Transcribed by David Price, email ccx074@coventry.ac.uk




TOWN GEOLOGY




PREFACE



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.

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.

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?

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.

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.

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.

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.

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.

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."

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 NOT 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.

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.


Though the mills of God grind slowly,
   Yet they grind exceeding small;
Though He sit, and wait with patience,
   With exactness grinds He all.


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.

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:

"The discoveries of Voltaic electricity, electromagnetism, and 
magnetic electricity, by Volta, OErsted, 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." {1}

"All this may be very true.  But of what practical use will physical 
science be to me?"

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.

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 Desmidiae, 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.

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.

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.

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.

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.

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.

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.

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.

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."

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.

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.

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.

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.

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.

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.

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.

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.

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?

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."

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.

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?

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--


To me the meanest flower that grows may give
Thoughts that do lie too deep for tears.


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."

Consider them.  If He has bid you do so, can you do so too much?

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.

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?

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?

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?

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.

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.

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."

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.

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.

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



I. THE SOIL OF THE FIELD {2}



My dear readers, let me, before touching on the special subject of 
this paper, say a few words on that of the whole series.

It is geology:  that is, the science which explains to us the RIND 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.

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.

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.

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.

But how shall we learn science by mere common sense?

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.

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.

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."

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.

Now, I ask of you to employ the same common sense when you read and 
think of Geology.

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.

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.

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.

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.

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?"

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.

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.

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.

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.

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.

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?

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?

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?

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?

Now for the soil of the field.

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.

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.

If there is, as there usually is, a river-meadow, or still better, an 
aestuary, 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.

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.

You all know from whence the soil comes which has filled up, in the 
course of ages, the great aestuaries below London, Stirling, Chester, 
or Cambridge.

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.

How does the mud get into the river?  The rain carries it thither.

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?

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 aestuary, and the changes 
which it has undergone, with which I will not frighten you at 
present.

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.

But have Rain and Rivers alone made the soil?

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 Beche's "Geological Observer;" and 
last, but not least, a very clever little book called "Rain and 
Rivers," by Colonel George Greenwood.

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.

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.

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.

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.

So much for the mechanical action of rain, in the shape of ice.  Now 
a few words on its chemical action.

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.

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.

If you ever go to Parkgate, in Cheshire, try if you cannot learn 
there a little geology.

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.

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 aestuary.  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 aestuary to 
escape freely out to sea.  They pile it up in shifting sand-banks 
about the mouth of the aestuary.  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.

Now, why should not that soil, whether in England or in Scotland, 
have been made by the same means as that of every aestuary.

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?

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?"

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.

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?

And that I propose to do in my next paper, when I speak of the 
pebbles in the street.

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.

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.

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.

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 aestuary, there is geology enough to be learnt, to explain the 
greater part of the making of all the continents on the globe.



II.  THE PEBBLES IN THE STREET



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.

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.

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--tomauns as they call them in some parts 
of Scotland--askers 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.

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.

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?

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.

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:

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.

Silurian grits (the common stones of the Lake mountains deposited by 
water), 43 per cent.

Ironstone, 1 per cent.

Carboniferous limestone, 5 per cent.

Permian or Triassic sandstones, i.e. rocks immediately round 
Liverpool, 12 per cent.

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?

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?

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.

What, then, brought the stones?

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.

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.

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.

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.

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.

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.

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--

How the stones got here;

How they were scratched and rounded;

How they were imbedded in clay;

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?

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.

We find underneath the glaciers, first a moraine profonde, consisting 
of the boulders and gravel, and earth, which the glacier has ground 
off the hillsides, and is carrying down with it.

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.

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.

We find, moreover, on the surface of the glaciers, moraines 
superieures--long lines of stones and dirt which had fallen from 
neighbouring cliffs, and are now travelling downward with the 
glaciers.

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.

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.

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. {3}

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.

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.

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.

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.

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.

No known agent can have scratched them as they are scratched, save 
ice, which is known to do so still elsewhere.

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.

No known agent, save ice, can have produced those rounded, and 
polished, and scored, and fluted rochers moutonnes "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.

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:


As a huge stone is sometimes seen to lie
Couched on the bald top of an eminence,
Wonder to all who do the same espy
By what means it could thither come, and whence;
So that it seems a thing endued with sense:
Like a sea-beast crawled forth, that on a shelf
Of rock or sand reposeth, there to sun itself.


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-a-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 Neufchatel, and stranded on the slopes of the Jura, nine 
hundred feet above the lake. {4}

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."

He says:  At the first glance, I can see symptoms a, b, c.  It is 
therefore probable that my patient has got complaint A.  But if he 
has he ought to have symptom d also.  If I find that, my guess will 
be yet more probable.  He ought also to have symptom e, 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.

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.

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.

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 aestuary 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.

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.

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.

