第 34 节
作者:
嘟嘟 更新:2021-02-20 05:57 字数:9322
colours mark the ancient rocks and high mountains of Mayo and Galway
and Kerry; which stand as barriers to keep the raging surf of the Atlantic
from bursting inland and beating away; as it surely would in course of time;
the low flat limestone plain of the middle of Ireland。 But the same coral…
reefs once stretched out far to the westward into the Atlantic Ocean; and
you may see the proof upon that map。 For in the western bays; in Clew
Bay with its hundred islands; and Galway Bay with its Isles of Arran; and
beautiful Kenmare; and beautiful Bantry; you see little blue spots; which
are low limestone islands; standing in the sea; overhung by mountains far
aloft。 You have often heard those islands in Kenmare Bay talked of; and
how some whom you know go to fish round them by night for turbot and
conger; and when you hear them spoken of again; you must recollect that
they are the last fragments of a great fringing coral…reef; which will in a
few thousand years follow the fate of the rest; and be eaten up by the
waves; while the mountains of hard rock stand round them still
unchanged。
Now look at England; and there you will see patches at least of a great
coral…reef which was forming at the same time as that Irish one; and on
which perhaps some of your schoolfellows have often stood。 You have
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MADAM HOW AND LADY WHY
heard of St。 Vincent's Rocks at Bristol; and the marble cliffs; 250 feet in
height; covered in part with rich wood and rare flowers; and the Avon
running through the narrow gorge; and the stately ships sailing far below
your feet from Bristol to the Severn sea。 And you may see; for here they
are; corals from St。 Vincent's Rocks; cut and polished; showing too that
they also; like the Dudley limestone; are made up of corals and of coral…
mud。 Now; whenever you see St。 Vincent's Rocks; as I suspect you very
soon will; recollect where you are; and use your fancy; to paint for
yourself a picture as strange as it is true。 Fancy that those rocks are what
they once were; a coral…reef close to the surface of a shallow sea。 Fancy
that there is no gorge of the Avon; no wide Severn seafor those were
eaten out by water ages and ages afterwards。 But picture to yourself the
coral sea reaching away to the north; to the foot of the Welsh mountains;
and then fancy yourself; if you will; in a canoe; paddling up through the
coral… reefs; north and still north; up the valley down which the Severn
now flows; up through what is now Worcestershire; then up through
Staffordshire; then through Derbyshire; into Yorkshire; and so on through
Durham and Northumberland; till your find yourself stopped by the Ettrick
hills in Scotland; while all to the westward of you; where is now the
greater part of England; was open sea。 You may say; if you know
anything of the geography of England; 〃Impossible! That would be to
paddle over the tops of high mountains; over the top of the Peak in
Derbyshire; over the top of High Craven and Whernside and Pen…y…gent
and Cross Fell; and to paddle too over the Cheviot Hills; which part
England and Scotland。〃 I know it; my child; I know it。 But so it was
once on a time。 The high limestone mountains which part Lancashire
and Yorkshirethe very chine and backbone of Englandwere once coral…
reefs at the bottom of the sea。 They are all made up of the carboniferous
limestone; so called; as your little knowledge of Latin ought to tell you;
because it carries the coal; because the coalfields usually lie upon it。 It
may be impossible in your eyes: but remember always that nothing is
impossible with God。
But you said that the coal was made from plants and trees; and did
plants and trees grow on this coral…reef?
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MADAM HOW AND LADY WHY
That I cannot say。 Trees may have grown on the dry parts of the reef;
as cocoa…nuts grow now in the Pacific。 But the coal was not laid down
upon it till long afterwards; when it had gone through many and strange
changes。 For all through the chine of England; and in a part of Ireland
too; there lies upon the top of the limestone a hard gritty rock; in some
places three thousand feet thick; which is commonly called 〃the mill…stone
grit。〃 And above that again the coal begins。 Now to make that 3000
feet of hard rock; what must have happened? The sea…bottom must have
sunk; slowly no doubt; carrying the coral…reefs down with it; 3000 feet at
least。 And meanwhile sand and mud; made from the wearing away of the
old lands in the North must have settled down upon it。 I say from the
Northfor there are no fossils; as far as I know; or sign of life; in these
rocks of mill…stone grit; and therefore it is reasonable to suppose that they
were brought from a cold current at the Pole; too cold to allow sea…beasts
to live;quite cold enough; certainly; to kill coral insects; who could only
thrive in warm water coming from the South。
Then; to go on with my story; upon the top of these mill…stone grits
came sand and mud; and peat; and trees; and plants; washed out to sea; as
far as we can guess; from the mouths of vast rivers flowing from the West;
rivers as vast as the Amazon; the Mississippi; or the Orinoco are now; and
so in long ages; upon the top of the limestone and upon the top of the mill…
stone grit; were laid down those beds of coal which you see burnt now in
every fire。
But how did the coral…reefs rise till they became cliffs at Bristol and
mountains in Yorkshire?
The earthquake steam; I suppose; raised them。 One earthquake
indeed; or series of earthquakes; there was; running along between
Lancashire and Yorkshire; which made that vast crack and upheaval in the
rocks; the Craven Fault; running; I believe; for more than a hundred miles;
and lifting the rocks in some places several hundred feet。 That
earthquake helped to make the high hills which overhang Manchester and
Preston; and all the manufacturing county of Lancashire。 That
earthquake helped to make the perpendicular cliff at Malham Cove; and
many another beautiful bit of scenery。 And that and other earthquakes; by
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MADAM HOW AND LADY WHY
heating the rocks from the fires below; may have helped to change them
from soft coral into hard crystalline marble as you see them now; just as
volcanic heat has hardened and purified the beautiful white marbles of
Pentelicus and Paros in Greece; and Carrara in Italy; from which statues
are carved unto this day。 Or the same earthquake may have heated and
hardened the limestones simply by grinding and squeezing them; or they
may have been heated and hardened in the course of long ages simply by
the weight of the thousands of feet of other rock which lay upon them。
For pressure; you must remember; produces heat。 When you strike flint
and steel together; the pressure of the blow not only makes bits of steel fly
off; but makes them fly off in red…hot sparks。 When you hammer a piece
of iron with a hammer; you will soon find it get quite warm。 When you
squeeze the air together in your pop…gun; you actually make the air inside
warmer; till the pellet flies out; and the air expands and cools again。 Nay;
I believe you cannot hold up a stone on the palm of your hand without that
stone after a while warming your hand; because it presses against you in
trying to fall; and you press against it in trying to hold it up。 And recollect
above all the great and beautiful example of that law which you were
lucky enough to see on the night of the 14th of November 1867; how those
falling stars; as I told you then; were coming out of boundless space;
colder than any ice on earth; and yet; simply by pressing against the a