THE MESOZOIC SYSTEM—THE TRIASSIC, OOLITIC, AND CRETACEOUS
FORMATIONS—THE EOCENE, MIOCENE, AND PLIOCENE—THE GLACIAL
PERIOD—PRE-HISTORIC MAN.
We trust that the general reader has gleaned from the foregoing chapter
some few ideas concerning the growth of plant and animal life in the
early periods of the world’s existence. From the Laurentian System
we have briefly traced the conformation of the globe at the dawn of
organic life through the Silurian Old Red Sandstone and Carboniferous
formations, indicating as we proceeded the chief points in the world’s
history, and the gradual development of life through many ages. There
is no real or bold line of demarcation drawn between these systems. As
seam unites to seam, and layer to layer, stratum upon stratum, so the
systems almost insensibly unite, and forms of life appear, mature, and
die away as the babe grows into the man, and dies away again to old age
and final extinction. So one system merges into another, each and all
a factor in the great work which was intended to prepare the earth for
the greatest and latest development of Nature—MAN!
[Illustration: Fig. 670.—Fossils of the Trias Group.
1. Ammonites nodosus.
2. Avicula socialis.
3. Possidonia minuta.
4. Encrinites moniliformis.]
But all this while the earth had been, as it still is, undergoing
continual change. Sometimes gradually, in the wearing away, or
elevation of beach or headland; sometimes suddenly, as when mighty
hills were upheaved and the deeply-laid granite or limestone was
lifted to the summits of the mountains from the depths of the sea. Land
and water came and went, and the ever-changing earth still brought
forth abundantly “the herb yielding seed after its kind,” and the
“moving things upon the ground after their kind,” ever improving and
developing till they culminated in the splendid vegetation and immense
animals of the Tertiary period, and lay silent afterwards in the cold
grasp of the great ice age for the thousands of years of the glacial
epoch.
[Illustration: Fig. 671.—Plesiosaurus.]
We now enter upon the TRIAS, or New (Upper) Red Sandstone, which is
divided into Upper and Lower Trias, “Keuper” and “Bunter.” We have
three principal headings in the Secondary System—the TRIASSIC (the
oldest), the OOLITIC, and the CRETACEOUS. In the first we find red
sandstones and shelly limestone; in the second, clays and shale; in the
last, chalk, or white limestone. In some districts there are traces of
volcanic action.
On the top of the “Upper Trias,” or “Keuper” formation, we have the
Lias, which succeeds the Rhætic beds, and in this we find many rich
traces of reptiles and birds which come now before us in the rising
scale of creation. In the seas of this period we have numerous
crustacea, the nautilus and the cuttle-fish. The _Saurians_ now come
before our retrospective vision. It is the “Reptile Age” in all its
development, and the huge labyrinthodon, the iguanodon, pterodactyle,
and ichthyosaurus testify to the magnitude of the fauna of the period.
The first mammal specimen, a marsupial, has been traced back to this
time; and the tropical temperature was favourable for luxuriant
vegetation, pines, and palms.
[Illustration: Fig. 672.—Restorations of Saurians, etc.]
In the swamps or shallow waters the great reptiles disported
themselves, and seized their prey, the water-fowl, which now appeared
in numbers, and of enormous size. Nor were insects absent. Numbers
of remains have been discovered; beetles, dragon-flies, grasshoppers,
etc., in multitudes yield us information, while the marine fossils,
star-fish, mollusca, and various fishes, are of frequent occurrence.
Animal and vegetable life during this period must have been very rich
and varied—literally leaving “footprints in the sands of time.”
[Illustration: Fig. 673.—Pterodactylus longirostris.]
The “Blue Lias” is a term familiar to every reader. It is a kind of
limestone mixed with clay, of a blue colour, and upon this we find the
Oolitic, or Oolite System—so called because it somewhat resembles the
roe of a fish. The Lias clays are used for bricks, and Whitby “jet” is
also obtained from the Upper Lias. Jet is really a lignite, or wood
in the process of transmutation. In this Lias formation, besides the
numerous fossil remains already mentioned, we find the “snakestones”
(ammonites), the stone-lily, and belemnites, with many nautili and
shells.
[Illustration: Fig. 674.—Ichthyosaurus.]
