will, for it is my duty as an +Englishman, train every Englishman over whom I can get influence in +the same scientific habit of mind, that I may, if possible, make him, +too, a rational and an able man.</p> +<p>And, therefore, knowing that most of you, my readers—probably +all of you, as you ought and must if you are Britons, think much of +social and political questions—-therefore, I say, I entreat you +to cultivate the scientific spirit by which alone you can judge justly +of those questions. I ask you to learn how to “conquer nature +by obeying her,” as the great Lord Bacon said two hundred and +fifty years ago. For so only will you in your theories and your +movements, draw “bills which nature will honour”—to +use Mr. Carlyle’s famous parable—because they are according +to her unchanging laws, and not have them returned on your hands, as +too many theorists’ are, with “no effects” written +across their backs.</p> +<p>Take my advice for yourselves, dear readers, and for your children +after you; for, believe me, I am showing you the way to true and useful, +and, therefore, to just and deserved power. I am showing you the +way to become members of what I trust will be—what I am certain +ought to be—the aristocracy of the future.</p> +<p>I say it deliberately, as a student of society and of history. +Power will pass more and more, if all goes healthily and well, into +the hands of scientific men; into the hands of those who have made due +use of that great heirloom which the philosophers of the seventeenth +century left for the use of future generations, and specially of the +Teutonic race.</p> +<p>For the rest, events seem but too likely to repeat themselves again +and again all over the world, in the same hopeless circle. Aristocracies +of mere birth decay and die, and give place to aristocracies of mere +wealth; and they again to “aristocracies of genius,” which +are really aristocracies of the noisiest, of mere scribblers and spouters, +such as France is writhing under at this moment. And when these +last have blown off their steam, with mighty roar, but without moving +the engine a single yard, then they are but too likely to give place +to the worst of all aristocracies, the aristocracy of mere “order,” +which means organised brute force and military despotism. And, +after that, what can come, save anarchy, and decay, and social death?</p> +<p>What else?—unless there be left in the nation, in the society, +as the salt of the land, to keep it all from rotting, a sufficient number +of wise men to form a true working aristocracy, an aristocracy of sound +and rational science? If they be strong enough (and they are growing +stronger day by day over the civilised world), on them will the future +of that world mainly depend. They will rule, and they will act—cautiously +we may hope, and modestly and charitably, because in learning true knowledge +they will have learnt also their own ignorance, and the vastness, the +complexity, the mystery of nature. But they will be able to rule, +they will be able to act, because they have taken the trouble to learn +the facts and the laws of nature. They will rule; and their rule, +if they are true to themselves, will be one of health and wealth, and +peace, of prudence and of justice. For they alone will be able +to wield for the benefit of man the brute forces of nature; because +they alone will have stooped, to “conquer nature by obeying her.”</p> +<p>So runs my dream. I ask my young readers to help towards making +that dream a fact, by becoming (as many of them as feel the justice +of my words) honest and earnest students of Natural Science.</p> +<p>But now: why should I, as a clergyman, interest myself specially +in the spread of Natural Science? Am I not going out of my proper +sphere to meddle with secular matters? Am I not, indeed, going +into a sphere out of which I had better keep myself, and all over whom +I may have influence? For is not science antagonistic to religion? +and, if so, what has a clergyman to do, save to warn the young against +it, instead of attracting them towards it?</p> +<p>First, as to meddling with secular matters. I grudge that epithet +of “secular” to any matter whatsoever. But I do more; +I deny it to anything which God has made, even to the tiniest of insects, +the most insignificant atom of dust. To those who believe in God, +and try to see all things in God, the most minute natural phenomenon +cannot be secular. It must be divine; I say, deliberately, divine; +and I can use no less lofty word. The grain of dust is a thought +of God; God’s power made it; God’s wisdom gave it whatsoever +properties or qualities it may possess; God’s providence has put +it in the place where it is now, and has ordained that it should be +in that place at that moment, by a train of causes and effects which +reaches back to the very creation of the universe. The grain of +dust can no more go from God’s presence, or flee from God’s +Spirit, than you or I can. If it go up to the physical heaven, +and float (as it actually often does) far above the clouds, in those +higher strata of the atmosphere which the aeronaut has never visited, +whither the Alpine snow-peaks do not rise, even there it will be obeying +physical laws which we term hastily laws of Nature, but which are really +the laws of God: and if it go down into the physical abyss; if it be +buried fathoms, miles, below the surface, and become an atom of some +rock still in the process of consolidation, has it escaped from God, +even in the bowels of the earth? Is it not there still obeying +physical laws, of pressure, heat, crystallisation, and so forth, which +are laws of God—the will and mind of God concerning particles +of matter? Only look at all created things in this light—look +at them as what they are, the expressions of God’s mind and will +concerning this universe in which we live—“the Word of God,” +as Bacon says, “revealed in facts”—and then you will +not fear physical science; for you will be sure that, the more you know +of physical science, the more you will know of the works and of the +will of God. At least, you will be in harmony with the teaching +of the Psalmist: “The heavens,” says he, “declare +the glory of God; and the firmament showeth His handiwork. There +is neither speech nor language where their voices are not heard among +them.” So held the Psalmist concerning astronomy, the knowledge +of the heavenly bodies; and what he says of sun and stars is true likewise +of the flowers around our feet, of which the greatest Christian poet +of modern times has said—</p> +<div class="GutenbergBlankLines1"><br /></div> +<p>To me the meanest flower that grows may give<br />Thoughts that do +lie too deep for tears.</p> +<div class="GutenbergBlankLines1"><br /></div> +<p>So, again, you will be in harmony with the teaching of St. Paul, +who told the Romans “that the invisible things of God are clearly +seen from the creation of the-world, being understood by the things +that are made, even His eternal power and Godhead;” and who told +the savages of Lycaonia that “God had not left Himself without +witness, in that He did good and sent men rain from heaven, and fruitful +seasons, filling men’s hearts with food and gladness.” +Rain and fruitful seasons witnessed to all men of a Father in heaven. +And he who wishes to know how truly St. Paul spoke, let him study the +laws which produce and regulate rain and fruitful seasons, what we now +call climatology, meteorology, geography of land and water. Let +him read that truly noble Christian work, Maury’s “Physical +Geography of the Sea;” and see, if he be a truly rational man, +how advanced science, instead of disproving, has only corroborated St. +Paul’s assertion, and how the ocean and the rain-cloud, like the +sun and stars, declare the glory of God. And if anyone undervalues +the sciences which teach us concerning stones and plants and animals, +or thinks that nothing can be learnt from them concerning God—allow +one who has been from childhood only a humble, though he trusts a diligent +student of these sciences—allow him, I say, to ask in all reverence, +but in all frankness, who it was who said, “Consider the lilies +of the field, how they grow.” “Consider the birds +of the air—and how your Heavenly Father feedeth them.”</p> +<p>Consider them. If He has bid you do so, can you do so too much?</p> +<p>I know, of course, the special application which our Lord made of +these words. But I know, too, from experience, that the more you +study nature, in all her forms the more you will find that the special +application itself is deeper, wider, more literally true, more wonderful, +more tender, and if I dare use such a word, more poetic, than the unscientific +man can guess.</p> +<p>But let me ask you further—do you think that our Lord in that +instance, and in those many instances in which He drew his parables +and lessons from natural objects, was leading men’s minds on to +dangerous ground, and pointing out to them a subject of contemplation +in the laws and processes of the natural world, and their analogy with +those of the spiritual world, the kingdom of God—a subject of +contemplation, I say, which it was not safe to contemplate too much?</p> +<p>I appeal to your common sense. If He who spoke these words +were (as I believe) none other than the Creator of the universe, by +whom all things were made, and without whom nothing was made that is +made, do you suppose that He would have bid you to consider His universe, +had it been dangerous for you to do so?</p> +<p>Do you suppose, moreover, that the universe, which He, the Truth, +the Light, the Love, has made, can be otherwise then infinitely worthy +to be considered? or that the careful, accurate, and patient consideration +of it, even to its minutest details, can be otherwise than useful to +man, and can bear witness of aught, save the mind and character of Him +who made it? And if so, can it be a work unfit for, unworthy of, +a clergyman—whose duty is to preach Him to all, and in all ways,—to +call on men to consider that physical world which, like the spiritual +world, consists, holds together, by Him, and lives and moves and has +its being in Him?</p> +<p>And here I must pause to answer an objection which I have heard in +my youth from many pious and virtuous people—better people in +God’s sight, than I, I fear, can pretend to be.</p> +<p>They used to say, “This would be all very true if there were +not a curse upon the earth.” And then they seemed to deduce, +from the fact of that curse, a vague notion (for it was little more) +that this world was the devil’s world, and that therefore physical +facts could not be trusted, because they were disordered, and deceptive, +and what not.</p> +<p>Now, in justice to the Bible, and in justice to the Church of England, +I am bound to say that such a statement, or anything like it, is contrary +to the doctrines of both. It is contrary to Scripture. According +to it, the earth is not cursed. For it is said in Gen. viii. 21, +“And the Lord said, I will not again curse the ground any more +for man’s sake. While the earth remaineth, seed-time and +harvest, cold and heat, summer and winter, day and night shall not cease.” +According to Scripture, again, physical facts are not disordered. +The Psalmist says, “They continue this day according to their +ordinance; for all things serve Thee.” And again, “Thou +hast made them fast for ever and ever. Thou hast given them a +law which cannot be broken.”</p> +<p>So does the Bible (not to quote over again the passages which I have +already given you from St. Paul, and One greater than St. Paul) declare +the permanence of natural laws, and the trustworthiness of natural phenomena +as obedient to God. And so does the Church of England. For +she has incorporated into her services that magnificent hymn, which +our forefathers called the Song of the Three Children; which is, as +it were, the very flower and crown of the Old Testament; the summing +up of all that is true and eternal in the old Jewish faith; as true +for us as for them: as true millions of years hence as it is now—which +cries to all heaven and earth, from the skies above our heads to the +green herb beneath our feet, “O all ye works of the Lord, bless +ye the Lord; praise Him and magnify Him for ever.” On that +one hymn I take my stand. That is my charter as a student of Natural +Science. As long as that is sung in an English church, I have +a right to investigate Nature boldly without stint or stay, and to call +on all who have the will, to investigate her boldly likewise, and with +Socrates of old, to follow the Logos whithersoever it leads.</p> +<p>The Logos. I must pause on that word. It meant at first, +no doubt, simply speech, argument, reason. In the mind of Socrates +it had a deeper meaning, at which he only dimly guessed; which was seen +more clearly by Philo and the Alexandrian Jews; which was revealed in +all its fulness to the beloved Apostle St. John, till he gathered speech +to tell men of a Logos, a Word, who was in the beginning with God, and +was God; by whom all things were made, and without Him was not anything +made that was made; and how in Him was Life, and the Life was the light +of men; and that He was none other than Jesus Christ our Lord.</p> +<p>Yes, that is the truth. And to that truth no man can add, and +from it no man can take away. And as long as we believe that as +long as we believe that in His light alone can we see light—as +long as we believe that the light around us, whether physical or spiritual, +is given by Him without whom nothing is made—so long we shall +not fear to meet Light, so long we shall not fear to investigate Life; +for we shall know, however strange or novel, beautiful or awful, the +discoveries we make may be, we are only following the Word whithersoever +He may lead us; and that He can never lead us amiss</p> +<div class="GutenbergBlankLines2"><br /><br /></div> +<h2>I. THE SOIL OF THE FIELD <a name="citation2"></a><a href="#footnote2">{2}</a></h2> +<div class="GutenbergBlankLines2"><br /><br /></div> +<p>My dear readers, let me, before touching on the special subject of +this paper, say a few words on that of the whole series.</p> +<p>It is geology: that is, the science which explains to us the <i>rind</i> +of the earth; of what it is made; how it has been made. It tells +us nothing of the mass of the earth. That is, properly speaking, +an astronomical question. If I may be allowed to liken this earth +to a fruit, then astronomy will tell us—when it knows—how +the fruit grew, and what is inside the fruit. Geology can only +tell us at most how its rind, its outer covering, grew, and of what +it is composed; a very small part, doubtless, of all that is to be known +about this planet.</p> +<p>But as it happens, the mere rind of this earth-fruit which has, countless +ages since, dropped, as it were, from the Bosom of God, the Eternal +Fount of Life—the mere rind of this earth-fruit, I say, is so +beautiful and so complex, that it is well worth our awful and reverent +study. It has been well said, indeed, that the history of it, +which we call geology, would be a magnificent epic poem, were there +only any human interest in it; did it deal with creatures more like +ourselves than stones, and bones, and the dead relics of plants and +beasts. Whether there be no human interest in geology; whether +man did not exist on the earth during ages which have seen enormous +geological changes, is becoming more and more an open question.</p> +<p>But meanwhile all must agree that there is matter enough for interest—nay, +room enough for the free use of the imagination, in a science which +tells of the growth and decay of whole mountain-ranges, continents, +oceans, whole tribes and worlds of plants and animals.</p> +<p>And yet it is not so much for the vastness and grandeur of those +scenes of the distant past, to which the science of geology introduces +us, that I value it as a study, and wish earnestly to awaken you to +its beauty and importance. It is because it is the science from +which you will learn most easily a sound scientific habit of thought. +I say most easily; and for these reasons. The most important facts +of geology do not require, to discover them, any knowledge of mathematics +or of chemical analysis; they may be studied in every bank, every grot, +every quarry, every railway-cutting, by anyone who has eyes and common +sense, and who chooses to copy the late illustrious Hugh Miller, who +made himself a great geologist out of a poor stonemason. Next, +its most important theories are not, or need not be, wrapped up in obscure +Latin and Greek terms. They may be expressed in the simplest English, +because they are discovered by simple common sense. And thus geology +is (or ought to be), in popular parlance, the people’s science—the +science by studying which, the man ignorant of Latin, Greek, mathematics, +scientific chemistry, can yet become—as far as his brain enables +him—a truly scientific man.</p> +<p>But how shall we learn science by mere common sense?</p> +<p>First. Always try to explain the unknown by the known. +If you meet something which you have not seen before, then think of +the thing most like it which you have seen before; and try if that which +you know explains the one will not explain the other also. Sometimes +it will; sometimes it will not. But if it will, no one has a right +to ask you to try any other explanation.</p> +<p>Suppose, for instance, that you found a dead bird on the top of a +cathedral tower, and were asked how you thought it had got there. +You would say, “Of course, it died up here.” But if +a friend said, “Not so; it dropped from a balloon, or from the +clouds;” and told you the prettiest tale of how the bird came +to so strange an end, you would answer, “No, no; I must reason +from what I know. I know that birds haunt the cathedral tower; +I know that birds die; and therefore, let your story be as pretty as +it may, my common sense bids me take the simplest explanation, and say—it +died here.” In saying that, you would be talking scientifically. +You would have made a fair and sufficient induction (as it is called) +from the facts about birds’ habits and birds’ deaths which +you know.</p> +<p>But suppose that when you took the bird up you found that it was +neither a jackdaw, nor a sparrow nor a swallow, as you expected, but +a humming-bird. Then you would be adrift again. The fact +of it being a humming-bird would be a new fact which you had not taken +into account, and for which your old explanation was not sufficient; +and you would have to try a new induction—to use your common sense +afresh—saying, “I have not to explain merely how a dead +bird got here, but how a dead humming-bird.”</p> +<p>And now, if your imaginative friend chimed in triumphantly with: +“Do you not see that I was right after all? Do you not see +that it fell from the clouds? that it was swept away hither, all the +way from South America, by some south-westerly storm, and wearied out +at last, dropped here to find rest, as in a sacred-place?” what +would you answer? “My friend, that is a beautiful imagination; +but I must treat it only as such, as long as I can explain the mystery +more simply by facts which I do know. I do not know that humming-birds +can be blown across the Atlantic alive. I do know they are actually +brought across the Atlantic dead; are stuck in ladies’ hats. +I know that ladies visit the cathedral; and odd as the accident is, +I prefer to believe, till I get a better explanation, that the humming-bird +has simply dropped out of a lady’s hat.” There, again, +you would be speaking common sense; and using, too, sound inductive +method; trying to explain what you do not know from what you do know +already.</p> +<p>Now, I ask of you to employ the same common sense when you read and +think of Geology.</p> +<p>It is very necessary to do so. For in past times men have tried +to explain the making of the world around them, its oceans, rivers, +mountains, and continents, by I know not what of fancied cataclysms +and convulsions of nature; explaining the unknown by the still more +unknown, till some of their geological theories were no more rational, +because no more founded on known facts, than that of the New Zealand +Maories, who hold that some god, when fishing, fished up their islands +out of the bottom of the ocean. But a sounder and wiser school +of geologists now reigns; the father of whom, in England at least, is +the venerable Sir Charles Lyell. He was almost the first of Englishmen +who taught us to see—what common sense tells us—that the +laws which we see at work around us now have been most probably at work +since the creation of the world; and that whatever changes may seem +to have taken place in past ages, and in ancient rocks, should be explained, +if possible, by the changes which are taking place now in the most recent +deposits—in the soil of the field.</p> +<p>And in the last forty years—since that great and sound idea +has become rooted in the minds of students, and especially of English +students, geology has thriven and developed, perhaps more than any other +science; and has led men on to discoveries far more really astonishing +and awful than all fancied convulsions and cataclysms.</p> +<p>I have planned this series of papers, therefore, on Sir Charles Lyell’s +method. I have begun by trying to teach a little about the part +of the earth’s crust which lies nearest us, which we see most +often; namely, the soil; intending, if my readers do me the honour to +read the papers which follow, to lead them downward, as it were, into +the earth; deeper and deeper in each paper, to rocks and minerals which +are probably less known to them than the soil in the fields. Thus +you will find I shall lead you, or try to lead you on, throughout the +series, from the known to the unknown, and show you how to explain the +latter by the former. Sir Charles Lyell has, I see, in the new +edition of his “Student’s Elements of Geology,” begun +his book with the uppermost, that is, newest, strata, or layers; and +has gone regularly downwards in the course of the book to the lowest +or earliest strata; and I shall follow his plan.</p> +<p>I must ask you meanwhile to remember one law or rule, which seems +to me founded on common sense; namely, that the uppermost strata are +really almost always the newest; that when two or more layers, whether +of rock or earth—or indeed two stones in the street, or two sheets +on a bed, or two books on a table—any two or more lifeless things, +in fact, lie one on the other, then the lower one was most probably +put there first, and the upper one laid down on the lower. Does +that seem to you a truism? Do I seem almost impertinent in asking +you to remember it? So much the better. I shall be saved +unnecessary trouble hereafter.</p> +<p>But some one may say, and will have a right to say, “Stop—the +lower thing may have been thrust under the upper one.” Quite +true: and therefore I said only that the lower one was most probably +put there first. And I said “most probably,” because +it is most probable that in nature we should find things done by the +method which costs least force, just as you do them. I will warrant +that when you want to hide a thing, you lay something down on it ten +times for once that you thrust it under something else. You may +say, “What? When I want to hide a paper, say, under the +sofa-cover, do I not thrust it under?”</p> +<p>No, you lift up the cover, and slip the paper in, and let the cover +fall on it again. And so, even in that case, the paper has got +into its place first.</p> +<p>Now why is this? Simply because in laying one thing on another +you only move weight. In thrusting one thing under another, you +have not only to move weight, but to overcome friction. That is +why you do it, though you are hardly aware of it: simply because so +you employ less force, and take less trouble.</p> +<p>And so do clays and sands and stones. They are laid down on +each other, and not thrust under each other, because thus less force +is expended in getting them into place.</p> +<p>There are exceptions. There are cases in which nature does +try to thrust one rock under another. But to do that she requires +a force so enormous, compared with what is employed in laying one rock +on another, that (so to speak) she continually fails; and instead of +producing a volcanic eruption, produces only an earthquake. Of +that I may speak hereafter, and may tell you, in good time, how to distinguish +rocks which have been thrust in from beneath, from rocks which have +been laid down from above, as every rock between London and Birmingham +or Exeter has been laid down. That I only assert now. But +I do not wish you to take it on trust from me. I wish to prove +it to you as I go on, or to do what is far better for you: to put you +in the way of proving it for yourself, by using your common sense.</p> +<p>At the risk of seeming prolix, I must say a few more words on this +matter. I have special reasons for it. Until I can get you +to “let your thoughts play freely” round this question of +the superposition of soils and rocks, there will be no use in my going +on with these papers.</p> +<p>Suppose then (to argue from the known to the unknown) that you were +watching men cleaning out a pond. Atop, perhaps, they would come +to a layer of soft mud, and under that to a layer of sand. Would +not common sense tell you that the sand was there first, and that the +water had laid down the mud on the top of it? Then, perhaps, they +might come to a layer of dead leaves. Would not common sense tell +you that the leaves were there before the sand above them? Then, +perhaps, to a layer of mud again. Would not common sense tell +you that the mud was there before the leaves? And so on down to +the bottom of the pond, where, lastly, I think common sense would tell +you that the bottom of the pond was there already, before all the layers +which were laid down on it. Is not that simple common sense?</p> +<p>Then apply that reasoning to the soils and rocks in any spot on earth. +If you made a deep boring, and found, as you would in many parts of +this kingdom, that the boring, after passing through the soil of the +field, entered clays or loose sands, you would say the clays were there +before the soil. If it then went down into sandstone, you would +say—would you not?—that sandstone must have been here before +the clay; and however thick—even thousands of feet—it might +be, that would make no difference to your judgment. If next the +boring came into quite different rocks; into a different sort of sandstone +and shales, and among them beds of coal, would you not say—These +coal-beds must have been here before the sandstones? And if you +found in those coal-beds dead leaves and stems of plants, would you +not say—Those plants must have been laid down here before the +layers above them, just as the dead leaves in the pond were?