You may have noticed, if you have made many journeys to diff

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THE

PUZZLE OF LIFE.

LONDON: PRINTED BY

SPOTTISWOODE AND CO., NEW-STREET SQUARE

AND PARLIAMENT STREET

[Illustration:

_Frontispiece_

_The Mammoth._]

THE PUZZLE OF LIFE;

AND

HOW IT HAS BEEN PUT TOGETHER.

A SHORT HISTORY OF THE FORMATION OF THE EARTH,

WITH ITS VEGETABLE AND ANIMAL LIFE,

FROM THE EARLIEST TIMES,

INCLUDING AN ACCOUNT OF

_PRE-HISTORIC MAN, his WEAPONS, TOOLS and WORKS_.

BY

ARTHUR NICOLS, F.R.G.S.

_WITH ILLUSTRATIONS by FREDERICK WADDY._

SECOND EDITION.

LONDON:

LONGMANS, GREEN, AND CO.

1877.

_All rights reserved._

TO

MY YOUNG FRIENDS

BEATRIX, GUY, SYLVIA, MAY, AND GERALD.

THE CHILDREN OF

GEORGE DU MAURIER.

PREFACE

TO

THE SECOND EDITION.

The favourable reception accorded to the first edition has induced me

to give the present a more definite educational character. Foot-notes

are appended, referring to the position in the British Museum of all

the principal antiquities, fossils, and implements mentioned in the

text; so that the specimens can easily be found by any young student

who wishes, with the book in his hand, to make himself familiar with

these records of past time. This will probably facilitate the search

for and recognition of specimens by the reader.

The additions to the text consist chiefly of a more extended account of

the deposition of chalk and other deep-sea formations, founded on the

results of the “Challenger” and “Tuscarora” expeditions, and a sketch

of the earthworks of the Ohio mound-builders and the stone monuments

of Easter Island. Examples of pre-historic art and lake-dwellings have

been added to the illustrations.

A. N.

HAMPSTEAD: _March 1877_.

PREFACE

TO

THE FIRST EDITION.

Having found that children could be interested in the history of life

upon the Earth, and that it appealed forcibly to their understanding,

I considered that a little book upon the subject might give them

the taste for more extended study in after years. The difficulty of

treating the, to them, novel conclusions of geology, often founded on

abstract reasoning, in language simple in form yet stating clearly the

great principles upon which this reasoning rests, will probably be

apparent on every page. Breadth, rather than minuteness, has been aimed

at, in the belief that a general view, not overcrowded with details,

is likely to be the most impressive. Thus, in the geological part the

leading features of the succession of strata have been preserved,

but no details of systematic classification entered into. Similarly,

Primeval Man is considered mainly with reference to gradual progress

from a rude to a more civilized condition. To have been more explicit,

where there is still much difference of opinion, would have obscured

the main facts of the evidence for man’s great antiquity.

The illustrations are typical examples of the three arbitrary but

convenient divisions of the history of life—the vegetable, the animal,

and the human—such as will be most readily met with in museums.

Slight as this sketch is, the liking for it shown by some intelligent

children, who saw it in manuscript, encouraged me to believe that there

are many others to whom it might prove interesting.

Some acquaintance with the leading facts in science is daily becoming

more necessary to those who aspire to liberal culture, and instruction

in them is a recognised feature in the curriculum of some public and

leading private schools. Thus, it is hoped that the present volume

may to some extent serve as a text-book without the severity of such

a form. The best English and foreign authorities have been consulted,

and other trustworthy sources—as papers read before scientific

societies—drawn upon, bringing the information down to the latest time.

Though these pages are designed for young persons, other readers,

perhaps, who are not familiar with the subject, may find some interest

in them if they are not deterred by the necessarily simple style.

My thanks are due to Mr. H. B. WOODWARD, of the Geological Survey

of England and Wales, for some valuable suggestions made during the

progress of the work.

A. N.

HAMPSTEAD: _November 1876_.

CONTENTS.

PAGE

THE FRAMEWORK OF THE PUZZLE 1

THE GEOLOGICAL PART 17

THE VEGETABLE PART 56

THE ANIMAL PART 77

THE HUMAN PART 120

CONCLUSION 168

INDEX 171

ILLUSTRATIONS.

THE MAMMOTH _Frontispiece_

I. UPHEAVAL: SUBSIDENCE: DENUDATION 51

II. DIFFERENT KINDS OF PLANTS OF THE COAL FORESTS 65

III. TRILOBITE 79

IV. FOOTPRINTS OF LABYRINTHODON: FOOTPRINTS OF BIRDS,

(2) WITH MARKS OF RAIN-DROPS 83

V. FISH-REPTILES 87

VI. BIRD-REPTILES 93

VII. FOSSILS OF THE CHALK 97

VIII. GIGANTIC IRISH STAG (CERVUS MEGACEROS) 108

IX. THE MEGATHERIUM 112

X. 1. FLINT ARROW-HEAD; 2. STONE AXE IN HANDLE; 3. FLINT KNIFE;

4. BONE HARPOON; 5. BONE NEEDLES; 6. SCEPTRE MADE OF HORN;

7. MARROW SPOON 129

XI. EXAMPLES OF PRE-HISTORIC DRAWINGS 135

XII. LAKE-DWELLINGS 148

XIII. THE GUADALOUPE HUMAN FOSSIL 159

THE

PUZZLE OF LIFE.

