Vol. 57.] OKIGIN OF THE DTJNMAIL EATSE. 197 



Ambleside. He had experienced personally the possibilities of 

 rainfall in the Lake District, and had made allowance for it in hi& 

 statement that the existing streams on the Dunmail Raise were 

 misfits. An observer of any experience should have no difficulty 

 in making allowance for variations in volume of streams, as the 

 flood-marks were certain signs of the maximum volume attained 

 by the stream. With regard to the solid geology he had said 

 nothing, as that had been fully treated by other authors. He had 

 contemplated the possibility of the depression of the Dunmail Eaise 

 being due to a band of softer rock, but could find no support for the 

 supposition, either in the solid geology or in the form of the Dunmail 

 Raise itself. The form of a valley depended on the rock in which 

 it was carved ; but this did not affect the progressive widening of 

 the presumed Dunmail Valley from north to south, or the direction 

 of the tributary valleys. In speaking of the extraordinary character 

 of the gap, he had looked to the rarity of recorded cases of reversal 

 of drainage by upheaval, to the recognition of the old valley across 

 the barrie]*, and to the depth to which the old river had cut its 

 valley through the rising mountain-mass before its course was 

 finally interrupted. 



