CORNISH POST-TERTIARY GEOLOGY. 



Whilst the abstract of a long paper when read may provoke but 

 a partial discussion, the Keferee has the power, as in my case, of 

 creating objections against a paper, which could be fairly quashed 

 in discussion, with the questionable satisfaction of knowing that his 

 victim is perfectly defenceless. I have, therefore, availed myself of 

 the only possible means of redress, as I conceive that the suppression 

 of opinions founded on facts and long investigation, and put forward 

 solely to supply a deficiency and arrive at the truth, is very likely 

 to prejudice their subsequent communications, unless (as I think the 

 foregoing correspondence will show) it can be proved that the 

 papers in every way fulfilled the requirements of the rules laid 

 down for the Eeferee's guidance, and that his recommendation to 

 print them in short abstract must therefore be attributed to ignorance 

 of their contents, and of the well-known work of previous observers 

 in the same field. 



If future discoveries should prove the classification I have adopted 

 to be erroneous, they would be none the less welcome for presenting 

 new lights, which, in the present state of the subject, are much to be 

 desired, and for settling the object in view, namely, a true statement 

 of the recent geological vicissitudes experienced by Cornwall, though 

 that statement should necessitate the complete abandonment of ray 

 present opinions. The absence of connecting links, and the isola- 

 tion of the older superficial deposits in Devon and Cornwall, taught 

 me the value of guarded opinions in the face of doubtful or negative 

 evidence ; and no better proof of the value of waiting on facts can 

 be adduced than the admirable work of Sir H. de la Beche, as 

 embodied in his Eeport on the Geology of Devon, Cornwall, and 

 West Somerset, which owes its imperishable excellence to the extent 

 and accuracy of his observations, and tlie discrimination which he 

 displayed in not committing himself to definite opinions where direct 

 evidence was not obtainable. 



To conclude, had the Eeferee simply recommended the printing 

 of the following papers in brief abstract on account of their length 

 and the number of quotations, I should have printed them without 

 this preface, which is written in vindication of my work, and in 

 answer to objections which I should hardly have deemed worthy a 

 reply had they been urged in discussion. W. A. E. U. 