_THE FRAMEWORK OF THE PUZZLE._

You must often have looked with wondering eyes at this World of ours,

and asked yourselves questions about it. How did it come here? What is

it made of? How old is it? All of them questions not to be answered

without a great deal of thought and study, and even then not so

perfectly as we should like. It is easy to say “It is here,” and “It is

made of earth,” and “It surely must be old,” but that will not satisfy

us. We want to know something more certain than this, if possible. We

can see that a clock goes with wheels, but we are not very intelligent

people if we do not want to find out what makes the clock go. One way

of finding out is to pull things to pieces, but we cannot exactly do

this with the World. We must think about it, and put together all the

knowledge we can gain from the outside and inside, and from the other

Worlds around us, which we can see, and when we have done this we may

get something like answers to our questions.

How did it come here? But this is not quite the right way of asking the

question, because the World is never for two moments together in the

same place. It is travelling in a great circle round the Sun at the

rate of more than sixty thousand miles an hour, and has been ever since

it was formed. That is a wonderful arrangement by which all Worlds

travel round some other World larger than themselves, in greater or

less circles, and we do not know why it is, though we are certain that

it is so. The Moon travels round us once in about every month, and we

and the Moon together round the Sun once in every year.

Then again, other planets, with their moons, such as Jupiter, for

instance, travel round the Sun in much larger circles than our World,

and take many years to do the journey, while Venus, which is nearer the

Sun than we are, travels in a much smaller circle, and takes less time.

We do not perceive that we are moving so fast because everything we

see is moving equally fast with us; but there is no doubt that we are

spinning along at sixty thousand miles an hour.

If we ask an astronomer how our World came into existence, he will tell

us that it is probably a mass separated from the Sun, that it was once

red-hot, and that it slowly cooled down until animals and plants could

live upon it. He will tell us besides, that he can see mountains and

valleys in our Moon, and land and sea, snow and clouds, on the planet

Mars, with his great telescopes. When he thinks about the planets and

our own World, then he believes them to be pieces of some much larger

World—perhaps the Sun—which now travel round the Sun and receive their

light and heat from it. The World is made of what we call “earth,” and

it is of this I mean to tell you now—how it was formed, what changes

have taken place in it, what plants and animals have lived upon it,

and what reasons there are for thinking that it is an exceedingly old

place, with a long and interesting story to tell.

Little was known thirty or forty years ago by the most learned men

about the age of our World, and it was thought that the human race

had not lived here very long. It was indeed known that many large

animals, whose huge bones have been found, must have lived before man

came to inhabit the Earth, and that even far smaller creatures—such

as fishes, and crabs, and insects, and shell-fish—most probably lived

for many generations, and died and left their bones and shells in the

soil long before the first man or the first tribes of men came to

share the World with them. I hope to be able to tell you something of

the strange and beautiful history of all these animals, and of man

himself, and to show you what reasons there are now for thinking that

the human race has inhabited this Earth for a very long time indeed,

and how all this knowledge has been gained and put together piece by

piece. It is something like the different parts of a puzzle-map, which

might be scattered all over the house, and found at one time or another

in different places, and at last made up altogether. Some parts of

the puzzle have not been found yet certainly; but so many have been

collected, and they fit into one another so well, that we can begin to

see its real shape and size. It will perhaps be a very long time before

some of the missing pieces are found; but in the meantime we can go on

without them, and put the framework together, and no doubt in time we

shall see what our puzzle, the history of life on the Earth, was like.

