Geology of England and Wales, 



567 



We find no fault with the authors or publishers, as often it does 

 happen that a slight difference in arrangement makes a great 

 difference in the usefulness of the work to either teachers or 

 students. But we gladly welcome any author who will keep us 

 posted in the newest views arrived at by those who have made 

 special branches their peculiar study, and who have sufficient 

 knowledge of collateral facts to weigh the evidence brought forward, 

 and sufficient courage to give up widely received views. 



The great judge who so long sat in our final court of appeal has 

 passed to his rest. We waited for Lyell's decision on all geological 

 questions; but new cases are still continually coming forward to 

 be tried, and new evidence justifies our pleading over again more 

 than one ancient cause. 



It has long been felt, and frequently brought forward at the 

 Geological Society and elsewhere, that at many different horizons 

 our present divisions are not true to nature. Though brackets 

 drawn provisionally to include doubtful beds at the top or base of 

 a deposit have been by some defended as the expression of a decided 

 opinion, founded upon clear evidence, still as our knowledge has 

 advanced it has become obvious that some changes must be made. 



Theoretically we allow that deposition has probably been con- 

 tinuous through all geologic time ; but it has been locally inter- 

 rupted, and practically we take the local interruptions to mark off 

 our groups. 



Section at Snowdown, Chard, (p. 245.) 



2. Calcareous Sandstone. 

 1, Chert Beds. 



I Upper Greensand. 



4. Lower Chalk. 

 3. Chloritic Marl. 



We have peculiar advantages for this in the British Isles, where 

 the series of stratified rocks is so well represented that it is easy to 

 construct a chronological table so full and complete that we can 

 classify foreign synchronous or homotaxial episodes by reference to 

 it better than to any other local scheme proposed. Therefore it 

 is especially important not to burden it with a classification or 

 nomenclature which is not true to nature. Bearing all this in mind, 



