But if you go to the Chalk Downs of Wiltshire, you see these temples
in their true grandeur. You have all heard of Stonehenge on
Salisbury Plain. Some of you may have heard of the great Druid
temple at Abury in Wilts, which, were it not all but destroyed,
would be even grander than Stonehenge. These are made of this same
sugar-sandstone.
But where did the sandstone come from? You may say, it "grew" of
itself in our sands and gravels; but it certainly did not "grow" on
the top of a bare chalk down. The Druids must have brought the
stones thither, then, from neighbouring gravel-pits. They brought
them, no doubt: but not from gravel-pits. The stones are found
loose on the downs on the top of the bare chalk, in places where
they plainly have not been put by man.
For instance, near Marlborough is a long valley in the chalk, which,
for perhaps half a mile, is full of huge blocks of this sandstone,
lying about on the turf. The "gray wethers" the shepherds call
them. One look at them would show you that no man's hand had put
them there. They look like a river of stone, if I may so speak; as
if some mighty flood had rolled them along down the valley, and
there left them behind as it sunk.
Now, whence did they come?
Many answers have been given to that question. It was supposed by
many learned men that they had been brought from the sandstone
mountains of Wales, like the rolled pebbles of which I spoke just
now. But the answer to that was, that these great stones are not
rolled: they are all squarish, more or less; their edges are often
sharp and fresh, instead of being polished almost into balls, as
they would have been in rolling two hundred miles along a sea-
bottom, before such a tremendous current as would have been needed
to carry them.
Then rose a very clever guess. They must have been carried by
icebergs, as much silt and stones (we know) has been carried, and
have dropped, like them, to the bottom, when the icebergs melted.
There is great reason in that; but we have cause now to be certain
that they did not come from Wales. That they are not pieces of a
rock older than the chalk, but much younger; that they were very
probably formed close to where they now lie.
Now--how do we know that?
If you are not tired with all this close reasoning, I will tell
you.--If you are, say so: but as I said at first, I want to show
you what steady and sharp head-work this same geology requires, even
in the nearest gravel-pit.
Well, then. I do not think our gravel-pit will tell us what we
want: but I know one which will.
You have all heard of Lady Grenville's lovely place, Dropmore,
beyond Maidenhead; where the taste of that good and great man, the
late Lord Grenville, converted into a paradise of landscape-
gardening art a barren common, full of clay and gravel-pits. Lord
Grenville wanted stones for rockwork; in those pits he found some
blocks, of the same substance as those of Stonehenge or Pirbright.
And they contain the answer. The upper surface of most of them is
the usual clear sugar-sandstone: but the under surface of many has
round pebbles imbedded in it, looking just like plums in a pudding;
the smaller above and the larger below, as if they had sunk slowly
through the fluid sand, before the whole mass froze, as it were,
suddenly together. And these pebbles are nothing else than rolled
chalk flints.
That settles the matter. The pebbles could not come from Wales;
there are no flints there. They could not have been made before the
chalk; for out of the chalk they came; and the only explanation
which is left to us, I believe, is, that over the tops of the chalk
downs; over our heads where we stand now, there once stretched
layers of sand and gravel, "Tertiary strata" as I have been calling
them to you; and among them layers of this same hard sandstone.
When the floods came they must have swept away all these soft sands
and gravels (possibly to make the Bagshot sands, of which I shall
speak presently), and left the chalk downs bare; but while they had
strength to move the finer particles, they had not generally
strength to move these sandstone blocks, but let them drop through,
and remain upon the freshly-bared floor of chalk, as the only relics
of a tertiary land long since swept away; while some were carried
off, possibly by icebergs, as far as Pirbright, and dropped, as the
icebergs melted, both there, at Dogmersfield, and also, though few
and small, in Eversley and the neighbourhood.
But how came these tertiary sandstones to be so very hard, while the
strata around them are so soft?
Ladies and gentlemen, I know no more than you. Experience seems to
say that stone will not harden into that sugary crystalline state,
save under the influence of great heat: but I do not know how the
heat should have got to that layer in particular. Possibly there
may have been eruptions of steam, of boiling water holding silex
(flint) in solution--a very rare occurrence: but something similar
is still going on in the famous Geysers or boiling springs of
Iceland. However, I have no proof that this was the cause. I
suppose we shall find out some day how it happened; for we must
never despair of finding out anything which depends on facts.
Part of the town of Odiham, and of North Warnborough, stands, I
believe, upon these lower beds, which are called by geologists the
Woolwich and Reading beds, and the Plastic clays, from the good
brick earth which is so often found among them. But as soon as you
get to Hook Common, and to Dogmersfield Park, you enter on a fresh
deposit; the great bed of the London clay.
