158 Geological Society : — 



errors of observation are distributed according to a continuous 

 differentiate function (Congress, p. 164). But has the 

 objection much weight in general ; with reference, say, to a 

 molecular medley (14), or to an average of statistics prolonged 

 indefinitely under stable conditions ? 



On the" whole it appears from the explanations which 

 Professor Sampson has offered in the Philosophical Magazine 

 that he designed to repair or reconstruct the edifice founded 

 by Laplace. But, according to the view here taken, the 

 operation was calculated to weaken the foundation and to 

 damage the structure at other points. IS 1 or were there 

 compensating advantages in the additions proposed as im- 

 provements. On a first view the danger to the structure was 

 more apparent than the intention to make repairs. It was 

 natural, then, that one who was deeply impressed by the use 

 and beauty of the edifice should protest strongly against an 

 attack upon it, though made by an expert whose authority on 



ithematical subjects commands great respect. 



mai 



XII. Proceedings of Learned Societies. 



GEOLOGICAL SOCIETY. 



[Continued from vol. xl. p. 826. j 



February 20th, 1920.— Mr. Gr. W. Lamplugh, F.B.S., President, 

 in the Chair. 



I^HE Pkesidext in his Anniversary Address discussed Some 

 .Features of the Pleistocene Grlaciation of England, 

 dealing principally with the changes brought about by the ice in the 

 surface-features of our country. With the aid of a sketch-map he 

 showed that over 5000 square miles of English land, or about one- 

 tenth of the whole country, would vanish if the drifts were removed, 

 as the ' solid ' rocks lie below sea-level in tracts of this extent. A 

 further area of about 10,000 square miles is overspread by drift of 

 sufficient thickness wholly to mask the ' solid ' land-forms, so that 

 rather more than one-quarter of the country owes its present shape 

 to Glacial and Postglacial deposits. Another 20,000 square miles 

 was glaciated, and more or less modified, but without losing the 

 dominating features of its rocky framework. The remainder of 

 the country was affected only by the intensification of the atmo- 

 spheric agencies, whereby its original features were accentuated. 

 In a general sense, the hill- districts have not been greatly changed, 

 but the lowlands have been in most parts completely altered. 



The source of the huge mass of material contained in certain of 

 the lowland drift-sheets was next considered, and the opinion was 

 expressed that a large portion of this was an addition to the land, 

 ■ brought in bv the ice from outside our present coast-line. The 