The OOLITE, or JURASSIC, underlies the chalk, and overlies the Trias
formation. The term “Jurassic” originates from the Jura range, which is
almost entirely composed of Oolitic strata. These strata are greatly
distorted by pressure, and when we reach Switzerland and the familiar
Alps, we find gneiss, crystalline, limestones, and schists, into which
the Oolite has been metamorphosed. The Oolite is divided into Upper,
Middle, and Lower, consisting of the following:—
{ Pembroke Beds.
Upper Oolite { Portland “
{ Kimmeridge Clay.
{ Calcareous Grit.
Middle Oolite { Coral Rag.
{ Oxford Clay.
{ “Cornbrash”—Forest Marble.
{ Stansfield Slate.
Lower Oolite { Bath Oolite.
{ Fuller’s Earth.
{ Inferior Oolite.
[Illustration: Fig. 675.—Sketch-map of various geological formations.]
The Oolite formation (_see_ Map) occupies a stretch of country in
England extending from Yorkshire into Dorset. The Great Oolite holds
the Fuller’s earth, and the Bath stone is also well known. The
Stonesfield slate holds many remains of reptiles. It is a kind of
shelly limestone, and is used for roofing purposes. The Forest Marble
(so called from Wychwood Forest) is a sandy limestone holding marine
fossils. It is used for ornaments. The Coral Rag and Oxford clay are
rich in fossils, and the former, as its name implies, is composed of
ancient coral reef. The Portland beds produce the well-known building
stone. The Purbecks, of which there are three divisions, appear to have
been deposited in fresh water, and occur in Dorsetshire.
All the Oolite strata supply organic remains. We have plants and ferns,
reptiles, and a number of new genera of conchifera and cephalopods,
star-fish, urchins, and the enormous bats, and the terrible
megalosaurus, and the cetiosaurus, steneosaurus, and pliosaurus, of
enormous size. One very remarkable bird has been found in the Bavarian
limestone of this period; it is called the Archæopteryx, which is
described as having a leg-bone and foot like the familiar birds, but
the tail is lizard-like, with feathers springing from each joint.
Sponges, corals, and fish, and many other forms of animal life are
found in the Oolites. The reptiles must have had it all their own way
in this period, for there were both carnivorous and vegetable feeders,
and teeth of the pliosaurus have been found which measure fifteen
inches, the jaws being six feet long. We have seen that corals must
have built up their reefs in the waters, which then overlaid the land
we call the United Kingdom.
There must have been great changes during this period, and the strata
are chiefly marine. The Wealden formations are the exceptions, and
in the fresh-water deposits insect forms abound. The appearance and
variety of animal and vegetable life must have been curious and
interesting.
The Weald or “Wold” of Kent is often spoken of, and it extends with the
Surrey and Sussex Wealden formations for some distance. The strata are
of fresh-water deposition, differing in this from the chalk, although
the Wealden beds are included in the Cretaceous Group, which is
composed as follows:—
{ Wealden.
Lower { Greensand.
{ “Gault.”
{ Upper Greensand.
{ Chalk Marl.
Upper { Chalk (without Flint).
{ Chalk (with Flint).
{ Maestricht.
The “Wealden” formation is divided into Hastings sand and Weald
clay. The former consists of clay and sandy beds, and is observable
at Hastings, and in the neighbourhood of Tunbridge. The Weald clay
consists of blue and brown clays, with sandstone, and the limestone
known as “Sussex Marble,” which is formed by the _paludina_ of the
rivers. There is another division often seen in Dorsetshire, and
called the Punfield beds, which partake both of marine and fresh-water
remains, which are distinct in the true Wealden and cretaceous
formations, the former being of fresh, and the latter of salt-water
origin.
