out flints)
1 Greensand and gault
\ Wealden clay, &c.
("Portland stone
I Kimmeridge clay
Coral rag
I Oxford clay
^ Combrash and forest
marble
j Great oolite
I Fullers' earth
[Lower oolite
Lias clay and lime-
stone
New red marl and
sandstone
Coal
Millstone grit
Mountain limestone
Old red sandstone
Silurian limestones and
slates
I Cambrian slates
Laurentian rocks
IGNEOUS, [ Greenstone, basalt
or Volcanic -j Porphyry
Rocks (Granite, &c.
Fossil Man, with stone im-
plements, &c., mammoth,
hippopotamus, rhinoce-
ros, Irish stag, cave lion,
&c.
Numerous shell-fish, mas-
todon
Turtles, crocodiles, shell-
fish
Foraminifera, &c. , sponges,
corals, sea-urchins, shell-
fish (Belemnites, Am-
monites, &c.), fishes
Immense reptiles, the Ich-
thyosaurus, Plesiosaurus,
Megalosaurus, Pterodac-
tyl, &c.
Animals allied to the opos-
sum and kangaroo
Cycads and other plants
Ferns, club-mosses, a few
firs, calamites, &c., in
great abundance
Numerous corals, shell-
fish, trilobites, fishes, &c.
The Laurentian rocks con-
tain the oldest known
fossil, the Eozoon (or
" life-dawn animal ")
Of various ages (no fossils)
THE CHANGES HAVE BEEN GRADUAL. 43
If you read this table upwards from the
bottom you will notice that life began in a
very small way with Eozoon (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 fora-
minifera, 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.
You must always keep in mind that the
greatest of these changes have taken place
very slowly. Mountains have been raised,
and whole continents have been sunk by
movements so slow that if the hands of a
clock went only once round the dial in a year
the hand would go faster than these mountains
44 THE GEOLOGICAL PART.
have risen or the continents sunk. Almost
always whenever there has been sudden and
violent action it has been near volcanoes or
during- earthquakes ; but these things, terrible
as they are to the people living near, disturb
only a very small part of the surface, and
such violence neither buried the coal beds
nor raised the slate hills of Wales. Many of
the small effects of the internal force of the
earth have been sudden and violent, but the
greatest and grandest have been slower than
anything we can imagine.
If this had not been so, we should not
find fossil shells just as they sank quietly to
the bottom of ancient seas, quite undisturbed.
We should not find delicate ferns and insects
with all their breakable parts perfectly pre-
served, and as lightly laid as if you had
put them away carefully in a cabinet upon
cotton wool. Yet many of these have sunk
down hundreds of feet below the open air
where they must have lived. We find the
ripple marks of the waves on old sandstones,
and even the prints of the feet of birds and
animals as they walked upon that rock when
THE ICE AGE. 45
it was soft sand, and the little pits made
by rain-drops on the moist earth. All this
speaks of stillness, and gentle movement, no
violence. So slowly and softly have these
rocks settled down, that we can read in them
the history of the life that was. But if there
had been any sudden and rough movement
all these fossils might have been broken up
and we should have had nothing but frag-
ments, and the "puzzle of life" could never
have been put together. Nature's forces are
immense, but they work slowly, irresistibly,
and majestically.
THE ICE AGE.
We have seen now what the principal rocks
are made of and the way in which their places
have been changed by upheaval and depres-
sion. Water, as we know, has been at work
and has done great things in all ages of the
World's history. I have called it " one of
Nature's most powerful tools," and when we
look at the quantity of chalk alone that there
is in the world, and remember that this was all
laid down in water, and perhaps a great part
46 THE GEOLOGICAL PART.
of its lime carried down by rivers to the seas
where it settled to the bottom, after the
corals and small shell-fish had worked it into
their bodies, we are right in thinking water
a great Magician indeed. Why, even so
small a river as the Thames carries down to
the sea every year as much dissolved earth
as would make a good large hill ; and what
must such rivers as the Nile, the Amazon,
the Mississippi, and the great Chinese rivers
do ! There must have been gigantic rivers,
too, in the old times, or else it would have
been impossible that the deep sandstone and
slate beds could have been formed ; for these
are all laid down by the washing away of
earth in water.