Before telling you what its parts are, I ought to say where many of

them have been found, and how they are still being looked for. They are

found _upon_ the ground, _under_ it, in caves, in rivers, and in the

sea. Since railways have been in use a great many tunnels have been

made, as well as very deep cuttings through hills, and some of these

are several miles long. In this way we have come to know something

of the Earth below the surface. Some of these tunnels are bored right

through high hills and even mountains, and the cuttings are deep

enough to hide high houses if they were put into them. While digging

these the workmen have found many of the parts of our puzzle, which

are the bones of animals, and fishes, and shells, and even smaller

things—such as insects. These could not possibly have been put there

by anyone, because they were many, many yards below the surface, and,

until they were dug up, nobody imagined that they could be there. Many

other things besides have been dug out of these places, but nearer the

surface, such as weapons and tools made of flint, and stone, and bone,

and metal, and pieces of rough crockery, and various ornaments, all

of which must at some time or other have been made and used by people

very like ourselves. In digging canals, too, the same kinds of things

have been found, and some caves are almost filled up with them. We have

other means, too, of knowing what is under the surface of the ground

we walk upon. Many of the coal-mines are so deep that the Tower of

London, or St. Paul’s Cathedral, or York Minster, or even the Pyramids

of Egypt could be buried in them! In digging these the workmen have

had to go through a great quantity of earth, sometimes chalk, sand, or

gravel, or clay or limestone, layer upon layer, placed, like a pile

of books of different kinds and different thicknesses, one upon the

other, until they have come to the coal. In these different layers of

earth parts of the puzzle have been found, and we shall see by-and-by

what parts have been found in the coal itself. Then again, when deep

mines are made to get the metals, iron and gold and silver, these

layers of earth have to be dug through; and when the beautiful kinds

of stone, like marble and limestone, are wanted, they must be dug out

of the sides of the hills, and in doing this still more pieces of the

puzzle come to hand. But there are other places where Nature herself

seems to have shown us some of them without the trouble of searching

for them. In many parts of the World, by the sea, and on the banks of

rivers, there are cliffs hundreds of feet high, like the chalk cliffs

at Dover and Ramsgate, and the sandy cliffs at Folkestone and on the

south coast of Devonshire. These cliffs have been cut into by the sea

very gradually, and a kind of wall has been left, and from the sides of

the cliffs great numbers of the pieces of the puzzle, bones, shells,

&c., have been collected and taken away to museums. But the little we

can do with our mines and railway tunnels is nothing in comparison with

the work of Nature. In some of the great mountain chains—the Andes, the

Himalayas, and the Alps, for instance—parts of the sides of mountains

have fallen down, and rents many miles long have been left, showing

what had been buried there in the different kinds of soil; and where

rivers have cut deep, narrow channels through the earth, like the

Cañons of Colorado, these natural miners have turned out more of the

parts of “the puzzle of life” than we can with all our labour.

It will not be easy at first to understand all the wonders I have to

show you, but, when we get further on, you will see them one by one,

and there will be very little difficulty. You know now where these

things are to be found: principally in the ground you walk upon,

without knowing all there is beneath you. The creatures here are

much more wonderful than any of the monsters of fairy tale or fable,

because the works of God are greater than the imagination of men who

have invented the stories of flying dragons and griffins, and trees

which grew up into the skies; but I cannot help thinking that this

imagination shows what men thought _might_ once have been, and we shall

see that “truth is stranger than fiction.” Creatures really did live on

this Earth of such strange shapes and great size that the imaginations

of those who wrote the fairy tales did not exaggerate much; and, though

we know that no flying serpents or immense birds like the Roc are

living now, and that there is no beanstalk which grows up into the sky

while we are asleep, we shall see that there were lizards as large as

whales, and birds taller than elephants, and great sloths stronger than

the rhinoceros or hippopotamus, and ferns as high as oak trees, and

mosses as large as gooseberry bushes; and that perhaps these animals

and plants grew much faster than they do now, and that their dead

bodies form a very large part of the earth of our World. This is not

imagination, and when you go to a museum you can see all these wonders

for yourselves, just as they were taken out of the earth; but of course

the bones only of the animals are there. The flesh has long since gone

away, and some of the stalks and fronds (leaves) only of the ferns

remain to show us how large they must have been when they were alive

and growing.

It will be necessary to use a few scientific names, most of which are

borrowed from the Greek and Latin languages, but I will explain the

meaning of them all, so that they will be easily remembered. First of

all, then, the pieces of the puzzle are called _fossils_, and the name

comes from a Latin word meaning “dug out;” because they have been dug

out of the ground either by man in making railways and mines, or by

Nature in the many ways in which she works by cutting down cliffs and

scooping out valleys. These fossils are bones of animals and fishes,

the skins, shells, and wings of insects, and the stalks and leaves

of plants, some of which have lain so very long in the ground that

they have become as hard and heavy as stone. But the shape of them

always remains, and the moment you look at them you see that they once

belonged to living creatures.

I shall give you pictures of some of these fossils; and no doubt you

will be able to find some like them in the chalk and sands of the

seaside—beautiful shells and bones of fishes. You may pick these out

of the cliffs, and then go to the pools of salt water left among the

rocks by the ebbing tide, and compare your fossils with the living

shell-fish, and see how nearly those inhabitants of the ancient oceans

resemble the creatures we find now, sporting in the water, just as

these fossils did when the sand and chalk cliffs were under the sea.

Of course all the bright colours are gone from the fossils, for the

colour of animals fades away soon after they die, and the flesh does

not last long; but the hard parts—the bones and shells—are not easily

destroyed, because they are made of the same material as rocks. And

when we look at the fossil plants we see the same thing. The colours of

the green stems and leaves have quite faded, but the delicate shapes of

the leaves and branches, and the grain of the wood, can still be seen,

and you will have no doubt that they once lived and bore flowers and

fruit, and died, as plants are living and dying every day.