The remains of enormous reptiles are numerous in the Wealden
formations; crocodiles, lizards, turtles of gigantic size have been
discovered, and most curious fossils have been disinterred in the
Hastings district. The “Greensands” are separated by what is termed
gault, a stiff blue clay found in Norfolk, Essex, and Kent. The Lower
Greensand includes the well-known Kentish rag, or limestone, of which
so many churches are built. The Upper Greensand is supposed to be a
seashore deposit on the sides of an extensive ocean or sea, at the
bottom of which the chalk was formed. After the Wealden beds were
formed, they were covered by these greensand estuary-beds, or littoral
strata. In these series new forms of life appeared, and the waters
became the receptacle of myriads of mollusca, etc., which in time
formed the great chalk cliffs and downs so often referred to. The chalk
is interstratified with sand, which as “gault” and “greensand” was
probably the sand of the ocean bed before the chalk was formed upon
it, and the seas must have supported many marine reptiles, for stony
“nodules,” or coprolites, which are the fossil excreta of the animals,
are found, and now used for manure, after being buried for thousands
of years. Examination of these remains has resulted in the discovery
of the teeth and bones of fish which had been devoured by the gigantic
reptiles. An illustration of a shell thus discovered is annexed.
[Illustration: Fig. 676.—Echinus (Hemicidarus intermedia, Chalk).]
[Illustration: Fig. 677.—Nautilus Inequalis.]
[Illustration: Fig. 678.—Ammonite from the chalk.]
We have in a former chapter spoken of the chalk and its formation. We
know that it is composed of the minute foraminifera. The fossil remains
are very numerous in chalk and all of a marine kind, such as the
ammonites, belemnites, and such cephalopods, and the echinus, bivalve
mollusca, crustacea, etc. We have occasionally flints appearing in the
chalk, and this circumstance has given rise to some speculation as to
how the flints got there, for they consist of nearly pure silica; and
the theory of the petrifaction of sponges, madrepores, etc., has been
started to account for their presence. Dr. Carpenter says: “It may be
stated, as a fact beyond all question, that nodular flint and other
analogous concretions (such as agates) may generally be considered
as fossilised sponges or alcyonian zoophytes, since not only are
their external forms and their superficial markings often highly
characteristic of those organisms, but when sections of them are made
sufficiently thin to be transparent, a spongy texture may be most
distinctly recognised in their interior.”
It is now generally admitted that the decaying animal matter acts
upon the silicious spiculæ of sponges, etc., and the silica is thus
deposited.
We may then surmise that at some very distant period the whole extent
of the British Isles was submerged, as well as portions of the
continent, and after the strata had been deposited the sea and land
were disturbed by volcanic action. While the secondary strata were
being deposited, very little relative alteration took place, as the
deposits are seen to lie “conformably.” But when the great convulsion
which upheaved the Apennines occurred, the chalk was raised as we find
it in the cliffs and downs, which were the beds of seas. This is the
last of the great convulsions which the earth has undergone, for the
tertiary strata, which afterwards began to be deposited, rest in the
hollows or basins (chiefly in the chalk) then left; the alterations in
and since these deposits appear to consist chiefly of the upheaval of
certain localities, the depression of others, the evaporation of inland
lakes, and the wear and tear of the land from these causes, which are
still in continuous action (as from the washing down of cliffs by the
sea, and the formation of mud deposits at the mouths of rivers), or the
volcanic agencies which in some places (as in Ireland) have cast up
basalt over the chalk.
[Illustration: Fig. 679.—Mosasaurus (Maestricht).]
There is a sort of transition formation which is classed with the
Cretaceous System, and termed “Maestricht,” after the town in Belgium.
It appears that this is an upper chalk layer, an intermediary between
the Secondary and Tertiary, and here on the banks of the Meuse we find
the Mosasaurus, the “lizard of the Meuse,” of whose remains we give
specimens in the illustration. This transition chalk—as we may call it
to distinguish it—must have been laid down at a later period than the
flinty chalk, and we find it in many places. It serves therefore as a
fitting introduction to the Tertiary Period of Geological time.
THE TERTIARY PERIOD.
We now enter upon a period when the animal creation attained its
greatest development, the “Age of Mammals”; for they were then the
kings of creation. The Tertiary Period is divided into three stages,
viz.—
The EOCENE, or the Dawning of the now _existing_ creation.
The MIOCENE, or the Middle, or “minority” of existing creation.
The PLIOCENE, or the Recent, or still more developed period.
We will glance at them in that order, which Sir C. Lyell introduced.
[Illustration: Fig. 680.—Skull of the Dinotherium.]
