S28 Reports and Proceedings — Geological Society of London. 



oceans. This would have altered the prevalent direction of the winds 

 and the distribution of rainfall; thus the anticyclone of the European 

 ice-sheet may have caused cyclonic storms to pass farther south than 

 at present, bringing oceanic winds over the Sahara, which formerly 

 enjoyed a humid climate. Dead shells are rarely found now on 

 the eastern shores of Norfolk and Suifolk, though they are driven 

 on to the Dutch coast by westerly gales. Shell-debris in the Upper 

 Crag-beds of East Anglia shows that easterly gales were common at 

 that period. This may have been due to the altered path of cyclones, 

 caused by the glacial conditions which were becoming established in 

 regions to the north of Great Britain. The abundance of mammoth- 

 remains along the shores of the Polar Sea and the alternate humidity 

 and desiccation of the basin of Nevada may have resulted from 

 allied causes. 



It is difficult, however, to restore hypothetically the meteorological 

 conditions of the Pleistocene epoch on the theory that the maximum 

 glaciation of the eastern and western continents was contemporaneous. 

 In that case an enormous anticyclone would have extended from the 

 pole southward over both continents at the same time, causing 

 cyclonic conditions in the Atlantic both in Summer and Winter. 

 Such a condition of things would have flooded Western Europe with, 

 warm southerly winds. No such meteorological difficulties arise if 

 the hypothesis that the more important glacial and interglacial 

 periods alternated in the western and eastern continents be adopted. 

 Thus persistent and excessive cold in North America during the 

 Winter of 1898-99 was coincident with abnormal warmth in Europe ; 

 the winds were northerly and polar in America, southerly and 

 strictly complementary in Europe. 



On the other hand, the effect of an ice-sheet anticyclone extending 

 from Greenland to Central Europe might have been to force the 

 storm-tracks of the North Atlantic to the south-west, producing 

 warm south-easterly winds in Labrador, which would have tended, 

 moreover, to divert the surface-currents of the North Atlantic from 

 the European to the American coast. The glaciation of Great 

 Britain could only have happened at a time when the Icelando- 

 British Channel was closed. No permanent ice-sheet could have 

 existed in Britain and Scandinavia while the influence of the Gulf 

 Stream was as it is at present. 



It is possible that the shifting of glacial conditions from one side 

 of the Atlantic to the other may have been due to differential 

 earth -movements. 



The views taken in this paper afford a simpler explanation of 

 geological 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, were due to 

 astronomical or physical causes, it is suggested that the climate of 

 the Northern Hemisphere being, from some unexplained cause, colder 

 than that of our era, conditions of comparative warmth or cold may 

 have been more or less local, affecting the great continental areas 

 ^t different periods. 



