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boulders, and their strange interweaving with others derived from 

 different and often widely separated sources. Nothing is commoner 

 in the drift of open districts than to find in one mass of boulder 

 clay or other glacial deposit stones whose several parent sources 

 are radial to the extent of ninety, or more, degrees to each other 

 and their present location. There is no difficulty in understanding 

 how this complex crossing and interweaving was brought about if 

 the reader grasps the idea that the materials of the drift consist of 

 old preglacial weathered detritus transported hither and thither 

 in, on, or under the ice, under various conditions of glacial action, 

 and liberated as a sediment on the spot where it is now found 

 when the last great mass of ice melted. This last point will be 

 discussed in a little more detail when treating more especially of 

 the origin of drift deposits. 



In the present paper it may be noticed that no reference what- 

 ever has been made to the action of floating ice. I have not 

 thought it worth while to do so, as the facts observable in the area 

 under notice are all dead against the view that floating ice has had 

 even the smallest share in any of the phenomena presented by the 

 Edenside drifts. On the other hand, as I have shewn in my paper 

 in the Quarterly Journal already referred to, land ice, and land ice 

 alone, can satisfactorily account for all the phenomena. 



Propagation of Force through Ice. — Another property of ice, of 

 some importance in its bearing upon the subject presently to be 

 discussed, might almost be stated in connection with the last, — it 

 is that the motion of a confluent stream of ice arising from two 

 tributaries meeting at an angle is affected to a considerable distance 

 down stream by the direction of flow of the more powerful tribu- 

 taries. The line of swiftest motion of the Mer de Glace is affected 

 in this way by the Glacier du Geant ail the way down from Trelaport 

 to the termination of the glacier, just as the line of swiftest motion 

 of a river would have been affected under the same conditions. 

 It was contended that the field evidence in the North of England 

 suCTo-ested that we might push this analogy between the behaviour 

 of a river and that of a glacier even farther than that, and infer 



J 