You have got so far now that you know what fossils are, and where they

may be found. You know that they are the small and large pieces of the

“puzzle of life”—of all sorts of different shapes and sizes—and you

know that they are scattered about the Earth, deep down in coal-mines,

on the tops of mountains, at the bottoms of rivers, in deep caves,

and under the sea. The patience and industry of clever men have been

well spent in gathering together all they can find, and arranging

them in museums for our instruction, and making a history of them

which is more wonderful than the Arabian Nights, and more beautiful

because it is all _true_. And, though you may think it strange that I

promise to show you creatures more marvellous than those of the fairy

tales, I shall keep that promise faithfully. We shall find no Genii

with wonderful lamps and magic rings, because they never really lived,

though it gave us much pleasure and amusement to read about them; but

we shall see what God, the greatest Genius of all, has done by means of

His magicians—the laws of Nature. These magicians have built up high

mountains and dug out valleys, and sent mighty rivers sweeping down

to the sea, and even filled up oceans with sand and chalk, and buried

ancient forests deep down under sea and land. They worked with fire,

and air, and water; not quickly, but with such strength that nothing

could resist them, and they gradually moulded the Earth into the

beautiful thing it is, so that

In contemplation of created things,

By steps we may ascend to God.—_Milton._

But, lovely as the Earth is, we should not perhaps have thought so

much of it if there had been nothing to discover. We see that it has

been prepared for us an immensely long time ago; and when we know a

little, we want to search further and find out what the whole plan of

Creation is, so far as we can. You will be surprised when you know how

many signs of past life there are around you—many more than you can see

with the eye. The Earth is one great burying-place of creatures which

have passed away. You are walking over their dead and fossil bodies

at almost every step. They are built into the walls of our houses,

and there are millions of them in some of the commonest stones of the

pavement. Those round, smooth pebbles, called flint stones, which we

pick out of the gravel walks, were once partly such soft tender things

as sponges; but time has hardened them, and they have been rolled

together in seas and rivers by the always moving water until they have

become quite different to look at from the rough blue flints they were

when they were washed out of the chalk beds. When you are walking

along the sands of some seacoasts, you are treading on little specks

of these small flints which have been ground down fine in that great

mill, the ocean. The sponges, then, did some part in the building up of

the Earth. The very chalk you draw with is composed of the shells of

sea-animals. Your slates and slate pencils were once a fine mud at the

bottom of the sea, since become so hard that it is used for covering

the roofs of our houses, and in this mud lived myriads of small

shell-fish which have sometimes left their frail houses in the slate

beds to tell us how they were made. That slate is the hardened mud of

an old sea bottom, there is no doubt at all.

There are many other things in common use which show us the life that

was.

Perhaps you did not know that coals are _compressed plants_, and that

we are now burning the vegetation of the past time! But these will be

described in their right places by-and-by, and you will see how certain

it is that some of the commonest things we use were living creatures

and graceful plants.

Here is “the framework” of the puzzle, and I think you will agree with

me that we shall have pleasure in putting it together with all the

queerly-shaped pieces we shall find in the following chapters. We have

fossil plants to show us what grew upon the Earth, fossil bones to tell

us what animals lived here, and thousands of different kinds of fossil

shells and fishes to show us that the seas in the long past time were

crowded with life; and besides, though there are no written histories

of the men whom we shall read about, they, too, have left many things

which they used in the caves where they lived and in their graves, to

make us feel certain that they were some of the oldest people that

ever lived. With all these things to help us, it will be strange if we

cannot make out a great deal of the history of life upon our Earth.

_THE GEOLOGICAL PART._

You will have learned from other books something about the size and

shape of our World: for instance, that it is a great round body, or

rather more like an orange, a little flatter one way than the other,

and about 8,000 miles through, from one side to the other, and that

it turns round once in every twenty-four hours; but I have only to

tell you now what it is made of. The material is called rock, earth,

or soil; and there are many kinds of it, such as granite, gravel,

clay, sand, chalk, mud, and so on; and we shall see that many of these

different soils contain different fossils.

It is supposed that a very long time passed while these were being

laid one upon another, and before many plants or animals lived here,

and there are good reasons for thinking that underneath these soils

the Earth is very hot, perhaps in a melting state, because we know

that volcanoes like Vesuvius and Ætna throw out flame and smoke and

lava, which is melted earth and rock; and that this lava has run down

the sides of the mountains for miles, in a great stream of liquid

material, and covered up and destroyed whole villages and towns. You

have heard of earthquakes, when the ground shakes and cracks, and

houses are thrown down, as they have often been in Spain, Italy, and

South America. This convinces us that the inside of the earth must be

very different from the outside. Two or three years ago Mount Vesuvius

was boiling up, and the people of Naples feared that it would throw

out some of the terrible lava and red-hot cinders, and burn up their

vineyards and perhaps injure their city; and during the last two or

three years many people have been killed by earthquakes in South

America. These things seldom happen in the North of Europe, and when

they do they are only slightly felt, and people are not killed, neither

are houses thrown down. Still, this shows that there must be some

great force underneath us, and very much heat. We see nothing of this

when we look upon the green fields, and we should scarcely think it

possible if there were not histories about these eruptions, as they are

called. But when I tell you that I have felt the Earth tremble, and

seen fire rushing out from the top of a high mountain whose sides were

covered with snow, you will understand how real it is—though it may

seem so strange.

People at one time liked to fancy that powerful spirits lived in

volcanoes and made them their workshops: but we know better now.

Well, the interior of the Earth is evidently very different from the

part we live upon; and it is the outside we have to think about now,

which would be dreadfully cold if the sun did not shine upon it, though

the inside is so hot.