</p> +<p>If you then came to a layer of limestone, would you not say the same? +And if you found that limestone full of shells and corals, dead, but +many of them quite perfect, some of the corals plainly in the very place +in which they grew, would you not say—These creatures must have +lived down here before the coal was laid on top of them? And if, +lastly, below the limestone you came to a bottom rock quite different +again, would you not say—The bottom rock must have been here before +the rocks on the top of it?</p> +<p>And if that bottom rock rose up a few miles off, two thousand feet, +or any other height, into hills, what would you say then? Would +you say: “Oh, but the rock is not bottom rock; is not under the +limestone here, but higher than it. So perhaps in this part it +has made a shift, and the highlands are younger than the lowlands; for +see, they rise so much higher?” Would not that be as wise +as to say that the bottom of the pond was not there before the pond +mud, because the banks round the pond rose higher than the mud?</p> +<p>Now for the soil of the field.</p> +<p>If we can understand a little about it, what it is made of, and how +it got there, we shall perhaps be on the right road toward understanding +what all England—and, indeed, the crust of this whole planet—is +made of; and how its rocks and soils got there.</p> +<p>But we shall best understand how the soil in the field was made, +by reasoning, as I have said, from the known to the unknown. What +do I mean? This: On the uplands are fields in which the soil is +already made. You do not know how? Then look for a field +in which the soil is still being made. There are plenty in every +lowland. Learn how it is being made there; apply the knowledge +which you learn from them to the upland fields which are already made.</p> +<p>If there is, as there usually is, a river-meadow, or still better, +an æstuary, near your town, you have every advantage for seeing +soil made. Thousands of square feet of fresh-made soil spread +between your town and the sea; thousands more are in process of being +made.</p> +<p>You will see now why I have begun with the soil in the field; because +it is the uppermost, and therefore latest, of all the layers; and also +for this reason, that, if Sir Charles Lyell’s theory be true—as +it is—then the soils and rocks below the soil of the field may +have been made in the very same way in which the soil of the field is +made. If so, it is well worth our while to examine it.</p> +<p>You all know from whence the soil comes which has filled up, in the +course of ages, the great æstuaries below London, Stirling, Chester, +or Cambridge.</p> +<p>It is river mud and sand. The river, helped by tributary brooks +right and left, has brought down from the inland that enormous mass. +You know that. You know that every flood and freshet brings a +fresh load, either of fine mud or of fine sand, or possibly some of +it peaty matter out of distant hills. Here is one indisputable +fact from which to start. Let us look for another.</p> +<p>How does the mud get into the river? The rain carries it thither.</p> +<p>If you wish to learn the first elements of geology by direct experiment, +do this: The next rainy day—the harder it rains the better—instead +of sitting at home over the fire, and reading a book about geology, +put on a macintosh and thick boots, and get away, I care not whither, +provided you can find there running water. If you have not time +to get away to a hilly country, then go to the nearest bit of turnpike +road, or the nearest sloping field, and see in little how whole continents +are made, and unmade again. Watch the rain raking and sifting +with its million delicate fingers, separating the finer particles from +the coarser, dropping the latter as soon as it can, and carrying the +former downward with it toward the sea. Follow the nearest roadside +drain where it runs into a pond, and see how it drops the pebbles the +moment it enters the pond, and then the sand in a fan-shaped heap at +the nearest end; but carries the fine mud on, and holds it suspended, +to be gradually deposited at the bottom in the still water; and say +to yourself: Perhaps the sands which cover so many inland tracts were +dropped by water, very near the shore of a lake or sea, and by rapid +currents. Perhaps, again, the brick clays, which are often mingled +with these sands, were dropped, like the mud in the pond, in deeper +water farther from the shore, and certainly in stilt water. But +more. Suppose once more, then, that looking and watching a pond +being cleared out, under the lowest layer of mud, you found—as +you would find in any of those magnificent reservoirs so common in the +Lancashire hills—a layer of vegetable soil, with grass and brushwood +rooted in it. What would you say but: The pond has not been always +full. It has at some time or other been dry enough to let a whole +copse grow up inside it?</p> +<p>And if you found—as you will actually find along some English +shores—under the sand hills, perhaps a bed of earth with shells +and bones; under that a bed of peat; under that one of blue silt; under +that a buried forest, with the trees upright and rooted; under that +another layer of blue silt full of roots and vegetable fibre; perhaps +under that again another old land surface with trees again growing in +it; and under all the main bottom clay of the district—what would +common sense tell you? I leave you to discover for yourselves. +It certainly would not tell you that those trees were thrust in there +by a violent convulsion, or that all those layers were deposited there +in a few days, or even a few years; and you might safely indulge in +speculations about the antiquity of the æstuary, and the changes +which it has undergone, with which I will not frighten you at present.</p> +<p>It will be fair reasoning to argue thus. You may not be always +right in your conclusion, but still you will be trying fairly to explain +the unknown by the known.</p> +<p>But have Rain and Rivers alone made the soil?</p> +<p>How very much they have done toward making it you will be able to +judge for yourselves, if you will read the sixth chapter of Sir Charles +Lyell’s new “Elements of Geology,” or the first hundred +pages of that admirable book, De la Bêche’s “Geological +Observer;” and last, but not least, a very clever little book +called “Rain and Rivers,” by Colonel George Greenwood.</p> +<p>But though rain, like rivers, is a carrier of soil, it is more. +It is a maker of soil, likewise; and by it mainly the soil of an upland +field is made, whether it be carried down to the sea or not.</p> +<p>If you will look into any quarry you will see that however compact +the rock may be a few feet below the surface, it becomes, in almost +every case, rotten and broken up as it nears the upper soil, till you +often cannot tell where the rock ends and the soil begins.</p> +<p>Now this change has been produced by rain. First, mechanically, +by rain in the shape of ice. The winter rain gets into the ground, +and does by the rock what it has done by the stones of many an old building. +It sinks into the porous stone, freezes there, expands in freezing, +and splits and peels the stone with a force which is slowly but surely +crumbling the whole of Northern Europe and America to powder.</p> +<p>Do you doubt me? I say nothing but what you can judge of yourselves. +The next time you go up any mountain, look at the loose broken stones +with which the top is coated, just underneath the turf. What has +broken them up but frost? Look again, as stronger proof, at the +talus of broken stones—screes, as they call them in Scotland; +rattles, as we call them in Devon—which lie along the base of +many mountain cliffs. What has brought them down but frost? +If you ask the country folk they will tell you whether I am right or +not. If you go thither, not in the summer, but just after the +winter’s frost, you will see for yourselves, by the fresh frost-crop +of newly-broken bits, that I am right. Possibly you may find me +to be even more right than is desirable, by having a few angular stones, +from the size of your head to that of your body, hurled at you by the +frost-giants up above. If you go to the Alps at certain seasons, +and hear the thunder of the falling rocks, and see their long lines—moraines, +as they are called—sliding slowly down upon the surface of the +glacier, then you will be ready to believe the geologist who tells you +that frost, and probably frost alone, has hewn out such a peak as the +Matterhorn from some vast table-land; and is hewing it down still, winter +after winter, till some day, where the snow Alps now stand, there shall +be rolling uplands of rich cultivable soil.</p> +<p>So much for the mechanical action of rain, in the shape of ice. +Now a few words on its chemical action.</p> +<p>Rain water is seldom pure. It carries in it carbonic acid; +and that acid, beating in shower after shower against the face of a +cliff—especially if it be a limestone cliff—weathers the +rock chemically; changing (in case of limestone) the insoluble carbonate +of lime into a soluble bicarbonate, and carrying that away in water, +which, however clear, is still hard. Hard water is usually water +which has invisible lime in it; there are from ten to fifteen grains +and more of lime in every gallon of limestone water. I leave you +to calculate the enormous weight of lime which must be so carried down +to the sea every year by a single limestone or chalk brook. You +can calculate it, if you like, by ascertaining the weight of lime in +each gallon, and the average quantity of water which comes down the +stream in a day; and when your sum is done, you will be astonished to +find it one not of many pounds, but probably of many tons, of solid +lime, which you never suspected or missed from the hills around. +Again, by the time the rain has sunk through the soil, it is still less +pure. It carries with it not only carbonic acid, but acids produced +by decaying vegetables—by the roots of the grasses and trees which +grow above; and they dissolve the cement of the rock by chemical action, +especially if the cement be lime or iron. You may see this for +yourselves, again and again. You may see how the root of a tree, +penetrating the earth, discolours the soil with which it is in contact. +You may see how the whole rock, just below the soil, has often changed +in colour from the compact rock below, if the soil be covered with a +dense layer of peat or growing vegetables.</p> +<p>But there is another force at work, and quite as powerful as rain +and rivers, making the soil of alluvial flats. Perhaps it has +helped, likewise, to make the soil of all the lowlands in these isles—and +that is, the waves of the sea.</p> +<p>If you ever go to Parkgate, in Cheshire, try if you cannot learn +there a little geology.</p> +<p>Walk beyond the town. You find the shore protected for a long +way by a sea-wall, lest it should be eaten away by the waves. +What the force of those waves can be, even on that sheltered coast, +you may judge—at least you could have judged this time last year—by +the masses of masonry torn from their iron clampings during the gale +of three winters since. Look steadily at those rolled blocks, +those twisted stanchions, if they are there still; and then ask yourselves—it +will be fair reasoning from the known to the unknown—What effect +must such wave-power as that have had beating and breaking for thousands +of years along the western coasts of England, Scotland, Ireland? +It must have eaten up thousands of acres—whole shires, may be, +ere now. Its teeth are strong enough, and it knows neither rest +nor pity, the cruel hungry sea. Give it but time enough, and what +would it not eat up? It would eat up, in the course of ages, all +the dry land of this planet, were it not baffled by another counteracting +force, of which I shall speak hereafter.</p> +<p>As you go on beyond the sea-wall, you find what it is eating up. +The whole low cliff is going visibly. But whither is it going? +To form new soil in the æstuary. Now you will not wonder +how old harbours so often become silted up. The sea has washed +the land into them. But more, the sea-currents do not allow the +sands of the æstuary to escape freely out to sea. They pile +it up in shifting sand-banks about the mouth of the æstuary. +The prevailing sea-winds, from whatever quarter, catch up the sand, +and roll it up into sand-hills. Those sand-hills are again eaten +down by the sea, and mixed with the mud of the tide-flats, and so is +formed a mingled soil, partly of clayey mud, partly of sand; such a +soil as stretches over the greater part of all our lowlands.</p> +<p>Now, why should not that soil, whether in England or in Scotland, +have been made by the same means as that of every æstuary.</p> +<p>You find over great tracts of East Scotland, Lancashire, Norfolk, +etc., pure loose sand just beneath the surface, which looks as if it +was blown sand from a beach. Is it not reasonable to suppose that +it is? You find rising out of many lowlands, crags which look +exactly like old sea-cliffs eaten by the waves, from the base of which +the waters have gone back. Why should not those crags be old sea-cliffs? +Why should we not, following our rule of explaining the unknown by the +known, assume that such they are till someone gives us a sound proof +that they are not; and say—These great plains of England and Scotland +were probably once covered by a shallow sea, and their soils made as +the soil of any tide-flat is being made now?</p> +<p>But you may say, and most reasonably “The tide-flats are just +at the sea-level. The whole of the lowland is many feet above +the sea; it must therefore have been raised out of the sea, according +to your theory: and what proofs have you of that?”</p> +<p>Well, that is a question both grand and deep, on which I shall not +enter yet; but meanwhile, to satisfy you that I wish to play fair with +you, I ask you to believe nothing but what you can prove for yourselves. +Let me ask you this: suppose that you had proof positive that I had +fallen into the river in the morning; would not your meeting me in the +evening be also proof positive that somehow or other I had in the course +of the day got out of the river? I think you will accept that +logic as sound.</p> +<p>Now if I can give you proof positive, proof which you can see with +your own eyes, and handle with your own hands, and alas! often feel +but too keenly with your own feet, that the whole of the lowlands were +once beneath the sea; then will it not be certain that, somehow or other, +they must have been raised out of the sea again?</p> +<p>And that I propose to do in my next paper, when I speak of the pebbles +in the street.</p> +<p>Meanwhile I wish you to face fairly the truly grand idea, which all +I have said tends to prove true—that all the soil we see is made +by the destruction of older soils, whether soft as clay, or hard as +rock; that rain, rivers, and seas are perpetually melting and grinding +up old land, to compose new land out of it; and that it must have been +doing so, as long as rain, rivers, and seas have existed. “But +how did the first land of all get made?” I can only reply: +A natural question: but we can only answer that, by working from the +known to the unknown. While we are finding out how these later +lands were made and unmade, we may stumble on some hints as to how the +first primeval continents rose out of the bosom of the sea.</p> +<p>And thus I end this paper. I trust it has not been intolerably +dull. But I wanted at starting to show my readers something of +the right way of finding out truth on this and perhaps on all subjects; +to make some simple appeals to your common sense; and to get you to +accept some plain rules founded on common sense, which will be of infinite +use to both you and me in my future papers.</p> +<p>I hope, meanwhile, that you will agree with me, that there is plenty +of geological matter to be seen and thought over in the neighbourhood +of any town.</p> +<p>Be sure, that wherever there is a river, even a drain; and a stone +quarry, or even a roadside bank; much more where there is a sea, or +a tidal æstuary, there is geology enough to be learnt, to explain +the greater part of the making of all the continents on the globe.</p> +<div class="GutenbergBlankLines2"><br /><br /></div> +<h2>II. THE PEBBLES IN THE STREET</h2> +<div class="GutenbergBlankLines2"><br /><br /></div> +<p>If you, dear reader, dwell in any northern town, you will almost +certainly see paving courts and alleys, and sometimes—to the discomfort +of your feet—whole streets, or set up as bournestones at corners, +or laid in heaps to be broken up for road-metal, certain round pebbles, +usually dark brown or speckled gray, and exceedingly tough and hard. +Some of them will be very large—boulders of several feet in diameter. +If you move from town to town, from the north of Scotland as far down +as Essex on the east, or as far down as Shrewsbury and Wolverhampton +(at least) on the west, you will still find these pebbles, but fewer +and smaller as you go south. It matters not what the rocks and +soils of the country round may be. However much they may differ, +these pebbles will be, on the whole, the same everywhere.</p> +<p>But if your town be south of the valley of the Thames, you will find, +as far as I am aware, no such pebbles there. The gravels round +you will be made up entirely of rolled chalk flints, and bits of beds +immediately above or below the chalk. The blocks of “Sarsden” +sandstone—those of which Stonehenge is built—and the “plum-pudding +stones” which are sometimes found with them, have no kindred with +the northern pebbles. They belong to beds above the chalk.</p> +<p>Now if, seeing such pebbles about your town, you inquire, like a +sensible person who wishes to understand something of the spot on which +he lives, whence they come, you will be shown either a gravel-pit or +a clay-pit. In the gravel the pebbles and boulders lie mixed with +sand, as they do in the railway cutting just south of Shrewsbury; or +in huge mounds of fine sweet earth, as they do in the gorge of the Tay +about Dunkeld, and all the way up Strathmore, where they form long grassy +mounds—<i>tomauns</i> as they call them in some parts of Scotland—<i>askers</i> +as they call them in Ireland. These mounds, with their sweet fresh +turf rising out of heather and bog, were tenanted—so Scottish +children used to believe—by fairies. He that was lucky might +hear inside them fairy music, and, the jingling of the fairy horses’ +trappings. But woe to him if he fell asleep upon the mound, for +he would be spirited away into fairyland for seven years, which would +seem to him but one day. A strange fancy; yet not so strange as +the actual truth as to what these mounds are, and how they came into +their places.</p> +<p>Or again, you might find that your town’s pebbles and boulders +came out of a pit of clay, in which they were stuck, without any order +or bedding, like plums and raisins in a pudding. This clay goes +usually by the name of boulder-clay. You would see such near any +town in Cheshire and Lancashire; or along Leith shore, near Edinburgh; +or, to give one more instance out of hundreds, along the coast at Scarborough. +If you walk along the shore southward of that town, you will see, in +the gullies of the cliff, great beds of sticky clay, stuffed full of +bits of every rock between the Lake mountains and Scarborough, from +rounded pebbles of most ancient rock down to great angular fragments +of ironstone and coal. There, as elsewhere, the great majority +of the pebbles have nothing to do with the rock on which the clay happens +to lie, but have come, some of them, from places many miles away.</p> +<p>Now if we find spread over a low land pebbles composed of rocks which +are only found in certain high lands, is it not an act of common sense +to say—These pebbles have come from the highlands? And if +the pebbles are rounded, while the rocks like them in the highlands +always break off in angular shapes, is it not, again, an act of mere +common sense to say—These pebbles were once angular, and have +been rubbed round, either in getting hither or before they started hither?</p> +<p>Does all this seem to you mere truism, my dear reader? If so, +I am sincerely glad to hear it. It was not so very long ago that +such arguments would have been considered not only no truisms, but not +even common sense.</p> +<p>But to return, let us take, as an example, a sample of these boulder +clay pebbles from the neighbourhood of Liverpool and Birkenhead, made +by Mr. De Rance, the government geological surveyor:</p> +<p>Granite, greenstone, felspar porphyry, felstone, quartz rock (all +igneous rocks, that is, either formed by, or altered by volcanic heat, +and almost all found in the Lake mountains), 37 per cent.</p> +<p>Silurian grits (the common stones of the Lake mountains deposited +by water), 43 per cent.</p> +<p>Ironstone, 1 per cent.</p> +<p>Carboniferous limestone, 5 per cent.</p> +<p>Permian or Triassic sandstones, <i>i.e</i>. rocks immediately round +Liverpool, 12 per cent.</p> +<p>Now, does not this sample show, as far as human common sense can +be depended on, that the great majority of these stones come from the +Lake mountains, sixty or seventy miles north of Liverpool? I think +your common sense will tell you that these pebbles are not mere concretions; +that is, formed out of the substance of the clay after it was deposited. +The least knowledge of mineralogy would prove that. But, even +if you are no mineralogist, common sense will tell you, that if they +were all concreted out of the same clay, it is most likely that they +would be all of the same kind, and not of a dozen or more different +kinds. Common sense will tell you, also, that if they were all +concreted out of the same clay, it is a most extraordinary coincidence, +indeed one too strange to be believed, if any less strange explanation +can be found—that they should have taken the composition of different +rocks which are found all together in one group of mountains to the +northward. You will surely say—If this be granite, it has +most probably come from a granite mountain; if this be grit, from a +grit-stone mountain, and so on with the whole list. Why—are +we to go out of our way to seek improbable explanations, when there +is a probable one staring us in the face?</p> +<p>Next—and this is well worth your notice—if you will examine +the pebbles carefully, especially the larger ones, you will find that +they are not only more or less rounded, but often scratched; and often, +too, in more than one direction, two or even three sets of scratches +crossing each other; marked, as a cat marks an elder stem when she sharpens +her claws upon it; and that these scratches have not been made by the +quarrymen’s tools, but are old marks which exist—as you +may easily prove for yourself—while the stone is still lying in +its bed of clay. Would it not be an act of mere common sense to +say—These scratches have been made by the sharp points of other +stones which have rubbed against the pebbles somewhere, and somewhen, +with great force?</p> +<p>So far so good. The next question is—How did these stones +get into the clay? If we can discover that, we may also discover +how they wore rounded and scratched. We must find a theory which +will answer our question; and one which, as Professor Huxley would say, +“will go on all-fours,” that is, will explain all the facts +of the case, and not only a few of them.</p> +<p>What, then, brought the stones?</p> +<p>We cannot, I think, answer that question, as some have tried to answer +it, by saying that they were brought by Noah’s flood. For +it is clear, that very violent currents of water would be needed to +carry boulders, some of them weighing many tons, for many miles. +Now Scripture says nothing of any such violent currents; and we have +no right to put currents, or any other imagined facts, into Scripture +out of our own heads, and then argue from them as if not we, but the +text of Scripture had asserted their existence.</p> +<p>But still, they may have been rolled hither by water. That +theory certainly would explain their being rounded; though not their +being scratched. But it will not explain their being found in +the clay.</p> +<p>Recollect what I said in my first paper: that water drops its pebbles +and coarser particles first, while it carries the fine clayey mud onward +in solution, and only drops it when the water becomes still. Now +currents of such tremendous violence as to carry these boulder stones +onward, would have carried the mud for many miles farther still; and +we should find the boulders, not in clay, but lying loose together, +probably on a hard rock bottom, scoured clean by the current. +That is what we find in the beds of streams; that is just what we do +not find in this case.</p> +<p>But the boulders may have been brought by a current, and then the +water may have become still, and the clay settled quietly round them. +What? Under them as well as over them? On that theory also +we should find them only at the bottom of the clay. As it is, +we find them scattered anywhere and everywhere through it, from top +to bottom. So that theory will not do. Indeed, no theory +will do which supposes them to have been brought by water alone.</p> +<p>Try yourself, dear reader, and make experiments, with running water, +pebbles, and mud. If you try for seven years, I believe, you will +never contrive to make your pebbles lie about in your mud, as they lie +about in every pit in the boulder clay.</p> +<p>Well then, there we are at fault, it seems. We have no explanation +drawn from known facts which will do—unless we are to suppose, +which I don’t think you will do, that stones, clay, and all were +blown hither along the surface of the ground, by primeval hurricanes, +ten times worse than those of the West Indies, which certainly will +roll a cannon a few yards, but cannot, surely, roll a boulder stone +a hundred miles.</p> +<p>Now, suppose that there was a force, an agent, known—luckily +for you, not to you—but known too well to sailors and travellers; +a force which is at work over the vast sheets of land at both the north +and south poles; at work, too, on every high mountain range in the world, +and therefore a very common natural force; and suppose that this force +would explain all the facts, namely—</p> +<p>How the stones got here;</p> +<p>How they were scratched and rounded;</p> +<p>How they were imbedded in clay;</p> +<p>because it is notoriously, and before men’s eyes now, carrying +great stones hundreds of miles, and scratching and rounding them also; +carrying vast deposits of mud, too, and mixing up mud and stones just +as we see them in the brick-pits,—Would not our common sense have +a right to try that explanation?