Geological Society. 577 



The pity and pathos of it all ! That one of the authors 

 undoubted industry should devote his time to writing a volume of 

 over 1000 pages which, apart from questions of actual error, 

 consist of little better than a mass of fauciful and extravagant 

 speculations. 



LVJ. Proceedings of Learned Societies. 



GEOLOGICAL SOCIETY. 



. [Continued from p. 324.] 



May 8th, 1901.— J. J. H. TeaU, Esq., M.A., V.P.R.S., 



President, in the Chair. 



THE following communication was read : — 

 ' The Influence of the Winds upon Climate during the Pleisto- 

 cene Epoch ; a Palgeo-Meteorological Explanation of some Geolo- 

 gical Problems.' By E. W. Harmer, Esq., E.G.S. 



"Winds are an important factor in determining the distribution of 

 climatic zones. Deviations of the isotherms from the normal are 

 generally connected with the direction of the prevalent winds. The 

 influence of marine currents is indirect rather than direct. Changes 

 of wind cause marked and sudden changes in the weather, though 

 the general direction of ocean-currents remains the same. Permanent 

 alterations in climate during past epochs w r ould have equally 

 resulted from permanent changes in the wind. Anomalous weather 

 is due to some unusual arrangement of high and low-pressure areas. 

 Former cases of anomalous climate can only have occurred when 

 the meteorological conditions were favourable. 



Continental areas tend to be cyclonic in summer and anticyclonic 

 in winter, while the reverse is broadly true of the oceans. During 

 the Glacial Period ice-covered areas would have remained more or 

 less anticyclonic throughout the year, while low-pressure areas must 

 have prevailed in regions to the south of them and over the adjoining 

 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 Suffolk, 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 ma) T 

 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 