I have called this “the Geological Part,” and the name Geological comes

from two Greek words meaning “a talk about the earth;” but now you know

it in its English dress it will be easy to recollect it. Geology is

then the study of the many kinds of rocks and fossils which makeup our

World, but we must know something of the way in which they are placed.

You may have noticed, if you have made many journeys to different

parts of England or Wales, that the rocks or soils are very different

in various places. Sometimes we find numerous chalk-pits, as in parts

of Kent, or Sussex; if we go into Devonshire we may notice the very

red colour of the soil and of the cliffs, especially near Sidmouth,

Dawlish, and Teignmouth; in North Wales we find great quarries and

hills of slate; while around London we see a great deal of clay used

for making bricks, and called the London clay, as well as many pits in

gravel so useful for making paths and mending roads, and in Kent and

Sussex chalk cliffs and hills are common.

Now after studying these various rocks all over our country, we find

that there is a certain regular order in which they are found; some

have been made a long time before others, and while most kinds contain

some fossils, those found in the oldest rocks are much less like the

living plants and animals than the fossils we find in the newer rocks.

But you will want to know how it is that we can tell that one rock

is older than another, when both appear at the surface of the earth.

It would take a long time to make sure of this for ourselves, but

it will be enough to say that the various cliffs, quarries, and

railway-cuttings often show one kind of rock resting upon another,

and these always occur in a certain order. Thus we never find the

Chalk resting on the London Clay, but we constantly find the London

Clay resting on the Chalk. And this is proved in another way, by deep

well-borings. Underneath London many wells have been carried down right

through the London Clay, and if only continued deep enough they always

reach the Chalk. In the same way, the order of the other rocks has

been ascertained in different parts of the country, by examining all

the pits and quarries, and cliffs and cuttings, with the help of what

knowledge can be obtained from deep mines and wells.

You will now begin to wonder why the older rocks should appear at the

surface. I have told you about earthquakes, and you will find that many

dreadful earthquakes must in former times have ravaged our country.

The reason why the old rocks come to the surface is because they have

been lifted up sometimes violently, but more often very slowly. And the

newer rocks which formerly rested on them have very often been quite

washed away, either by the sea or by rivers and little streams which

formerly acted upon them.

Suppose then we take six books, some thick and some thin, and pile

them up together on the table, the lowest being a good thick one. The

lowest we will call granite, the next slate, the third sandstone, the

fourth coal, the fifth chalk, and the sixth the London clay. These will

represent some of the principal kinds of earths, and you can fancy many

more with other names coming between them; but the London clay can

never be below the granite nor the chalk below the coal, for the great

coal beds were formed long before the chalk and clay. They generally

come in much the same order as we have named them, hard rocks like

granite at the bottom, and softer earths, like sandstone, chalk and

clay, a long way above them. But we do not always find all these earths

in one place even if we dig ever so deeply, though the granite would

always be found at the bottom if we went deep enough.

Sometimes the granite and other old rocks have been pushed through

the upper layers by some great force, and have broken them and risen

above them in magnificent mountain chains, like those of the Andes in

South, and the Rocky Mountains in North America, the Wicklow Mountains

in Ireland, the Grampians in Scotland, and the Cornish mountains in

England. We can easily suppose that the lowest of our books (the

granite book) has been pushed upwards by some great force from below,

and parts of it broken through the others, and raised high above them;

and this is what has actually been done with real rocks. And as this

kind of upheaval has taken place at different periods of the earths

history, we find that granites have come to the surface at different

times.

When the layers are thus broken through they are often tilted up on end

and tumbled about in confusion. But where there has been no disturbance

like this, they generally rest evenly upon one another in their proper

order.

Granite, and rocks of the same kind, are not in the least like chalk,

or clay, or even sandstone, and when once you have seen any of these

you will not be likely to mistake it for the others. Granite is

excessively hard, and has a beautiful appearance when polished, with a

number of brilliant white and some dark specks in it. It is used for

paving the streets of towns, for which purpose it is cut into oblong

blocks, and for the pillars of fine buildings. Sometimes it is dark

brown, sometimes reddish, but generally a bluish grey. This rock is

composed of a great quantity of crystals, and for this reason it is

thought it must have been melted at one time by intense heat in the

earth, and afterwards slowly cooled. Chalk is very different, and

sandstone, though it is also hard, not in the least like granite.

HOW THE ROCKS WERE FORMED.

What I have just said is about all that we know of the formation of the

oldest and hardest granite rocks: but there is something going on now

which confirms the belief that the materials of which they are made

were melted together by a greater heat than we can make in our furnaces

for melting iron; for I should tell you that it is easier to melt iron

and copper than granite rocks. Volcanoes often throw out melted earths

which when cooled appear to be made of much the same materials as these

granites.

SANDSTONE.