The Eocene formation is shown in what is termed the “London Basin,”
here illustrated by a section in which we find soft sands without
fossils (Thanet Beds), and a kindred kind in Surrey, in which fossils
(marine) are found. After these we get the “Reading and Woolwich”
beds as we ascend. These are of clay and pebbles, etc., with river
fossils. The Oldhaven beds are included on the map; they occur towards
Blackheath and Herne Bay. The London clay is very stiff, and in some
places blue. It is full of fossils of birds, beasts, fruits, and
vegetables, trees, reptiles, and fish, and the variety of the organic
remains appears to indicate the fact that at one time the Thames flowed
through swampy ground to the sea, in which dwelt, in a warm climate,
immense mammalia, such as the megatherium, glyptodon, tapir, etc., and
some turtles of enormous size.
It is also on record from late observations that these immense animals
were even mixed up, and almost fabulous creatures inhabited the land
where England now is. We read of antelope-horses, lion-like bears,
and camel-stags. The vegetation was then of a tropical kind, and
in the deep forests and jungles these enormous animals—the mammoth
dinotherium, and such species—roamed and plunged in the swamps at the
mouth of the Thames. At length these types died away, and gave place to
the elephant and the hippopotamus, and the climate by degrees became
less warm, and still slowly decreased in temperature.
A glance at Sir C. Lyell’s “Principles of Geology” will show us how,
as we examine the more modern strata, we find a great increase in the
European lands, which may have been compensated by the submersion
of the Pacific islands. During the period of the vegetation of the
Secondary epochs, our climate (between the lias and the chalk) was
favourable to a tropical growth. Enormous rivers flowed through our
islands, and gigantic crocodiles, etc., with flying reptiles, were
masters of the land. There were numerous fishes, but the reptiles did
not appear in such very great numbers.
[Illustration: Fig. 681.—Section across the London Basin (W. Whitaker).
_a_ Lower Bagshot sand (of Hampstead).
_b_ London Clay.
_c_ Reading and Woolwich beds (including the Oldhaven beds, which
occur in the south only).
_d_ Thanet sand (crops out on the south only).
_e_ Chalk with flints.
_f_ Chalk without flints.
_g_ Upper Greensand (crops out on the south only).
_h_ Gault.
_i_ Lower Greensand.
_k_ Wealden beds (on the south only).
_l_ Oolitic clays (shown only on the north, but proved to occur on the
south beyond the range of the section, by the sub-Wealden boring,
near Battle, in Sussex).
x Old rocks, shown by borings at Kentish Town and at Meux’s Brewery,
to pass under the London basin.
]
These large and elephantine animals must have existed while the climate
of Northern Europe underwent some very considerable changes. We read
of the woolly rhinoceros, and the hairy elephant, or mastodon, which
has been found in Siberia. Reindeer appeared in England, and we know
now that these animals inhabit cold countries. The mountains were
considerably elevated during the latter Tertiary period; snow fell and
ice formed upon the summits of the mountains, while glaciers crept down
the sides. The warm, almost tropical climate of the prior ages was
gradually but surely giving way to the Ice Age; the earth was slowly
dipping, and the sun’s rays had less power.
Professor Ramsay says the “assemblage of fossils found in the London
clay point to the fact that the whole of these strata were deposited in
the estuary of a great continental river comparable to the Amazon and
the Ganges. The palm-nuts and the host of other plants help to prove
it, and the remains of river tortoises, crocodiles, snakes, marsupials,
and several tapir-like mammals, all point in the same direction. The
estuarine conditions begun during the deposit of the Woolwich and
Reading beds were still going on when the London clay was thrown down;
with this difference, that by sinking of the area the estuary had
become longer, wider, and deeper, but still remained connected with a
vast continent, through which the Eocene river flowed.”
[Illustration: Fig. 682.—Anoplotherium commune: palæotherium magnum and
minus; and crocodile.]
The Miocene deposits are not so generally important in the United
Kingdom, but in America very valuable fossils have been discovered
in these strata. The Pliocene strata extend along the east of Great
Britain, where they are denominated “Crag,” as Norfolk Crag, Red
Crag, Coralline Crag. Underneath these mammalian remains have been
discovered. After the Pliocene we come to the Post-Pliocene, which
really closes the long Tertiary period. During these ages the gradual
development of created beings apparently reached its height. It was
towards the end of the Middle Eocene that the great mountain chain
of Europe came into existence, which is connected, as any casual
observer may see, with the Himalaya. In fact, the whole chain, from the
Thibetian range through India, the Caucasus, Alps, and Pyrenees, is
continuous, and formed of the same material (“nummulitic limestone”).
