348 CHALK ESCARPMENT. [l889. 



Prestwich was on very affectionate terms with Dr 

 Gustave Plarr, the eminent mathematician, who left 

 Strasburg during the siege, and thenceforward made 

 England his home. Madame Plarr had been an old 

 and valued friend of the Prestwich family, and was 

 nearly connected by marriage. 



J. Prestwich to Gr. Plarr. 



DARENT-HULME, SHOREHAM, SEVENOAKS, 21th June 1889. 



MY DEAR GUSTAVE, I am glad we shall have the pleasure of 

 seeing you on the 6th July. I will then endeavour (if time per- 

 mit) to answer your query respecting the Chalk escarpment. I 

 would not attempt it in a letter, for a volume would hardly 

 suffice for the conflicting opinions and evidence. I may, how- 

 ever, say that Lyell's theory of sea action and sea cliffs is now 

 generally abandoned. 1 You will find a chapter on the subject 

 in Eamsay's ' Physical Geology and Geography/ if you have the 

 book. With our united kind regards to all your party, I am, 

 sincerely yours, JOSEPH PRESTWICH. 



The short geological expeditions during the summer 

 gave the greatest pleasure to Professor Prestwich, 

 whose health with vigilant care had improved, and 

 who seemed to have drifted out of the condition which 

 had led to frequent and serious illnesses during a 

 series of years. The following note from the skilful 

 physician whom he had once or twice consulted may 

 not be out of place : 



Sir Andrew Clark to J. Prestwich. 



16 CAVENDISH SQUARE, 26A Oct. 1889. 



DEAR PROFESSOR PRESTWICH, I have received the copy which 

 you have been pleased to send me of your work on ' Geology,' and 

 I return you my grateful thanks for this valuable and welcome 

 expression of your consideration. 



1 Lyell himself abandoned this theory in his 'Student's Elements of 

 Geology,' 1871, p. 81. 



