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PROF. EDWAED HULL, LL.D., F.R.S., 



the land. That is shown by the gorges on the south side of the 

 great Weald Valley, where you have rivers flowing from the Weald 

 northwards to the Thames and southward into the English Channel. 

 These rivers have been flowing in that direction from the time they 

 originally flowed, when their source was higher than the Chalk. 

 They have continually flowed down and eroded the Chalk until 

 at the present time the river valleys are deep gorges, transversely 

 crossing the, chalk, and have been eroded, as I have said, at the 

 same time that the land was being raised and at the same time as the 

 surface was being lowered by denudation. 



But a larger consideration is suggested by Professor Hull's paper, 

 and that is the cause of this great mass of ice being in this valley 

 at the Post-pliocene period. It seems to me that we cannot 

 dissociate this from those great features of the glacial period we 

 know of in the European area. We have had glacial conditions in this 

 country extending southwards to the Thames, and we have glacial 

 conditions in various parts of Europe extending over a very much 

 larger area. Those conditions were evidenced in a paper brought 

 before the Institute by Professor Hull some time ago on the glacial 

 conditions on an extensive scale occurring in the south of Europe.* 

 It seems to me that all these glacial phenomena must be due to 

 some one great cause. What is that one great cause The 

 origin of glacial phenomena has been attributed to astronomical 

 changes ; but it seems to me they may be more probably accounted 

 for by geographical changes, such as by elevations of large areas. 

 If there were a general elevation of the northern portion of Europe, 

 continued for a sufficient length of time and of sufficient dimensions, 

 we might get a repetition of the glacial conditions of which we have 

 such abundant records as having occurred in the past. If the whole 

 of Switzerland were higher, by 2,000 feet, or even 1,000 feet than 

 at present we should have glacial phenomena, which we have in 

 different parts of Switzerland, extending over a much greater area 

 than the glacial phenomena described by Professor Hull to-day. 

 It seems to me to be unnecessary to bring in these astronomical causes 

 to account for the glacial epoch. We can recognise the enormous 

 thickness of the ice in the Valley of Lucerne at a distance of nearly 



* "Another Possible Cause of the Glacial Epoch," Trans. Vict. Imt., 

 vol. xxxi. 



