312 E. C. ANDREWS. 



thalwegs themselves, and they pass downstream into steep 

 channel slopes interrupted by large "steps" which possess 

 basins on the "treads." 



England (The Pennines and the Lake District). — The 

 Midland Railway in its passage from Carlisle to Kirkby 

 Stephen follows the valley of the Eden or Esk. For some 

 distance it skirts the bank of a young valley, thence it rises 

 into an older and broader valley of the same stream. Still 

 farther into the range this valley is left in turn and a third 

 older and enveloping valley is ascended. The "valley in 

 valley" forms here traversed represent repeated stream 

 revivals in later Tertiary time. The upper valley has all 

 the characteristics of a deglaciated trough. Its sides are 

 generally devoid of spurs, and in section it is apparently 

 U-shaped. It heads in a broad upland valley or immature 

 peneplain, due to ordinary stream development. Above 

 this, however, may be seen the remnants of an old and 

 dismantled surface which survives in the fairly even-topped 

 peaks and ridges rising out of the old upland valley level. 



Both the upland valley level and the lower canons or 

 valleys appear to have been strongly modified by ice scour. 

 The later valleys sunken in the upland valley level, how- 

 ever, are those which apparently possess the most charac- 

 teristic forms belonging to all recently deglaciated valleys, 

 while the broad upland valley level itself has suffered much 

 less from the ice action. This is to be expected from a 

 knowledge of the mechanics of streams. 



English Lakes. — In this region one finds a wonderful 

 development of lake basins, facetted spurs, hanging valleys, 

 ice swept cols, and cirques. Moreover, the situation of 

 the rock basins, hanging valleys and other forms is such as 

 to suggest the agency of a stream in their formation. Con- 

 sider for example, the decided removal of spurs at the heads 

 of such lakes as Derwentwater, the formation of young cliffs 