—to suspect that this force, which +we do not see at work in Britain now, may have been at work here ages +since? That would at least be reasoning from the known to the +unknown. What state of things, then, do we find among the highest +mountains; and over whole countries which, though not lofty, lie far +enough north or south to be permanently covered with ice?</p> +<p>We find, first, an ice-cap or ice-sheet, fed by the winter’s +snows, stretching over the higher land, and crawling downward and outward +by its own weight, along the valleys, as glaciers.</p> +<p>We find underneath the glaciers, first a <i>moraine profonde</i>, +consisting of the boulders and gravel, and earth, which the glacier +has ground off the hillsides, and is carrying down with it.</p> +<p>These stones, of course, grind, scratch, and polish each other; and +in like wise grind, scratch, and polish the rock over which they pass, +under the enormous weight of the superincumbent ice.</p> +<p>We find also, issuing from under each glacier a stream, carrying +the finest mud, the result of the grinding of the boulders against each +other and the glacier.</p> +<p>We find, moreover, on the surface of the glaciers, <i>moraines supérieures</i>—long +lines of stones and dirt which had fallen from neighbouring cliffs, +and are now travelling downward with the glaciers.</p> +<p>Their fate, if the glacier ends on land, is what was to be expected. +The stones from above the glacier fall over the ice-cliff at its end, +to mingle with those thrown out from underneath the glacier, and form +huge banks of boulders, called terminal moraines, while the mud runs +off, as all who have seen glaciers know, in a turbid torrent.</p> +<p>Their fate, again, is what was to be expected if the glacier ends, +as it commonly does in Arctic regions, in the sea. The ice grows +out to sea-ward for more than a mile sometimes, about one-eighth of +it being above water, and seven-eighths below, so that an ice-cliff +one hundred feet high may project into water eight hundred feet deep. +At last, when it gets out of its depth, the buoyancy of the water breaks +it off in icebergs, which float away, at the mercy of tides and currents, +often grounding again in shallower water, and ploughing the sea-bottom +as they drag along it. These bergs carry stones and dirt, often +in large quantities; so that, whenever a berg melts or capsizes, it +strews its burden confusedly about the sea-floor.</p> +<p>Meanwhile the fine mud which is flowing out from under the ice goes +out to sea likewise, colouring the water far out, and then subsiding +as a soft tenacious ooze, in which the stones brought out by the ice +are imbedded. And this ooze—so those who have examined it +assert—cannot be distinguished from the brick-clay, or fossiliferous +boulder-clay, so common in the North. A very illustrious Scandinavian +explorer, visiting Edinburgh, declared, as soon as he saw the sections +of boulder-clay exhibited near that city, that this was the very substance +which he saw forming in the Spitzbergen ice-fiords. <a name="citation3"></a><a href="#footnote3">{3}</a></p> +<p>I have put these facts as simply and baldly as I can, in order that +the reader may look steadily at them, without having his attention drawn +off, or his fancy excited, by their real poetry and grandeur. +Indeed, it would have been an impertinence to have done otherwise; for +I have never seen a live glacier, by land or sea, though I have seen +many a dead one. And the public has had the opportunity, lately, +of reading so many delightful books about “peaks, passes, and +glaciers,” that I am bound to suppose that many of my readers +know as much, or more, about them than I do.</p> +<p>But let us go a step farther; and, bearing in our minds what live +glaciers are like, let us imagine what a dead glacier would be like; +a glacier, that is, which had melted, and left nothing but its skeleton +of stones and dirt.</p> +<p>We should find the faces of the rock scored and polished, generally +in lines pointing down the valleys, or at least outward from the centre +of the highlands, and polished and scored most in their upland or weather +sides. We should find blocks of rock left behind, and perched +about on other rocks of a different kind. We should find in the +valleys the old moraines left as vast deposits of boulder and shingle, +which would be in time sawn through and sorted over by the rivers. +And if the sea-bottom outside were upheaved, and became dry land, we +should find on it the remains of the mud from under the glacier, stuck +full of stones and boulders iceberg-dropped. This mud would be +often very irregularly bedded; for it would have been disturbed by the +ploughing of the icebergs, and mixed here and there with dirt which +had fallen from them. Moreover, as the sea became shallower and +the mud-beds got awash one after the other, they would be torn about, +re-sifted, and re-shaped by currents and by tides, and mixed with shore-sand +ground out of shingle-beach, thus making confusion worse confounded. +A few shells, of an Arctic or northern type, would be found in it here +and there. Some would have lived near those later beaches, some +in deeper water in the ancient ooze, wherever the iceberg had left it +in peace long enough for sea-animals to colonise and breed in it. +But the general appearance of the dried sea-bottom would be a dreary +and lifeless waste of sands, gravels, loose boulders, and boulder-bearing +clays; and wherever a boss of bare rock still stood up, it would be +found ground down, and probably polished and scored by the ponderous +icebergs which had lumbered over it in their passage out to sea.</p> +<p>In a word, it would look exactly as vast tracts of the English, Scotch, +and Irish lowlands must have looked before returning vegetation coated +their dreary sands and clays with a layer of brown vegetable soil.</p> +<p>Thus, and I believe thus only, can we explain the facts connected +with these boulder pebbles. No agent known on earth can have stuck +them in the clay, save ice, which is known to do so still elsewhere.</p> +<p>No known agent can have scratched them as they are scratched, save +ice, which is known to do so still elsewhere.</p> +<p>No known agent—certainly not, in my opinion, the existing rivers—can +have accumulated the vast beds of boulders which lie along the course +of certain northern rivers; notably along the Dee about Aboyne—save +ice bearing them slowly down from the distant summits of the Grampians.</p> +<p>No known agent, save ice, can have produced those rounded, and polished, +and scored, and fluted <i>rochers moutonnés</i> “sheep-backed +rocks”—so common in the Lake district; so common, too, in +Snowdon, especially between the two lakes of Llanberis; common in Kerry; +to be seen anywhere, as far as I have ascertained, around the Scotch +Highlands, where the turf is cleared away from an unweathered surface +of the rock, in the direction in which a glacier would have pressed +against it had one been there. Where these polishings and scorings +are found in narrow glens, it is, no doubt, an open question whether +some of them may not be the work of water. But nothing but the +action of ice can have produced what I have seen in land-locked and +quiet fords in Kerry—ice-flutings in polished rocks below high-water +mark, so large that I could lie down in one of them. Nothing but +the action of ice could produce what may be seen in any of our mountains—whole +sheets of rock ground down into rounded flats, irrespective of the lie +of the beds, not in valleys, but on the brows and summits of mountains, +often ending abruptly at the edge of some sudden cliff, where the true +work of water, in the shape of rain and frost, is actually destroying +the previous work of ice, and fulfilling the rule laid down (I think +by Professor Geikie in his delightful book on Scotch scenery as influenced +by its geology), that ice planes down into flats, while water saws out +into crags and gullies; and that the rain and frost are even now restoring +Scotch scenery to something of that ruggedness and picturesqueness which +it must have lost when it lay, like Greenland, under the indiscriminating +grinding of a heavy sheet of ice.</p> +<p>Lastly; no known agent, save ice, will explain those perched boulders, +composed of ancient hard rocks, which may be seen in so many parts of +these islands and of the Continent. No water power could have +lifted those stones, and tossed them up high and dry on mountain ridges +and promontories, upon rocks of a totally different kind. Some +of my readers surely recollect Wordsworth’s noble lines about +these mysterious wanderers, of which he had seen many a one about his +native hills:</p> +<div class="GutenbergBlankLines1"><br /></div> +<p>As a huge stone is sometimes seen to lie<br />Couched on the bald +top of an eminence,<br />Wonder to all who do the same espy<br />By +what means it could thither come, and whence;<br />So that it seems +a thing endued with sense:<br />Like a sea-beast crawled forth, that +on a shelf<br />Of rock or sand reposeth, there to sun itself.</p> +<div class="GutenbergBlankLines1"><br /></div> +<p>Yes; but the next time you see such a stone, believe that the wonder +has been solved, and found to be, like most wonders in Nature, more +wonderful than we guessed it to be. It is not a sea-beast which +has crawled forth, but an ice-beast which has been left behind; lifted +up thither by the ice, as surely as the famous Pierre-à-bot, +forty feet in diameter, and hundreds of boulders more, almost as large +as cottages, have been carried by ice from the distant Alps right across +the lake of Neufchâtel, and stranded on the slopes of the Jura, +nine hundred feet above the lake. <a name="citation4"></a><a href="#footnote4">{4}</a></p> +<p>Thus, I think, we have accounted for facts enough to make it probable +that Britain was once covered partly by an ice-sheet, as Greenland is +now, and partly, perhaps, by an icy sea. But, to make assurance +more sure, let us look for new facts, and try whether our ice-dream +will account for them also. Let us investigate our case as a good +medical man does, by “verifying his first induction.”</p> +<p>He says: At the first glance, I can see symptoms <i>a</i>, <i>b</i>, +<i>c</i>. It is therefore probable that my patient has got complaint +A. But if he has he ought to have symptom <i>d</i> also. +If I find that, my guess will be yet more probable. He ought also +to have symptom <i>e</i>, and so forth; and as I find successively each +of these symptoms which are proper to A, my first guess will become +more and more probable, till it reaches practical certainty.</p> +<p>Now let us do the same, and say—If this strange dream be true, +and the lowlands of the North were once under an icy sea, ought we not +to find sea-shells in their sands and clays? Not abundantly, of +course. We can understand that the sea-animals would be too rapidly +covered up in mud, and too much disturbed by icebergs and boulders, +to be very abundant. But still, some should surely be found here +and there.</p> +<p>Doubtless; and if my northern-town readers will search the boulder-clay +pits near them, they will most probably find a few shells, if not in +the clay itself, yet in sand-beds mixed with them, and probably underlying +them. And this is a notable fact, that the more species of shells +they find, the more they will find—if they work out their names +from any good book of conchology—of a northern type; of shells +which notoriously, at this day, inhabit the colder seas.</p> +<p>It is impossible for me here to enter at length on a subject on which +a whole literature has been already written. Those who wish to +study it may find all that they need know, and more, in Lyell’s +“Student’s Elements of Geology,” and in chapter xii. +of his “Antiquity of Man.” They will find that if +the evidence of scientific conchologists be worth anything, the period +can be pointed out in the strata, though not of course in time, at which +these seas began to grow colder, and southern and Mediterranean shells +to disappear, their places being taken by shells of a temperate, and +at last of an Arctic climate; which last have since retreated either +toward their native North, or into cold water at great depths. +From Essex across to Wales, from Wales to the æstuary of the Clyde, +this fact has been verified again and again. And in the search +for these shells, a fresh fact, and a most startling one, was discovered. +They are to be found not only in the clay of the lowlands, but at considerable +heights up the hills, showing that, at some time or other, these hills +have been submerged beneath the sea.</p> +<p>Let me give one example, which any tourist into Wales may see for +himself. Moel Tryfaen is a mountain over Carnarvon. Now +perched on the side of that mountain, fourteen hundred feet above the +present sea-level, is an ancient sea-beach, five-and-thirty feet thick, +lying on great ice-scratched boulders, which again lie on the mountain +slates. It was discovered by the late Mr. Trimmer, now, alas! +lost to Geology. Out of that beach fifty-seven different species +of shells have been taken; eleven of them are now exclusively Arctic, +and not found in our seas; four of them are still common to the Arctic +seas and to our own; and almost all the rest are northern shells.</p> +<p>Fourteen hundred feet above the present sea: and that, it must be +understood, is not the greatest height at which such shells may be found +hereafter. For, according to Professor Ramsay, drift of the same +kind as that on Moel Tryfaen is found at a height of two thousand three +hundred feet.</p> +<p>Now I ask my readers to use their common sense over this astounding +fact—which, after all, is only one among hundreds; to let (as +Mr. Matthew Arnold would well say) their “thought play freely” +about it; and consider for themselves what those shells must mean. +I say not may, but must, unless we are to believe in a “Deus quidam +deceptor,” in a God who puts shells upon mountain-sides only to +befool honest human beings, and gives men intellects which are worthless +for even the simplest work. Those shells must mean that that mountain, +and therefore the mountains round it, must have been once fourteen hundred +feet at least lower than they are now. That the sea in which they +were sunk was far colder than now. That icebergs brought and dropped +boulders round their flanks. That upon those boulders a sea-beach +formed, and that dead shells were beaten into it from a sea-bottom close +by. That, and no less, Moel Tryfaen must mean.</p> +<p>But it must mean, also, a length of time which has been well called +“appalling.” A length of time sufficient to let the +mountain sink into the sea. Then length of time enough to enable +those Arctic shells to crawl down from the northward, settle, and propagate +themselves generation after generation; then length of time enough to +uplift their dead remains, and the beach, and the boulders, and all +Snowdonia, fourteen hundred feet into the air. And if anyone should +object that the last upheaval may have been effected suddenly by a few +tremendous earthquakes, we must answer—We have no proof of it. +Earthquakes upheave lands now only by slight and intermittent upward +pulses; nay, some lands we know to rise without any earthquake pulses, +but by simple, slow, upward swelling of a few feet in a century; and +we have no reason, and therefore no right, to suppose that Snowdonia +was upheaved by any means or at any rate which we do not witness now; +and therefore we are bound to allow, not only that there was a past +“age of ice,” but that that age was one of altogether enormous +duration.</p> +<p>But meanwhile some of you, I presume, will be ready to cry—Stop! +It may be our own weakness; but you are really going on too fast and +too far for our small imaginations. Have you not played with us, +as well as argued with us, till you have inveigled us step by step into +a conclusion which we cannot and will not believe? That all this +land should have been sunk beneath an icy sea? That Britain should +have been as Greenland is now? We can’t believe it, and +we won’t.</p> +<p>If you say so, like stout common-sense Britons, who have a wholesome +dread of being taken in with fine words and wild speculations, I assure +you I shall not laugh at you even in private. On the contrary, +I shall say—what I am sure every scientific man will say—So +much the better. That is the sort of audience which we want, if +we are teaching natural science. We do not want haste, enthusiasm, +<i>gobe-moucherie</i>, as the French call it, which is agape to snap +up any new and vast fancy, just because it is new and vast. We +want our readers to be slow, suspicious, conservative, ready to “gib,” +as we say of a horse, and refuse the collar up a steep place, saying—I +must stop and think. I don’t like the look of the path ahead +of me. It seems an ugly place to get up. I don’t know +this road, and I shall not hurry over it. I must go back a few +steps, and make sure. I must see whether it is the right road; +whether there are not other roads, a dozen of them perhaps, which would +do as well and better than this.</p> +<p>This is the temper which finds out truth, slowly, but once and for +all; and I shall be glad, not sorry, to see it in my readers.</p> +<p>And I am bound to say that it has been by that temper that this theory +has been worked out, and the existence of this past age of ice, or glacial +epoch, has been discovered, through many mistakes, many corrections, +and many changes of opinion about details, for nearly forty years of +hard work, by many men, in many lands.</p> +<p>As a very humble student of this subject, I may say that I have been +looking these facts in the face earnestly enough for more than twenty +years, and that I am about as certain that they can only be explained +by ice, as I am that my having got home by rail can only be explained +by steam.</p> +<p>But I think I know what startles you. It is the being asked +to believe in such an enormous change in climate, and in the height +of the land above the sea. Well—it is very astonishing, +appalling—all but incredible, if we had not the facts to prove +it. But of the facts there can be no doubt. There can be +no doubt that the climate of this northern hemisphere has changed enormously +more than once. There can be no doubt that the distribution of +land and water, the shape and size of its continents and seas, have +changed again and again. There can be no doubt that, for instance, +long before the age of ice, the whole North of Europe was much warmer +than it is now.</p> +<p>Take Greenland, for instance. Disco Island lies in Baffin’s +Bay, off the west coast of Greenland, in latitude 70°, far within +the Arctic circle. Now there certain strata of rock, older than +the ice, have not been destroyed by the grinding of the ice-cap; and +they are full of fossil plants. But of what kind of plants? +Of the same families as now grow in the warmer parts of the United States. +Even a tulip-tree has been found among them. Now how is this to +be explained?</p> +<p>Either we must say that the climate of Greenland was then so much +warmer than now, that it had summers probably as hot as those of New +York; or we must say that these leaves and stems were floated thither +from the United States. But if we say the latter, we must allow +a change in the shape of the land which is enormous. For nothing +now can float northward from the United States into Baffin’s Bay. +The polar current sets <i>out</i> of Baffin’s Bay southward, bringing +icebergs down, not leaves up, through Davis’s Straits. And +in any case we must allow that the hills of Disco Island were then the +bottom of a sea: or how would the leaves have been deposited in them +at all?</p> +<p>So much for the change of climate and land which can be proved to +have gone on in Greenland. It has become colder. Why should +it not some day become warmer again?</p> +<p>Now for England. It can be proved, as far as common sense can +prove anything, that England was, before the age of ice, much warmer +than it is now, and grew gradually cooler and cooler, just as, while +the age of ice was dying out, it grew warmer again.</p> +<p>Now what proof is there of that?</p> +<p>This. Underneath London—as, I dare say, many of you know—there +lies four or five hundred feet of clay. But not ice-clay. +Anything but that, as you will see. It belongs to a formation +late (geologically speaking), but somewhat older than those Disco Island +beds.</p> +<p>And what sort of fossils do we find in it?</p> +<p>In the first place, the shells, which are abundant, are tropical—Nautili, +Cones, and such like. And more, fruits and seeds are found in +it, especially at the Isle of Sheppey. And what are they? +Fruits of Nipa palms, a form only found now at river-mouths in Eastern +India and the Indian islands; Anona-seeds; gourd-seeds; Acacia fruits—all +tropical again; and Proteaceous plants too—of an Australian type. +Surely your common sense would hint to you, that this London clay must +be mud laid down off the mouth of a tropical river. But your common +sense would be all but certain of that, when you found, as you would +find, the teeth and bones of crocodiles and turtles, who come to land, +remember, to lay their eggs; the bones, too, of large mammals, allied +to the tapir of India and South America, and the water-hog of the Cape. +If all this does not mean that there was once a tropic climate and a +tropic river running into some sea or other where London now stands, +I must give up common sense and reason as deceitful and useless faculties; +and believe nothing, not even the evidence of my own senses.</p> +<p>And now, have I, or have I not, fulfilled the promise which I made—rashly, +I dare say some of you thought—in my first paper? Have I, +or have I not, made you prove to yourself, by your own common sense, +that the lowlands of Britain were underneath the sea in the days in +which these pebbles and boulders were laid down over your plains? +Nay, have we not proved more? Have we not found that that old +sea was an icy sea? Have we not wandered on, step by step, into +a whole true fairyland of wonders? to a time when all England, Scotland, +and Ireland were as Greenland is now? when mud streams have rushed down +from under glaciers on to a cold sea-bottom, when “ice, mast high, +came floating by, as green as emerald?” when Snowdon was sunk +for at least fourteen hundred feet of its height? when (as I could prove +to you, had I time) the peaks of the highest Cumberland and Scotch mountains +alone stood out, as islets in a frozen sea?</p> +<p>We want to get an answer to one strange question, and we have found +a group of questions stranger still, and got them answered too. +But so it is always in science. We know not what we shall discover. +But this, at least, we know, that it will be far more wonderful than +we had dreamed. The scientific explorer is always like Saul of +old, who set out simply to find his father’s asses, and found +them—and a kingdom besides.</p> +<p>I should have liked to have told you more about this bygone age of +ice. I should have liked to say something to you on the curious +question—which is still an open one—whether there were not +two ages of ice; whether the climate here did not, after perhaps thousands +of years of Arctic cold, soften somewhat for a while—a few thousand +years, perhaps—and then harden again into a second age of ice, +somewhat less severe, probably, than the first. I should have +liked to have hinted at the probable causes of this change—indeed, +of the age of ice altogether—whether it was caused by a change +in the distribution of land and water, or by change in the height and +size of these islands, which made them large enough, and high enough, +to carry a sheet of eternal snow inland; or whether, finally, the age +of ice was caused by an actual change in the position of the whole planet +with regard to its orbit round the sun—shifting at once the poles +and the tropics; a deep question that latter, on which astronomers, +whose business it is, are still at work, and on which, ere young folk +are old, they will have discovered, I expect, some startling facts. +On that last question, I, being no astronomer, cannot speak. But +I should have liked to have said somewhat on matters on which I have +knowledge enough, at least, to teach you how much there is to be learnt. +I should have liked to tell the student of sea-animals—how the +ice-age helps to explain, and is again explained by, the remarkable +discoveries which Dr. Carpenter and Mr. Wyville Thompson have just made, +in the deep-sea dredgings in the North Atlantic. I should have +liked to tell the botanist somewhat of the pro-glacial flora—the +plants which lived here before the ice, and lasted, some of them at +least, through all those ages of fearful cold, and linger still on the +summits of Snowdon, and the highest peaks of Cumberland and Scotland. +I should have liked to have told the lovers of zoology about the animals +which lived before the ice—of the mammoth, or woolly elephant; +the woolly rhinoceros, the cave lion and bear, the reindeer, the musk +oxen, the lemmings and the marmots which inhabited Britain till the +ice drove them out southward, even into the South of France; and how +as the ice retreated, and the climate became tolerable once more, some +of them—the mammoth and rhinoceros, the bison, the lion, and many +another mighty beast reoccupied our lowlands, at a time when the hippopotamus, +at least in summer, ranged freely from Africa and Spain across what +was then dry land between France and England, and fed by the side of +animals which have long since retreated to Norway and to Canada. +I should have liked to tell the archæologist of the human beings—probably +from their weapons and their habits—of the same race as the present +Laplanders, who passed northward as the ice went back, following the +wild reindeer herds from the South of France into our islands, which +were no islands then, to be in their turn driven northward by stronger +races from the east and south. But space presses, and I fear that +I have written too much already.</p> +<p>At least, I have turned over for you a few grand and strange pages +in the book of nature, and taught you, I hope, a key by which to decipher +their hieroglyphics. At least, I have, I trust, taught you to +look, as I do, with something of interest, even of awe, upon the pebbles +in the street.