92 DE LA BECHE. [l854. 



you observe, merely a representative diagram. It probably 

 conveys my idea as well as a more natural section. . . . 



It seems to me evident that such a mass of materials derived 

 apparently from the Chalk and Greensands, combined with the 

 distinct thinning off of the chalk, before it was covered by the 

 Tertiaries, as we approached the Wealden, indicates clearly the 

 destruction and removal of a large portion of the Chalk within 

 the Wealden area before the Drift period. Mr Trimmer in his 

 diagram does not seem to allow for the facts. I shall be most 

 happy on my return to town in a week or ten days to draw out 

 a more correct section, and remain, my dear Sir Charles, yours 

 very truly, J. PRESTWICH. 



My first communication connected with this subject will be on 

 the Ked and Mammaliferous Crags. This I hope to have ready 

 in the spring. 



Many years elapsed, however, before his papers on 

 these subjects were communicated to the Geological 

 Society. 



At Easter, in 1854, Prestwich, Austen, Daniel 

 Sharpe, and Forbes paid another visit to France, to 

 explore the districts called the Pays de Bray. 1 



This year was notable in the life of Prestwich for 

 the production of several papers, but was most memor- 

 able from the fact of a proposition having been 

 made to him, which, if it had been accepted, must 

 have altered his whole life. Sir Henry De la Beche, 

 the well-known founder of the Geological Survey, 

 his good and constant friend, wrote to Prestwich 

 offering him the Professorship of Geology at the 

 Thomason College, Roorkee, adding as an inducement 

 that it would be an opportunity for working out the 

 geology of the Himalayas. In the kindest way Sir 

 Henry gave him to understand that every facility 

 would be afforded him for the furtherance of this 



1 Memoir of Forbes, p. 531. 



