KEXDALL: THE (JLACIER LAKES OF CLEVELAND. 
•23 
the ice could not affect the position of the overflow. Subse- 
quently, perhaps in post-Glacial times, the final drainage of 
Lake Eskdale was achieved, and the great gorge of Crunkley 
Gill, 125 feet deep, completed (Fig. 7). 
About a mile l3elow Crunkley Gill, the steep hillside on the 
south of Eskdale is excavated by a vevy perfect example of an 
*' in-and-out " channel. Sunny-Brake Slack (Fig. 8). the channel 
Fig. 8. 
MAI' AND SECTION OF SUNNY BRAKE SLACK " IN-AND-OUT." 
in question, is about 75 feet deep, with sharply-cut sides and 
a broad peaty floor falling to the east. The excavation was 
commenced above the 475-foot contour, and it cuts through 
the 425 nearly to the 400-foot contour. The main Esk Valley 
here descends to 275 feet, and at the 475-foot contour it is three- 
quarters of a mile wide, so that it mil hardly be believed that 
the post-Glacial denudation could have achieved all this ; but 
besides this, it is not the habit of rivers to forsake a rock-gorge 
on account of the difficulty of cutting in it. 