</p> +<div class="GutenbergBlankLines2"><br /><br /></div> +<h2>III. THE STONES IN THE WALL</h2> +<div class="GutenbergBlankLines2"><br /><br /></div> +<p>This is a large subject. For in the different towns of these +islands, the walls are built of stones of almost every age, from the +earliest to the latest; and the town-geologist may find a quite different +problem to solve in the nearest wall, on moving from one town to another +twenty miles off. All I can do, therefore, is to take one set +of towns, in the walls of which one sort of stones is commonly found, +and talk of them; taking care, of course, to choose a stone which is +widely distributed. And such, I think, we can find in the so-called +New Red sandstone, which, with its attendant marls, covers a vast tract—and +that a rich and busy one—of England. From Hartlepool and +the mouth of the Tees, down through Yorkshire and Nottinghamshire; over +the manufacturing districts of central England; down the valley of the +Severn; past Bristol and the Somersetshire flats to Torquay in South +Devon; up north-westward through Shropshire and Cheshire; past Liverpool +and northward through Lancashire; reappearing again, north of the Lake +mountains, about Carlisle and the Scotch side of the Solway Frith, stretches +the New Red sandstone plain, from under which everywhere the coal-bearing +rocks rise as from a sea. It contains, in many places, excellent +quarries of building-stone; the most famous of which, perhaps, are the +well-known Runcorn quarries, near Liverpool, from which the old Romans +brought the material for the walls and temples of ancient Chester, and +from which the stone for the restoration of Chester Cathedral is being +taken at this day. In some quarters, especially in the north-west +of England, its soil is poor, because it is masked by that very boulder-clay +of which I spoke in my last paper. But its rich red marls, wherever +they come to the surface, are one of God’s most precious gifts +to this favoured land. On them, one finds oneself at once in a +garden; amid the noblest of timber, wheat, roots, grass which is green +through the driest summers, and, in the western counties, cider-orchards +laden with red and golden fruit. I know, throughout northern Europe, +no such charming scenery, for quiet beauty and solid wealth, as that +of the New Red marls; and if I wished to show a foreigner what England +was, I should take him along them, from Yorkshire to South Devon, and +say—There. Is not that a country worth living for,—and +worth dying for if need be?</p> +<p>Another reason which I have for dealing with the New Red sandstone +is this—that (as I said just now) over great tracts of England, +especially about the manufacturing districts, the town-geologist will +find it covered immediately by the boulder clay.</p> +<p>The townsman, finding this, would have a fair right to suppose that +the clay was laid down immediately, or at least soon after, the sandstones +or marls on which it lies; that as soon as the one had settled at the +bottom of some old sea, the other settled on the top of it, in the same +sea.</p> +<p>A fair and reasonable guess, which would in many cases, indeed in +most, be quite true. But in this case it would be a mistake. +The sandstone and marls are immensely older than the boulder-clay. +They are, humanly speaking, some four or five worlds older.</p> +<p>What do I mean? This—that between the time when the one, +and the time when the other, was made, the British Islands, and probably +the whole continent of Europe, have changed four or five times; in shape; +in height above the sea, or depth below it; in climate; in the kinds +of plants and animals which have dwelt on them, or on their sea-bottoms. +And surely it is not too strong a metaphor, to call such changes a change +from an old world to a new one.</p> +<p>Mind. I do not say that these changes were sudden or violent. +It is far more probable that they are only part and parcel of that vast +but slow change which is going on everywhere over our whole globe. +I think that will appear probable in the course of this paper. +But that these changes have taken place, is my main thesis. The +fact I assert; and I am bound to try and prove it. And in trying +to do so, I shall no longer treat my readers, as I did in the first +two papers, like children. I shall take for granted that they +now understand something of the method by which geological problems +are worked out; and can trust it, and me; and shall state boldly the +conclusions of geologists, only giving proof where proof is specially +needed.</p> +<p>Now you must understand that in England there are two great divisions +of these New Red sandstones, “Trias,” as geologists call +them. An upper, called in Germany Keuper, which consists, atop, +of the rich red marl, below them, of sandstones, and of those vast deposits +of rock-salt, which have been long worked, and worked to such good purpose, +that a vast subsidence of land has just taken place near Nantwich in +Cheshire; and serious fears are entertained lest the town itself may +subside, to fill up the caverns below, from whence the salt has been +quarried. Underneath these beds again are those which carry the +building-stone of Runcorn. Now these beds altogether, in Cheshire, +at least, are about 3,400 feet thick; and were not laid down in a year, +or in a century either.</p> +<p>Below them lies a thousand feet of sandstones, known in Germany by +the name of “Bunter,” from its mottled and spotted appearance. +What lies under them again, does not concern us just now.</p> +<p>I said that the geologists called these beds the Trias; that is, +the triple group. But as yet we have heard of only two parts of +it. Where is the third?</p> +<p>Not here, but in Germany. There, between the Keuper above and +the Bunter below, lies a great series of limestone beds, which, from +the abundance of fossils which they contain, go by the name of Muschelkalk. +A long epoch must therefore have intervened between the laying down +of the Bunter and of the Keuper. And we have a trace of that long +epoch, even in England. The Keuper lies, certainly, immediately +on the Bunter; but not always “conformably” on it. +That is, the beds are not exactly parallel. The Bunter had been +slightly tilted, and slightly waterworn, before the Keuper was laid +on it.</p> +<p>It is reasonable, therefore, to suppose, that the Bunter in England +was dry land, and therefore safe from fresh deposit, through ages during +which it was deep enough beneath the sea in Germany, to have the Muschelkalk +laid down on it. Here again, then, as everywhere, we have evidence +of time—time, not only beyond all counting, but beyond all imagining.</p> +<p>And now, perhaps, the reader will ask—If I am to believe that +all new land is made out of old land, and that all rocks and soils are +derived from the wear and tear of still older rocks, off what land came +this enormous heap of sands more than 5,000 feet thick in places, stretching +across England and into Germany?</p> +<p>It is difficult to answer. The shape and distribution of land +in those days were so different from what they are now, that the rocks +which furnished a great deal of our sandstone may be now, for aught +I know, a mile beneath the sea.</p> +<p>But over the land which still stands out of the sea near us there +has been wear and tear enough to account for any quantity of sand deposit. +As a single instance—It is a provable and proven fact—as +you may see from Mr. Ramsay’s survey of North Wales—that +over a large tract to the south of Snowdon, between Port Madoc and Barmouth, +there has been ground off and carried away a mass of solid rock 20,000 +feet thick; thick enough, in fact, if it were there still, to make a +range of mountains as high as the Andes. It is a provable and +proven fact that vast tracts of the centre of poor old Ireland were +once covered with coal-measures, which have been scraped off in likewise, +deprived of inestimable mineral wealth. The destruction of rocks—“denudation” +as it is called—in the district round Malvern, is, I am told, +provably enormous. Indeed, it is so over all Wales, North England, +and West and North Scotland. So there is enough of rubbish to +be accounted for to make our New Red sands. The round pebbles +in it being, I believe, pieces of Old Red sandstone, may have come from +the great Old Red sandstone region of South East Wales and Herefordshire. +Some of the rubbish, too, may have come from what is now the Isle of +Anglesey.</p> +<p>For you find in the beds, from the top to the bottom (at least in +Cheshire), particles of mica. Now this mica could not have been +formed in the sand. It is a definite crystalline mineral, whose +composition is well known. It is only found in rocks which have +been subjected to immense pressure, and probably to heat. The +granites and mica-slates of Anglesey are full of it; and from Anglesey—as +likely as from anywhere else—these thin scales of mica came. +And that is about all that I can say on the matter. But it is +certain that most of these sands were deposited in a very shallow water, +and very near to land. Sand and pebbles, as I said in my first +paper, could not be carried far out to sea; and some of the beds of +the Bunter are full of rounded pebbles. Nay, it is certain that +their surface was often out of water. Of that you may see very +pretty proofs. You find these sands ripple-marked, as you do shore-sands +now. You find cracks where the marl mud has dried in the sun: +and, more, you find the little pits made by rain. Of that I have +no doubt. I have seen specimens, in which you could not only see +at a glance that the marks had been made by the large drops of a shower, +but see also from what direction the shower had come. These delicate +markings must have been covered up immediately with a fresh layer of +mud or sand. How long since? How long since that flag had +seen the light of the sun, when it saw it once again, restored to the +upper air by the pick of the quarryman? Who can answer that? +Not I.</p> +<p>Fossils are very rare in these sands; it is not easy to say why. +It may be that the red oxide of iron in them has destroyed them. +Few or none are ever found in beds in which it abounds. It is +curious, too, that the Keuper, which is all but barren of fossils in +England, is full of them in Würtemberg, reptiles, fish, and remains +of plants being common. But what will interest the reader are +the footprints of a strange beast, found alike in England and in Germany—the +Cheirotherium, as it was first named, from its hand-like feet; the Labyrinthodon, +as it is now named, from the extraordinary structure of its teeth. +There is little doubt now, among anatomists, that the bones and teeth +of the so-called Labyrinthodon belong to the animal which made the footprints. +If so, the creature must have been a right loathly monster. Some +think him to have been akin to lizards; but the usual opinion is that +he was a cousin of frogs and toads. Looking at his hands and other +remains, one pictures him to oneself as a short, squat brute, as big +as a fat hog, with a head very much the shape of a baboon, very large +hands behind and small ones in front, waddling about on the tide flats +of a sandy sea, and dragging after him, seemingly, a short tail, which +has left its mark on the sand. What his odour was, whether he +was smooth or warty, what he ate, and in general how he got his living, +we know not. But there must have been something there for him +to eat; and I dare say that he was about as happy and about as intellectual +as the toad is now. Remember always that there is nothing alive +now exactly like him, or, indeed, like any animal found in these sandstones. +The whole animal world of this planet has changed entirely more than +once since the Labyrinthodon waddled over the Cheshire flats. +A lizard, for instance, which has been found in the Keuper, had a skull +like a bird’s, and no teeth—a type which is now quite extinct. +But there is a more remarkable animal of which I must say a few words, +and one which to scientific men is most interesting and significant.</p> +<p>Both near Warwick, and near Elgin in Scotland, in Central India, +and in South Africa, fossil remains are found of a family of lizards +utterly unlike anything now living save one, and that one is crawling +about, plentifully I believe—of all places in the world—in +New Zealand. How it got there; how so strange a type of creature +should have died out over the rest of the world, and yet have lasted +on in that remote island for long ages, ever since the days of the New +Red sandstone, is one of those questions—quite awful questions +I consider them—with which I will not puzzle my readers. +I only mention it to show them what serious questions the scientific +man has to face, and to answer, if he can. Only the next time +they go to the Zoological Gardens in London, let them go to the reptile-house, +and ask the very clever and courteous attendant to show them the Sphenodons, +or Hatterias, as he will probably call them—and then look, I hope +with kindly interest, at the oldest Conservatives they ever saw, or +are like to see; gentlemen of most ancient pedigree, who have remained +all but unchanged, while the whole surface of the globe has changed +around them more than once or twice.</p> +<p>And now, of course, my readers will expect to hear something of the +deposits of rock-salt, for which Cheshire and its red rocks are famous. +I have never seen them, and can only say that the salt does not, it +is said by geologists, lie in the sandstone, but at the bottom of the +red marl which caps the sandstone. It was formed most probably +by the gradual drying up of lagoons, such as are depositing salt, it +is said now, both in the Gulf of Tadjara, on the Abyssinian frontier +opposite Aden, and in the Runn of Cutch, near the Delta of the Indus. +If this be so, then these New Red sandstones may be the remains of a +whole Sahara—a sheet of sandy and all but lifeless deserts, reaching +from the west of England into Germany, and rising slowly out of the +sea; to sink, as we shall find, beneath the sea again.</p> +<p>And now, as to the vast period of time—the four or five worlds, +as I called it—which elapsed between the laying down of the New +Red sandstones and the laying down of the boulder-clays.</p> +<p>I think this fact—for fact it is—may be better proved +by taking readers an imaginary railway journey to London from any spot +in the manufacturing districts of central England—begging them, +meanwhile, to keep their eyes open on the way.</p> +<p>And here I must say that I wish folks in general would keep their +eyes a little more open when they travel by rail. When I see young +people rolling along in a luxurious carriage, their eyes and their brains +absorbed probably in a trashy shilling novel, and never lifted up to +look out of the window, unconscious of all that they are passing—of +the reverend antiquities, the admirable agriculture, the rich and peaceful +scenery, the like of which no country upon earth can show; unconscious, +too, of how much they might learn of botany and zoology, by simply watching +the flowers along the railway banks and the sections in the cuttings: +then it grieves me to see what little use people make of the eyes and +of the understanding which God has given them. They complain of +a dull journey: but it is not the journey which is dull; it is they +who are dull. Eyes have they, and see not; ears have they, and +hear not; mere dolls in smart clothes, too many of them, like the idols +of the heathen.</p> +<p>But my readers, I trust, are of a better mind. So the next +time they find themselves running up southward to London—or the +reverse way—let them keep their eyes open, and verify, with the +help of a geological map, the sketch which is given in the following +pages.</p> +<p>Of the “Black Countries”—the actual coal districts +I shall speak hereafter. They are in England either shores or +islands yet undestroyed, which stand out of the great sea of New Red +sandstone, and often carry along their edges layers of far younger rocks, +called now Permian, from the ancient kingdom of Permia, in Russia, where +they cover a vast area. With them I will not confuse the reader +just now, but will only ask him to keep his eye on the rolling plain +of New Red sands and marls past, say, Birmingham and Warwick. +After those places, these sands and marls dip to the south-east, and +other rocks and soils appear above them, one after another, dipping +likewise towards the south-east—that is, toward London.</p> +<p>First appear thin layers of a very hard blue limestone, full of shells, +and parted by layers of blue mud. That rock runs in a broad belt +across England, from Whitby in Yorkshire, to Lyme in Dorsetshire, and +is known as Lias. Famous it is, as some readers may know, for +holding the bones of extinct monsters—Ichthyosaurs and Plesiosaurs, +such as the unlearned may behold in the lake at the Crystal Palace. +On this rock lie the rich cheese pastures, and the best tracts of the +famous “hunting shires” of England.</p> +<p>Lying on it, as we go south-eastward, appear alternate beds of sandy +limestone, with vast depths of clay between them. These “oolites,” +or freestones, furnish the famous Bath stone, the Oxford stone, and +the Barnack stone of Northamptonshire, of which some of the finest cathedrals +are built—a stone only surpassed, I believe, by the Caen stone, +which comes from beds of the same age in Normandy. These freestones +and clays abound in fossils, but of kinds, be it remembered, which differ +more and more from those of the lias beneath, as the beds are higher +in the series, and therefore nearer. There, too, are found principally +the bones of that extraordinary flying lizard, the Pterodactyle, which +had wings formed out of its fore-legs, on somewhat the same plan as +those of a bat, but with one exception. In the bat, as any one +may see, four fingers of the hand are lengthened to carry the wing, +while the first alone is left free, as a thumb: but in the Pterodactyle, +the outer or “little” finger alone is lengthened, and the +other four fingers left free—one of those strange instances in +nature of the same effect being produced in widely different plants +and animals, and yet by slightly different means, on which a whole chapter +of natural philosophy—say, rather, natural theology—will +have to be written some day.</p> +<p>But now consider what this Lias, and the Oolites and clays upon it +mean. They mean that the New Red sandstone, after it had been +dry land, or all but dry land (as is proved by the footprints of animals +and the deposits of salt), was sunk again beneath the sea. Each +deposit of limestone signifies a long period of time, during which that +sea was pure enough to allow reefs of coral to grow, and shells to propagate, +at the bottom. Each great band of clay signifies a long period, +during which fine mud was brought down from some wasting land in the +neighbourhood. And that land was not far distant is proved by +the bones of the Pterodactyle, of Crocodiles, and of Marsupials; by +the fact that the shells are of shallow-water or shore species; by the +presence, mixed with them, of fragments of wood, impressions of plants, +and even wing-shells of beetles; and lastly, if further proof was needed, +by the fact that in the “dirt-bed” of the Isle of Portland +and the neighbouring shores, stumps of trees allied to the modern sago-palms +are found as they grew in the soil, which, with them, has been covered +up in layers of freshwater shale and limestone. A tropic forest +has plainly sunk beneath a lagoon; and that lagoon, again, beneath the +sea.</p> +<p>And how long did this period of slow sinking go on? Who can +tell? The thickness of the Lias and Oolites together cannot be +less than a thousand feet. Considering, then, the length of time +required to lay down a thousand feet of strata, and considering the +vast difference between the animals found in them, and the few found +in the New Red sandstone, we have a right to call them another world, +and that one which must have lasted for ages.</p> +<p>After we pass Oxford, or the Vale of Aylesbury, we enter yet another +world. We come to a bed of sand, under which the freestones and +their adjoining clays dip to the south-east. This is called commonly +the lower Greensand, though it is not green, but rich iron-red. +Then succeeds a band of stiff blue clay, called the Gault, and then +another bed of sand, the upper Greensand, which is more worthy of the +name, for it does carry, in most places, a band of green or “glauconite” +sand. But it and the upper layers of the lower Greensand also, +are worth our attention; for we are all probably eating them from time +to time in the form of bran.</p> +<p>It had been long remarked that certain parts of these beds carried +admirable wheatland; it had been remarked, too, that the finest hop-lands—those +of Farnham, for instance, and Tunbridge—lay upon them: but that +the fertile band was very narrow; that, as in the Surrey Moors, vast +sheets of the lower Greensand were not worth cultivation. What +caused the striking difference?</p> +<p>My beloved friend and teacher, the late Dr. Henslow, when Professor +of Botany at Cambridge, had brought to him by a farmer (so the story +ran) a few fossils. He saw, being somewhat of a geologist and +chemist, that they were not, as fossils usually are, carbonate of lime, +but phosphate of lime—bone-earth. He said at once, as by +an inspiration, “You have found a treasure—not a gold-mine, +indeed, but a food-mine. This is bone-earth, which we are at our +wits’ end to get for our grain and pulse; which we are importing, +as expensive bones, all the way from Buenos Ayres. Only find enough +of them, and you will increase immensely the food supply of England, +and perhaps make her independent of foreign phosphates in case of war.”</p> +<p>His advice was acted on; for the British farmer is by no means the +stupid personage which townsfolk are too apt to fancy him. This +bed of phosphates was found everywhere in the Greensand, underlying +the Chalk. It may be traced from Dorsetshire through England to +Cambridge, and thence, I believe, into Yorkshire. It may be traced +again, I believe, all round the Weald of Kent and Sussex, from Hythe +to Farnham—where it is peculiarly rich—and so to Eastbourne +and Beachey Head; and it furnishes, in Cambridgeshire, the greater part +of those so-called “coprolites,” which are used perpetually +now for manure, being ground up, and then treated with sulphuric acid, +till they become a “soluble super-phosphate of lime.”</p> +<p>So much for the useless “hobby,” as some fancy it, of +poking over old bones and stones, and learning a little of the composition +of this earth on which God has placed us.</p> +<p>How to explain the presence of this vast mass of animal matter, in +one or two thin bands right across England, I know not. That the +fossils have been rolled on a sea-beach is plain to those who look at +them. But what caused so vast a destruction of animal life along +that beach, must remain one of the buried secrets of the past.</p> +<p>And now we are fast nearing another world, which is far younger than +that coprolite bed, and has been formed under circumstances the most +opposite to it. We are nearing, by whatever rail we approach London, +the escarpment of the chalk downs.</p> +<p>All readers, surely, know the white chalk, the special feature and +the special pride of the south of England. All know its softly-rounded +downs, its vast beech woods, its short and sweet turf, its snowy cliffs, +which have given—so some say—to the whole island the name +of Albion—the white land. But all do not, perhaps, know +that till we get to the chalk no single plant or animal has been found +which is exactly like any plant or animal now known to be living. +The plants and animals grow, on the whole, more and more like our living +forms as we rise in the series of beds. But only above the chalk +(as far as we yet know) do we begin to find species identical with those +living now.</p> +<p>This in itself would prove a vast lapse of time. We shall have +a further proof of that vast lapse when we examine the chalk itself. +It is composed—of this there is now no doubt—almost entirely +of the shells of minute animalcules; and animalcules (I use an unscientific +word for the sake of unscientific readers) like these, and in some cases +identical with them, are now forming a similar deposit of mud, at vast +depths, over the greater part of the Atlantic sea-floor. This +fact has been put out of doubt by recent deep-sea dredgings. A +whole literature has been written on it of late. Any reader who +wishes to know it, need only ask the first geologist he meets; and if +he has the wholesome instinct of wonder in him, fill his imagination +with true wonders, more grand and strange than he is like to find in +any fairy tale. All I have to do with the matter here is, to say +that, arguing from the known to the unknown, from the Atlantic deep-sea +ooze which we do know about, to the chalk which we do not know about, +the whole of the chalk must have been laid down at the bottom of a deep +and still ocean, far out of the reach of winds, tides, and even currents, +as a great part of the Atlantic sea-floor is at this day.</p> +<p>Prodigious! says the reader. And so it is. Prodigious +to think that that shallow Greensand shore, strewed with dead animals, +should sink to the bottom of an ocean, perhaps a mile, perhaps some +four miles deep. Prodigious the time during which it must have +lain as a still ocean-floor. For so minute are the living atomies +which form the ooze, that an inch, I should say, is as much as we can +allow for their yearly deposit; and the chalk is at least a thousand +feet thick. It may have taken, therefore, twelve thousand years +to form the chalk alone. A rough guess, of course, but one as +likely to be two or three times too little as two or three times too +big. Such, or somewhat such, is the fact. It had long been +suspected, and more than suspected; and the late discoveries of Dr. +Carpenter and Mr. Wyville Thompson have surely placed it beyond doubt.</p> +<p>Thus, surely, if we call the Oolitic beds one new world above the +New Red sandstone, we must call the chalk a second new world in like +wise.</p> +<p>I will not trouble the reader here with the reasons why geologists +connect the chalk with the greensands below it, by regular gradations, +in spite of the enormous downward leap, from sea-shore to deep ocean, +which the beds seem (but only seem) to have taken. The change—like +all changes in geology—was probably gradual. Not by spasmodic +leaps and starts, but slowly and stately, as befits a God of order, +of patience, and of strength, have these great deeds been done.</p> +<p>But we have not yet done with new worlds or new prodigies on our +way to London, as any Londoner may ascertain for himself, if he will +run out a few miles by rail, and look in any cutting or pit, where the +surface of the chalk, and the beds which lie on it, are exposed.</p> +<p>On the chalk lie—especially in the Blackheath and Woolwich +district—sands and clays. And what do they tell us?</p> +<p>Of another new world, in which the chalk has been lifted up again, +to form gradually, doubtless, and at different points in succession, +the shore of a sea.</p> +<p>But what proof is there of this?