Ice, which is only solid water, has also
been a powerful tool in shaping the surface
of the Earth, but it has not been always at
work as water has. Ice now covers only a
comparatively small part of the globe near the
north and south poles, and mountains like
those in Switzerland ; but by watching what
ice is doing now in these places we are able
to be certain that there has been a time when
ICEBERGS AND GLACIERS. 47
it covered Scotland, Cumberland, Wales,
Sweden and Norway, and nearly all North
America. In watching the great " rivers of
ice," called glaciers, in the Alps, for instance,
we see that they slip down from the moun-
tains slowly, creeping on year by year, and
bringing with them pieces of rock and stones.
We see also where they have melted that they
have been grinding the rocks beneath them
with their great weight, and have cut grooves
into, and scraped and polished the hardest
granite. The stones underneath the glaciers
have been pressed so heavily upon the rocks
that they have left deep marks, and we find
the same kinds of marks and heaps of stones
in many mountains where there are no
glaciers now. There are other things too
which convince us that a great ice sheet
spread over almost the whole of Great Britain.
When the huge icebergs break away from
the frozen shores of Greenland and North
America, they often have frozen into their
ice large blocks of rock, sand, gravel, &c.,
and when they drift into the warmer seas of
the south they melt, and of course these
48 THE GEOLOGICAL PART.
blocks or " boulders," as they are called, sink
to the bottom. Just the same kind of boul
ders are found in many parts of the world,
where icebergs never come now, and as they
are of a different rock from that on which
they lie, they must have been brought there
somehow. We naturally suppose then that
they were brought by icebergs. Sometimes
boulders of granite have been found thus
among clay, many miles from where there
are any granite rocks on the surface, and
there can be no doubt that they were origin-
ally frozen into an iceberg, which floated away
with them and when it melted left them so far
from their native place. In many of the mid-
land and eastern counties once floated these
icebergs, dropping the stones and boulders
which they brought away from the Welsh,
Cumberland, and Scottish mountains.
The climate of the earth must have been
fearfully cold when our country was covered
with ice, just as Greenland is now. Geologists
suppose that there must have been more
than one age of ice, and that between these
ages the climate of the world was pretty
DENUDATION. 49
much the same as at present, although it is
certain that there were periods when Eng-
land was much warmer, because many of
the fossil plants could not have grown in a
cold climate.
You will want to know whether there
were any land animals living during the ice
periods. It is impossible to be quite certain,
but it is most likely that the mammoth was
living both before and during the last ice age,
because its bones have been found among
the earths brought down by the glaciers.
1 have said all you will be likely to re-
member at present about the nature of the
different rocks, but it will help you to under-
stand better how they have been laid one
upon the other, and how they have been
moved and broken by upheaval and sub-
sidence, if you look at the drawings on
page 51.
DENUDATION.
It has often happened that some of the
harder and older rocks, like granite and
slate, have pushed themselves through those
50 THE GEOLOGICAL PART.
earths lying above them, and then the sea
or a great river has washed away all the
earths from one side of the rock. The rain,
too, falling for thousands of years, has swept
them down into the valleys and mixed them
together. This is called denudation, or
" laying bare " the harder rocks by washing
the softer ones away from them. Those
beds of pebbles on the sea shore also have
been battering against the rocks for ages and
very gradually wearing them away, as you
can see if you watch the stones being
driven into and sucked out of holes and
cracks by every wave. Thus, both the
loose stones and the solid rocks get polished
and ground away, and Nature is always
destroying and making again by turns. If
this destruction went on continually without
any raising of the land to make up for it, the
surface of the whole Earth would in time
become level ; but old sea beds are always
being slowly raised above the water and
prepared for the growth of plants and the
habitation of animals.
If you watch the little rills of water on
Denudation.
E 2
DENUDA TION. 53
any rainy day, trickling down a hill, or the
springs which bubble up at the foot of cliffs
on the sea shore, you will see an example of
denudation in a small way. The earth is
washed off the surface here and there, and
carried down and laid up in banks in some
places, and the harder ground underneath is
laid bare. Little beds of stones are collected
in one place, and sticks and straws and such
light things in another, and this is just what
has been done on a large scale in mountain
regions, all over the world for many cen-
turies.
