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NOTES ON THE GEOLOGY OF SCENERY. 
By the Editor. 
I. Stratification. 
INCE 1900, when our Vice-President, Professor Hen- 
slow, aroused our interest by his papers on “ How 
Scenery is Made,” many of us have, no doubt, enjoyed 
the reading of our President’s volume on the “ Scenery 
of England.” My present intention is in no way to challenge 
comparison with the work of such masters of observation and 
exposition, but merely to note briefly a few points which any 
tyro may see for himself, illustrating what I have to say by some 
photographs taken, and kindly placed at my disposal, by Mr. 
Caradoc Mills, of Llanrwst. 
One of the first points that strikes the investigator of the 
rock-structure of the earth is that some rocks appear in masses, 
often of enormous thickness and extent, exhibiting little or no 
division into layers or difference in apparent composition ; whilst 
others are so markedly divided into beds or “ strata,” often 
differing slightly in texture or composition, that the name 
“ stratified ” seems self-explanatory. Further examination of 
these two great groups of rocks show that the former, or “un- 
stratified,” type is very often of a crystalline texture, and some- 
times obviously composed of a mixture of several different 
crystalline mineral substances ; whilst the “ stratified ” rocks 
are, in general, not crystalline, each bed, or “stratum,” appear- 
ing to be of a uniform granular or earthy texture. Such 
extended examination, moreover, will probably suggest that the 
crystalline unstratified rocks do not yield any fossil shells or 
other animal or plant remains to the most persistent hammerer ; 
whilst if the granular stratified rock be a clay, or still more, if it 
be chalk or limestone, he will almost certainly light upon some, 
and may find the rock practically made up of them. 
It may also occur to our supposed tyro that the crystalline 
unstratified rocks often present the steep slopes and jagged out- 
lines of true mountain scenery, whilst in the more placid sur- 
roundings of low hills or great plains he finds that the rocks are 
stratified. 
More extended experience may tend to qualify some of these 
first impressions of the rocks. In the Scottish Highlands may 
be seen many a mile of crystalline rock exhibiting a very 
distinct system of alternating layers of two or three different 
minerals ; and in South Devon, in a confused hotch-potch of 
various rocks, coralline marbles bordering on masses of granite, 
or on series of pure sandstone almost destitute of fossils, 
granular, non-crystalline rocks may be found, which a careful 
chemical examination will show to be powdered pumice-like 
lava, and which will yet yield a few fossils. 
In interpreting the past by the present — the cardinal principle 
