472 ME. F. W. HAEMER OS THE [Aug. IQOI, 



the summers are, however, warm in the former, owiog to the south- 

 erly winds which there prevail intermittently at that season. Were 

 it not for this, Labrador might even now resume its glaciated 

 condition. 



The accumulation of an ice-sheet in North America would not 

 necessarily have prevented Western Europe from enjoying a climate 

 as temperate as that of the present time ; it might even have raised 

 the winter-temperature of the latter region. On the other hand, it 

 seems probable that the effect of the anticyclone of an ice-sheet, 

 extending eastward from Greenland, over Great Britain, Scandinavia, 

 and Northern Europe, would have been to change the prevalent 

 alignment of the low-pressure system of the North Atlantic, 

 producing warm south-easterly winds in Labrador and New England 

 during the winter, instead of the northerly winds now prevalent 

 there. The alteration in the direction of the winds would have 

 tended, moreover, to divert the warm surface-currents of the 

 North Atlantic from the European to the American coast. 



The maximum glaciation of Great Britain could only have taken 

 place at a time when the Icelando-British channel was closed, 

 either by an elevation of the submarine ridge connecting those 

 countries, or by its being blocked with ice ; or perhaps under the 

 influence of both causes combined. There is evidence to shew that 

 alterations in the level of this region did occur during the Glacial 

 Period. It is possibly to differential earth-movements of elevation 

 and subsidence in different parts of the Northern Hemisphere that 

 the suggested shifting of glacial conditions from one side of the 

 Atlantic to the other may have been due. 



The views here taken afford a simpler explanation of the geolo- 

 gical facts than those usually adopted. Instead of supposing that 

 the climatic changes of the Great Ice Age, several times recurrent 

 at intervals of a few thousand years only, were due to astronomical 

 or extra-telluric causes, it is suggested that the average temperature of 

 the Northern Hemisphere during the Pleistocene Epoch being, from 

 some hitherto unexplained cause, lower than that of our own era, 

 conditions of comparative warmth or cold may have been more or 

 less local, as they now are, and that the more important variations 

 of climate during that epoch may have affected the great continental 

 areas at different periods„ 



XI. Appendix. 



Two important communications, to which it is necessary briefly to 

 refer, have recently appeared on the climate question : one from 

 Prof. T. C. Chamberlin, of Chicago,^ the other from Dr. Nils Ekholm, 

 of Stockholm.^ The first I had not seen when, in September 1900, 

 I submitted to the Meeting of the British Association, at Bradford, 



1 Journ. Geol. Chicago, vol. vii (1899) pp. 545, 667, & 751. 



2 Quart. Journ. Eoy. Met. See. vol. xxvii (1901) p. 1. 



^ 