I give you a rough section, from a deep well at Dogmersfield House;
from which you may see how steeply the chalk dips down here under
the clay, so that Odiham stands, as it were, on the chalk beach of
the clay sea.
In boring that well there were pierced:
Forty feet of the upper sands (the Bagshot sands), of which I shall
speak presently.
Three hundred and thirty feet of London clay.
Then about forty feet of mottled clays and sands.
Whether the chalk was then reached, I do not know. It must have
been close below. But these mottled clays and sands abound in water
(being indeed the layer which supplies the great breweries in
London, and those soda-water bottles on dumb-waiters which squirt in
Trafalgar Square); and (I suppose) the water being reached, the
boring ceased.
Now, this great bed of London clay, even more than the sands below
it, deserves the title of a new creation.
As a proof--some of you may recollect, when the South-Western
Railway was in making, seeing shells--some of them large and
handsome ones--Nautili, taken out of the London clay cutting near
Winchfield.
Nautili similar to them (but not the same) are now only found in the
hottest parts of the Indian seas; and what is more, not one of those
shells is the same as the shells you find in the chalk. Throughout
this great bed of London clay, the shells, the remains of plants and
animals, are altogether a new creation. If you look carefully at
the London clay shells, you will be struck with their general
likeness to fresh East Indian shells; and rightly so. They do
approach our modern live shells in form, far more than any which
preceded them; and indeed, a few of the London clay shells exist
still in foreign seas; in the beds, again, above the clay, you will
meet with still more species which are yet alive; while in the
chalk, and below the chalk, you never meet, I believe, with a single
recent shell. It is for this reason that the London clay is said to
be Eocene, that is, the dawn of the new creation.
The chalk, I told you, seems to have been deposited at the bottom of
a still and deep ocean. But the London clay, we shall find, was
deposited in a comparatively shallow sea, least in depth toward High
Clere on the west, and deepening towards London and the mouth of the
Thames.
For not only is the clay deeper as you travel eastward, but--and
this is a matter to which geologists attach great importance--the
character of the shells differs in different parts of the clay.
You must know that certain sorts of shells live in deep water, and
certain in shallow. You may prove this to yourselves, on a small
scale, whenever you go to the seaside. You will find that the shell
which crawl on the rocks about high-water mark are different from
those which you find at low-tide mark; and those again different
from the shells which are brought up by the oyster-dredgers from the
sea outside. Now, the lower part of the clay, near here, contains
shallow-water shells: but if you went forty miles to the eastward,
you would find in the corresponding lower beds of the clay, deep-
water shells, and far above them, shallow-water shells such as you
find here: a fact which shows plainly that this end of the clay sea
was shallowest, and therefore first filled up.
But again--and this is a very curious fact--between the time of the
Plastic clays and sands, with their oyster-beds and black pebbles,
and that of the London clay, great changes had taken place. The
Plastic clay and sands were deposited during a period of earthquake,
of upheaval and subsidence of ancient lands; and therefore of
violent currents and flood waves, seemingly rushing down from, or
round the shores of that Wealden island to the south of us, on the
shore of which island Odiham once stood. We know this from the
great irregularity of the beds: while the absence of that
irregularity proves to us that the London clay was deposited in a
quiet sea.
But more. A great change in the climate of this country had taken
place meanwhile; slowly perhaps: but still it had taken place.
In the lowest clay above the chalk are found at Reading many leaves,
and buds, and seeds of trees, showing that there was dry land near;
and these trees, as far as the best botanists can guess, were trees
like those we have in England now. Not of the same species, of
course: but still trees belonging to a temperate climate, which had
its regular warm summer and cold winter.
But before the London clay had been all deposited, this temperate
climate had changed to a tropical one; and the plants and animals of
the upper part of the London clay had begun to resemble rather those
of the mouths of the African slave-rivers.
Extraordinary as this is, it is certainly true.
We know that the country near the mouth of the Thames, and probably
the land round us here, was low rich soil, some half under water,
some overflowed by rivers; some by fresh or brackish pools. We know
all this; for we find the shells which belong to a shallow sea,
mixed with fresh-water ones. We know, too, that the climate of this
rich lowland was a tropical one. We know that the neighbourhood of
the Isle of Sheppey, at the mouth of the Thames, was covered with
rich tropic vegetation; with screw pines and acacias, canes and
gourds, tenanted by opossums, bats, and vultures: that huge snakes
twined themselves along the ground, tortoises dived in the pools,
and crocodiles basked on the muds, while the neighbouring seas
swarmed with sharks as huge and terrible as those of a West Indian
shore.
