WARREN UPHAM, ESQ., ON CAUSES OF THE ICE AGE. 233 



in tbe regions where those inter-glacial beds occur. They rest 

 upon the ground-moraine of an ice-sheet which flowed south to the 

 hills of Middle Germany : and they are overlaid by the ground- 

 moraine of another ice-sheet which flowed south to the region 

 lying between the valleys of the Elbe and the AUer. The inter- 

 ;pretation of the evidence is obvious. The inter-glacial flora could 

 not possibly have flourished in the vicinity of a mer de glace — at 

 the time of its growth snow and ice could not have been developed 

 in Europe on a larger scale than at present. 



I need not prolong these remarks. My argument against the 

 author's " epeirogenic " hypothesis has been set forth in the paper 

 I recently gave to the Society, and remains unanswered by Mr. 

 Upham in his present communication. ; 



Major-Greneral Dratsox, F.R.A.S., writes : — 



Mr. Warren Upham has done me the honour of referring to 

 some of my books, in which I have given geometrical proofs of a 

 ■movement of the Earth, which movement had never before been 

 defined in detail. 



It was the certainty of the accuracy of geometry, that caused 

 me to state, 22 years ago, that the Ice Age lasted only about 18,000 

 years, terminated not longer than 7,000 years ago, and that the 

 glaciation of the two hemispheres was contemporaneoas. 



Mr. Upham states : — 



Sir John Herschel computed, however, that its limits {i.e., the obliquity) 

 ■of variation during the last 100,000 years has not exceeded 1° 21'. 



All Herschel did was to copy the opinions of M. La Place, that 

 the Plane of the Ecliptic could not vary more than 1° 21' according 

 to accepted theories. But the variation in the obliquity is depen- 

 dent mainly on the course traced by the Earth's axis ; and this 

 course M. La Place failed even to examine. 



In my book. Untrodden Ground, I devoted chapter 8 to showing 

 this oversight of La Place, and how error had been repeated and 

 promulgated by the repetition of the incorrect statement, that 

 because the plane of the ecliptic was supposed to vary only 1° 21', 

 therefore the obliquity could vary only 1° 21'. 