But we know more of the manner of the formation of sandstone. This rock

is composed of rounded grains of sand just like that we find upon the

sea shore. If you take a handful of this sand and squeeze it tightly,

it will keep together a little while. Now suppose a quantity of this

sand was pressed by a very great weight—the weight of a large hill

for instance—after many years the grains would stick firmly together,

and become a sort of stone. It is in this way the sandstones must have

been formed, and perhaps heat helped the work, though not so great a

heat as melted the granite. The sand, after it had been washed upon

the sea shore, became gradually covered with other earths hundreds of

feet thick, and the immense weight above it pressed it into stone: but

you may imagine how very long a time it took to do this. Sandstones

are used for building, but they do not last very long; the frost makes

little cracks in them and they soon crumble away to the grains of sand

of which they were made. Several fossils are found in some of these

sandstones, which have been formed at many different periods of the

earth’s history.

CHALK.

You have seen those high cliffs of chalk along the south coast of

England, perhaps, and you have wondered what that beautiful white

earth was, and how it came there. It is found in many parts of the

world, and the south and south-east of England are to a great extent

composed of it. The material is called by chemists carbonate of lime.

It is almost entirely made up of minute shells called _foraminifera_,

from two Latin words which mean that there are many openings or

chambers in their shells, and there are many beautiful fossils called

_ammonites_ imbedded in the chalk. These are shell-fish, two or three

inches, and sometimes a foot across, and their shape is very like that

of the young leaves of the common fern before it has opened in the

spring.

Millions of these tiny foraminifera are living now in parts of the

Atlantic and Pacific oceans, and when they die their shells sink to the

bottom and form a greyish mud, something like chalk.

When H.M.S. “Challenger” was sent out in the year 1873, to find out

what was at the bottom of the deepest seas of the World, great interest

was felt in the expedition, because we were sure that we should learn

something about the manner in which some of the rocks were formed.

We knew that the whole of the beds of the present seas must be

receiving the washings of the rivers and the bodies of many fishes and

animals, and that the rocks of the future must be forming down there

by these accumulations. Long lines were let down from the ship with a

dredge at the end, and thus parts of the bottom of the sea were brought

up and carefully examined. It was found that the washings, stones,

clay, and mud of the land were carried hundreds of miles out to sea,

and laid upon the bottom. But in the deeper parts, where the Alps would

be almost covered—there was a fine grey mud composed almost entirely of

the shells of the little foraminifera, and this, no doubt, is the chalk

of future times, or perhaps limestone of a harder kind. Deeper, too,

than where this grey mud is found, there is a reddish mud, exceedingly

fine and soft. We cannot exactly say yet whether this is formed from

the remains of shell-fish; but it is, at all events, very like the clay

of the land, and in some future time will most likely become like

that stiff mud we know so well. So that even the materials for bricks

are being made now, and perhaps when all those hundreds of islands

scattered about the Pacific Ocean are joined into one great Continent,

this red mud will be raised and made use of for building the houses of

new peoples and nations.

When we see this going on now, of course it is very easy to conclude

that the chalk, a great deal of which is above the sea now, must have

been formed in the same way at the bottom of an ancient ocean, and

afterwards raised by the same kind of upward force which made the

granite break through other earths.

If we did not know that the same cause was at work now, and that the

same kinds of shell-fish were living and laying down new beds of chalk

under the sea, we should not know how to account for the quantities of

chalk in the world. For innumerable ages these little creatures have

thus been paving the floor of the ocean with their dead bodies, and you

may suppose that countless millions of them must have lived and died!

In some of the chalks the shells of the foraminifera can be quite

distinctly seen with a microscope, and when these are compared with the

shells of living ones, they are seen to be almost exactly alike. Next

time you pass through one of the railway cuttings through the chalk

in going to Brighton, or Ramsgate, or Dover, remember that those high

cliffs were built up by these Liliputian giants under the sea, and you

may think of the chalk as “foraminifera earth”.

COAL.

You see this black shining substance almost every day, and you know it

is dug up from very deep pits where the poor miners are often killed by

explosions of gas escaping from it. But it is as well to know what it

is and how it comes to be so useful to us. In the language of chemistry

it is called “carbon”, and a great writer has given it the poetical

name of “compressed sunlight”. But you will ask how sunlight could

possibly get into a deep mine, and how it could be compressed there.

You will see that the explanation is really quite simple by-and-by.

This coal was once above ground, and was a splendid forest of waving

palm-trees, and ferns, and gigantic mosses, as you will see by the

pictures of the fossils of them.

Many of the animals and plants of past times were giants compared to

those living now, of the same species or kind, and many of the plants

of the present time are dwarfs to those of the same kind which formed

the coal beds. Many generations of trees must have grown and died, and

others must have sprung up, and so on, until beds of them, some ten,

others twenty, or even thirty feet thick, were formed. Here, buried in

the coal, are the stems, leaves, bark, roots, fruit, and seeds of these

trees, and we can have no doubt that almost the whole of the coal is

composed of them. You must not expect to find the shapes of these in

every piece of coal you may happen to look at, because most of it has

been greatly changed by the great weight and pressure upon it, and the

length of time: but it is certainly all the same substance—wood turned

into coal. The fossil plants of the coal are of course entirely black,

but there is no mistake about their having once been living plants.

