J. Q. Ooodchild — On Drift. 505 



of the very same rock lias been transported in opposite directions 

 towards the heart of the mountains by the strong ujDper currents 

 which were setting in from Scotland. 



Many similar cases occur in the Eden Valley, but perhaps the 

 most striking is that of the very peculiar granite of Dufton, close 

 under Cross Fell, blocks of which have been floated in the ice, 

 amongst other directions, across to Shap, where I have picked them 

 out of the till ; while, on the other hand, the well-known granite of 

 Shap is well represented by several large blocks close to the Dufton 

 granite in situ. Both of these opposing currents have again been 

 crossed at various other angles up to right angles by others which 

 conveyed the boulders from the north and north-west of the Lake 

 District — as, for instance, the red syenite of Buttermere — and the 

 numerous varieties of granite and other crystalline rocks from 

 Galloway, up the Eden Valley and over Stainmoor. It is easy to 

 multiply examples, but those just given will probably suffice. 



One explanation of these facts assumes that the very fact of the 

 difference between the directions of transportal of boulders and the 

 trend of the scratches is in itself sufficient evidence of the action of 

 floating ice ; but the boulders which, according to this hypothesis, 

 have come by floating ice, occur under precisely the same conditions 

 as the associated boulders of local origin, and usually occur through- 

 out all the drifts of a district in which they hajjpen to be found. 

 Hence, whatever explanation is adopted for one class of boulders 

 will apply equally well to those with which it is associated. 



In some of the wider valleys, in situations eminently favourable 

 for the formation of detached glaciers, striae are to be found going 

 right across the path which an ordinary glacier would take ; and often 

 elsewhere, other such traces of the ice-sheet as could only have been 

 formed at or near the climax of the Glacial Period remain unobliterated 

 by any newer set which followed the ordinary lines of drainage. 



On the whole, therefore, the evidence seems to point to the con- 

 clusion that after the climax of the Glacial Period, the great ice-sheet 

 did not break up by degrees into smaller detached glaciers which 

 would efface from the low ground all traces of the previous occupa- 

 tion by the larger stream, but that it quietly melted away without 

 again advancing over any of its old ground. 



It will be well here to take a review of the condition and probable 

 contents of the ice-sheet just before it began to ebb. 



It has been shown that the effect of the various crossing currents 

 at different levels would be to bring together, over any given spot, 

 a great variety of boulders from various sources, and which would 

 be dispersed throughout the entire thickness of the ice. The direc- 

 tions in which these boulders had moved need not necessarily 

 coincide with the path taken by the sole of the ice, but would in 

 many cases be even directly opposite. The ablation and compensa- 

 ting turgesence, consequent upon the pressure of fresh supplies from 

 the various feeders of the main stream, would tend to bring anything 

 in the ice to higher levels, until it finally rose to the surface at 

 whatever elevation this may locally have had. Any organic remains 