It is all very wonderful, ladies and gentlemen: but be it is: and
all we can say is, with the Mussulman--"God is great."
And then--when, none knows but God--there came a time in which some
convulsion of nature changed the course of the sea currents, and
probably destroyed a vast tract of land between England and France,
and probably also, that sunken island of Atlantis of which old Plato
dreamed--the vast tract which connected for ages Ireland, Cornwall,
Brittany, and Portugal. That convulsion covered up the rich clays
with those barren sands and gravels, which now rise in flat and
dreary steppes, on the Beacon Hill, Aldershot Moors, Hartford Bridge
Flat, Frimley ridges, and Windsor Forest. That rich old world was
all swept away, and instead of it desolation and barrenness, piling
up slowly on its ruins a desert of sand and shingle, rising inch by
inch out of a lifeless sea. There is something very awful to me in
the barrenness of those Bagshot sands, after the rich tropic life of
the London clay. Not a fossil is to be found in them for miles.
Save a few shells, I believe, near Pirbright, there is not a hint
that a living being inhabited that doleful sea.
But do not suppose, gentlemen and ladies, that we have yet got our
gravel-pit made, or that the way-worn pebbles of which it is
composed are near the end of their weary journey. Poor old stones!
Driven out of their native chalk, rolled for ages on a sea-beach,
they have tried to get a few centuries' sleep in the Eocene sands on
the top of the chalk hills behind us, while the London clay was
being deposited peacefully in the tropic sea below; and behold, they
are swept out, once more, and hurled pell-mell upon the clay, two
hundred feet over our heads.
Over our heads, remember. We have come now to a time when Hartford
Bridge Flats stretched away to the Beacon Hill, and many a mile to
the south-eastward--even down into Kent, and stretched also over
Winchfield and Dogmersfield hither.
What broke them up? What furrowed out their steep side-valleys?
What formed the magnificent escarpment of the Beacon Hill, or the
lesser one of Finchamstead Ridges? What swept away all but a thin
cap of them on the upper part of Dogmersfield Park, another under
Winchfield House; another at Bearwood, and so forth?
The convulsions of a third world; more fertile in animal life than
those which preceded it: but also, more terrible and rapid, if
possible, in its changes.
Of this third world, the one which (so to speak) immediately
preceded our own, we know little yet. Its changes are so
complicated that geologists have as yet hardly arranged them. But
what we can see, I will sketch for you shortly.
A great continent to the south--England, probably an island at the
beginning of the period, united to the continent by new beds--the
Mammoth ranging up to where we now stand.
Then a period of upheaval. The German Ocean becomes dry land. The
Thames, a far larger river than now, runs far eastward to join the
Seine, and the Rhine, and other rivers, which altogether flow
northward, in one enormous stream, toward the open sea between
Scotland and Norway.
And with this, a new creation of enormous quadrupeds, as yet
unknown. Countless herds of elephants pastured by the side of that
mighty river, where now the Norfolk fisherman dredges their teeth
and bones far out in open sea. The hippopotamus floundered in the
Severn, the rhinoceros ranged over the south-western counties;
enormous elk and oxen, of species now extinct, inhabited the vast
fir and larch forests which stretched from Norfolk to the farthest
part of Wales; hyenas and bears double the size of our modern ones,
and here and there the sabre-toothed tiger, now extinct, prowled out
of the caverns in the limestone hills, to seek their bulky prey.
We see, too, a period--whether the same as this, or after it, I know
not yet--in which the mountains of Wales and Cumberland rose to the
limits of eternal frost, and Snowdon was indeed Snowdon, an alp down
whose valleys vast glaciers spread far and wide; while the reindeer
of Lapland, the marmot of the Alps, and the musk ox of Hudson's Bay,
fed upon alpine plants, a few of whose descendants still survive, as
tokens of the long past age of ice. And at every successive
upheaval of the western mountains the displaced waters of the ocean
swept over the lower lands, filling the valley of the Thames and of
the Wey with vast beds of drift gravel, containing among its chalk
flints, fragments of stone from every rock between here and Wales,
teeth of elephants, skulls of ox and musk ox; while icebergs,
breaking away from the glaciers of the Welsh Alps, sailed down over
the spot where we now are, dropping their imbedded stones and silt,
to confuse more utterly than before the records of a world rocking
and throbbing above the shocks of the nether fire.