You will ask perhaps how the coal came to be buried so deep. It is not

so always, being sometimes at the surface. But just as the granite has

been pushed up through the other rocks, so has the coal in some places

been uplifted and in others has sunk down. It was often covered up by

other earths to a great depth, after the trees which composed it had

died; but where it is now at the surface these newer earths have been

afterwards worn away. When the sun shone upon these coal trees they

took its warmth and light into their stems and leaves, for they could

not live without, and this made them grow so fast and become so large

that it is not untrue to call coal “compressed sunlight.” Charcoal is

in some respects so like coal that it would seem to you at once that

they were probably the same material. Charcoal is simply burnt wood,

and when the coal forests had died down, and when these beds sank down

beneath other layers the pressure and heat together turned the wood

and leaves into a hard mass like charcoal in colour, but heavier and

more solid, and just enough of the stems and leaves have been left to

enable us to know with certainty that coal was once wood.

We light our fires now and drive our steam-engines with the heat of the

sun which shone upon the coal forests, and has been stored up for many

thousands of years in the Earth, to be brought out once more to give us

light and warmth.

CLAY AND MUD.

While the ancient forests were growing up to form the coal beds,

and the foraminifera were slowly building up the chalk, as I have

explained, the Earth was covered with water in some places which are

now dry land, and the sea now flows over parts of the World which were

once the habitations of plants and animals. These great changes have

left their marks upon many a mountain side, and many an old river or

sea bed has become filled up. A map of Europe during the chalk period

would show that the places where Paris, London, Copenhagen, and Berlin

now are were then under the ocean; but since then these places have

been lifted up, and mud, clay, and gravel swept over the chalk in many

places by the action of new rivers and seas. Water, you perceive, has

had a great deal to do with these changes, and indeed it is one of

Nature’s most powerful tools, for it can wash down rocks and cliffs and

cut its way in rivers for thousands of miles over the Earth’s surface.

It carries down mud, and clay, and gravel, and this soil, which has

been named alluvium, is one of the most interesting of all to us,

because it contains the bones of the immense animals we shall talk

about presently, as well as those of the oldest races of men with their

weapons and ornaments.

The mud age, and we are in the mud and gravel age now, belongs to what

is called the Tertiary period, and we shall see that this age has

lasted a very long time already, so long that though it is still going

on, the most extraordinary animals have lived and died, and not one of

them is now left alive. Still the same washing and cutting of water is

going on which buried their bones in swamps, and bogs, and river caves,

and may perhaps carry away some of the bones of us who are living now,

to be found ages afterwards by future generations who will read our

history in these silent witnesses, as we read the history of the tree

ferns and foraminifera in the coal and the chalk.

The present age of the World’s history is the Mud age, or, as we shall

call it in future, the Tertiary period, and I think you will agree with

me when I come to describe it, that it contains the most interesting of

all the pieces of “the puzzle of life.”

The earth of the Tertiary period is very different from a great many of

the older earths. Clay, mud, and gravel are the washings only of the

older rocks, the fine particles which have been worn off from them by

frost and water and carried down by rivers and left in large beds, and

sometimes they have a good deal of decayed wood and weeds mixed with

them. Here are found the bones of the great animals which were so much

larger and stronger than those of the same kind living now, or any that

lived before them.

UPHEAVAL AND DEPRESSION.

These two words are so often used in books on geology that we shall

not be able to get on without knowing their meaning. We have seen

that the rocks have been formed in a certain way—some by heat, some

by water, and some by dead forests—and that they lie over one another

in pretty regular order. But this order has sometimes been disturbed

and the layers have been tumbled about among one another very much. In

some places the older rocks, such as granite, slate, and sandstone,

have been pushed up through those above, and in others the coal has

sunk down and been covered with thick layers of chalk, sand, and mud.

When the force below pushes a layer up through the others it is called

_upheaval_, and when a layer sinks down it is called _depression_,

or _subsidence_. Both these actions are going on now in different

parts of the Earth. A great part of Sweden, Norway, and Denmark, of

Spitzbergen, Siberia, and the north of America, is being slowly raised

higher above the sea, as we know by the height their old sea beaches

now are above the water; while part of the shore of America opposite

to Europe and also the south of Greenland is slowly sinking down, as

we know by the remains of land animals and trees which are now covered

by the tide; and at many places on the coast of India this subsidence

is also going on. Nearer home, too, there is an example of it in the

island of Guernsey. All round the coast of this island, like that of

Jersey, are found tree trunks and other remains of old forest land

beneath the water. Old histories refer to this as dry land; and if a

map of it made in 1406 is correct, this land must have sunk about 150

feet since that time.

Thus we can see, even at the present time, the very same changes which

have worked upon our Earth for innumerable ages. It is now easy to

understand how the forests which must have grown above in the air

have, after a long time, sunk down to a great depth, and been turned

into coal, and covered with the sediment, sand, gravel, and chalk from

the seas which afterwards flowed over the places where they grew.

Sometimes the rocks by the sea shore are cut into terraces or steps

by the constant wear of the water, and when we see these water marks

far above the present level of the sea we know that the land must have

been lifted up gradually above the sea. There are many such terraces in

Norway. To prove whether this is so marks have been cut upon rocks at

a measured height above the sea, and after some years these marks have

been noticed to have been raised much above the water by the “upheaval”

of the earth at that place.

