Vol. 62.] ANNIVERSARY ADDEESS OF THE PRESIDENT. Cxiii 



ridge above Seathwaite Church, along a small stream flowing down 

 the ridge in a shatter-belt. When this stream tapped the river to 

 the north, the Long-House ridge would be turned into a wind-gap, 

 and the valley above the new gorge deepened, as also that of the 

 Grasgors tributary flowing through the notch, the summit of which 

 is now 25 feet below the Long-House ridge. Owing to the 

 deepening of the Tarn-Beck valley, the Seathwaite-Tarn valley 

 became converted into a hanging valley. 



In the meantime, a stream to the west of the Seathwaite stream, 

 occupying another shatter-belt, sawed through Wallabarrow to form 

 the present gorge of the Duddon, and thus caused the deepening 

 of the tributary of the Grasgors stream, converting the Grasgors 

 stream itself into a hanging valley. Finally, this tributary ex- 

 tending backward captured the waters of the Upper Duddon from 

 the Tarn-Beck valley, below Birks Bridge, giving rise to the present 

 drainage. 



It may be noted that the bottom of the Seathwaite gorge through 

 the Wallabarrow ridge is well- glaciated, showing that the diversion 

 from Long House occurred before the last occupation of the district 

 by ice, and my impression is that the whole of these diversions 

 were produced in pre-Glacial times, although it is extremely difficult 

 to prove that none of the changes were caused during an early 

 glaciation. 



The phenomena of the Duddon valley, then, go to show that an 

 ancient river belonging to the radial drainage impressed upon the 

 dome established its base-level, and had a meandering course from 

 Scawfell to a point not far from its estuary. After this there was 

 uplift and renewed activity, but the meandering stream, cutting on 

 the whole across the shatter-belts, was only deepened along its 

 original course where that happened to coincide with a shatter-belt 

 for some distance, as below Cockley Beck. Owing, however, to the 

 less resistance of the rocks along these shatter-belts, considerable 

 modifications of the drainage ensued, with the production of the 

 hanging valleys of the Upper Esk, and of Seathwaite Tarn and 

 Grasgors. 



The last valley that I propose to consider in detail is perhaps 

 the most interesting and the best known, namely Borrowdale. 



As in the case of the Duddon, it will render the description 

 clearer if two diagrams are examined side by side, the one showing 

 the present drainage, and the other that which I believe to have 



