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POPULAR SCIENCE REVIEW. 
tendency to extreme views, and particularly in attributing too 
much to marine action. 
We have seen that the effects of elevation and disturbance 
are not unimportant ; that, indeed, in the first place they gave 
the plan to the denuding forces ; rents and fractures, even faults 
— all have in some way influenced the minor features, while the 
dip of the strata and the texture of the different rocks have 
likewise affected the configuration of our land. In this respect 
the angle of repose is important, and may well be studied in 
our railway-cuttings. 
Professor Geikie has compared the work done by rain and 
rivers, and that done by the sea. It has been estimated that the 
Mississippi carries annually to the sea about 812,500,000,000 
lbs. of mud ! Allowing the sea to eat away a continent at 
the rate of ten feet in a century, and that on a moderate 
computation the land loses about a foot from its general surface 
in 6,000 years, then, before the sea could pare off more than a 
mere marginal strip of land, between seventy and eighty miles 
in breadth, the whole of Europe would be washed into the 
ocean by atmospheric denudation.* 
This estimate seems to do bare justice to the sea, but it is 
evident, as Professor Geikie remarks, that the extent of land 
exposed to subaerial or meteoric agencies far exceeds that 
exposed ^to the influence of the sea. 
All agencies, however, act in concert ; the landslip caused by 
rain and frost and the dip of the strata is removed by the sea, 
and the deposits formed at its bottom are upraised and returned 
to it again by rain and rivers. Thus we find that the whole 
plan of Nature is one of constant creation and decay. Man has 
done much to check the wasting action of the sea on our coasts 
by the erection of groynes and other defences, while by the 
cutting down of forests he has lessened the rainfall, and conse* 
quently diminished the effects of subaerial denudation. Never- 
theless, his power has been but feeble in the history of our 
planet, while his time on earth has really been but a moment 
compared with the long ages of geological time. And yet the 
history of each rock, if we consider Man as the ulterior object 
of creation, has not been one of chance or without design, when 
we look to the important benefit that they have conferred upon 
him by the various economic purposes they serve. Nor is the 
influence of our scenery to be looked upon as accidental, for 
what more powerful influence for good is there upon the mind 
of man than the contemplation of a beautiful landscape, and in 
learning from it something of the wondrous works of Nature as 
exhibited in the history of our rocks ? 
* “ Trans. Geol. Soc. Glasgow/’ vol. iii. p. 153. 