Generally this change of level has taken place gradually, and the

greatest work in moving the layers of earth and displacing them has

been very slow. But in some places violent and sudden shocks have

happened, tearing up the rocks and piling them up in heaps; and now

and then islands have suddenly appeared in the sea and vanished out

of sight completely in a short time. Islands have thus come up in the

Mediterranean Sea within the memory of man. In the year 1831 the island

of Julia suddenly appeared near the coast of Sicily, and since the year

186 B.C. no less than three islands have started up in the bay of the

island of Santorin. In this century islands have appeared among the

Azores, the Indian Archipelago, the Philippines, the Moluccas, and on

the coast of Kamtschatka and other places. Some of these have appeared

suddenly, others slowly, and they no doubt have been raised by a great

force from below.

You will see now how easy it is to account for the changes of the

places of the layers of rock. The same thing is going on now which

has been going on throughout all time, only perhaps with more energy

formerly than now, making mountains, islands, and continents, raising

up a large tract of land in one place and sinking an island or a sea

shore in another.

These changes have been of great use to us too. Suppose all England

had been covered with coal or slate, we should not have been able to

grow anything! As it is we have sand and gravel in one county, chalk in

another, slate or granite in another, and coal down below in several,

and we can grow a great variety of plants on all these different soils.

We have to thank “upheaval” and “depression” for this. The force which

is always working below us has turned up the different soils like a

gigantic plough, and brought some to the top and covered others, so

that instead of having to dig down deeper than ever we have yet, we

have only to go from one county to another to find the different rocks.

We know that we could not get at the coal in Sussex without going down

an unknown depth through the chalk and other earths, but we dig for it

in the North of England, where we know its depth below the surface.

I will try now to give you some idea of the way in which the rocks come

in their order, or the succession of formations as geologists call

it. If we started to walk from Wales to London the rocks we should

pass over would be—slate and flagstones in Wales, and going on towards

London, limestone, old red sandstone, more limestones, coal beds, new

red sandstone, oolite, greensand, chalk, and last London clay. We

might not always find each of these near the surface, but they would

be found to be the principal rocks on a line between Wales and London,

the oldest being in Wales and the newest or most recent as we get

nearer London. That word “oolite” which I used comes from two Greek

words meaning “roe” and “stone,” because the rock is composed of little

rounded grains of a chalky substance shaped like the hard roe of a

fish, or like sago before it is cooked.

If you look at the following table you will see how the principal rocks

are placed one upon the other, beginning at the lowest or oldest at the

bottom and going up to the newest at the top of the table, and on the

right hand side I have written the names of the principal fossils which

each kind of earth contains.

TABLE OF THE SUCCESSION OF FORMATIONS.

TERTIARY, or Upper Rocks

Peat bogs and caves Fossil Man, with stone implements,

River-mud and brickearth, &c., mammoth,

gravels, and hippopotamus, rhinoceros,

boulder clay (alluvium) Irish stag, cave lion,

&c.

Crag of Eastern Counties Numerous shell-fish, mastodon

London clay, &c. Turtles, crocodiles, shell-fish

SECONDARY, or Middle Rocks

Cretaceous

Chalk (with and without Foraminifera, &c., sponges,

flints) corals, sea-urchins, shell-fish

Greensand and gault (Belemnites, Ammonites,

Wealden clay, &c. &c.), fishes

Oolites

Portland stone

Kimmeridge clay

Coral rag Immense reptiles, the Ichthyosaurus,

Oxford clay Plesiosaurus,

Cornbrash and forest Megalosaurus, Pterodactyl,

marble &c.

Great oolite

Fullers’ earth Animals allied to the opossum

Lower oolite and kangaroo

Lias clay and limestone Cycads and other plants

New red marl and

sandstone

PRIMARY, or Lower Rocks

Coal Ferns, club-mosses, a few

Millstone grit firs, calamites, &c., in

Mountain limestone great abundance

Old red sandstone Numerous corals, shell-fish,

Silurian limestones and trilobites, fishes, &c.

slates

Cambrian slates The Laurentian rocks contain

Laurentian rocks the oldest known

fossil, the Eozöon (or

“life-dawn animal”)

IGNEOUS, or Volcanic Rocks

Greenstone, basalt Of various ages (no fossils)

Porphyry

Granite, &c.

If you read this table upwards from the bottom you will notice that

life began in a very small way with Eozöon (the “life-dawn animal”),

that fishes appeared afterwards, that the wonderful forests of the coal

period then grew and were covered up by other rocks and pressed into

solid coal, that numbers of great crocodile-like animals lived all

through the oolite time, how the deep wide beds of chalk were laid down

by humble foraminifera, and when we get to the recent newest beds of

gravel, mud, sand, clay, &c., the sweepings by water of the older rocks

ground down by ages of wear and tear, we have the mammoth, mastodon,

megatherium, and other great vegetable eaters, and lastly Man himself

with his simple weapons of stone, bone, and horn—our early forefathers.