HARDWICKE'S SCIEN CE-G OSS IP. 



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the stone resists disintegration to a greater 

 extent. 



Last summer I was wandering one day beneatli 

 the red sandstone cliffs along the coast of Fife. 

 Their base now stands some 20 feet above high- 

 water mark, but in former times the sea has formed 

 large caverns in them. Above these caver us and 

 around their outer sides the rock is eaten away 

 along the lines of bedding into those hour-glass- 

 shaped tiny columns, so characteristic of weathered 

 sandstones. I had been accustomed to regard 

 similarly weathered rocks far inland— such as those 

 of West Heath, in Sussex — as produced by atmo- 

 spheric agency, but here the thought M'ould suggest 

 itself, whether, after all, such was not the result of 

 old sea-action. In the evening, however, I took 

 my walk along the cliff-top, and came upon the so- 

 called Macduff's Castle, built of the same sandstone 

 as that forming the cliffs, and now in ruins. Any 

 lingering suspicions as to the power of the atmo- 

 sphere to honeycomb the cliffs below, were at once 

 dispetled, for some of the stones of the castle were 

 almost entirely eaten away, and all of them honey- 

 combed to a greater or less extent, all this weather- 

 ing having been effected within the lapse of a few 

 hundred years. 



But perhaps some will say, what Has all this to 

 do with the formation of scenery ? Much every 

 way ; this atmospheric decomposition and disin- 

 tegration of rocks is the fundamental fact of denu- 

 dation, and renders possible the more evident and 

 powerful mechanical action of running water, wind, 

 and frost. 



This mechanical action, too, will be sufficiently 

 recognized by most of us. Many, if not all of us, 

 have visited some mountainous district where the 

 power of running water is seen in its full force. 

 We have traced the tiny stream from its bubbling 

 fountain-head high up on the mountain downwards 

 to broad valleys and open plains; we have marked 

 every gradation from the little channel in which the 

 brooklet runs, down to the wide valley with its 

 rushing river ; we have watched the impetuous 

 waters ever wearing away the valley sides, and side 

 streams joining the main one, each issuing from its 

 own self-made glen. We must have noticed those 

 heaps of stones formed where small valleys open out 

 into wider ones, more or less conical hills of debris 

 brought down in winter's floods by streams often- 

 times dry throughout the summer. I am convinced 

 that no one with his reasoning powers about him 

 can see all this without being led to the conclusion 

 that the valleys have been carved out and the hills 

 sculptured by those very agents we see now at 

 work. The upper end of every lake is more or less 

 filled up by the mud, sand, and stones rolled down 

 from the mountains around, and the sides of every 

 valley are covered with fallen debris. The chemical 

 action of the air and rain-water is disintegrating 



and dissolving away the rocks, the freezing of the 

 water among their crevices is yearly shattering 

 them, and the licavy rainfall and flowing water is 

 for ever bearing away the loosened material to 

 lower and lower levels. 



There is yet another atmospheric agent which 

 has acted powerfully in this country at a recent 

 date, and may now be studied in operation in 

 Switzerland. I allude to ice in the form of glaciers. 

 We must not enter into this subject into detail, it 

 is too vast ; but those who have travelled among 

 the Alps will know something of its mode of action. 

 Suffice it to say that a glacier is a river of ice, 

 representing the snow-drainage of the mountains, 

 only flowing very much more slowly than an or- 

 dinary river; that the frost is constantly detaching 

 blocks of stone from the snowless peaks and crags 

 on either side of its course, whicli fall upon the 

 ice; that these blocks are carried onwards with 

 the glacier, forming long lines upon its surface, and 

 where it ends they are shot off and produce mounds 

 of stony rubbish, called terminal moraines. Not 

 only this, for as the ice moves slowly over its rocky 

 bed, it, aided by imprisoned stones, smooths, grinds, 

 polishes, and scratches it, rounding the rocks in a 

 very marked manner, and often leaving large blocks 

 of stone perched upon them. Thus is glacier-ice a 

 very powerful agent of denudation ; the rocky 

 fragments it bears from higher to lower levels are 

 innumerable, and since powerful streams flow from 

 the ends of glaciers, fully charged with sediment — 

 the grindings of the rocks— much that is brought 

 down by the ice is carried onwards by the running 

 water to fill up lakes and hollows in the valleys, or 

 to be carried finally out to sea. 



The whole of our English Lake district has been 

 thus ice-worn. In every valley you may mark the 

 rounded and scratched rocks and the old moraines 

 left by the retiring glaciers. 



But the person who has received no geological 

 training will argue — these atmospheric agencies you 

 have been enumerating are indeed effectual in doing 

 a certain amount of work, but surely they seem 

 quite inadequate to produce the great results you 

 ascribe tojthem ; the mountains and valleys change 

 not in form or shape. Has not the poet spoken of 

 the " everlasting hills " ? and am I to believe that 

 each mountain has been, in the main, separated 

 from its fellow by the action of the falling rain 

 and flowing stream ? To such a one I would answer, 

 the greatest ends of nature are worked out by 

 simplest means; insignificant agents working im- 

 mense periods may produce a result equal to that 

 effected by very powerful agents acting through a 

 short period. Picture to yourselves such action as 

 we have been speaking of, carried on through un- 

 told past ages, time [unthinkable, and need we 

 wonder that all these beautiful valleys and rock- 

 bound glens have been thus formed? To the length of 



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