There is no doubt that the whole northern hemisphere enjoyed at the
commencement of the Tertiary period a warm, not to say tropical,
climate, which got colder and colder.
We find the increase of animals and plants more fitted to the
requirements of man and our present climate. There are many signs of
the successive increase of land in Europe generally, while the contrast
the Tertiary period bears to the Secondary is very marked. In the
former we have extensive deposits in the waters of wide, open seas; in
the latter the depositions were evidently made where dry land, with its
accompanying bays and lakes, were extensive and numerous. The former
is marine, the latter lacustrine and marine. The seas of the Tertiary
period have lately been defined.
[Illustration: Fig. 683.—Megatherium cuvieri (_post-Pliocene_), S.
America.]
Sir Charles Lyell, in his “Principles of Geology,” shows us this, and
defines the European features at the commencement of the Tertiary
epoch. At that time, the British islands, with the exception of the
basins of London, the Isle of Wight, and Norfolk, had wholly emerged
from the deep. But a third part of France was still under water.
Italy consisted only of a long and narrow ridgy peninsula, branching
off from the Alps near Savona. Turkey and Greece, south of the Danube,
were laid dry; and a tract of land extended from the Vosges, through
central Germany, Bohemia, and the north of Hungary, perhaps to the
Balkan. But the whole of the north of Europe and Asia, from Holland
eastward to central Tartary, and from Saxony and the Carpathians
northward to Sweden, Lapland, and the Ural chain, lay beneath the
ocean. The same subterranean movements, which have subsequently raised
the wide plains of our northern continents above the sea-level, have
given great additional elevation to the then existing land. Thus the
Alps have certainly acquired an increased height of from two thousand
to four thousand feet since the commencement of the Tertiary period.
The Pyrenees, whose highest ridge consists of marine calcareous beds,
of the age of our chalk and greensand series, while the Tertiary
strata at their foot are horizontal, and reach only the height of a
few hundred feet above the sea, seem to have been entirely upheaved in
the comparatively brief interval between the deposition of the chalk
and these Tertiary strata. The Jura, also, owe a great part of their
present elevation to convulsions which happened after the deposition
of the Tertiary groups. On the other hand, it is possible that some
mountain-chains may have been lowered by subsidence, as well as by
meteoric degradation, during the same series of ages in this quarter
of the globe; and on some points shallows may have been depressed
into deep abysses. But, on the whole, everything tends to show that
the great predominance of land which now distinguishes the northern
hemisphere has been brought about only at a recent period, and Sir
Charles holds that the shifting of the continents is sufficient to
account for the variations of climate. We have every reason to believe
that before the Glacial epoch England and the Continent were united,
and during the Glacial period England and North America were joined,
viâ Greenland and Ireland. Mr. Dawkins says that England at that time
was six hundred feet above its present level. If so—and we cannot
question his conclusions—the Channel was then dry.
[Illustration: Fig. 684.—Cervus Megaceros (_Megaceros Hibernicus_):
Irish Elk.—Post-Pliocene.]
The “Great Ice Age” then came upon the world. For the information of
readers who wish to peruse the whole history of this epoch and its
causes, we may add that in Professor Geikie’s most interesting work,
they will find full details. We can only refer to it.
The gradual decrease of temperature upon the earth, which was the cause
of the Glacial period extending over the north of Europe, has been
attributed to the eccentricity of the earth’s orbit; and here astronomy
steps in to our assistance. We have read in the chapters on Astronomy,
how the movement of the earth, like a top near the end of its “spin,”
causes the “precession of the equinoxes,” and in connection with this
phenomenon the earth’s orbit becomes more and more circular at certain
periods of thousands of years, and goes away from the sun. We therefore
receive the light and heat at a greater angle. Consequently, less heat
is received, and ice is formed, as at the North and South Poles at
present.
[Illustration: Fig. 685.—Drift Ice.]