</p> +<p>The surface of the chalk is not flat and smooth, as it must have +been when at the bottom of the sea. It is eaten out into holes +and furrows, plainly by the gnawing of the waves; and on it lie, in +many places, large rolled flints out of chalk which has been destroyed, +beds of shore-shingle, beds of oysters lying as they grew, fresh or +brackish water-shells standing as they lived, bits of lignite (fossil +wood half turned to coal), and (as in Katesgrove pits at Reading) leaves +of trees. Proof enough, one would say, that the chalk had been +raised till part of it at least became dry land, and carried vegetation.</p> +<p>And yet we have not done. There is another world to tell of +yet.</p> +<p>For these beds (known as the Woolwich and Reading beds) dip under +that vast bed of London clay, four hundred and more feet thick, which +(as I said in my last chapter) was certainly laid down by the estuary +of some great tropic river, among palm-trees and Anonas, crocodiles +and turtles.</p> +<p>Is the reader’s power of belief exhausted?</p> +<p>If not: there are to be seen, capping almost every high land round +London, the remains of a fifth world. Some of my readers may have +been to Ascot races, or to Aldershot camp, and may recollect the table-land +of the sandy moors, perfectly flat atop, dreary enough to those to whom +they are not (as they have long been to me) a home and a work-field. +Those sands are several hundred feet thick. They lie on the London +clay. And they represent—the reader must take geologists’ +word for it—a series of beds in some places thousands of feet +thick, in the Isle of Wight, in the Paris basin, in the volcanic country +of the Auvergne, in Switzerland, in Italy; a period during which the +land must at first have swarmed with forms of tropic life, and then +grown—but very gradually—more temperate, and then colder +and colder still; till at last set in that age of ice, which spread +the boulder pebbles over all rocks and soils indiscriminately, from +the Lake mountains to within a few miles of London.</p> +<p>For everywhere about those Ascot moors, the top of the sands has +been ploughed by shore-ice in winter, as they lay a-wash in the shallow +sea; and over them, in many places, is spread a thin sheet of ice gravel, +more ancient, the best geologists think, than the boulder and the boulder-clay.</p> +<p>If any of my readers ask how long the period was during which those +sands of Ascot Heath and Aldershot have been laid down, I cannot tell. +But this we can tell. It was long enough to see such changes in +land and sea, that maps representing Europe during the greater part +of that period (as far as we can guess at it) look no more like Europe +than like America or the South Sea Islands. And this we can tell +besides: that that period was long enough for the Swiss Alps to be lifted +up at least 10,000 feet of their present height. And that was +a work which—though God could, if He willed it, have done it in +a single day—we have proof positive was not done in less than +ages, beside which the mortal life of man is as the life of the gnat +which dances in the sun.</p> +<p>And all this, and more—as may be proved from the geology of +foreign countries—happened between the date of the boulder-clay, +and that of the New Red sandstone on which it rests.</p> +<div class="GutenbergBlankLines2"><br /><br /></div> +<h2>IV. THE COAL IN THE FIRE</h2> +<div class="GutenbergBlankLines2"><br /><br /></div> +<p>My dear town-dwelling readers, let me tell you now something of a +geological product well known, happily, to all dwellers in towns, and +of late years, thanks to railroad extension, to most dwellers in country +districts: I mean coal.</p> +<p>Coal, as of course you know, is commonly said to be composed of vegetable +matter, of the leaves and stems of ancient plants and trees—a +startling statement, and one which I do not wish you to take entirely +on trust. I shall therefore spend a few pages in showing you how +this fact—for fact it is—was discovered. It is a very +good example of reasoning from the known to the unknown. You will +have a right to say at first starting, “Coal is utterly different +in look from leaves and stems. The only property which they seem +to have in common is that they can both burn.” True. +But difference of mere look may be only owing to a transformation, or +series of transformations. There are plenty in nature quite as +great, and greater. What can be more different in look, for instance, +than a green field of wheat and a basket of loaves at the baker’s? +And yet there is, I trust, no doubt whatsoever that the bread has been +once green wheat, and that the green wheat has been transformed into +bread—making due allowance, of course, for the bone-dust, or gypsum, +or alum with which the worthy baker may have found it profitable to +adulterate his bread, in order to improve the digestion of Her Majesty’s +subjects.</p> +<p>But you may say, “Yes, but we can see the wheat growing, flowering, +ripening, reaped, ground, kneaded, baked. We see, in the case +of bread, the processes of the transformation going on: but in the case +of coal we do not see the wood and leaves being actually transformed +into coal, or anything like it.”</p> +<p>Now suppose we laid out the wheat on a table in a regular series, +such as you may see in many exhibitions of manufactures; beginning with +the wheat plant at one end, and ending with the loaf at the other; and +called in to look at them a savage who knew nothing of agriculture and +nothing of cookery—called in, as an extreme case, the man in the +moon, who certainly can know nothing of either; for as there is neither +air nor water round the moon, there can be nothing to grow there, and +therefore nothing to cook—and suppose we asked him to study the +series from end to end. Do you not think that the man in the moon, +if he were half as shrewd as Crofton Croker makes him in his conversation +with Daniel O’Rourke, would answer after due meditation, “How +the wheat plant got changed into the loaf I cannot see from my experience +in the moon: but that it has been changed, and that the two are the +same thing I do see, for I see all the different stages of the change.” +And so I think you may say of the wood and the coal.</p> +<p>The man in the moon would be quite reasonable in his conclusion; +for it is a law, a rule, and one which you will have to apply again +and again in the study of natural objects, that however different two +objects may look in some respects, yet if you can find a regular series +of gradations between them, with all shades of likeness, first to one +of them and then to the other, then you have a fair right to suppose +them to be only varieties of the same species, the same kind of thing, +and that, therefore, they have a common origin.</p> +<p>That sounds rather magniloquent. Let me give you a simple example.</p> +<p>Suppose you had come into Britain with Brute, the grandson of Æneas, +at that remote epoch when (as all archaeologists know who have duly +read Geoffrey of Monmouth and the Arthuric legends) Britain was inhabited +only by a few giants. Now if you had met giants with one head, +and also giants with seven heads, and no others, you would have had +a right to say, “There are two breeds of giants here, one-headed +and seven-headed.” But if you had found, as Jack the Giant-Killer +(who belongs to the same old cycle of myths) appears to have found, +two-headed giants also, and three-headed, and giants, indeed, with any +reasonable number of heads, would you not have been justified in saying, +“They are all of the same breed, after all; only some are more +capitate, or heady, than others!”</p> +<p>I hope that you agree to that reasoning; for by it I think we arrive +most surely at a belief in the unity of the human race, and that the +Negro is actually a man and a brother.</p> +<p>If the only two types of men in the world were an extreme white type, +like the Norwegians, and an extreme black type, like the Negros, then +there would be fair ground for saying, “These two types have been +always distinct; they are different races, who have no common origin.” +But if you found, as you will find, many types of man showing endless +gradations between the white man and the Negro, and not only that, but +endless gradations between them both and a third type, whose extreme +perhaps is the Chinese—endless gradations, I say, showing every +conceivable shade of resemblance or difference, till you often cannot +say to what type a given individual belongs; and all of them, however +different from each other, more like each other than they are like any +other creature upon earth; then you are justified in saying, “All +these are mere varieties of one kind. However distinct they are +now, they were probably like each other at first, and therefore all +probably had a common origin.” That seems to me sound reasoning, +and advanced natural science is corroborating it more and more daily.</p> +<p>Now apply the same reasoning to coal. You may find about the +world—you may see even in England alone—every gradation +between coal and growing forest. You may see the forest growing +in its bed of vegetable mould; you may see the forest dead and converted +into peat, with stems and roots in it; that, again, into sunken forests, +like those to be seen below high-water mark on many coasts of this island. +You find gradations between them and beds of lignite, or wood coal; +then gradations between lignite and common or bituminous coal; and then +gradations between common coal and culm, or anthracite, such as is found +in South Wales. Have you not a right to say, “These are +all but varieties of the same kind of thing—namely, vegetable +matter? They have a common origin—namely, woody fibre. +And coal, or rather culm, is the last link in a series of transformations +from growing vegetation?”</p> +<p>This is our first theory. Let us try to verify it, as scientific +men are in the habit of doing, by saying, If that be true, then something +else is likely to be true too.</p> +<p>If coal has all been vegetable soil, then it is likely that some +of it has not been quite converted into shapeless coal. It is +likely that there will be vegetable fibre still to be seen here and +there; perhaps leaves, perhaps even stems of trees, as in a peat bog. +Let us look for them.</p> +<p>You will not need to look far. The coal, and the sands and +shales which accompany the coal, are so full of plant-remains, that +three hundred species were known to Adolphe Brongniart as early as 1849, +and that number has largely increased since.</p> +<p>Now one point is specially noticeable about these plants of the coal; +namely, that they may at least have grown in swamps.</p> +<p>First, you will be interested if you study the coal flora, with the +abundance, beauty, and variety of the ferns. Now ferns in these +islands grow principally in rocky woods, because there, beside the moisture, +they get from decaying vegetable or decaying rock, especially limestone, +the carbonic acid which is their special food, and which they do not +get on our dry pastures, and still less in our cultivated fields. +But in these islands there are two noble species, at least, which are +true swamp-ferns; the Lastræa Thelypteris, which of old filled +the fens, but is now all but extinct; and the Osmunda, or King-fern, +which, as all know, will grow wherever it is damp enough about the roots. +In Hampshire, in Devon, and Cornwall, and in the southwest of Ireland, +the King-fern too is a true swamp fern. But in the Tropics I have +seen more than once noble tree-ferns growing in wet savannahs at the +sea-level, as freely as in the mountain-woods; ferns with such a stem +as some of the coal ferns had, some fifteen feet in height, under which, +as one rode on horseback, one saw the blazing blue sky, as through a +parasol of delicate lace, as men might have long ages since have seen +it, through the plumed fronds of the ferns now buried in the coal, had +there only been a man then created to enjoy its beauty.</p> +<p>Next we find plants called by geologists Calamites. There is +no doubt now that they are of the same family as our Equiseta, or horse-tails, +a race which has, over most parts of the globe, dwindled down now from +twenty or thirty feet in height, as they were in the old coal measures, +to paltry little weeds. The tallest Equisetum in England—the +beautiful E. Telmateia—is seldom five feet high. But they, +too, are mostly mud and swamp plants; and so may the Calamites have +been.</p> +<p>The Lepidodendrons, again, are without doubt the splendid old representatives +of a family now dwindled down to such creeping things as our club-mosses, +or Lycopodiums. Now it is a certain fact, which can be proved +by the microscope, that a very great part of the best coal is actually +made up of millions of the minute seeds of club-mosses, such as grow—a +few of them, and those very small—on our moors; a proof, surely, +not only of the vast amount of the vegetation in the coal-making age, +but also of the vast time during which it lasted. The Lepidodendra +may have been fifty or sixty feet high. There is not a Lycopodium +in the world now, I believe, five feet high. But the club-mosses +are now, in these islands and elsewhere, lovers of wet and peaty soils, +and so may their huger prototypes have been, in the old forests of the +coal.</p> +<p>Of the Sigillariæ we cannot say as much with certainty, for +botanists are not agreed as to what low order of flowerless plants they +belong. But that they rooted in clay beds there is proof, as you +will hear presently.</p> +<p>And as to the Conifers, or pine-like trees—the Dadoxylon, of +which the pith goes by the name of Sternbergia, and the uncertain tree +which furnishes in some coal-measures bushels of a seed connected with +that of the yew—we may suppose that they would find no more difficulty +in growing in swamps than the cypress, which forms so large a portion +of the vegetation in the swamps of the Southern United States.</p> +<p>I have given you these hints, because you will naturally wish to +know what sort of a world it was in which all these strange plants grew +and turned into coal.</p> +<p>My answer is, that it was most probably just like the world in which +we are living now, with the one exception that the plants and animals +are different.</p> +<p>It was the fashion a few years since to explain the coal—like +other phenomena of geology—by some mere hypothesis of a state +of things quite unlike what we see now. We were brought up to +believe that in the Carboniferous, or coal-bearing era, the atmosphere +was intensely moist and hot, and overcharged with carbonic acid, which +had been poured out from the interior of the planet by volcanic eruptions, +or by some other convulsion. I forget most of it now: and really +there is no need to remember; for it is all, I verily believe, a dream—an +attempt to explain the unknown not by the known, but by the still more +unknown. You may find such theories lingering still in sensational +school-books, if you like to be unscientific. If you like, on +the other hand, to be scientific you will listen to those who tell you +that instead of there having been one unique carboniferous epoch, with +a peculiar coal-making climate, all epochs are carboniferous if they +get the chance; that coal is of every age, from that of the Scotch and +English beds, up to the present day. The great coal-beds along +the Rocky Mountains, for instance, are tertiary—that is, later +than the chalk. Coal is forming now, I doubt not, in many places +on the earth, and would form in many more, if man did not interfere +with the processes of wild nature, by draining the fens, and embanking +the rivers.</p> +<p>Let me by a few words prove this statement. They will give +you, beside, a fresh proof of Sir Charles Lyell’s great geological +rule—that the best way to explain what we see in ancient rocks +is to take for granted, as long as we can do so fairly, that things +were going on then very much as they are going on now.</p> +<p>When it was first seen that coal had been once vegetable, the question +arose—How did all these huge masses of vegetable matter get there? +The Yorkshire and Derbyshire coal-fields, I hear, cover 700 or 800 square +miles; the Lancashire about 200. How large the North Wales and +the Scotch fields are I cannot say. But doubtless a great deal +more coal than can be got at lies under the sea, especially in the north +of Wales. Coal probably exists over vast sheets of England and +France, buried so deeply under later rocks, that it cannot be reached +by mining. As an instance, a distinguished geologist has long +held that there are beds of coal under London itself, which rise, owing +to a peculiar disturbance of the strata, to within 1,000 or 1,200 feet +of the surface, and that we or our children may yet see coal-mines in +the marshes of the Thames. And more, it is a provable fact that +only a portion of the coal measures is left. A great part of Ireland +must once have been covered with coal, which is now destroyed. +Indeed, it is likely that the coal now known of in Europe and America +is but a remnant of what has existed there in former ages, and has been +eaten away by the inroads of the sea.</p> +<p>Now whence did all that enormous mass of vegetable soil come? +Off some neighbouring land, was the first and most natural answer. +It was a rational one. It proceeded from the known to the unknown. +It was clear that these plants had grown on land; for they were land-plants. +It was clear that there must have been land close by, for between the +beds of coal, as you all know, the rock is principally coarse sandstone, +which could only have been laid down (as I have explained to you already) +in very shallow water.</p> +<p>It was natural, then, to suppose that these plants and trees had +been swept down by rivers into the sea, as the sands and muds which +buried them had been. And it was known that at the mouths of certain +rivers—the Mississippi, for instance—vast rafts of dead +floating trees accumulated; and that the bottoms of the rivers were +often full of snags, etc.; trees which had grounded, and stuck in the +mud; and why should not the coal have been formed in the same way?</p> +<p>Because—and this was a serious objection—then surely +the coal would be impure—mixed up with mud and sand, till it was +not worth burning. Instead of which, the coal is usually pure +vegetable, parted sharply from the sandstone which lies on it. +The only other explanation was, that the coal vegetation had grown in +the very places where it was found. But that seemed too strange +to be true, till that great geologist, Sir W. Logan—who has since +done such good work in Canada—showed that every bed of coal had +a bed of clay under it, and that that clay always contained fossils +called Stigmaria. Then it came out that the Stigmaria in the under +clay had long filaments attached to them, while when found in the sandstones +or shales, they had lost their filaments, and seemed more or less rolled—in +fact, that the natural place of the Stigmaria was in the under clay. +Then Mr. Binney discovered a tree—a Sigillaria, standing upright +in the coal-measures with its roots attached. Those roots penetrated +into the under clay of the coal; and those roots were Stigmarias. +That seems to have settled the question. The Sigillarias, at least, +had grown where they were found, and the clay beneath the coal-beds +was the original soil on which they had grown. Just so, if you +will look at any peat bog you will find it bottomed by clay, which clay +is pierced everywhere by the roots of the moss forming the peat, or +of the trees, birches, alders, poplars, and willows, which grow in the +bog. So the proof seemed complete, that the coal had been formed +out of vegetation growing where it was buried. If any further +proof for that theory was needed, it would be found in this fact, most +ingeniously suggested by Mr. Boyd Dawkins. The resinous spores, +or seeds of the Lepidodendra make up—as said above—a great +part of the bituminous coal. Now those spores are so light, that +if the coal had been laid down by water, they would have floated on +it, and have been carried away; and therefore the bituminous coal must +have been formed, not under water, but on dry land.</p> +<p>I have dwelt at length on these further arguments, because they seem +to me as pretty a specimen as I can give my readers of that regular +and gradual induction, that common-sense regulated, by which geological +theories are worked out.</p> +<p>But how does this theory explain the perfect purity of the coal? +I think Sir C. Lyell answers that question fully in p. 383 of his “Student’s +Elements of Geology.” He tells us that the dense growths +of reeds and herbage which encompass the margins of forest-covered swamps +in the valley and delta of the Mississippi, in passing through them, +are filtered and made to clear themselves entirely before they reach +the areas in which vegetable matter may accumulate for centuries, forming +coal if the climate be favourable; and that in the cypress-swamps of +that region no sediment mingles with the vegetable matter accumulated +from the decay of trees and semi-aquatic plants; so that when, in a +very dry season, the swamp is set on fire, pits are burnt into the ground +many feet deep, or as far as the fire can go down without reaching water, +and scarcely any earthy residuum is left; just as when the soil of the +English fens catches fire, red-hot holes are eaten down through pure +peat till the water-bearing clay below is reached. But the purity +of the water in peaty lagoons is observable elsewhere than in the delta +of the Mississippi. What can be more transparent than many a pool +surrounded by quaking bogs, fringed, as they are in Ireland, with a +ring of white water-lilies, which you dare not stoop to pick, lest the +peat, bending inward, slide you down into that clear dark gulf some +twenty feet in depth, bottomed and walled with yielding ooze, from which +there is no escape? Most transparent, likewise, is the water of +the West Indian swamps. Though it is of the colour of coffee, +or rather of dark beer, and so impregnated with gases that it produces +fever or cholera when drunk, yet it is—at least when it does not +mingle with the salt water—so clear, that one might see every +marking on a boa-constrictor or alligator, if he glided along the bottom +under the canoe.</p> +<p>But now comes the question—Even if all this be true, how were +the forests covered up in shale and sandstone, one after another?</p> +<p>By gradual sinking of the land, one would suppose.</p> +<p>If we find, as we may find in a hundred coal-pits, trees rooted as +they grew, with their trunks either standing up through the coal, and +through the sandstone above the coal; their bark often remaining as +coal while their inside is filled up with sandstone, has not our common-sense +a right to say—The land on which they grew sank below the water-line; +the trees were killed; and the mud and sand which were brought down +the streams enveloped their trunks? As for the inside being full +of sandstone, have we not all seen hollow trees? Do we not all +know that when a tree dies its wood decays first, its bark last? +It is so, especially in the Tropics. There one may see huge dead +trees with their bark seemingly sound, and their inside a mere cavern +with touchwood at the bottom; into which caverns one used to peep with +some caution. For though one might have found inside only a pair +of toucans, or parrots, or a whole party of jolly little monkeys, one +was quite as likely to find a poisonous snake four or five feet long, +whose bite would have very certainly prevented me having the pleasure +of writing this book.</p> +<p>Now is it not plain that if such trees as that sunk, their bark would +be turned into lignite, and at last into coal, while their insides would +be silted up with mud and sand? Thus a core or pillar of hard +sandstone would be formed, which might do to the collier of the future +what they are too apt to do now in the Newcastle and Bristol collieries. +For there, when the coal is worked out below, the sandstone stems—“coal-pipes” +as the colliers call them—in the roof of the seam, having no branches, +and nothing to hold them up but their friable bark of coal, are but +too apt to drop out suddenly, killing or wounding the hapless men below.</p> +<p>Or again, if we find—as we very often find—as was found +at Parkfield Colliery, near Wolverhampton, in the year 1814—a +quarter of an acre of coal-seam filled. with stumps of trees as they +grew, their trunks broken off and lying in every direction, turned into +coal, and flattened, as coal-fossils so often are, by the weight of +the rock above—should we not have a right to say—These trees +were snapped off where they grew by some violent convulsion; by a storm, +or by a sudden inrush of water owing to a sudden sinking of the land, +or by the very earthquake shock itself which sank the land?</p> +<p>But what evidence have we of such sinkings? The plain fact +that you have coal-seam above coal-seam, each with its bed of under-clay; +and that therefore the land <i>must</i> have sunk ere the next bed of +soil could have been deposited, and the next forest have grown on it.</p> +<p>In one of the Rocky Mountain coal-fields there are more than thirty +seams of coal, each with its under-clay below it. What can that +mean but thirty or more subsidences of the land, and the peat of thirty +or more forests or peat-mosses, one above the other? And now if +any reader shall say, Subsidence? What is this quite new element +which you have brought into your argument? You told us that you +would reason from the known to the unknown. What do we know of +subsidence? You offered to explain the thing which had gone on +once by that which is going on now. Where is subsidence going +on now upon the surface of our planet? And where, too, upheaval, +such as would bring us these buried forests up again from under the +sea-level, and make them, like our British coal-field, dry land once +more?</p> +<p>The answer is—Subsidence and elevation of the land are common +now, probably just as common as they were in any age of this planet’s +history.</p> +<p>To give two instances, made now notorious by the writings of geologists. +As lately as 1819 a single earthquake shock in Cutch, at the mouth of +the Indus, sunk a tract of land larger than the Lake of Geneva in some +places to a depth of eighteen feet, and converted it into an inland +sea. The same shock raised, a few miles off, a corresponding sheet +of land some fifty miles in length, and in some parts sixteen miles +broad, ten feet above the level of the alluvial plain, and left it to +be named by the country-people the “Ullah Bund,” or bank +of God, to distinguish it from the artificial banks in the neighbourhood.