Editorial. 



In an article on " Englacial Drift," in the July number of the 

 American Geologist, my friend, Mr. Warren Upham, referring to 

 my article in the first number of this Journal on the Englacial 

 Drift of the Mississippi Basin, takes exception to the impression 

 conveyed respecting his views in the matter of rising glacial cur- 

 rents. The present writer, he says, " several times speaks of the 

 opinions of writers who believe in the considerable volume of 

 the englacial drift, as if they supposed the glacial currents to 

 move gradually upward from the ground to the ice surface. 

 Such a supposition, however, seems to me quite untenable. 

 Instead, in my own writings and those of most, if not all, of 

 these authors, the exposure of the drift on the surface of the ice- 

 sheet near its border, whence much of it was washed away to 

 form the eskers, kames, and valley drift, is ascribed wholly to 

 the superficial melting of the ice sheet, which is called ablation." 

 I very much regret to have given expression, or to have seemed 

 to have given expression, to the views of these writers in any 

 other terms than they would themselves have chosen, and I 

 cheerfully reproduce the corrective statement which Mr. Upham 

 makes. Until my attention was called to the matter, no other 

 interpretation of the views of these writers than that the supposed 

 rising glacial currents moved on gradually to the surface of the 

 ice occurred to me as possible, as no logical stopping place 

 short of that suggested itself. I do not see any other consistent 

 view now, but that does not affect the obligation to present 

 accurately the views actually held. I hope these writers will 

 credit me with attributing to them what seemed to be the most 

 logical aspect of the hypothesis entertained by them. The sup- 

 posed upward movement is attributed to differential motion 



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