In the uppermost sketch on page 51 you
will see how the granite has been lifted
up with the layers of other earth along its
sides, and afterwards even layers have been
deposited above ; in the second there has
been a great crack in the land, and a great
mass of rock has subsided, and the hollow has
become filled up in time with clay, and mould,
and rich soil, so that some one has built a
house and made a garden on it ; in the third
the river has cut a gorge in rocks which were
once continuous from cliff to cliff, wearing
54 THE GEOLOGICAL PART.
away the softer earths more easily than the
harder. If the Earth was cut into in different
places we should find the rocks arranged in a
very similar way to that in the three sketches.
BOILING SPRINGS, ETC.
In several different countries there are
very strange sights, but scarcely anything
is more astonishing than the fountains of
boiling water which shoot up out of the
ground. There are a good many of them
not far from us, in Iceland, and many
hundreds in Wyoming in America, and they
are called " geysers." Steam and boiling
water, and sometimes mud, are thrown up by
these natural fountains to a height of 200 feet
as high as the top of the spire of a church.
The water must come from a great depth
in the ground perhaps many thousand feet
down where the heat is intense. This water
springing up with clouds of snow-white steam,
and falling all round in showers, has a most
beautiful appearance. These geysers now and
then throw out very little water, just bubbling
up above the ground, and then travellers boil
BOILING SPRINGS, ETC. 55
eggs and chickens and such things in them,
and have a pic-nic near them. It is im-
possible to say how long they have lasted,
but we know from history that some have
been spouting out water for at least 2,000
years, and how much longer no one can tell.
They may have something to do with vol-
canoes, because water may have found its
way to the heated interior of the earth, and
being converted into steam, expands and
causes an eruption.
Now that we have some idea of the con-
struction of the Earth, we must go on to the
life of the wonderful plants and creatures
Xvhich have peopled it.
56 THE VEGETABLE PART.
THE VEGETABLE PART.
THE DAWN OF LIFE.
THE first beams of the rising sun, and the
first grey light of the morning, tell us of the
coming day ; but we cannot even think of
the dawn of that far-off day in the Earth's
history, when no voice of man or beast was
heard, and no trees or grass covered it, with-
out solemn wonder at the immense distance
that day is from us. A thousand ages are
in the sight of the Creator but as yesterday,
and the period of man's existence is only
a moment compared to that of the lowly
creatures which built up this World for him.
In the first seas and on the land nothing was
heard but the rushing of waters and the roar-
ing of the fires of volcanoes.
It is impossible to be quite certain
whether the first living things were animals
or plants ; but I think it most likely that
very simple plants grew first, and that very
THE DAWN OF LIFE. 57
simple animals came after or with them.
Among the first of these, or perhaps the very
first, were some small animals called Eozoon,
which means the " life-dawn animal," and
with them grew some simple plants. On the
banks of the St. Lawrence river in Canada
there is a great bed of rock called the
Laurentian rocks, made almost entirely of
the tiny remains of the " life-dawn animal,"
which, when we look at them through a micro-
scope, are found to possess nearly the same
structure as some lowly organized shells
living in the seas now. These rocks are
found in many parts of the world besides
in Eastern America, Bavaria, Scotland, and
Norway ; and in some places their thickness
has been estimated at thirty thousand feet, or
nearly six miles, or one hundred times as
thick as St. Paul's Cathedral is high ! These
little creatures you see were at work over
a great part of the Earth's surface, and you
may fancy how many thousands of thousands
of years it took them to build up these rocks.
The " life-dawn animal " is far older than the
chalk-building foraminifera, and so far as we
58 THE VEGETABLE PART.
know it lived alone in its seas. There were
none of the beautiful twisted ammonite shell-
fish, nor the shark-like fishes of the chalk
seas. The eozoon was the only kind of
living creature, the " lord of creation " for the
time ; and though storms raged in the seas
it inhabited, the water was so deep that it
lived on undisturbed. When you are able
to use a microscope you will be able to see
the traces left by these tiny animals in what
is now hard stone. 1
Life began in a very small way : there
were none of the great land animals we
have now ; but these seemingly insignificant
builders were at work so long that they
made the immense rocks I have told you of.