</p> +<p>Again: in the valley of the Mississippi—a tract which is now, +it would seem, in much the same state as central England was while our +coal-fields were being laid down—the earthquakes of 1811-12 caused +large lakes to appear suddenly in many parts of the district, amid the +dense forests of cypress. One of these, the “Sunk Country,” +near New Madrid, is between seventy and eighty miles in length, and +thirty miles in breadth, and throughout it, as late as 1846, “dead +trees were conspicuous, some erect in the water, others fallen, and +strewed in dense masses over the bottom, in the shallows, and near the +shore.” I quote these words from Sir Charles Lyell’s +“Principles of Geology” (11th edit.), vol. i. p. 453. +And I cannot do better than advise my readers, if they wish to know +more of the way in which coal was formed, to read what is said in that +book concerning the Delta of the Mississippi, and its strata of forests +sunk where they grew, and in some places upraised again, alternating +with beds of clay and sand, vegetable soil, recent sea-shells, and what +not, forming, to a depth of several hundred feet, just such a mass of +beds as exists in our own coal-fields at this day.</p> +<p>If, therefore, the reader wishes to picture to himself the scenery +of what is now central England, during the period when our coal was +being laid down, he has only, I believe, to transport himself in fancy +to any great alluvial delta, in a moist and warm climate, favourable +to the growth of vegetation. He has only to conceive wooded marshes, +at the mouth of great rivers, slowly sinking beneath the sea; the forests +in them killed by the water, and then covered up by layers of sand, +brought down from inland, till that new layer became dry land, to carry +a fresh crop of vegetation. He has thus all that he needs to explain +how coal-measures were formed. I myself saw once a scene of that +kind, which I should be sorry to forget; for there was, as I conceived, +coal, making, or getting ready to be made, before my eyes: a sheet of +swamp, sinking slowly into the sea; for there stood trees, still rooted +below high-water mark, and killed by the waves; while inland huge trees +stood dying, or dead, from the water at their roots. But what +a scene—a labyrinth of narrow creeks, so narrow that a canoe could +not pass up, haunted with alligators and boa-constrictors, parrots and +white herons, amid an inextricable confusion of vegetable mud, roots +of the alder-like mangroves, and tangled creepers hanging from tree +to tree; and overhead huge fan-palms, delighting in the moisture, mingled +with still huger broad-leaved trees in every stage of decay. The +drowned vegetable soil of ages beneath me; above my head, for a hundred +feet, a mass of stems and boughs, and leaves and flowers, compared with +which the richest hothouse in England was poor and small. But +if the sinking process which was going on continued a few hundred years, +all that huge mass of wood and leaf would be sunk beneath the swamp, +and covered up in mud washed down from the mountains, and sand driven +in from the sea; to form a bed many feet thick, of what would be first +peat, then lignite, and last, it may be, coal, with the stems of killed +trees standing up out of it into the new mud and sand-beds above it, +just as the Sigillariæ and other stems stand up in the coal-beds +both of Britain and of Nova Scotia; while over it a fresh forest would +grow up, to suffer the same fate—if the sinking process went on—as +that which had preceded it.</p> +<p>That was a sight not easily to be forgotten. But we need not +have gone so far from home, at least, a few hundred years ago, to see +an exactly similar one. The fens of Norfolk and Cambridgeshire, +before the rivers were embanked, the water pumped off, the forests felled, +and the reed-beds ploughed up, were exactly in the same state. +The vast deposits of peat between Cambridge and the sea, often filled +with timber-trees, either fallen or upright as they grew, and often +mixed with beds of sand or mud, brought down in floods, were formed +in exactly the same way; and if they had remained undrained, then that +slow sinking, which geologists say is going on over the whole area of +the Fens, would have brought them gradually, but surely, below the sea-level, +to be covered up by new forests, and converted in due time into coal. +And future geologists would have found—they may find yet, if, +which God forbid, England should become barbarous and the trees be thrown +out of cultivation—instead of fossil Lepidodendra and Sigillariæ, +Calamites and ferns, fossil ashes and oaks, alders and poplars, bulrushes +and reeds. Almost the only fossil fern would have been that tall +and beautiful Lastræa Thelypteris, once so abundant, now all but +destroyed by drainage and the plough.</p> +<p>We need not, therefore, fancy any extraordinary state of things on +this planet while our English coal was being formed. The climate +of the northern hemisphere—Britain, at least, and Nova Scotia—was +warmer than now, to judge from the abundance of ferns; and especially +of tree-ferns; but not so warm, to judge from the presence of conifers +(trees of the pine tribe), as the Tropics. Moreover, there must +have been, it seems to me, a great scarcity of animal-life. Insects +are found, beautifully preserved; a few reptiles, too, and land-shells; +but very few. And where are the traces of such a swarming life +as would be entombed were a tropic forest now sunk; which is found entombed +in many parts of our English fens? The only explanation which +I can offer is this—that the club-mosses, tree-ferns, pines, and +other low-ranked vegetation of the coal afforded little or no food for +animals, as the same families of plants do to this day; and if creatures +can get nothing to eat, they certainly cannot multiply and replenish +the earth. But, be that as it may, the fact that coal is buried +forest is not affected.</p> +<p>Meanwhile, the shape and arrangements of sea and land must have been +utterly different from what they are now. Where was that great +land, off which great rivers ran to deposit our coal-measures in their +deltas? It has been supposed, for good reasons, that north-western +France, Belgium, Holland, and Germany were then under the sea; that +Denmark and Norway were joined to Scotland by a continent, a tongue +of which ran across the centre of England, and into Ireland, dividing +the northern and southern coal-fields. But how far to the west +and north did that old continent stretch? Did it, as it almost +certainly did long ages afterwards, join Greenland and North America +with Scotland and Norway? Were the northern fields of Nova Scotia, +which are of the same geological age as our own, and contain the same +plants, laid down by rivers which ran off the same continent as ours? +Who can tell now? That old land, and all record of it, save what +these fragmentary coal-measures can give, are buried in the dark abyss +of countless ages; and we can only look back with awe, and comfort ourselves +with the thought—Let Time be ever so vast, yet Time is not Eternity.</p> +<p>One word more. If my readers have granted that all for which +I have argued is probable, they will still have a right to ask for further +proof.</p> +<p>They will be justified in saying: “You say that coal is transformed +vegetable matter; but can you show us how the transformation takes place? +Is it possible according to known natural laws?”</p> +<p>The chemist must answer that. And he tells us that wood can +become lignite, or wood-coal, by parting with its oxygen, in the shape +of carbonic acid gas, or choke-damp; and then common or bituminous coal, +by parting with its hydrogen, chiefly in the form of carburetted hydrogen—the +gas with which we light our streets. That is about as much as +the unscientific reader need know. But it is a fresh corroboration +of the theory that coal has been once vegetable fibre, for it shows +how vegetable fibre can, by the laws of nature, become coal. And +it certainly helps us to believe that a thing has been done, if we are +shown that it can be done.</p> +<p>This fact explains, also, why in mines of wood-coal carbonic acid, +<i>i.e</i>. choke-damp, alone is given off. For in the wood-coal +a great deal of the hydrogen still remains. In mines of true coal, +not only is choke-damp given off, but that more terrible pest of the +miners, fire-damp, or explosive carburetted hydrogen and olefiant gases. +Now the occurrence of that fire-damp in mines proves that changes are +still going on in the coal: that it is getting rid of its hydrogen, +and so progressing toward the state of anthracite or culm—stone-coal +as it is sometimes called. In the Pennsylvanian coal-fields some +of the coal has actually done this, under the disturbing force of earthquakes; +for the coal, which is bituminous, like our common coal, to the westward +where the strata are horizontal, becomes gradually anthracite as it +is tossed and torn by the earthquake faults of the Alleghany and Appalachian +mountains.</p> +<p>And is a further transformation possible? Yes; and more than +one. If we conceive the anthracite cleared of all but its last +atoms of oxygen, hydrogen, and nitrogen, till it has become all but +pure carbon, it would become—as it has become in certain rocks +of immense antiquity, graphite—what we miscall black-lead. +And, after that, it might go through one transformation more, and that +the most startling of all. It would need only perfect purification +and crystallisation to become—a diamond; nothing less. We +may consider the coal upon the fire as the middle term of a series, +of which the first is live wood, and the last diamond; and indulge safely +in the fancy that every diamond in the world has probably, at some remote +epoch, formed part of a growing plant.</p> +<p>A strange transformation; which will look to us more strange, more +truly poetical, the more steadily we consider it.</p> +<p>The coal on the fire; the table at which I write—what are they +made of? Gas and sunbeams; with a small percentage of ash, or +earthy salts, which need hardly be taken into account.</p> +<p>Gas and sunbeams. Strange, but true.</p> +<p>The life of the growing plant—and what that life is who can +tell?—laid hold of the gases in the air and in the soil; of the +carbonic acid, the atmospheric air, the water—for that too is +gas. It drank them in through its rootlets: it breathed them in +through its leaf-pores, that it might distil them into sap, and bud, +and leaf, and wood. But it has to take in another element, without +which the distillation and the shaping could never have taken place. +It had to drink in the sunbeams—that mysterious and complex force +which is for ever pouring from the sun, and making itself partly palpable +to our senses as heat and light. So the life of the plant seized +the sunbeams, and absorbed them, buried them in itself—no longer +as light and heat, but as invisible chemical force, locked up for ages +in that woody fibre.</p> +<p>So it is. Lord Lytton told us long ago, in a beautiful song, +how</p> +<div class="GutenbergBlankLines1"><br /></div> +<p>The Wind and the Beam loved the Rose.</p> +<div class="GutenbergBlankLines1"><br /></div> +<p>But Nature’s poetry was more beautiful than man’s. +The wind and the beam loved the rose so well that they made the rose—or +rather, the rose took the wind and the beam, and built up out of them, +by her own inner life, her exquisite texture, hue, and fragrance.</p> +<p>What next? The rose dies; the timber tree dies; decays down +into vegetable fibre, is buried, and turned to coal: but the plant cannot +altogether undo its own work. Even in death and decay it cannot +set free the sunbeams imprisoned in its tissue. The sun-force +must stay, shut up age after age, invisible, but strong; working at +its own prison-cells; transmuting them, or making them capable of being +transmuted by man, into the manifold products of coal—coke, petroleum, +mineral pitch, gases, coal-tar, benzole, delicate aniline dyes, and +what not, till its day of deliverance comes.</p> +<p>Man digs it, throws it on the fire, a black, dead-seeming lump. +A corner, an atom of it, warms till it reaches the igniting point; the +temperature at which it is able to combine with oxygen.</p> +<p>And then, like a dormant live thing, awaking after ages to the sense +of its own powers, its own needs, the whole lump is seized, atom after +atom, with an infectious hunger for that oxygen which it lost centuries +since in the bottom of the earth. It drinks the oxygen in at every +pore; and burns.</p> +<p>And so the spell of ages is broken. The sun-force bursts its +prison-cells, and blazes into the free atmosphere, as light and heat +once more; returning in a moment into the same forms in which it entered +the growing leaf a thousand centuries since.</p> +<p>Strange it all is, yet true. But of nature, as of the heart +of man, the old saying stands—that truth is stranger than fiction.</p> +<div class="GutenbergBlankLines2"><br /><br /></div> +<h2>V. THE LIME IN THE MORTAR</h2> +<div class="GutenbergBlankLines2"><br /><br /></div> +<p>I shall presume in all my readers some slight knowledge about lime. +I shall take for granted, for instance, that all are better informed +than a certain party of Australian black fellows were a few years since.</p> +<p>In prowling on the track of a party of English settlers, to see what +they could pick up, they came—oh joy!—on a sack of flour, +dropped and left behind in the bush at a certain creek. The poor +savages had not had such a prospect of a good meal for many a day. +With endless jabbering and dancing, the whole tribe gathered round the +precious flour-bag with all the pannikins, gourds, and other hollow +articles it could muster, each of course with a due quantity of water +from the creek therein, and the chief began dealing out the flour by +handfuls, beginning of course with the boldest warriors. But, +horror of horrors, each man’s porridge swelled before his eyes, +grew hot, smoked, boiled over. They turned and fled, man, woman, +and child, from before that supernatural prodigy; and the settlers coming +back to look for the dropped sack, saw a sight which told the whole +tale. For the poor creatures, in their terror, had thrown away +their pans and calabashes, each filled with that which it was likely +to contain, seeing that the sack itself had contained, not flour, but +quick-lime. In memory of which comi-tragedy, that creek is called +to this day, “Flour-bag Creek.”</p> +<p>Now I take for granted that you are all more learned than these black +fellows, and know quick-lime from flour. But still you are not +bound to know what quick-lime is. Let me explain it to you.</p> +<p>Lime, properly speaking, is a metal, which goes among chemists by +the name of calcium. But it is formed, as you all know, in the +earth, not as a metal, but as a stone, as chalk or limestone, which +is a carbonate of lime; that is, calcium combined with oxygen and carbonic-acid +gases.</p> +<p>In that state it will make, if it is crystalline and hard, excellent +building stone. The finest white marble, like that of Carrara +in Italy, of which the most delicate statues are carved, is carbonate +of lime altered and hardened by volcanic heat. But to make mortar +of it, it must be softened and then brought into a state in which it +can be hardened again; and ages since, some man or other, who deserves +to rank as one of the great inventors, one of the great benefactors +of his race, discovered the art of making lime soft and hard again; +in fact of making mortar. The discovery was probably very ancient; +and made, probably like most of the old discoveries, in the East, spreading +Westward gradually. The earlier Greek buildings are cyclopean, +that is, of stone fitted together without mortar. The earlier +Egyptian buildings, though the stones are exquisitely squared and polished, +are put together likewise without mortar. So, long ages after, +were the earlier Roman buildings, and even some of the later. +The famous aqueduct of the Pont du Gard, near Nismes, in the south of +France, has, if I recollect right, no mortar whatever in it. The +stones of its noble double tier of circular arches have been dropped +into their places upon the wooden centres, and stand unmoved to this +day, simply by the jamming of their own weight; a miracle of art. +But the fact is puzzling; for these Romans were the best mortar makers +of the world. We cannot, I believe, surpass them in the art even +now; and in some of their old castles, the mortar is actually to this +day harder and tougher than the stones which it holds together. +And they had plenty of lime at hand if they had chosen to make mortar. +The Pont du Gard crosses a limestone ravine, and is itself built of +limestone. But I presume the cunning Romans would not trust mortar +made from that coarse Nummulite limestone, filled with gritty sand, +and preferred, with their usual carefulness, no mortar at all to bad.</p> +<p>But I must return, and tell my readers, in a few words, the chemical +history of mortar. If limestone be burnt, or rather roasted, in +a kiln, the carbonic acid is given off—as you may discover by +your own nose; as many a poor tramp has discovered too late, when, on +a cold winter night, he has lain down by the side of the burning kiln +to keep himself warm, and woke in the other world, stifled to death +by the poisonous fumes.</p> +<p>The lime then gives off its carbonic acid, and also its water of +crystallisation, that is, water which it holds (as do many rocks) locked +up in it unseen, and only to be discovered by chemical analysis. +It is then anhydrous—that is, waterless—oxide of lime, what +we call quick-lime; that which figured in the comi-tragedy of “Flour-bag +Creek;” and then, as you may find if you get it under your nails +or into your eyes, will burn and blister like an acid.</p> +<p>This has to be turned again into a hard and tough artificial limestone, +in plain words, into mortar; and the first step is to slack it—that +is, to give it back the water which it has lost, and for which it is +as it were thirsting. So it is slacked with water, which it drinks +in, heating itself and the water till it steams and swells in bulk, +because it takes the substance of the water into its own substance. +Slacked lime, as we all know, is not visibly wetter than quick-lime; +it crumbles to a dry white powder in spite of all the water which it +contains.</p> +<p>Then it must be made to set, that is, to return to limestone, to +carbonate of lime, by drinking in the carbonic acid from water and air, +which some sorts of lime will do instantly, setting at once, and being +therefore used as cements. But the lime usually employed must +be mixed with more or less sand to make it set hard: a mysterious process, +of which it will be enough to tell the reader that the sand and lime +are said to unite gradually, not only mechanically, that is, by sticking +together; but also in part chemically—that is, by forming out +of themselves a new substance, which is called silicate of lime.</p> +<p>Be that as it may, the mortar paste has now to do two things; first +to dry, and next to take up carbonic acid from the air and water, enough +to harden it again into limestone: and that it will take some time in +doing. A thick wall, I am informed, requires several years before +it is set throughout, and has acquired its full hardness, or rather +toughness; and good mortar, as is well known, will acquire extreme hardness +with age, probably from the very same cause that it did when it was +limestone in the earth. For, as a general rule, the more ancient +the strata is in which the limestone is found, the harder the limestone +is; except in cases where volcanic action and earthquake pressure have +hardened limestone in more recent strata, as in the case of the white +marbles of Carrara in Italy, which are of the age of our Oolites, that +is, of the freestone of Bath, etc., hardened by the heat of intruded +volcanic rocks.</p> +<p>But now: what is the limestone? and how did it get where it is—not +into the mortar, I mean, but into the limestone quarry? Let me +tell you, or rather, help you to tell yourselves, by leading you, as +before, from the known to the unknown. Let me lead you to places +unknown indeed to most; but there may be sailors or soldiers among my +readers who know them far better than I do. Let me lead you, in +fancy, to some island in the Tropic seas. After all, I am not +leading you as far away as you fancy by several thousand miles, as you +will see, I trust, ere I have done.</p> +<p>Let me take you to some island: what shall it be like? Shall +it be a high island, with cliff piled on cliff, and peak on peak, all +rich with mighty forests, like a furred mantle of green velvet, mounting +up and up till it is lost among white clouds above? Or shall it +be a mere low reef, which you do not see till you are close upon it; +on which nothing rises above the water, but here and there a knot of +cocoa-nut palms or a block of stone, or a few bushes, swarming with +innumerable sea-fowl and their eggs? Let it be which you will: +both are strange enough; both beautiful; both will tell us a story.</p> +<p>The ship will have to lie-to, and anchor if she can; it may be a +mile, it may be only a few yards, from the land. For between it +and the land will be a line of breakers, raging in before the warm trade-wind. +And this, you will be told, marks the edge of the coral reef.</p> +<p>You will have to go ashore in a boat, over a sea which looks unfathomable, +and which may be a mile or more in depth, and search for an opening +in the reef, through which the boat can pass without being knocked to +pieces.</p> +<p>You find one: and in a moment, what a change! The deep has +suddenly become shallow; the blue white, from the gleam of the white +coral at the bottom. But the coral is not all white, only indeed +a little of it; for as you look down through the clear water, you find +that the coral is starred with innumerable live flowers, blue, crimson, +grey, every conceivable hue; and that these are the coral polypes, each +with its ring of arms thrust out of its cell, who are building up their +common habitations of lime. If you want to understand, by a rough +but correct description, what a coral polype is: all who have been to +the sea-side know, or at least have heard of, sea-anemones. Now +coral polypes are sea-anemones, which make each a shell of lime, growing +with its growth. As for their shapes, the variety of them, the +beauty of them, no tongue can describe them. If you want to see +them, go to the Coral Rooms of the British or Liverpool Museums, and +judge for yourselves. Only remember that you must re-clothe each +of those exquisite forms with a coating of live jelly of some delicate +hue, and put back into every one of the thousand cells its living flower; +and into the beds, or rather banks, of the salt-water flower garden, +the gaudiest of shell-less sea-anemones, such as we have on our coasts, +rooted in the cracks, and live shells and sea-slugs, as gaudy as they, +crawling about, with fifty other forms of fantastic and exuberant life. +You must not overlook, too, the fish, especially the parrot-fish, some +of them of the gaudiest colours, who spend their lives in browsing on +the live coral, with strong clipping and grinding teeth, just as a cow +browses the grass, keeping the animal matter, and throwing away the +lime in the form of an impalpable white mud, which fills up the interstices +in the coral beds.</p> +<p>The bottom, just outside the reef, is covered with that mud, mixed +with more lime-mud, which the surge wears off the reef; and if you have, +as you should have, a dredge on board, and try a haul of that mud as +you row home, you may find, but not always, animal forms rooted in it, +which will delight the soul of a scientific man. One, I hope, +would be some sort of Terebratula, or shell akin to it. You would +probably think it a cockle: but you would be wrong. The animal +which dwells in it has about the same relationship to a cockle as a +dog has to a bird. It is a Brachiopod; a family with which the +ancient seas once swarmed, but which is rare now, all over the world, +having been supplanted and driven out of the seas by newer and stronger +forms of shelled animals. The nearest spot at which you are likely +to dredge a live Brachiopod will be in the deep water of Loch Fyne, +in Argyleshire, where two species still linger, fastened, strangely +enough, to the smooth pebbles of a submerged glacier, formed in the +open air during the age of ice, but sunk now to a depth of eighty fathoms. +The first time I saw those shells come up in the dredge out of the dark +and motionless abyss, I could sympathise with the feelings of mingled +delight and awe which, so my companion told me, the great Professor +Owen had in the same spot first beheld the same lingering remnants of +a primæval world.</p> +<p>The other might be (but I cannot promise you even a chance of dredging +that, unless you were off the coast of Portugal, or the windward side +of some of the West India Islands) a live Crinoid; an exquisite starfish, +with long and branching arms, but rooted in the mud by a long stalk, +and that stalk throwing out barren side branches; the whole a living +plant of stone. You may see in museums specimens of this family, +now so rare, all but extinct. And yet fifty or a hundred different +forms of the same type swarmed in the ancient seas: whole masses of +limestone are made up of little else but the fragments of such animals.</p> +<p>But we have not landed yet on the dry part of the reef. Let +us make for it, taking care meanwhile that we do not get our feet cut +by the coral, or stung as by nettles by the coral insects. We +shall see that the dry land is made up entirely of coral, ground and +broken by the waves, and hurled inland by the storm, sometimes in huge +boulders, mostly as fine mud; and that, under the influence of the sun +and of the rain, which filters through it, charged with lime from the +rotting coral, the whole is setting, as cement sets, into rock. +And what is this? A long bank of stone standing up as a low cliff, +ten or twelve feet above high-water mark. It is full of fragments +of shell, of fragments of coral, of all sorts of animal remains; and +the lower part of it is quite hard rock. Moreover, it is bedded +in regular layers, just such as you see in a quarry. But how did +it get there? It must have been formed at the sea-level, some +of it, indeed, under the sea; for here are great masses of madrepore +and limestone corals imbedded just as they grew. What lifted it +up? Your companions, if you have any who know the island, have +no difficulty in telling you. It was hove up, they say, in the +earthquake in such and such a year; and they will tell you, perhaps, +that if you will go on shore to the main island which rises inside the +reef, you may see dead coral beds just like these lying on the old rocks, +and sloping up along the flanks of the mountains to several hundred +feet above the sea. I have seen such many a time.