i;0 GEOLOGY [CHAP. IX 



Letter 515 I forget whether you go as far as to support Ramsay 1 

 about lakes as large as the Italian ones : if so, I would myself 

 modify the passage a little, for these great lakes have always 

 made me tremble for Ramsay, yet some of the American 

 geologists support him about the still larger N. American 

 lakes. I have always believed in the main in Ramsay's views 

 from the date of publication, and argued the point with Lyell, 

 and am convinced that it is a very interesting step in Geology, 

 and that you were quite right to allude to it. 



Letter 516 To D. Mackintosh. 



Down, Feb. 28th, 1882. 



I have read Professor Geikie's essay, 2 and it certainly 

 appears to me that he underrated the importance of floating 

 ice. Memory extending back for half a century is worth a 

 little, but I can remember nothing in Shropshire like till or 

 ground moraine, yet I can distinctly remember the appearance 

 of many sand and gravel beds in some of which I found 

 marine shells. I think it would be well worth your while to 

 insist (but perhaps you have done so) on the absence of till, 

 if absent in the Western Counties, where you find many erratic 

 boulders. 



I was pleased to read the last sentence in Geikie's essay 

 about the value of your work. 3 



1 " Glacial Origin of Lakes in Switzerland, Black Forest, etc." (Quart. 

 Journ. GeoL Soc., Vol. XVIII., pp. 185-204, 1862). Sir John Lubbock 

 (Lord Avebury) gives a brief statement of Ramsay's views concerning the 

 origin of lakes (Presidential Address, Brit. Assoc. iSSi, p. 22): "Prof. 

 Ramsay divides lakes into three classes : (i) Those which are due to 

 irregular accumulations of drift, and which are generally quite shallow ; 

 (2) those which are formed by moraines ; and (3) those which occupy 

 true basins scooped by glaciers out of the solid rocks. To the latter 

 class belong, in his opinion, most of the great Swiss and Italian lakes. 

 . . . Professor Ramsay's theory seems, therefore, to account for a large 

 number of interesting facts." Sir Archibald Geikie has given a good 

 summary of Ramsay's theory in his Memoir of Sir Andrew Crombie 

 Ramsay, p. 361, London, 1895. 



- "The Intercrossing: of Erratics in Glacial Deposits," by James Geikie, 

 Scottish Naturalist, 1881. 



3 The concluding paragraph reads as follows : " I cannot conclude 

 this paper without expressing my admiration for the long-continued and 

 successful labours of the well-known geologist whose views I have been 