But this is not all. About this time some
very simple plants grew on the land, and
were carried down by the rivers and formed
deep beds. After a long time these became
covered up with different earths and were
turned into the substance called " black-lead,"
which you use in drawing pencils. But this
1 Specimen in Table-case 15, Room V., North Gallery
British Museum.
THE FIRST PLANT LIFE. 59
is not really lead ; it is almost pure carbon
in fact, the oldest kind of coal so old that it
will not now burn like coal, and is entirely
made up of fossil plants crushed out of shape,
so that we cannot now trace their forms, as
we can the plants of the coal. When then
you next take up a drawing pencil it will
be easy to remember that the black sub-
stance which marks the paper was once a
living plant, now changed by heat and pres-
sure into almost pure carbon. As the name
eozoon has been given to the " life-dawn
animal," I will give this black-lead the name
of Eodendron> or the "dawn-plant." 1
Two very simple forms of life then
occupied the earth and sea at the earliest
time when anything at all was living, and
strangely enough we use the dead bodies of
both of them. We build houses of the rocks
the eozoon laid down at the bottom of the
sea, and the beautiful art of drawing is car-
ried on with the carbon from the first plant
life of the world the eodendron.
1 The name Eophyton has also been suggested for the
earliest vegetable forms.
60 THE VEGETABLE PART.
I must take you away presently to the
coal, and sandstone, and chalk, and show you
how plants and animals gradually increased
in number and size, and fishes began to
inhabit the seas, and all living things were
slowly going on to greater perfection ; for as
time went on there was a steady progress
from creatures like the eozoon, which had
scarcely any power of moving about, to the
active, quarrelsome and greedy things like
crabs and lobsters which came after them,
and the gigantic ferns of the coal beds.
The peaceful " life-dawn animals " drew their
food from the vegetable substances dissolved
in the waters, though they perhaps also lived
on animals still smaller than themselves ; but,
by-and-by, creatures, which must have been
monsters to them, swarmed in the seas and
devouied their smaller companions wholesale ;
and in time the Earth became very much the
same as it is now, a place where the struggle
for life is always going on. It is certain that
animals have fed upon one another from the
very beginning ; but this is no doubt a wise
law of the Creator to prevent them from
ANCIENT FOSSIL PLANTS. 61
increasing too fast, as they would do if all that
were born lived, and none were destroyed.
We know much less about the vegetation
the plants and grasses of the early ages
of the world than of the animals ; because
plants rot away faster than bones and shells,
and, besides, are less likely to be found in
places where they would be preserved. A
dead tree might be eaten up entirely by
insects, as the white ants eat up fallen trees
in a short time in tropical countries, and
what is left of them crumbles away to fine
powder and mixes with the soil. Immense
trees are thus devoured now by millions of
tiny insects no longer than your thumb nail,
in India and Australia. No such thing as a
whole and perfect fossil tree with every twig
and leaf has been found ; but then the coal
beds are really great forests which have been
buried for so long a time that they have
quite altered in appearance. Still, among
these coal beds we often find the bark, fruit,
stems, and branches of trees very much like
firs, and ferns, and huge club-mosses, which
have the same shape they had when living,
62 THE VEGETABLE PART.
though they are quite black, and burn exactly
like coal.
But there were plants long before the
coal forests lived, and many fossil sea weeds
are found in the old sandstones and lime-
stones in Wales and other places. 1 The Old
Red Sandstone, whose position you can see
below the coal in the table of succession of
formations, page 42, does not give us many
fossil plants, though fishes and shells are
common. This rock is found in Scotland,
Herefordshire, Devonshire, and Ireland, as
well as other places, and is often more than
2,000 feet thick. It was not all formed in
salt water we know, because many of the fossil
fishes and shells it contains are fresh water
kinds. It must all have been made of the
pieces of still older rocks worn away by
rivers and settled like a sediment in immense
lakes, some of which were fresh water. Then,
after the Old Red Sandstone, came a time
when the limestones below the coal were
laid down at the bottom of a vast sea, and
1 Divisions A and B of Case r, Room I., North Gallery,
contain some of the oldest known fossil plants.
