290 Prof. A. C. Ramsay on the Glacial Theory of Lake- Basins. 



of the Permian strata in the Jermyn Street Museum, and then 

 to judge if the subject as described by me does not, to say the 

 least, deserve the measure of attention which it has received in 

 the Manuals of Professor Phillips*, Professor Jukes, and Mr. 

 Page. 



I feel convinced that the same conclusions which I drew for 

 the Rothliegende of part of England will yet be extended to 

 much of that of Northern Germany ; for though marls and 

 gravels are interstratined with it, these, as in our post-pliocene 

 drift, are exceptional, and the main characteristic of this vast 

 formation (2600 feet thick) in the Thuringerwald is the flattened 

 and subangular nature of its blocks, some of which are of large 

 size. Similar erratic deposits are now forming in Baffin^ Bay 

 and the Western Atlantic. 



Mr. Godwin-Austen long ago suggested the ice-borne character 

 of great blocks in the New Red Sandstone of Devonshire ; and 

 the Oolitic strata of the east of Scotland contain such numbers 

 of huge angular blocks, that their possibly though scarcely pro- 

 bably glacial origin constantly suggested itself to my mind when 

 I noted the facts during a journey with Sir Roderick Murchi- 

 son in 1859. The local character of the blocks, chiefly but not 

 entirely Oolitic, is adverse to the view ; but the smashed condition 

 of many of the shells in the interstratified oolitic clays is analo- 

 gous to the state of the shells in the upper drifts all over Britain. 



It may not be generally known that Escher von der Linth is 

 aware of boulders in the cretaceous strata of the Alps, and God- 

 win-Austen has suggested a similar origin for boulders some- 

 times found in the British chalk ; and surely, though unnoticed 

 by him in the f Elements/ Sir Charles is conversant with the 

 clear-sighted observations of Gastaldi, who attributes the for- 

 mation of certain conglomerates (with scratched stones), and 

 the transport of the huge boulders that lie in them, to the agency 

 of floating icebergs that, descending into a miocene sea, broke 

 from Alpine glaciers, and carried their freights to the neighbour- 

 hood of what is now Turin, from the far-off region where the 

 Lago Maggiore at present lies. 



Geologists, then, some of them of the highest eminence, have 

 actually written of " the agency of ice " in several geological 

 epochs; and, whether in these epochs or in others mentioned 

 above, it is clear that erratic- and boulder-phenomena not easily 

 to be accounted for exist in many formations, these phenomena 

 being not unlike those that are brought about by floating ice in 

 the present day. The subject of the ancient agency of glaciers 

 and floating ice is indeed far too prominent to be disposed 



* Professor Phillips does not agree with me, but still in a note he takes 

 care to notice ray opinion. 



