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their structure, whether they would easily break up or not ; 
their unequal hardness, whether one would give way more 
readily than another ; these, and such like qualities, ought to 
affect the shape of the ground very considerably, and on 
examination we find they do. The Mountain Limestone 
country is, taken altogether, tame" and monotonous, with 
broad flats and large rolling hills, but no very marked or 
sharp features, and this is only what we should expect from 
the homogeneous character of the rock, which causes it to 
yield equally in all directions to atmospheric agencies. Of 
course, I except from the above sweeping condemnation the 
beautiful valleys which the rivers have cut like trenches 
across the general plateau. When we pass to the gritstone 
country beyond, we find a vastly different type of scenery. 
Here ranges of hill, steep on one side and with a gentler slope 
on the other, run across the country in long parallel lines, 
forming the well-known " edges " of the district. On 
examination we find that each of these edges is formed of one 
of the thick, massive gritstones, whose outcrop makes a little 
cliff at the top, while the slope below and the valley between 
it and the beginning of the next ridge are formed of the 
softer shale; — and we see at once that it is the superior 
hardness of the gritstone that has enabled it to hold out 
against the denuding forces better than the shale, and stand 
up in bolder relief. Here, then, unequal hardness of the 
rocks has given rise to variety in feature, while in the case 
of the Mountain Limestone uniform hardness has produced 
sameness of outline. The scenery of the Coal-measures is 
similar to that of the Millstone-grit, but much less marked ; 
and this of course arises from the fact that the hard beds are 
not so thick and much more changeable. The escarpments 
formed by some of the Lower Coal- measure sandstones are 
quite equal to any Millstone- grit edge, but as we get higher 
in the measures, and the sandstones become poorer and 
