madam how and lady why(豪夫人和怀女士)-第13节
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such crater…lakes in Italy； as you will see if ever you go there； as you may
see in English galleries painted by Wilson； a famous artist who died before
you were born。 You recollect Lord Macaulay's ballad； 〃The Battle of the
Lake Regillus〃？ Then that Lake Regillus （if I recollect right） is one of
these round crater lakes。 Many such deep clear blue lakes have I seen in
the Eifel； in Germany； and many a curious plant have I picked on their
shores； where once the steam blasted； and the earthquake roared； and the
ash…clouds rushed up high into the heaven； and buried all the land around
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in dust； which is now fertile soil。 And long did I puzzle to find out why
the water stood in some craters； while others； within a mile of them
perhaps； were perfectly dry。 That I never found out for myself。 But
learned men tell me that the ashes which fall back into the crater； if the
bottom of it be wet from rain； will sometimes 〃set〃 （as it is called） into a
hard cement； and so make the bottom of the great bowl waterproof； as if it
were made of earthenware。
But what gives the craters this cup…shape at first？
ThinkWhile the steam and stones are being blown out； the crater is
an open funnel； with more or less upright walls inside。 As the steam
grows weaker； fewer and fewer stones fall outside； and more and more fall
back again inside。 At last they quite choke up the bottom of the great
round hole。 Perhaps； too； the lava or melted rock underneath cools and
grows hard； and that chokes up the hole lower down。 Then； down from
the round edge of the crater the stones and cinders roll inward more and
more。 The rains wash them down； the wind blows them down。 They
roll to the middle； and meet each other； and stop。 And so gradually the
steep funnel becomes a round cup。 You may prove for yourself that it
must be so； if you will try。 Do you not know that if you dig a round hole
in the ground； and leave it to crumble in； it is sure to become cup… shaped
at last； though at first its sides may have been quite upright； like those of a
bucket？ If you do not know； get a trowel and make your little
experiment。
And now you ought to understand what 〃cone〃 and 〃crater〃 mean。 And
more； if you will think for yourself； you may guess what would come out
of a volcano when it broke out 〃in an eruption；〃 as it is usually called。
First； clouds of steam and dust （what you would call smoke）； then volleys
of stones； some cool； some burning hot； and at the last； because it lies
lowest of all； the melted rock itself； which is called lava。
And where would that come out？ At the top of the chimney？ At the
top of the cone？
No。 Madam How； as I told you； usually makes things make
themselves。 She has made the chimney of the furnace make itself； and
next she will make the furnace…door make itself。
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The melted lava rises in the craterthe funnel inside the cone but it
never gets to the top。 It is so enormously heavy that the sides of the cone
cannot bear its weight； and give way low down。 And then； through ashes
and cinders； the melted lava burrows out； twisting and twirling like an
enormous fiery earth…worm； till it gets to the air outside； and runs off
down the mountain in a stream of fire。 And so you may see （as are to be
seen on Vesuvius now） two eruptions at onceone of burning stones above；
and one of melted lava below。
And what is lava？
That； I think； I must tell you another time。 For when I speak of it I
shall have to tell you more about Madam How； and her ways of making
the ground on which you stand； than I can say just now。 But if you want to
know （as I dare say you do） what the eruption of a volcano is like； you
may read what follows。 I did not see it happen； for I never had the good
fortune of seeing a mountain burning； though I have seen many and many
a one which has been burntextinct volcanos； as they are called。
The man who saw ita very good friend of mine； and a very good man
of science alsowent last year to see an eruption on Vesuvius； not from the
main crater； but from a small one which had risen up suddenly on the
outside of it； and he gave me leave （when I told him that I was writing for
children） to tell them what he saw。
This new cone； he said； was about 200 feet high； and perhaps 80 or
100 feet across at the top。 And as he stood below it （it was not safe to go
up it） smoke rolled up from its top； 〃rosy pink below；〃 from the glare of
the caldron； and above 〃faint greenish or blueish silver of indescribable
beauty； from the light of the moon。〃 But moreBy good chance； the
cone began to send out； not smoke only； but brilliant burning stones。
〃Each explosion；〃 he says； 〃was like a vast girandole of rockets； with a
noise （such as rockets would make） like the waves on a beach； or the wind
blowing through shrouds。 The mountain was trembling the whole time。
So it went on for two hours and more； sometimes eight or ten explosions
in a minute； and more than 1000 stones in each； some as large as two
bricks end to end。 The largest ones mostly fell back into the crater； but
the smaller ones being thrown higher； and more acted on by the wind； fell
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in immense numbers on the leeward slope of the cone〃 （of course； making
it bigger and bigger； as I have explained already to you）； and of course； as
they were intensely hot and bright； making the cone look as if it too was
red…hot。 But it was not so； he says； really。 The colour of the stones was
rather 〃golden； and they spotted the black cone over with their golden
showers； the smaller ones stopping still； the bigger ones rolling down； and
jumping along just like hares。〃 〃A wonderful pedestal；〃 he says； 〃for the
explosion which surmounted it。〃 How high the stones flew up he could
not tell。 〃There was generally one which went much higher than the rest；
and pierced upwards towards the moon； who looked calmly down；
mocking such vain attempts to reach her。〃 The large stones； of course；
did not rise so high； and some； he says； 〃only just appeared over the rim of
the cone； above which they came floating leisurely up； to show their
brilliant forms and intense white light for an instant； and then subside
again。〃
Try and picture that to yourselves； remembering that this was only a
little side eruption； of no more importance to the whole mountain than the
fall of a slate off the roof is of importance to the whole house。 And then
think how mean and weak man's fireworks； and even man's heaviest
artillery； are compared with the terrible beauty and terrible strength of
Madam How's artillery underneath our feet。
C / ｜ / ｜
A /…＋… E / ｜ /…
＋… E Ground / ｜ B Ground …/
｜ ｜ D ｜ ｜ D ｜ D ｜ ＋…＋＋
…＋…＋ ｜ ｜ ｜ ｜ ｜ ｜
Now look at this figure。 It represents a section of a volcano； that is；
one cut in half to show you the inside。 A is the cone of cinders。 B； the
black line up through the middle； is the funnel； or crack； through which
steam； ashes； lava； and everything else rises。 C is the crater mouth。 D
D D； which looks broken； are the old rocks which the steam heaved up and
burst before it could get out。 And what are the black lines across； marked
E E E？ They are the streams of lava which have burrowed out； some
co
