Geological Society of London. 89 



grooves at the bottom of the pan. This consideration was thought 

 to explain the fact of the greater depth of Buttermere and Crum- 

 mock than of Derwentwater and Bassenthwaite, although the size and 

 thickness of the old glacier in the former case was probably less 

 than in the latter. In conclusion, the au'Lhor stated that he hoped 

 to test the results obtained in these cases by bringing forward in a 

 future paper like details of Wastwater and other lakes and moun- 

 tains in the district. 



Discussion. — Mr. Campbell said that he had listened with great pleasure to 

 the able paper of the author. He was not himself acquainted with the Lake- 

 district, but he knew many similar districts in which similar phenomena existed. 

 He agreed with the author's conclusion, that these lake-basins were the result of 

 glacial erosion. But if ice could do so much it might have done more. In confir- 

 mation of the author's views, Mr. Campbell said that in the Caucasus there are 

 very few lakes. He had found no glacial phenomena in the whole range, except 

 one small moraine near the only lake in Daghistan. 



Mr. Evans inquired what effect the varying hardness of the strata, their trend 

 and dip, might have had on the formation of the basins, and how the presence of 

 islands was to be explained. He mentioned that at the present day the rainfall at 

 Seathwaite was in some years nearly 200 inches, which, if there were sufficient 

 cold, would suffice even now for an enormous supply of ice. 



Mr. Seeley inquired whether the position of the lake-basins in the supposed 

 glacier had any definite relation to the positions of smaller affluent glaciers, and 

 ■whether the lake-basins were to be attributed to that relation. 



Mr. Godwin- Austen remarked on the acceptance which the Chairman's views 

 had received, and the support which they were receiving. There was little doubt 

 of the former existence of ice over a large portion of this part of Europe, but 

 whether it would have existed in such thickness as was required by some geologists 

 was another question. He doubted as to the power of glaciers to drive ice 

 forward to any great extent over land either up a slope or over a horizontal space. 

 He considered that the paper would add a great interest to the country to which 

 it related. 



Capt. Douglas Galton disputed the power of ice to act in a manner materially 

 different from that of water. Owing to the friction of the ice at the bottom of a 

 glacier, he thought its flow would be so much retarded that its excavating power 

 would be almost annihilated. 



The Author, in reply, stated that the basins in all the cases he had cited were 

 excavated in the Skiddaw slate, the hardness' of which was nearly uniform. The 

 dip of the strata was very variable, but he could not point to any spot where the 

 depth of the lake was connected with the dip. The islands in Derwentwater 

 might be the result of an old moraine left by the glaciers in retreating up the 

 valley. The position of the lakes was in the direct line of the principal glaciers. 

 The thickness of the ice was proved by the existence of scratches along the sides 

 of the valleys, such as could not have been produced in any other way. The 

 probability was that the ice had been even thicker than shown by these marks. 

 Though the laws of motion of ice were the same as those of water, yet the action 

 of a hard body was of necessity different from that of a liquid. 



The Chairman was so accustomed to meet with papers such as this, confirming 

 his original views, that he was almost becoming weary of the subject. He con- 

 sidered, however, that the sections given by the author on a true scale were of 

 very great value, as calculated to give a correct idea of the actual phenomena, and 

 as showing the value of De la Beche's maxims with regard to such diagrams. He 

 inquired whether there could be any difficulty in a body of ice some thousands of 

 feet in thickness cutting out such inconsiderable hollows as those shown, just in 

 the same manner as running water would excavate its channel more deeply at one 

 spot than another, if from local circumstances the rapidity of its motion were 

 increased. ' 



2. " On the Traces of a Great Ice-sheet in the Southern part of the 

 Lake-district and in North Wales." By D. Mackintosh, Esq., F.G.S. 