At last the convulsions get weak. The German Ocean becomes sea once
more; the north-western Alps sink again to a level far lower even
than their present one; only to rise again, but not so high as
before; sea-beaches and sea-shells fill many of our lower valleys;
whales by hundreds are stranded (as in the Farnham vale) where is
now dry land. Gradually the sunken land begins to rise again, and
falls perhaps again, and rises again after that, more and more
gently each time, till as it were the panting earth, worn out with
the fierce passions of her fiery youth, has sobbed herself to sleep
once more, and this new world of man is made. And among it, I know
not when, or by what diluvial wave out of hundreds which swept the
Pleistocene earth, was deposited our little gravel-pit, from which
we started on our journey through three worlds.
When?
Enough for us that He knows when, in whose hand are the times and
the seasons--God the Father of the spirits of all flesh.
And now, ladies and gentlemen, take from hence a lesson. I have
brought you a long and a strange road. Starting from this seemingly
uninteresting pit, we have come upon the records of three older
worlds, and on hints of worlds far older yet. We have come to them
by no theories, no dreams of the fancy, but by plain honest
reasoning, from plain honest facts. That wonderful things had
happened, we could see: but why they had happened, we saw not.
When we began to ask the reason of this thing or of that, remember
how we had to stop, and laying our hands upon our mouths, only say
with the Mussulman: "God is great." We pick our steps, by lanthorn
light indeed, and slowly, but still surely and safely, along a dark
and difficult road: but just as we are beginning to pride ourselves
on having found our way so cleverly, we come to an edge of darkness;
and see before our feet a bottomless abyss, down which our feeble
lanthorn will not throw its light a yard.
Such is true science. Is it a study to make men conceited and self-
sufficient? Believe it not. If a scientific man, or one who calls
himself so, be conceited, the conceit was there before the science;
part of his natural defects: and if it stays there long after he
has really given himself to the patient study of nature, then is he
one of those of whom Solomon has said: "Though you pound a fool in
a mortar among wheat with a pestle, yet will not his folly depart
from him."
For what more fit to knock the conceit out of a student, than being
pounded by these same hard facts--which tell him just enough to let
him know--how little he knows? What more fit to make a man patient,
humble, reverent, than being stopped short, as every man of science
is, after each half-dozen steps, by some tremendous riddle which he
cannot explain--which he may have to wait years to get explained--
which as far as he can see will never be explained at all?
The poet says: "An undevout astronomer is mad," and he says truth.
It is only those who know a little of nature, who fancy that they
know much. I have heard a young man say, after hearing a few
popular chemical lectures, and seeing a few bottle and squirt
experiments: Oh, water--water is only oxygen and hydrogen!--as if
he knew all about it. While the true chemist would smile sadly
enough at the youth's hasty conceit, and say in his heart: "Well,
he is a lucky fellow. If he knows all about it, it is more than I
do. I don't know what oxygen IS, or hydrogen, either. I don't even
know whether there are any such things at all. I see certain
effects in my experiments which I must attribute to some cause, and
I call that cause oxygen, because I must call it something; and
other effects which I must attribute to another cause, and I call
that hydrogen. But as for oxygen, I don't know whether it really
exists. I think it very possible that it is only an effect of
something else--another form of a something, which seems to make
phosphorus, iodine, bromine, and certain other substances: and as
for hydrogen--I know as little about it. I don't know but what all
the metals, gold, silver, iron, tin, sodium, potassium, and so
forth, are not different forms of hydrogen, or of something else
which is the parent of hydrogen. In fact, I know but very little
about the matter; except this, that I do know very little; and that
the more I experiment, and the more I analyse, the more unexpected
puzzles and wonders I find, and the more I expect to find till my
dying day. True, I know a vast number of facts and laws, thank God;
and some very useful ones among them: but as to the ultimate and
first causes of those facts and laws, I know no more than the
shepherd-boy outside; and can say no more than he does, when he
reads in the Psalms at school: "I, and all around me, are fearfully
and wonderfully made; marvellous are Thy works, and that my soul
knoweth right well."
And so, my friends, though I have seemed to talk to you of great
matters this night; of the making and the destruction of world after
world: yet what does all I have said come to? I have not got one
step beyond what the old Psalmist learnt amid the earthquakes and
volcanoes of the pastures and the forests of Palestine, three
thousand years ago. I have not added to his words; I have only
given you new facts to prove that he had exhausted the moral lesson
of the subject, when he said:
These all wait upon thee, that thou mayest give them their meat in
due season.
Thou givest, and they gather: thou openest thy hand, and they are
filled with good.
Thou hidest thy face, they are troubled; thou takest away their
breath; they die and return to their dust.
Thou sendest forth thy spirit, they are created; and thou renewest
the face of the earth.
But--The glory of the Lord shall endure for ever. The Lord shall
rejoice in his works. Amen.