416 SUPERIOR SANDSTONES. 



geological relations, and as it presents scarcely 

 any variety of character, that chapter would have 

 been nearly a vacant attempt to preserve an use- 

 less appearance of regularity. 



For these reasons, it appeared preferable to 

 place the whole of the sandstones which follow 

 the lowest, under one title ; referring the reader 

 to geological writers for those distinctions which 

 confer on them their peculiar interest ; and con- 

 densing into one catalogue, all the mineral varie- 

 ties which are the peculiar objects of this work. 



Where it has appeared possible to refer any 

 variety to a known position among British strata, 

 it has been done in the Synopsis. But this part 

 of the subject is unavoidably imperfect ; as the 

 minute distinctions of many of these local rocks, 

 are scarcely definable in words, and as many of the 

 most important, are derived from oeconomical 

 uses, dependent also on properties which cannot 

 be described in an intelligible manner. 



There is not much to be said on the general 

 forms and mineral characters of these sandstones, 

 which would not be a repetition of that which 

 has already been stated in the preceding chapter. 