Doctor Croll has pointed out that the great eccentricity of the earth’s
orbit existed about 210,000 years ago, when there was a difference
between the nearest and farthest position of the earth and the sun
of 12,000,000 of miles at least.[28] This is a very considerable
distance even in the enormous spaces which intervene between us and
the other planets of the solar system, and about that time the Glacial
period arrived. Perhaps we may make this clearer by going back to the
precession of the equinoxes.
The earth moves in an orbit called an ellipse, and the sun is not in
the centre of this nearly circular path. We can now understand that
the earth comes nearer to the sun sometimes and recedes at others.
These points of nearest approach and greatest distance are termed
_perihelion_ and _aphelion_. In the latter case we are about 9,000,000
of miles farther from the sun than when in perihelion—that is, when
the greatest “eccentricity” is reached. In addition to this the
axis of the earth is continually changing in direction by reason of
solar attraction at the equator. This shifting, as explained in the
astronomical section, is very slight every year, and in the course of
24,000 years the conditions of the seasons will have completely changed
round and back again,—for the northern and southern conditions will be
reversed in our hemisphere. Day and night come twenty minutes earlier
every year. We are now nearer the sun in winter as shown in diagram
(page 497); when we change we shall be nearest the sun in summer and
farthest in winter.
[Illustration: Fig. 686.—The Mer de Glace.]
Doctor Croll, who has done much in his most interesting paper on
changes of climate[29], tells us how this eccentricity of the earth’s
orbit produced indirectly the Glacial epoch. He shows how, if in a
period of the greatest “eccentricity” our winter came in aphelion, we
should receive one-fifth less heat than now, but a correspondingly
greater heat in summer. But if our winter under such circumstances fall
(as now) in perihelion, the difference between winter and summer would
be practically _nil_, because the sun during a period of the earth’s
great eccentricity “could not warm the hemisphere whose summer happened
to arrive in perihelion.” No doubt the sun’s rays would be very
powerful, but the earth being covered with ice and snow could not be
warmed; fogs would accrue and hide the sun, as at present in Antarctic
summers, when the cold is very great. The warm ocean currents would
be stopped, and the northern portion of our hemisphere would be, as it
undoubtedly was, frozen over and covered with snow.
[Illustration: Fig. 687.—Mammoth and Irish Elk.]
When we consider the millions of years since the earth is supposed to
have been launched into space, we can imagine that the Glacial periods
would occur frequently, and considering the very slow “precession”
movement there, and the alternating tropical climate with graduations
of temperature for thousands of years they would last long. The great
Glacial period is computed to have begun 240,000 years ago and lasted
160,000 years with alternations of comparative summer; and so the years
went on, season succeeding season, altering the appearance of the
earth, and causing successive changes in the distribution of animal and
vegetable life. Then the great mammalia, the mammoth and hippopotamus,
with the hyæna, lion, and other felidæ came, and went when Arctic
animals usurped their places. At the later Glacial epoch man must have
arrived in Britain, and “this being so,” says Professor Geikie, “it is
startling to recall in imagination those grand geological revolutions
of which he must have been a witness.... He entered Britain at a time
when our country was joined to Europe across the bed of the German
Ocean; at a time when the winters were still severe enough to freeze
over the rivers in the south of England; at a time when glaciers
nestled in our upland and mountain valleys, and the Arctic mammalia
occupied the land. He lived here long enough to witness a complete
change of climate, to see the Arctic mammalia vanish from England, and
the hippopotamus and its congeners take their places. At a later date,
and while a mild and genial climate still continued, he beheld the sea
slowly gain upon the land, until, little by little, step by step, a
large portion of our country was submerged—a submergence which, as we
know, reached in Wales to the extent of 1,300 feet or thereabouts.”
We find that the land underwent many subsequent changes; it rose from
the sea, was again covered with ice, and many parts of Europe were
devastated by immense glaciers—that of the Rhone extending for more
than two hundred miles. Then came vegetation as the ice gave way, and
luxuriance of the tropics reigned; more cold after that, then more
heat, till the ice was finally driven to its mountain fastnesses, and
“Britain for the last time became continental. Neolithic man came
upon the scene; his palæolithic predecessor had, as far as Britain
and northern Europe are concerned, vanished for ever.” The inquiry
respecting the arrival and presence of man in Britain would lead us too
far in pursuit. The fact has been established that man was living in
the Thames valley while tropical animals were in the country, and he
has been classed by Professor Boyd-Dawkins amongst the mid-pleistocene
mammalia, and at that distant period, man as man, and not as an
intermediate form connecting the human race with the lower animals, was
present in Europe.
