452 THE ICE AGE IN NORTH AMERICA. 



Humber, and partly a decomposed millstone grit or Bunter 

 sandstone ; and the supposed Welsh erratics on Frankley Hill 

 at a height of eight hundred feet to be in place and due to an 

 outcrop of the palaeozoic floor. 



The conclusion that the glacial phenomena of England are 

 due neither to a universal ice-cap nor to a marine submergence, 

 but to a number of glaciers bordered by temporary fresh- water 

 lakes, is in accordance with all the observations of the author 

 in England and elsewhere.* 



It is fair to add, however, that soon after this meeting of 

 the British Association at which this paper was read, his 

 observations at Frankley Hill, in Worcestershire, and west- 

 ward, led Professor Lewis to waver in his views, and he had 

 resolved to go over all the ground again; but his untimely 

 death prevented the accomplishment of this plan. Probably 

 there can be little doubt of the correctness of Mr. Upham's 

 conclusion that, if Lewis had lived, he would have accepted 

 the opinions of the majority of the geologists of Great Brit- 

 ain, that land-ice really extended at one time as far south as 

 the Thames. " Still, small portions of northern England 

 escaped glaciation ; . . . and these tracts of the high moor- 

 lands in eastern Yorkshire and of the eastern flank of the 

 Pennine Chain are similar to the driftless area of southwest- 

 ern Wisconsin." It would seem from Professor Lewis's facts 

 about a moraine in England, as well as from those presently 

 to be stated concerning Professor Salisbury's discoveries in 

 northern Germany, that the farthest extent of the ice-front is, 

 in Europe as well as in America, considerably in advance of the 

 well-defined terminal moraine, and suggests the same difference 

 of interpretation as here — i. e., this moraine is either the rem- 

 nant of a later glacial period or it is a moraine of retrocession, 



* See also "American Journal of Science," vol. cxxxii, 1886, pp. 433-438; 

 "Proceedings of the Boston Society of Natural History," 1887; "UeberGla- 

 cialerscheinungen bei Gommern unweit Magdeburg " (" Zeitschr. d. Deutscben 

 geolog. Gesellschaft, Jabrg., 1883," pp. 831-848), and " Mittheilungen ueber 

 das Quartaer am Nordrande des Harzes" (ibid., " Jahrg., 1885," pp, 897-905), 

 von F. Wahnschaffe, in Berlin. 



