188 Reports and Proceedings — 



2. Former higher level of the plane of saturation before the valleys 

 were cut down to their present depth. 



3. Increase in the rainfall. 



None of these theories is sufficient to account for the origin of 

 Coombes and the transport of Coombe Rock. There is no evidence 

 of submergence whilst the Coombes were being eroded ; on the con- 

 trary, the descent of the Coombes to the sea-level near Rottingdean 

 and elsewhere, is suggestive of a slight elevation. The deep trench- 

 ing of the Downs by valleys, and the consequent lowering of the 

 plane of saturation, is applicable to many of the slightly inclined 

 Coombes, but the whole structure of the country shows that the 

 outlet for the water must have been as clear then as now. Since 

 the dry chalk valleys play no part in the present superficial drainage, 

 it would make but little difference in the plane of saturation if they 

 were filled up again. If springs had formerly existed in the higher 

 valleys, their gi-adual failure would have left evidence in the shape 

 of gravel deposits and terraces. Moreover, as an objection, both to 

 the first and second theories, it is urged that if valleys had been cut 

 back by springs, some of them should fall to the north, where most 

 of the springs occur, whereas the Coombes open to the south. Lastly 

 he finds no traces of the " hypothetical Pluvial period." 



In suggesting an origin for the dry valleys and Coombe Rock, he 

 considers that the fauna and flora, both at Fisherton and Bovey 

 Tracey, point to a great degree of cold, from 20° to 30° lower than 

 what now prevails in the South of England. The ground would 

 thus be frozen to the depth of several hundred feet, and the drainage 

 system of the chalk entirely modified. There would be no under- 

 ground circulation. The summer rains would immediately run off 

 any steep slope, often in violent torrents. These would tear up the 

 layer of rubble already loosened by the frost, carrying down masses 

 of unthawed chalk too rapidly for solvents to have much effect. No 

 Coombe Rock is found in valleys that have a greater slope than 100 

 feet per mile. There is no need of excessive rainfall ; it might have 

 been a dry period corresponding to that of the Loss. 



If the time had not been short, all soft rocks in the South of 

 England would have been planed down to one gently undulating 

 surface like the plains of Russia and Siberia. Such Tundra-con- 

 ditions may have occurred more than once. 



2. '' Probable Amount of former Glaciation of Norway, as demon- 

 strated by the Present Condition of Rocks upon and near the Western 

 Coast." By W. F. Stanley, Esq., F.G.S. 



The observations on which this paper are based were made in June 

 last, during a voyage along the west coast of Norway. Inland con- 

 ditions were also noted in the Hardanger and Sogne Fjords, and a 

 few trips up some of the valleys enabled these inland observations 

 to be further extended. The author limited his work in searching 

 for outline evidence of ice-action. The aspect of the coast for hun- 

 dreds of miles consecutively has a uniform character of jagged and 

 pointed rocks nearly to the sea-level. At the mouths of the fjords 

 the rocks are more rouaded, particularly at heights less than 100 ft. 