The stone implements which have been found in river beds and in
caverns, associated with the bones of various animals, such as the
elephant, rhinoceros, hyæna, bear, and others prove this. These very
ancient and rudely-fashioned implements have been divided into two
classes, the Palæolithic and the Neolithic, by Sir John Lubbock. First
the stone implements were used, and stone was superseded by bronze and
iron. Then we come to the historic period. In the neolithic period
we find stone implements in the lake dwellings of Switzerland and
Constance (as well as the Lake of Neuchatel), all of which have lately
developed many treasures. Bronze tools have also been found, and so the
gradual progress of man as a fashioner of weapons can be traced from
age to age.
From the “river-drift” man we descend to the cave-man, who is supposed
to have been identical with the Esquimaux. When Britain became an
island the cave-man seems to have disappeared from our country, and in
the prehistoric age the earliest of the present inhabitants came here,
and brought with them domestic animals; then the Celts of the bronze
age, and then the iron. The wild beasts gradually disappeared, and
domestic ones occupied their places under civilized conditions.[30]
So we come from the “Glacial period” to the open door of history
through the antechamber of the prehistoric time.
The prehistoric is the arbitrary division between the post-pliocene or
pleistocene and the known “historic” periods of the world’s history,
and we must dismiss it with a few general remarks, for the changes
which we have attempted to follow are still taking place in the earth;
volcanoes and earthquakes are unsettling the strata, and adding to the
physical and geographical record which will some day have to be written
by posterity and future geologists. We can see in those prehistoric
times traces of men (hunters and fishers) existing with difficulty,
mayhap, in the midst of enormous quadrupeds, and fighting for existence
with the bears and many other formidable foes. We have noticed the
stone ages, the rough and the smooth as they may be called, and we can
picture the primitive agriculture and work of the neolithic man. But
it is by no means to be believed that neolithic man in Britain was a
race all over the world. We may assume that in eastern climes the human
race were in a more civilized condition as improvements made their way
slowly westward. Our island history commences in the time of Julius
Cæsar. Eastern chronicles go back many thousands of years farther.
[Illustration: Fig. 688.—Carboniferous Flora.]
It is so short a time, geologically speaking, since man appeared within
the limits of history, that the earth’s changes, except from direct
volcanic action or water erosion, are very trifling. The change is, as
we said, continually proceeding; ceaselessly the earth is wearing away,
and depositing her riches where she is undisturbed by civilization and
man’s excavations and intrusions. The rock is worn by water; the grit
is carried down and deposited to form sedimentary rocks as of old; the
lime will continue to assist the coral to be built up; and the chalk
cliffs will be born under the sea, and our organic remains shall be
found to tell remote ages that we were an enlightened people. For all
we can tell, and it is by no means unlikely another recurring cycle of
Arctic and Tropical periods will in time pass over our earth; the bear
and reindeer, the hippopotamus and the rhinoceros, may again inhabit
our islands. If our generation be destroyed, the purely animal creation
with the vegetable world will reign over the land, and new forests
will deposit new coal measures for the support and comfort of a new
generation of highly organized beings, when our remains shall have
passed away to the borders of a “prehistoric” age.
We have seen in the foregoing brief sketch how the world has arrived at
its present beautiful condition,—how it has been step by step prepared
for us, how nature’s forces have been and are still working according
to the immutable laws of the Universe. And, after all, how little we
know! What scraps of intelligence only are we able to gather up from
the boundless quantity of material which must have been laid down, yet
what wondrous results scientists have been able to adduce from even
these comparatively scanty specimens! The sea and land are ever telling
us the same old story. Man’s research and Bible teaching are found hand
in hand in cordial and reverent agreement. Nothing is altered since
the day that the Divine command, “Let there be light,” went forth into
space, and till the earth be destroyed the same forces will continue in
operation, guided by the Hand that made it—“ever faithful, ever sure.”
FOOTNOTES:
[28] It might reach 14,000,000 of miles at a maximum.
[29] “Physical Causes of Change of Climate,” _Phil. Mag._, 1864.
[30] See Dawkins’ “Early Man in Britain.”