i8;6 RELIEVED OF GEOLOGICAL LECTURESHIP 335 



rocks are mostly fresh-water or estuarine deposits, that 

 may give some sign of an old valley ; but in Wales 

 there is a great thickness of Lingula Flags and 

 Tremadoc Slates between the Cambrian strata and 

 the volcanic series. ... I know all the New Red 

 series of England north of the Severn, and it contains 

 no volcanic rocks. In Devon it does, see De La 

 Beche's Report on Devon and Cornwall, chap, vii., 

 where you will find something directly bearing on your 

 question in re valleys and volcanoes. 



' We have no Liassic or Oolitic volcanic rocks, and 

 none in the Wealden, though that formation must have 

 been deposited at the mouth of a great river-valley. 

 Neither have we any Cretaceous or Eocene igneous 

 rocks, though there is in these formations evidence of 

 the mouth of another big river-valley. 



' The Eifel volcanoes are, in general, on the top of 

 a plateau, in which, however, there were pre- Miocene 

 valleys, if these volcanoes be Miocene. ... I think 

 your letter gives me a glimmering of what you are 

 thinking about in the matter of these old river-valleys 

 and volcanoes, and the subject is quite a new idea to 

 me, and will be to others when you work it out.' 



To Miss Johnes he wrote on the 2nd March : 4 1 

 have pretty good news to tell of myself. This is my 

 last year of delivering lectures in the Royal School of 

 Mines. This will be a very considerable relief in point 

 of work. As I had pay and fees as a professor, they 

 cut off that part of the salary given to Sir Roderick, 

 supposed to represent the Museum as distinct from 

 the Survey. Now they are to add ^300 a year to 

 the Survey salary for the Museum, and cut off the 

 Professorship salary, etc., and for that "crowning 

 mercy" I am very glad, and so is Louisa. The fear 



