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another as the ice moved, always keeping between the ice and the 

 rock, and that it ceased to accumulate when the movements of the 

 ice had ceased, and was then left just in its present position and 

 with its present characteristics, when the ice finally disappeared. 

 That seemed a very plausible view ; and much of the Till, which 

 at first sight looks like a stony paste quite devoid of stratification, 

 seemed to be exactly the kind of material that, one would think, 

 must of necessity result from the action of such causes, which all 

 are agreed must have been at work on that spot. 



Then in regard to the distribution of the boulders so plentifully 

 scattered about the districts where the Till occurs, nothing could 

 be more natural than to suppose that they represent some of the 

 material transported on the surface of the ice, and left stranded in 

 their present position when the ice retired from there. In the 

 cases where the boulders lay at higher levels than their parent 

 masses — a phenomenon of much more common occurrence than 

 many persons suppose — the agency of floating ice distributing 

 boulders during an imaginary period of submergence was called in 

 to meet the case. The same agent was usually invoked to explain 

 the puzzling phenomena of the crossing and interweaving of boulders 

 derived from sources situated at remote bearings from each other 

 in relation to the point where they now rest. 



Detritus in modern Bergs and Glaciers. — Strangely enough it 

 seems to have been assumed, almost on all hands, that the ice of 

 the Glacial Period was practically free from detritus of any kind : 

 perhaps because freedom from included materials was supposed to 

 be one of the most marked characteristics of modern glaciers, as 

 as well as of even the larger masses of ice seen in the form of 

 bergs. Yet a study of almost any full account of the glacial 

 phenomena of the Arctic, or better still, of the Antarctic regions, 

 must have shewn that this supposed purity of the ice is more 

 apparent than real. One has but to refer to so well-known a book 

 as LyeWs Elements — to say nothing of others— to see that voyagers 

 make mention, again and again, of the vast quantities of mud and 

 stony material transported in the ice, and forming part of its mass. 



