.26 THE HAFSL0 LAKE AND THE SOLYORX VALLEY. [3IarchlQI3, 



Discussion. 



Dr. J. W. Evans congratulated the Author, not only on the 

 excellence of the photographs that he had shown, hut also on the 

 •clearness with which he had placed before his audience the problems 

 in glacial geology presented by the district. The Author's sug- 

 gestion that some of the lake-basins had been eroded by sub-glacial 

 streams was similar to that brought forward by "Werth to explain 

 the formation of the depressions in morainic material. These 

 depressions, which are now filled by the sea, are, according to 

 "Werth, known in Schleswig-Holstein as fohrden, in Sweden as 

 fjarde, and in Denmark as fjorde, which are not to be con- 

 founded, of course, with the fiords of Western Norway. The 

 traces of a former waterfall in the disused outlet appeared to the 

 speaker to be such as would be caused by a merely temporary out- 

 flow in that direction. 



Dr. A. P. Young thought that the possible action of waterfalls 

 issuing from the glaciers themselves should be borne in mind, when 

 considering the erosion which has taken place at the end of a 

 glacier. 



Mr. G. "W. Young asked whether the Author considered the 

 transverse or the longitudinal set of valleys to be the older, and also 

 what were the causes that he suggested to account for the diversion 

 of the drainage into its present course. 



The Authok, in reply, stated that those valleys which ran at 

 right angles to the strike of the sedimentary rocks were the older, 

 and that he attached greater importance to the action of water 

 flowing under the ice than was usually attributed to it. 