PLANTS OF THE COAL FORESTS. 63
here the remains of land plants are of course
few. Then it seems there must have been
a very long time when there were large
continents all over the world raised above
the seas, but not very much, and on these
the forests grew which afterwards became
coal fields. Until this time the plants had
been mostly water weeds, reeds, rushes, and
sea weeds, and it was not until England and
Ireland became one continent, as they were
once and covered with woods, that the great
period of vegetation began.
The growth of plants was then most
wonderful ; but although coal is found in
many different parts of the world, it was not
all formed at one time, and though it is
plentiful in England and Wales, Scotland,
Ireland, France, Belgium, Russia, Hungary,
Australia, New Zealand, China, and Borneo,
it is older in some countries than in others.
It is fortunate, however, that this useful
material was made in Nature's workshop in
so many different countries, or it would have
to be carried from one to another. The coal
forests were not the same trees as we have
64 THE VEGETABLE PART.
now oaks, elms, ashes, limes, and so on.
Most of them had rather hollow trunks and
splendid waving tops like ferns and reeds,
though there were some like our fir-trees.
If you lie down in the long grass before
it is mown, and look through the stalks
and fancy yourself an inch high only, you
will have some idea how the coal forest
would have looked if you had lived then.
But there were no human beings on the
Earth then, and I do not think there were
any large animals, at least none have been
found in the coal itself, except in Switzer-
land, where a few bones of the mammoth
(an ancient elephant) and of the rhinoceros
have been discovered in the much newer
beds of coal, and also those of a large reptile
like a crocodile in the coal beds of Ohio
in America.
In such immense forests insects must
certainly have been plentiful, and some of
the fossil bodies of beetles, dragon-flies, and
spiders, have been preserved, and a few tree
lizards. 1 Of course the edges of the coal
1 Fossil insects in Table-case No. 14, Room V.
Calamites.
Different Kinds of Plants of the Coal Forests.
PLANTS OF THE COAL FORESTS. 67
forests were washed here and there by the
salt sea, and there must have been some fresh
water rivers and ponds, for we find both fresh
and salt water shells in these beds. It was
almost dark in these forests, so thickly 'did the
plants grow together. There were enormous
club-mosses close together and as high as most
houses, with their leaves interlaced making a
complete network to shut out the sun. But
the sun which shone on the forests was warm,
and the air which went through them was soft,
or they would not have grown so wonder-
fully. Indeed, there can be no doubt that the
climate of northern regions was once much
warmer than it is now. A thick bed of coal
was discovered by the Arctic Expedition
in 1875-6 actually within five hundred miles
of the North Pole, where the ice on the sea
is now thirty or forty feet thick ! 1 The
forest which formed this coal could only have
grown in a temperate climate, and there are
no forests there now ; it is so intensely cold
they could not live. There must then have
been a great change in the climate of the
1 In 8i44/ N. latitude.
F 2
68 THE VEGETABLE PART,
Arctic regions since that coal was living ve-
getation. The few plants and mosses which
can live there now are of a very different
and more hardy kind than those of the coal
forests!
If you look at the engraving facing page 64,
you will see a drawing of one of the tree
ferns with its delicate fronds which grew
so abundantly in the coal forests, and there
are many other plants, some like the common
" mare's tails," or catamites, growing in shallow
ponds and ditches now only the " mare's
tails " or calamites of the coal forests were as
high as poplars. 1 You can imagine what a
splendid sight these forests of ferns, club-
mosses, and "mare's tails," must have been,
and what a multitude of beautiful insects and
butterflies' must have flitted about in them ;
but their frail bodies have almost all perished,
so that we know very little of the animated
creatures of the time.
Besides several sorts of coal both soft and
hard there is a substance called " lignite,"
1 Specimens of plants from the coal in Cases No. 2, 3, 4,
in Room I.
LIGNITE, JET, AMBER, AND PEAT. 69