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inseparable bond of cause and effect. Not more certainly does 
the oscillating mercury speak to us of meteoric changes, than the 
petrological variations of a district or a country are indicated by 
the varying character of its profile. I remember on one occasion 
when standing on the north coast of Ireland, near the Giant’s 
Causeway, and looking out seaward, being greatly struck with the out- 
line of the Island of Rathlin, one part of which is quite low and very 
even in form, the other being much higher and somewhat irregular in 
inoutline. It occurred to me that there must be some difference in 
the rocks of the two parts of the island to cause this difference in 
the outline ; and upon enquiry, I found that the low and even- 
looking portion was composed of chalk, which is comparatively 
soft and easily denuded, whilst the higher and more irregular 
portion proved to be formed of basalt, a rock which is much 
harder than chalk, and not by any means so easily acted on by 
the atmosphere and other denuding agents; whence its more 
prominent appearance. 
In this way we might go on from one part of the country to 
another almost ad infinitum, adducing examples in illustration of 
the great influence of geological structure on scenery. So far we 
have principally concerned ourselves with changes in lithological 
composition, which is but a part—although a very important part 
—of what is embraced in the phrase, geological structure. I would 
like now, before concluding, briefly to notice how scenery may 
be, and in fact, is influenced in other ways, as, for instance, by 
the dip of the strata, by joints, and by faults. 
In walking across country from Ennerdale to Whitehaven, it 
may have been noticed by some of you that those valleys, or those 
parts of valleys, which have a north and south direction, are as a 
rule, steeper on the west side than on the east. The explanation 
of this is as follows. The general dip of the rocks in that part of 
the district is to the west, so that the valleys or parts of valleys 
having a north and south direction are at right angles, or nearly 
so, to the dip. Now every quarrymen knows, and it is apparent 
to almost everybody, that it is much easier to work towards the 
rise of the strata than to the dip, because in working up-hill, so to 