</p> +<p>Thus you find the coral being converted gradually into a limestone +rock, either fine and homogeneous, composed of coral grown into pulp, +or filled with corals and shells, or with angular fragments of older +coral rock. Did you never see that last? No? Yes, +you have a hundred times. You have but to look at the marbles +commonly used about these islands, with angular fragments imbedded in +the mass, and here and there a shell, the whole cemented together by +water holding in solution carbonate of lime, and there see the very +same phenomenon perpetuated to this day.</p> +<p>Thus, I think, we have got first from the known to the unknown; from +a tropic coral island back here to the limestone hills of Great Britain; +and I did not speak at random when I said that I was not leading you +away as far as you fancied by several thousand miles.</p> +<p>Examine any average limestone quarry from Bristol to Berwick, and +you will see there all that I have been describing; that is, all of +it which is not soft animal matter, certain to decay. You will +see the lime-mud hardened into rock beds; you will see the shells embedded +in it; you will see the corals in every stage of destruction; you will +see whole layers made up of innumerable fragments of Crinoids—no +wonder they are innumerable, for, it has been calculated, there are +in a single animal of some of the species 140,000 joints—140,000 +bits of lime to fall apart when its soft parts decay. But is it +not all there? And why should it not have got there by the same +process by which similar old coral beds get up the mountain sides in +the West Indies and elsewhere; namely, by the upheaving force of earthquakes? +When you see similar effects, you have a right to presume similar causes. +If you see a man fall off a house here, and break his neck; and some +years after, in London or New York, or anywhere else, find another man +lying at the foot of another house, with his neck broken in the same +way, is it not a very fair presumption that he has fallen off a house +likewise?</p> +<p>You may be wrong. He may have come to his end by a dozen other +means: but you must have proof of that. You will have a full right, +in science and in common sense, to say—That man fell off the house, +till some one proves to you that he did not.</p> +<p>In fact, there is nothing which you see in the limestones of these +isles—save and except the difference in every shell and coral—which +you would not see in the coral-beds of the West Indies, if such earthquakes +as that famous one at St. Thomas’s, in 1866, became common and +periodic, upheaving the land (they needs upheave it a very little, only +two hundred and fifty feet), till St. Thomas’s, and all the Virgin +Isles, and the mighty mountain of Porto Rico, which looms up dim and +purple to the west, were all joined into dry land once more, and the +lonely coral-shoal of Anegada were raised, as it would be raised then, +into a limestone table-land, like that of Central Ireland, of Galway, +or of County Clare.</p> +<p>But you must clearly understand, that however much these coralline +limestones have been upheaved since they were formed, yet the sea-bottom, +while they were being formed, was sinking and not rising. This +is a fact which was first pointed out by Mr. Darwin, from the observations +which he made in the world-famous <i>Voyage of the Beagle</i>; and the +observations of subsequent great naturalists have all gone to corroborate +his theory.</p> +<p>It was supposed at first, you must understand, that when a coral +island rose steeply to the surface of the sea out of blue water, perhaps +a thousand fathoms or more, that fact was plain proof that the little +coral polypes had begun at the bottom of the sea, and, in the course +of ages, built up the whole island an enormous depth.</p> +<p>But it soon came out that that theory was not correct; for the coral +polypes cannot live and build save in shallow water—say in thirty +to forty fathoms. Indeed, some of the strongest and largest species +work best at the very surface, and in the cut of the fiercest surf. +And so arose a puzzle as to how coral rock is often found of vast thickness, +which Mr. Darwin explained. His theory was, and there is no doubt +now that it is correct, that in these cases the sea-bottom is sinking; +that as it sinks, carrying the coral beds down with it, the coral dies, +and a fresh live crop of polypes builds on the top of the houses of +their dead ancestors: so that, as the depression goes on, generation +after generation builds upwards, the living on the dead, keeping the +upper surface of the reef at the same level, while its base is sinking +downward into the abyss.</p> +<p>Applying this theory to the coral reef of the Pacific Ocean, the +following interesting facts were made out:</p> +<p>That where you find an Island rising out of deep water, with a ring +of coral round it, a little way from the shore—or, as in Eastern +Australia, a coast with a fringing reef (the Flinders reef of Australia +is eleven thousand miles long)—that is a pretty sure sign that +that shore, or mountain, is sinking slowly beneath the sea. That +where you find, as you often do in the Pacific, a mere atoll, or circular +reef of coral, with a shallow pond of smooth water in the centre, and +deep sea round, that is a pretty sure sign that the mountain-top has +sunk completely into the sea, and that the corals are going on building +where its peak once was.</p> +<p>And more. On working out the geography of the South Sea Islands +by the light of this theory of Mr. Darwin’s, the following extraordinary +fact has been discovered:</p> +<p>That over a great part of the Pacific Ocean sinking is going on, +and has been going on for ages; and that the greater number of the beautiful +and precious South Sea Islands are only the remnants of a vast continent +or archipelago, which once stretched for thousands of miles between +Australia and South America.</p> +<p>Now, applying the same theory to limestone beds, which are, as you +know, only fossil coral reefs, we have a right to say, when we see in +England, Scotland, Ireland, limestones several thousand feet thick, +that while they were being laid down as coral reef, the sea-bottom, +and probably the neighbouring land, must have been sinking to the amount +of their thickness—to several thousand feet—before that +later sinking which enabled several hundred feet of millstone grit to +be laid down on the top of the limestone.</p> +<p>This millstone grit is a new and a very remarkable element in our +strange story. From Derby to Northumberland it forms vast and +lofty moors, capping, as at Whernside and Penygent, the highest limestone +hills with its hard, rough, barren, and unfossiliferous strata. +Wherever it is found, it lies on the top of the “mountain,” +or carboniferous limestone. Almost everywhere, where coal is found +in England, it lies on the millstone grit. I speak roughly, for +fear of confusing my readers with details. The three deposits +pass more or less, in many places, into each other: but always in the +order of mountain limestone below, millstone grit on it, and coal on +that again.</p> +<p>Now what does its presence prove? What but this? That +after the great coral reefs which spread over Somersetshire and South +Wales, around the present estuary of the Severn,—and those, once +perhaps joined to them, which spread from Derby to Berwick, with a western +branch through North-east Wales,—were laid down—after all +this, I say, some change took place in the sea-bottom, and brought down +on the reefs of coral sheets of sand, which killed the corals and buried +them in grit. Does any reader wish for proof of this? Let +him examine the “cherty,” or flinty, beds which so often +appear where the bottom of the millstone grit is passing into the top +of the mountain limestone—the beds, to give an instance, which +are now quarried on the top of the Halkin Mountain in Flintshire, for +chert, which is sent to Staffordshire to be ground down for the manufacture +of china. He will find layers in those beds, of several feet in +thickness, as hard as flint, but as porous as sponge. On examining +their cavities he will find them to be simply hollow casts of innumerable +joints of Crinoids, so exquisitely preserved, even to their most delicate +markings, that it is plain they were never washed about upon a beach, +but have grown where, or nearly where, they lie. What then, has +happened to them? They have been killed by the sand. The +soft parts of the animals have decayed, letting the 140,000 joints (more +or less) belonging to each animal fall into a heap, and be imbedded +in the growing sand-rock; and then, it may be long years after, water +filtering through the porous sand has removed the lime of which the +joints were made, and left their perfect casts behind.</p> +<p>So much for the millstone grits. How long the deposition of +sand went on, how long after it that second deposition of sands took +place, which goes by the name of the “gannister,” or lower +coal-measures, we cannot tell. But it is clear, at least, that +parts of that ancient sea were filling up and becoming dry land. +For coal, or fossilised vegetable matter, becomes more and more common +as we ascend in the series of beds; till at last, in the upper coal-measures, +the enormous wealth of vegetation which grew, much of it, where it is +now found, prove the existence of some such sheets of fertile and forest-clad +lowland as I described in my last paper.</p> +<p>Thousands of feet of rich coral reef; thousands of feet of barren +sands; then thousands of feet of rich alluvial forest—and all +these sliding into each other, if not in one place, then in another, +without violent break or change; this is the story which the lime in +the mortar and the coal on the fire, between the two, reveal.</p> +<div class="GutenbergBlankLines2"><br /><br /></div> +<h2>VI. THE SLATES ON THE ROOF</h2> +<div class="GutenbergBlankLines2"><br /><br /></div> +<p>The slates on the roof should be, when rightly understood, a pleasant +subject for contemplation to the dweller in a town. I do not ask +him to imitate the boy who, cliff-bred from his youth, used to spend +stolen hours on the house-top, with his back against a chimney-stalk, +transfiguring in his imagination the roof-slopes into mountain-sides, +the slates into sheets of rock, the cats into lions, and the sparrows +into eagles. I only wish that he should—at least after reading +this paper—let the slates on the roof carry him back in fancy +to the mountains whence they came; perhaps to pleasant trips to the +lakes and hills of Cumberland, Westmoreland, and North Wales; and to +recognise—as he will do if he have intellect as well as fancy—how +beautiful and how curious an object is a common slate.</p> +<p>Beautiful, not only for the compactness and delicacy of its texture, +and for the regularity and smoothness of its surface, but still more +for its colour. Whether merely warm grey, as when dry, or bright +purple, as when wet, the colour of the English slate well justifies +Mr. Ruskin’s saying, that wherever there is a brick wall and a +slate roof there need be no want of rich colour in an English landscape. +But most beautiful is the hue of slate, when, shining wet in the sunshine +after a summer shower, its blue is brought out in rich contrast by golden +spots of circular lichen, whose spores, I presume, have travelled with +it off its native mountains. Then, indeed, it reminds the voyager +of a sight which it almost rivals in brilliancy—of the sapphire +of the deep ocean, brought out into blazing intensity by the contrast +of the golden patches of floating gulf-weed beneath the tropic sun.</p> +<p>Beautiful, I say, is the slate; and curious likewise, nay, venerable; +a most ancient and elaborate work of God, which has lasted long enough, +and endured enough likewise, to bring out in it whatsoever latent capabilities +of strength and usefulness might lie hid in it; which has literally +been—as far as such words can apply to a thing inanimate—</p> +<div class="GutenbergBlankLines1"><br /></div> +<p>Heated hot with burning fears,<br />And bathed in baths of hissing +tears,<br />And battered by the strokes of doom<br />To shape and use.</p> +<div class="GutenbergBlankLines1"><br /></div> +<p>And yet it was at first naught but an ugly lump of soft and shapeless +ooze.</p> +<p>Therefore, the slates to me are as a parable, on which I will not +enlarge, but will leave each reader to interpret it for himself. +I shall confine myself now to proofs that slate is hardened mud, and +to hints as to how it assumed its present form.</p> +<p>That slate may have been once mud, is made probable by the simple +fact that it can be turned into mud again. If you grind tip slate, +and then analyse it, you will find its mineral constituents to be exactly +those of a fine, rich, and tenacious clay. The slate districts +(at least in Snowdon) carry such a rich clay on them, wherever it is +not masked by the ruins of other rocks. At Ilfracombe, in North +Devon, the passage from slate below to clay above, may be clearly seen. +Wherever the top of the slate beds, and the soil upon it, is laid bare, +the black layers of slate may be seen gradually melting—if I may +use the word—under the influence of rain and frost, into a rich +tenacious clay, which is now not black, like its parent slate, but red, +from the oxidation of the iron which it contains.</p> +<p>But, granting this, how did the first change take place?</p> +<p>It must be allowed, at starting, that time enough has elapsed, and +events enough have happened, since our supposed mud began first to become +slate, to allow of many and strange transformations. For these +slates are found in the oldest beds of rocks, save one series, in the +known world; and it is notorious that the older and lower the beds in +which the slates are found, the better, that is, the more perfectly +elaborate, is the slate. The best slates of Snowdon—I must +confine myself to the district which I know personally—are found +in the so-called “Cambrian” beds. Below these beds +but one series of beds is as yet known in the world, called the “Laurentian.” +They occur, to a thickness of some eighty thousand feet, in Labrador, +Canada, and the Adirondack mountains of New York: but their representatives +in Europe are, as far as is known only to be found in the north-west +highlands of Scotland, and in the island of Lewis, which consists entirely +of them. And it is to be remembered, as a proof of their inconceivable +antiquity, that they have been upheaved and shifted long before the +Cambrian rocks were laid down “unconformably” on their worn +and broken edges.</p> +<p>Above the “Cambrian” slates—whether the lower and +older ones of Penrhyn and Llanberris, which are the same—one slate +mountain being worked at both sides in two opposite valleys—or +the upper and newer slates of Tremadoc, lie other and newer slate-bearing +beds of inferior quality, and belonging to a yet newer world, the “Silurian.” +To them belong the Llandeilo flags and slates of Wales, and the Skiddaw +slates of Cumberland, amid beds abounding in extinct fossil forms. +Fossil shells are found, it is true, in the upper Cambrian beds. +In the lower they have all but disappeared. Whether their traces +have been obliterated by heat and pressure, and chemical action, during +long ages; or whether, in these lower beds, we are actually reaching +that “Primordial Zone” conceived of by M. Barrande, namely, +rocks which existed before living things had begun to people this planet, +is a question not yet answered. I believe the former theory to +be the true one. That there was life, in the sea at least, even +before the oldest Cambrian rocks were laid down, is proved by the discovery +of the now famous fossil, the Eozoon, in the Laurentian limestones, +which seems to have grown layer after layer, and to have formed reefs +of limestone as do the living coral-building polypes. We know +no more as yet. But all that we do know points downwards, downwards +still, warning us that we must dig deeper than we have dug as yet, before +we reach the graves of the first living things.</p> +<p>Let this suffice at present for the Cambrian and Laurentian rocks.</p> +<p>The Silurian rocks, lower and upper, which in these islands have +their chief development in Wales, and which are nearly thirty-eight +thousand feet thick; and the Devonian or Old Red sandstone beds, which +in the Fans of Brecon and Carmarthenshire attain a thickness of ten +thousand feet, must be passed through in an upward direction before +we reach the bottom of that Carboniferous Limestone of which I spoke +in my last paper. We thus find on the Cambrian rocks forty-five +thousand feet at least of newer rocks, in several cases lying unconformably +on each other, showing thereby that the lower beds had been upheaved, +and their edges worn off on a sea-shore, ere the upper were laid down +on them; and throughout this vast thickness of rocks, the remains of +hundreds of forms of animals, corals, shells, fish, older forms dying +out in the newer rocks, and new ones taking their places in a steady +succession of ever-varying forms, till those in the upper beds have +become unlike those in the lower, and all are from the beginning more +or less unlike any existing now on earth. Whole families, indeed, +disappear entirely, like the Trilobites, which seem to have swarmed +in the Silurian seas, holding the same place there as crabs and shrimps +do in our modern seas. They vanish after the period of the coal, +and their place is taken by an allied family of Crustaceans, of which +only one form (as far as I am aware) lingers now on earth, namely, the +“King Crab,” or Limulus, of the Indian Seas, a well-known +animal, of which specimens may sometimes be seen alive in English aquaria. +So perished in the lapse of those same ages, the armour-plated or “Ganoid” +fish which Hugh Miller made so justly famous—and which made him +so justly famous in return—appearing first in the upper Silurian +beds, and abounding in vast variety of strange forms in the old Red +Sandstone, but gradually disappearing from the waters of the world, +till their only representatives, as far as known, are the Lepidostei, +or “Bony Pikes,” of North America; the Polypteri of the +Nile and Senegal; the Lepidosirens of the African lakes and Western +rivers; the Ceratodus or Barramundi of Queensland (the two latter of +which approach Amphibians), and one or two more fantastic forms, either +rudimentary or degraded, which have lasted on here and there in isolated +stations through long ages, comparatively unchanged while all the world +is changed around them, and their own kindred, buried like the fossil +Ceratodus of the Trias beneath thousands of feet of ancient rock, among +creatures the likes whereof are not to be found now on earth. +And these are but two examples out of hundreds of the vast changes which +have taken place in the animal life of the globe, between the laying +down of the Cambrian slates and the present time.</p> +<p>Surely—and it is to this conclusion I have been tending throughout +a seemingly wandering paragraph—surely there has been time enough +during all those ages for clay to change into slate.</p> +<p>And how were they changed?</p> +<p>I think I cannot teach my readers this more simply than by asking +them first to buy Sheet No. LXXVIII. S.E. (Bangor) of the Snowdon district +of the Government Geological Survey, which may be ordered at any good +stationer’s, price 3s.; and study it with me. He will see +down the right-hand margin interpretations of the different colours +which mark the different beds, beginning with the youngest (alluvium) +atop, and going down through Carboniferous Limestone and Sandstone, +Upper Silurian, Lower Silurian, Cambrian, and below them certain rocks +marked of different shades of red, which signify rocks either altered +by heat, or poured out of old volcanic vents. He will next see +that the map is covered with a labyrinth of red patches and curved lines, +signifying the outcrop or appearance at the surface of these volcanic +beds. They lie at every conceivable slope; and the hills and valleys +have been scooped out by rain and ice into every conceivable slope likewise. +Wherefore we see, here a broad patch of red, where the back of a sheet +of Lava, Porphyry, Greenstone, or what not is exposed; there a narrow +line curving often with the curve of the hill-side, where only the edge +of a similar sheet is exposed; and every possible variety of shape and +attitude between these two. He will see also large spaces covered +with little coloured dots, which signify (as he will find at the margin) +beds of volcanic ash. If he look below the little coloured squares +on the margin, he will see figures marking the strike, or direction +of the inclination of the beds—inclined, vertical, horizontal, +contorted; that the white lines in the map signify faults, <i>i.e</i>. +shifts in the strata; the gold lines, lodes of metal—the latter +of which I should advise him strongly, in this district at least, not +to meddle with: but to button up his pockets, and to put into the fire, +in wholesome fear of his own weakness and ignorance, any puffs of mining +companies which may be sent him—as one or two have probably been +sent him already.</p> +<p>Furnished with which keys to the map, let him begin to con it over, +sure that there is if not an order, still a grand meaning in all its +seeming confusion; and let him, if he be a courteous and grateful person, +return due thanks to Professor Ramsay for having found it all out; not +without wondering, as I have often wondered, how even Professor Ramsay’s +acuteness and industry could find it all out.</p> +<p>When my reader has studied awhile the confusion—for it is a +true confusion—of the different beds, he will ask, or at least +have a right to ask, what known process of nature can have produced +it? How have these various volcanic rocks, which he sees marked +as Felspathic Traps, Quartz Porphyries, Greenstones, and so forth, got +intermingled with beds which he is told to believe are volcanic ashes, +and those again with fossil-bearing Silurian beds and Cambrian slates, +which he is told to believe were deposited under water? And his +puzzle will not be lessened when he is told that, in some cases, as +in that of the summit of Snowdon, these very volcanic ashes contain +fossil shells.</p> +<p>The best answer I can give is to ask him to use his imagination, +or his common sense; and to picture to himself what must go on in the +case of a submarine eruption, such as broke out off the coast of Iceland +in 1783 and 1830, off the Azores in 1811, and in our day in more than +one spot in the Pacific Ocean.</p> +<p>A main bore or vent—or more than one—opens itself between +the bottom of the sea and the nether fires. From each rushes an +enormous jet of high-pressure steam and other gases, which boils up +through the sea, and forms a cloud above; that cloud descends again +in heavy rain, and gives out often true lightning from its under side.</p> +<p>But it does more. It acts as a true steam-gun, hurling into +the air fragments of cold rock rasped off from the sides of the bore, +and fragments also of melted lava, and clouds of dust, which fall again +into the sea, and form there beds either of fine mud or of breccia—that +is, fragments of stone embedded in paste. This, the reader will +understand, is no fancy sketch, as far as I am concerned. I have +steamed into craters sawn through by the sea, and showing sections of +beds of ash dipping outwards and under the sea, and in them boulders +and pebbles of every size, which had been hurled out of the crater; +and in them also veins of hardened lava, which had burrowed out through +the soft ashes of the cone. Of those lava veins I will speak presently. +What I want the reader to think of now is the immense quantity of ash +which the steam-mitrailleuse hurls to so vast a height into the air, +that it is often drifted many miles down to leeward. To give two +instances: The jet of steam from Vesuvius, in the eruption of 1822, +rose more than four miles into the air; the jet from the Souffrière +of St. Vincent in the West Indies, in 1812, probably rose higher; certainly +it met the N.E. trade-wind, for it poured down a layer of ashes, several +inches thick, not only on St. Vincent itself, but on Barbadoes, eighty +miles to windward, and therefore on all the sea between. Now let +us consider what that represents—a layer of fine mud, laid down +at the bottom of the ocean, several inches thick, eighty miles at least +long, and twenty miles perhaps broad, by a single eruption. Suppose +that hardened in long ages (as it would be under pressure) into a bed +of fine grained Felstone, or volcanic ash; and we can understand how +the ash-beds of Snowdonia—which may be traced some of them for +many square miles—were laid down at the bottom of an ancient sea.</p> +<p>But now about the lavas or true volcanic rocks, which are painted +(as is usual in geological maps) red. Let us go down to the bottom +of the sea, and build up our volcano towards the surface.</p> +<p>First, as I said, the subterranean steam would blast a bore. +The dust and stones, rasped and blasted out of that hole would be spread +about the sea-bottom as an ash-bed sloping away round the hole; then +the molten lava would rise in the bore, and flow out over the ashes +and the sea-bottom—perhaps in one direction, perhaps all round. +Then, usually, the volcano, having vented itself, would be quieter for +a time, till the heat accumulated below, and more ash was blasted out, +making a second ash-bed; and then would follow a second lava flow. +Thus are produced the alternate beds of lava and ash which are so common.</p> +<p>Now suppose that at this point the volcano was exhausted, and lay +quiet for a few hundred years, or more. If there was any land +near, from which mud and sand were washed down, we might have layers +on layers of sediment deposited, with live shells, etc., living in them, +which would be converted into fossils when they died; and so we should +have fossiliferous beds over the ashes and lavas. Indeed, shells +might live and thrive in the ash-mud itself, when it cooled, and the +sea grew quiet, as they have lived and thriven in Snowdonia.</p> +<p>Now suppose that after these sedimentary beds are laid down by water, +the volcano breaks out again—what would happen?</p> +<p>Many things: specially this, which has often happened already.</p> +<p>The lava, kept down by the weight of these new rocks, searches for +the point of least resistance, and finds it in a more horizontal direction. +It burrows out through the softer ash-beds, and between the sedimentary +beds, spreading itself along horizontally. This process accounts +for the very puzzling, though very common case in Snowdon and elsewhere, +in which we find lavas interstratified with rocks which are plainly +older than those lavas. Perhaps when that is done the volcano +has got rid of all its lava, and is quiet. But if not, sooner +or later, it bores up through the new sedimentary rocks, faulting them +by earthquake shocks till it gets free vent, and begins its layers of +alternate ash and lava once more.