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.

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.

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.

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, 
gobe-moucherie, 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.

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.

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.

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.

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.

Take Greenland, for instance.  Disco Island lies in Baffin's Bay, off 
the west coast of Greenland, in latitude 70 degrees, 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?

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 OUT 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?

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?

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.

Now what proof is there of that?

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.

And what sort of fossils do we find in it?

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.

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?

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.

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 archaeologist 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.

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.



III.  THE STONES IN THE WALL



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?

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.

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.

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.

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.

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.

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.

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.

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?

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.

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.

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?

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.

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.

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.

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 Wurtemberg, 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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?

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."

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."

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.

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.

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.

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.

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.

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.

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.

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.

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.

On the chalk lie--especially in the Blackheath and Woolwich district-
-sands and clays.  And what do they tell us?

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.

But what proof is there of this?

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.

And yet we have not done.  There is another world to tell of yet.

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.

Is the reader's power of belief exhausted?

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.

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.

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.

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.



IV.  THE COAL IN THE FIRE



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.

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.

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."

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.

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.

That sounds rather magniloquent.  Let me give you a simple example.

Suppose you had come into Britain with Brute, the grandson of AEneas, 
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!"

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.

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.

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?"

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.

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.

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.

Now one point is specially noticeable about these plants of the coal; 
namely, that they may at least have grown in swamps.

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 Lastraea 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.

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.

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.

Of the Sigillariae 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.

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.

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.

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.

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.

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.

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.

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.

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?

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.

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.

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.

But now comes the question--Even if all this be true, how were the 
forests covered up in shale and sandstone, one after another?

By gradual sinking of the land, one would suppose.

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.

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.

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?

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 MUST have sunk ere the next bed of soil could 
have been deposited, and the next forest have grown on it.

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?

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.

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.

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.

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 Sigillariae 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.

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 Sigillariae, 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 Lastraea 
Thelypteris, once so abundant, now all but destroyed by drainage and 
the plough.

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.

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.

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.

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?"

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.

This fact explains, also, why in mines of wood-coal carbonic acid, 
i.e. 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.

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.

A strange transformation; which will look to us more strange, more 
truly poetical, the more steadily we consider it.

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.

Gas and sunbeams.  Strange, but true.

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.

So it is.  Lord Lytton told us long ago, in a beautiful song, how


The Wind and the Beam loved the Rose.


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.

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.

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.

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.

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.

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.



V.  THE LIME IN THE MORTAR



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.

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."

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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 primaeval world.

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.

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.

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.

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.

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?

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.

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.

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 Voyage of the Beagle; 
and the observations of subsequent great naturalists have all gone to 
corroborate his theory.

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.

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.

Applying this theory to the coral reef of the Pacific Ocean, the 
following interesting facts were made out:

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.

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:

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.

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.

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.

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.

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.

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.



VI.  THE SLATES ON THE ROOF



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.

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.

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--


Heated hot with burning fears,
And bathed in baths of hissing tears,
And battered by the strokes of doom
To shape and use.


And yet it was at first naught but an ugly lump of soft and shapeless 
ooze.

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.

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.

But, granting this, how did the first change take place?

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.

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.

Let this suffice at present for the Cambrian and Laurentian rocks.

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.

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.

And how were they changed?

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.e. 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.

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.

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.

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.

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.

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 Souffriere 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.

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.

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.

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.

Now suppose that after these sedimentary beds are laid down by water, 
the volcano breaks out again--what would happen?

Many things:  specially this, which has often happened already.

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.

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:

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.

But what has all this to do with the slates?

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

The most remarkable, perhaps, and the most probable, is the theory of 
M. Elie de Beaumont, which is, in a few words, this:

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.

That it must be cooling, and giving off its heat into space.

That, therefore, as it cools, its crust must contract.

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.

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.

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?

A reasonable question, and one which admits of a full answer.

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.

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.

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.

It stands true, certainly, of the ancient Silurian rocks of Wales, 
Cumberland, Ireland, and Scotland.

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."

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.

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.

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.

And now, at last, we have got to the slates on the roof, and may 
disport ourselves over them--like the cats.

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.

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.

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.

If I am asked what that force was, I do not know.  I should advise 
young geologists to read what Sir Henry de la Beche 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.e. 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.e. electricity brought out by heat) may have acted on 
them.

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.

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.

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.

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.

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.

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.

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?

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?

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.



Footnotes:

{1}  See "Nature," No.  XXV.  (Macmillan & Co.)

{2}  These Lectures were delivered to the members of the Natural 
Science Class at Chester in 1871.

{3}  See a most charming paper on "The Physics of Arctic Ice," by Dr. 
Robert Brown of Campster, published in the Quarterly Journal of the 
Geological Society, 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.

{4}  See Lyell, "Antiquity of Man," p. 294 et seq.