</p> +<p>And consider this fact also: If near the first (as often happens) +there is another volcano, the lava from one may run over the lava from +the other, and we may have two lavas of different materials overlying +each other, which have come from different directions. The ashes +blown out of the two craters may mingle also, and so, in the course +of ages, the result may be such a confusion of ashes, lavas, and sedimentary +rocks as we find throughout most mountain ranges in Snowdon, in the +Lake mountains, in the Auvergne in France, in Sicily round Etna, in +Italy round Vesuvius, and in so many West Indian Islands; the last confusion +of which is very likely to be this:</p> +<p>That when the volcano has succeeded—as it did in the case of +Sabrina Island off the Azores in 1811, and as it did, perhaps often, +in Snowdonia—in piling up an ash cone some hundred feet out of +the sea; that—as has happened to Sabrina Island—the cone +is sunk again by earthquakes, and gnawn down at the same time by the +sea-waves, till nothing is left but a shoal under water. But where +have all its vast heaps of ashes gone? To be spread about over +the bottom of the sea, to mingle with the mud already there, and so +make beds of which, like many in Snowdon, we cannot say whether they +are of volcanic or of marine origin, because they are of both.</p> +<p>But what has all this to do with the slates?</p> +<p>I shall not be surprised if my readers ask that question two or three +times during this paper. But they must be kind enough to let me +tell my story my own way. The slates were not made in a day, and +I fear they cannot be explained in an hour: unless we begin carefully +at the beginning in order to end at the end. Let me first make +my readers clearly understand that all our slate-bearing mountains, +and most also of the non-slate-bearing ones likewise, are formed after +the fashion which I have described, namely, beneath the sea. I +do not say that there may not have been, again, and again, ash-cones +rising above the surface of the waves. But if so, they were washed +away, again and again, ages before the land assumed anything of its +present shape; ages before the beds were twisted and upheaved as they +are now.</p> +<p>And therefore I beg my readers to put out of their minds once and +for all the fancy that in any known part of these islands craters are +to be still seen, such as exist in Etna, or Vesuvius, or other volcanoes +now at work in the open air.</p> +<p>It is necessary to insist on this, because many people hearing that +certain mountains are volcanic, conclude—and very naturally and +harmlessly—that the circular lakes about their tops are true craters. +I have been told, for instance, that that wonderful little blue Glas +Llyn, under the highest cliff of Snowdon, is the old crater of the mountain; +and I have heard people insist that a similar lake, of almost equal +grandeur, in the south side of Cader Idris, is a crater likewise.</p> +<p>But the fact is not so. Any one acquainted with recent craters +would see at once that Glas Llyn is not an ancient one; and I am not +surprised to find the Government geologists declaring that the Llyn +on Cader Idris is not one either. The fact is, that the crater, +or rather the place where the crater has been, in ancient volcanoes +of this kind, is probably now covered by one of the innumerable bosses +of lava.</p> +<p>For, as an eruption ceases, the melted lava cools in the vents, and +hardens; usually into lava infinitely harder than the ash-cone round +it; and this, when the ash-cone is washed off, remains as the highest +part of the hill, as in the Mont Dore and the Cantal in France, and +in several extinct volcanoes in the Antilles. Of course the lava +must have been poured out, and the ashes blown out from some vents or +other, connected with the nether world of fire; probably from many successive +vents. For in volcanoes, when one vent is choked, another is wont +to open at some fresh point of least resistance among the overlying +rocks. But where are these vents? Buried deep under successive +eruptions, shifted probably from their places by successive upheavings +and dislocations; and if we wanted to find them we should have to quarry +the mountain range all over, a mile deep, before we hit upon here and +there a tap-root of ancient lava, connecting the upper and the nether +worlds. There are such tap-roots, probably, under each of our +British mountain ranges. But Snowdon, certainly, does not owe +its shape to the fact of one of these old fire vents being under it. +It owes its shape simply to the accident of some of the beds toward +the summit being especially hard, and thus able to stand the wear and +tear of sea-wave, ice, and rain. Its lakes have been formed quite +regardless of the lie of the rocks, though not regardless of their relative +hardness. But what forces scooped them out—whether they +were originally holes left in the ground by earthquakes, and deepened +since by rain and rivers, or whether they were scooped out by ice, or +by any other means, is a question on which the best geologists are yet +undecided—decided only on this—that craters they are not.</p> +<p>As for the enormous changes which have taken place in the outline +of the whole of the mountains, since first their strata were laid down +at the bottom of the sea: I shall give facts enough, before this paper +is done, to enable readers to judge of them for themselves.</p> +<p>The reader will now ask, naturally enough, how such a heap of beds +as I have described can take the shape of mountains like Snowdon.</p> +<p>Look at any sea cliff in which the strata are twisted and set on +slope. There are hundreds of such in these isles. The beds +must have been at one time straight and horizontal. But it is +equally clear that they have been folded by being squeezed laterally. +At least, that is the simplest explanation, as may be proved by experiment. +Take a number of pieces of cloth, or any such stuff; lay them on each +other and then squeeze them together at each end. They will arrange +themselves in folds, just as the beds of the cliff have done. +And if, instead of cloth, you take some more brittle matter, you will +find that, as you squeeze on, these folds will tend to snap at the points +of greatest tension or stretching, which will be of course at the anticlinal +and synclinal lines—in plain English, the tops and bottoms of +the folds. Thus cracks will be formed; and if the pressure goes +on, the ends of the layers will shift against each other in the line +of those cracks, forming faults like those so common in rocks.</p> +<p>But again, suppose that instead of squeezing these broken and folded +lines together any more, you took off the pressure right and left, and +pressed them upwards from below, by a mimic earthquake. They would +rise; and as they rose leave open space between them. Now if you +could contrive to squeeze into them from below a paste, which would +harden in the cracks and between the layers, and so keep them permanently +apart, you would make them into a fair likeness of an average mountain +range—a mess—if I may make use of a plain old word—of +rocks which have, by alternate contraction and expansion, helped in +the latter case by the injection of molten lava, been thrust about as +they are in most mountain ranges.</p> +<p>That such a contraction and expansion goes on in the crust of the +earth is evident; for here are the palpable effects of it. And +the simplest general cause which I can give for it is this: That things +expand as they are heated, and contract as they are cooled.</p> +<p>Now I am not learned enough—and were I, I have not time—to +enter into the various theories which philosophers have put forward, +to account for these grand phenomena.</p> +<p>The most remarkable, perhaps, and the most probable, is the theory +of M. Elie de Beaumont, which is, in a few words, this:</p> +<p>That this earth, like all the planets, must have been once in a state +of intense heat throughout, as its mass inside is probably now.</p> +<p>That it must be cooling, and giving off its heat into space.</p> +<p>That, therefore, as it cools, its crust must contract.</p> +<p>That, therefore, in contracting, wrinkles (for the loftiest mountain +chains are nothing but tiny wrinkles, compared with the whole mass of +the earth), wrinkles, I say, must form on its surface from time to time. +And that the mountain chains are these wrinkles.</p> +<p>Be that as it may, we may safely say this. That wherever the +internal heat of the earth tends (as in the case of volcanoes) towards +a particular spot, that spot must expand, and swell up, bulging the +rocks out, and probably cracking them, and inserting melting lava into +those cracks from below. On the other hand, if the internal heat +leaves that spot again, and it cools, then it must contract more or +less, in falling inward toward the centre of the earth; and so the beds +must be crumpled, and crushed, and shifted against each other still +more, as those of our mountains have been.</p> +<p>But here may arise, in some of my readers’ minds, a reasonable +question—If these upheaved beds were once horizontal, should we +not be likely to find them, in some places, horizontal still?</p> +<p>A reasonable question, and one which admits of a full answer.</p> +<p>They know, of course, that there has been a gradual, but steady, +change in the animals of this planet; and that the relative age of beds +can, on the strength of that known change, be determined generally by +the fossils, usually shells, peculiar to them: so that if we find the +same fashion of shells, and still more the same species of shells, in +two beds in different quarters of the world, then we have a right to +say—These beds were laid down at least about the same time. +That is a general rule among all geologists, and not to be gainsaid.</p> +<p>Now I think I may say, that, granting that we can recognise a bed +by its fossils, there are few or no beds which are found in one place +upheaved, broken, and altered by heat, which are not found in some other +place still horizontal, unbroken, unaltered, and more or less as they +were at first.</p> +<p>From the most recent beds; from the upheaved coral-rocks of the West +Indies, and the upheaved and faulted boulder clay and chalk of the Isle +of Moen in Denmark—downwards through all the strata, down to that +very ancient one in which the best slates are found, this rule, I believe, +stands true.</p> +<p>It stands true, certainly, of the ancient Silurian rocks of Wales, +Cumberland, Ireland, and Scotland.</p> +<p>For, throughout great tracts of Russia, and in parts of Norway and +Sweden, Sir Roderick Murchison discovered our own Silurian beds, recognisable +from their peculiar fossils. But in what state? Not contracted, +upheaved, and hardened to slates and grits, as they are in Wales and +elsewhere: but horizontal, unbroken, and still soft, because undisturbed +by volcanic rooks and earthquakes. At the bottom of them all, +near Petersburg, Sir Roderick found a shale of dried mud (to quote his +own words), “so soft and incoherent that it is even used by sculptors +for modelling, although it underlies the great mass of fossil-bearing +Silurian rocks, and is, therefore, of the same age as the lower crystalline +hard slates of North Wales. So entirely have most of these eldest +rocks in Russia been exempted from the influence of change, throughout +those enormous periods which have passed away since their accumulation.”</p> +<p>Among the many discoveries which science owes to that illustrious +veteran, I know none more valuable for its bearing on the whole question +of the making of the earth-crust, than this one magnificent fact.</p> +<p>But what a contrast between these Scandinavian and Russian rocks +and those of Britain! Never exceeding, in Scandinavia, a thousand +feet in thickness, and lying usually horizontal, as they were first +laid down, they are swelled in Britain to a thickness of thirty thousand +feet, by intruded lavas and ashes; snapt, turned, set on end at every +conceivable angle; shifted against each other to such an extent, that, +to give a single instance, in the Vale of Gwynnant, under Snowdon, an +immense wedge of porphyry has been thrust up, in what is now the bottom +of the valley, between rocks far newer than it, on one side to a height +of eight hundred, on the other to a height of eighteen hundred feet—half +the present height of Snowdon. Nay, the very slate beds of Snowdonia +have not forced their way up from under the mountain—without long +and fearful struggles. They are set in places upright on end, +then horizontal again, then sunk in an opposite direction, then curled +like sea-waves, then set nearly upright once more, and faulted through +and through, six times, I believe, in the distance of a mile or two; +they carry here and there on their backs patches of newer beds, the +rest of which has long vanished; and in their rise they have hurled +back to the eastward, and set upright, what is now the whole western +flank of Snowdon, a mass of rock which was then several times as thick +as it is now.</p> +<p>The force which thus tortured them was probably exerted by the great +mass of volcanic Quartz-porphyry, which rises from under them to the +north-west, crossing the end of the lower lake of the Llanberris; and +indeed the shifts and convulsions which have taken place between them +and the Menai Straits are so vast that they can only be estimated by +looking at them on the section which may be found at the end of Professor +Ramsay’s “Geological Survey of North Wales.” +But anyone who will study that section, and use (as with the map) a +little imagination and common sense, will see that between the heat +of that Porphyry, which must have been poured out as a fluid mass as +hot, probably, as melted iron, and the pressure of it below, and of +the Silurian beds above, the Cambrian mud-strata of Llanberris and Penrhyn +quarries must have suffered enough to change them into something very +different from mud, and, therefore, probably, into what they are now—namely, +slate.</p> +<p>And now, at last, we have got to the slates on the roof, and may +disport ourselves over them—like the cats.</p> +<p>Look at any piece of slate. All know that slate splits or cleaves +freely, in one direction only, into flat layers. Now any one would +suppose at first sight, and fairly enough, that the flat surface—the +“plane of cleavage”—was also the plane of bedding. +In simpler English we should say—The mud which has hardened into +the slate was laid down horizontally; and therefore each slate is one +of the little horizontal beds of it, perhaps just what was laid down +in a single tide. We should have a right to do so, because that +would be true of most sedimentary rocks. But it would not be true +of slate. The plane of bedding in slate has nothing to do with +the plane of cleavage. Or, more plainly, the mud of which the +slate is made may have been deposited at the sea-bottom at any angle +to the plane of cleavage. We may sometimes see the lines of the +true bedding—the lines which were actually horizontal when the +mud was laid down—in bits of slate, and find them sometimes perpendicular +to, sometimes inclined to, and sometimes again coinciding with the plane +of cleavage, which they have evidently acquired long after.</p> +<p>Nay, more. These parallel planes of cleavage, at each of which +the slate splits freely, will run through a whole mountain at the same +angle, though the beds through which they run may be tilted at different +angles, and twisted into curves.</p> +<p>Now what has made this change in the rook? We do not exactly +know. One thing is clear, that the particles of the now solid +rock have actually moved on themselves. And this is proved by +a very curious fact—which the reader, if he geologises about slate +quarries much, may see with his own eyes. The fossils in the slate +are often distorted into quaint shapes, pulled out long if they lie +along the plane of cleavage, or squeezed together, or doubled down on +both sides, if they lie across the plane. So that some force has +been at work which could actually change the shape of hard shells, very +slowly, no doubt, else it would have snapped and crumbled them.</p> +<p>If I am asked what that force was, I do not know. I should +advise young geologists to read what Sir Henry de la Bêche has +said on it in his admirable “Geological Observer,” pp. 706-725. +He will find there, too, some remarks on that equally mysterious phenomena +of jointing, which you may see in almost all the older rocks; it is +common in limestones. All we can say is, that some force has gone +on, or may be even now going on, in the more ancient rocks, which is +similar to that which produces single crystals; and similar, too, to +that which produced the jointed crystals of basalt, <i>i.e</i>. lava, +at the Giant’s Causeway, in Ireland, and Staffa, in the Hebrides. +Two philosophers—Mr. Robert Were Fox and Mr. Robert Hunt—are +of opinion that the force which has determined the cleavage of slates +may be that of the electric currents, which (as is well known) run through +the crust of the earth. Mr. Sharpe, I believe, attributes the +cleavage to the mere mechanical pressure of enormous weights of rock, +especially where crushed by earthquakes. Professor Rogers, again, +points out that as these slates may have been highly heated, thermal +electricity (<i>i.e</i>. electricity brought out by heat) may have acted +on them.</p> +<p>One thing at least is clear. That the best slates are found +among ancient lavas, and also in rocks which are faulted and tilted +enormously, all which could not have happened without a proportionately +enormous pressure, and therefore heat; and next, that the best slates +are invariably found in the oldest beds—that is, in the beds which +have had most time to endure the changes, whether mechanical or chemical, +which have made the earth’s surface what we see it now.</p> +<p>Another startling fact the section of Snowdonia, and I believe of +most mountain chains in these islands, would prove—namely, that +the contour of the earth’s surface, as we see it now, depends +very little, certainly in mountains composed of these elder rocks upon +the lie of the strata, or beds, but has been carved out by great forces, +long after those beds were not only laid down and hardened, but faulted +and tilted on end. Snowdon itself is so remarkable an instance +of this fact that, as it is a mountain which every one in these happy +days of excursion-trains and steamers either has seen or can see, I +must say a few more words about it.</p> +<p>Any one who saw that noble peak leaping high into the air, dominating +all the country round, at least upon three sides, and was told that +its summit consisted of beds much newer, not much older, than the slate-beds +fifteen hundred feet down on its north-western flank—any one, +I say, would have the right at first sight, on hearing of earthquake +faults and upheavals, to say—The peak of Snowdon has been upheaved +to its present height above and out of the lower lands around. +But when he came to examine sections, he would find his reasonable guess +utterly wrong. Snowdon is no swelling up of the earth’s +crust. The beds do not, as they would in that case, slope up to +it. They slope up from it, to the north-west in one direction, +and the south-south-west in the other; and Snowdon is a mere insignificant +boss, left hanging on one slope of what was once an enormous trough, +or valley, of strata far older than itself. By restoring these +strata, in the direction of the angles, in which they crop out, and +vanish at the surface, it is found that to the north-west—the +direction of the Menai Straits—they must once have risen to a +height of at least six or seven thousand feet; and more, by restoring +them, specially the ash-bed of Snowdon, towards the south-east—which +can be done by the guidance of certain patches of it left on other hills—it +is found that south of Ffestiniog, where the Cambrian rocks rise again +to the surface, the south side of the trough must have sloped upwards +to a height of from fifteen to twenty thousand feet, whether at the +bottom of the sea, or in the upper air, we cannot tell. But the +fact is certain, that off the surface of Wales, south of Ffestiniog +a mass of solid rock as high as the Andes has been worn down and carried +bodily away; and that a few miles south again, the peak of Arran Mowddy, +which is now not two thousand feet high, was once—either under +the sea or above it—nearer ten thousand feet.</p> +<p>If I am asked whither is all that enormous mass of rock—millions +of tons—gone? Where is it now? I know not. But +if I dared to hazard a guess, I should say it went to make the New Red +sandstones of England.</p> +<p>The New Red sandstones must have come from somewhere. The most +likely region for them to have come from is from North Wales, where, +as we know, vast masses of gritty rock have been ground off, such as +would make fine sandstones if they had the chance. So that many +a grain of sand in Chester walls was probably once blasted out of the +bowels of the earth into the old Silurian sea, and after a few hundreds +of thousands of years’ repose in a Snowdonian ash-bed, was sent +eastward to build the good old city and many a good town more.</p> +<p>And the red marl—the great deposit of red marl which covers +a wide region of England—why should not it have come from the +same quarter? Why should it not be simply the remains of the Snowdon +Slate? Mud the slate was, and into mud it has returned. +Why not? Some of the richest red marl land I know, is, as I have +said, actually being made now, out of the black slates of Ilfracombe, +wherever they are weathered by rain and air. The chemical composition +is the same. The difference in colour between black slate and +red marl is caused simply by the oxidation of the iron in the slate.</p> +<p>And if my readers want a probable cause why the sandstones lie undermost, +and the red marl uppermost—can they not find one for themselves? +I do not say that it is the cause, but it is at least a causa vera, +one which would fully explain the fact, though it may be explicable +in other ways. Think, then, or shall I think for my readers?</p> +<p>Then do they not see that when the Welsh mountains were ground down, +the Silurian strata, being uppermost, would be ground down first, and +would go to make the lower strata of the great New Red Sandstone Lowland; +and that being sandy, they would make the sandstones? But wherever +they were ground through, the Lower Cambrian slates would be laid bare; +and their remains, being washed away by the sea the last, would be washed +on to the top of the remains of the Silurians; and so (as in most cases) +the remains of the older rock, when redeposited by water, would lie +on the remains of the younger rock. And do they not see that (if +what I just said is true) these slates would grind up into red marl, +such as is seen over the west and south of Cheshire and Staffordshire +and far away into Nottinghamshire? The red marl must almost certainly +have been black slate somewhere, somewhen. Why should it not have +been such in Snowdon? And why should not the slates in the roof +be the remnants of the very beds which are now the marl in the fields?</p> +<p>And thus I end my story of the slates in the roof, and these papers +on Town Geology. I do so, well knowing how imperfect they are: +though not, I believe, inaccurate. They are, after all, merely +suggestive of the great amount that there is to be learnt about the +face of the earth and how it got made, even by the townsman, who can +escape into the country and exchange the world of man for the world +of God, only, perhaps, on Sundays—if, alas! even then—or +only once a year by a trip in a steamer or an excursion train. +Little, indeed, can he learn of the planet on which he lives. +Little in that direction is given to him, and of him little shall be +required. But to him, for that very reason, all that can be given +should be given; he should have every facility for learning what he +can about this earth, its composition, its capabilities; lest his intellect, +crushed and fettered by that artificial drudgery which we for a time +miscall civilisation, should begin to fancy, as too many do already, +that the world is composed mainly of bricks and deal, and governed by +acts of parliament. If I shall have awakened any townsmen here +and there to think seriously of the complexity, the antiquity, the grandeur, +the true poetry, of the commonest objects around them, even the stones +beneath their feet; if I shall have suggested to them the solemn thought +that all these things, and they themselves still more, are ordered by +laws, utterly independent of man’s will about them, man’s +belief in them; if I shall at all have helped to open their eyes that +they may see, and their ears that they may hear, the great book which +is free to all alike, to peasant as to peer, to men of business as to +men of science, even that great book of nature, which is, as Lord Bacon +said of old, the Word of God revealed in facts—then I shall have +a fresh reason for loving that science of geology, which has been my +favourite study since I was a boy.</p> +<div class="GutenbergBlankLines2"><br /><br /></div> +<p>Footnotes:</p> +<p><a name="footnote1"></a><a href="#citation1">{1}</a> See “Nature,” +No. XXV. (Macmillan & Co.)</p> +<p><a name="footnote2"></a><a href="#citation2">{2}</a> These +Lectures were delivered to the members of the Natural Science Class +at Chester in 1871.</p> +<p><a name="footnote3"></a><a href="#citation3">{3}</a> See a +most charming paper on “The Physics of Arctic Ice,” by Dr. +Robert Brown of Campster, published in the <i>Quarterly Journal of the +Geological Society</i>, June, 1870. This article is so remarkable, +not only for its sound scientific matter, but for the vividness and +poetic beauty of its descriptions, that I must express a hope that the +learned author will some day enlarge it, and publish it in a separate +form.</p> +<p><a name="footnote4"></a><a href="#citation4">{4}</a> See Lyell, +“Antiquity of Man,” p. 294 <i>et seq.</i></p> +<div class="GutenbergBlankLines3"><br /><br /><br /></div> +<p>***END OF THE PROJECT GUTENBERG EBOOK TOWN GEOLOGY***</p> +<pre> + + +***** This file should be named 10251-h.htm or 10251-h.zip****** + + +This and all associated files of various formats will be found in: +https://www.gutenberg.org/1/0/2/5/10251 + + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. 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