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line of watershed at the time the Eden and its associated rivers 
began to flow would seem to have been somewhere along a line 
joining, say, Penrith and Kirkby Stephen, and the drainage flowed 
away from this zone to every point of the compass—The Eden, 
The Tyne, The Tees, The Yore, The Swale, as well as The 
Derwent, The Esk, The Kent, and The Lune, all rose here. 
But at that time the greater part of the rock forming the whole 
surface of these parts was of such a nature as to waste at a faster 
rate, even than the comparatively-soft beds of the New Red. 
Consequently, some time after the river-courses were quite estab- 
lished, the general denudation, always in progress, had lowered 
the surface sufficiently to expose, first the core of the Siluro- 
Cambrian rocks forming the Lake District, and, next, the higher 
parts of the Carboniferous framework adjacent to that on the east 
and the north-east. Important modifications of the river courses 
ensued. A further lowering of the surface gradually developed 
more and more of the Lake District and more and more of the 
Carboniferous uplands; until, eventually, even the higher-lying 
parts of the New Red appeared through the rapidly-wasting cover 
of newer rocks. (See fig. 4, pl. 1.) By the time this stage was 
attained, the rocks then forming the basin of the Eden presented 
very considerable diversities in their powers of resistance to atmos- 
pheric waste. Frost and thaw, rain and drought, heat and cold, 
affect all rocks more or less, and constantly tend to reduce them 
to a transportable form ready for their removal by the rivers, and 
their rearrangement beneath the waves of the sea. But rocks do 
not all yield alike : some may waste at even four or five times the 
rate that others do. Putting this ratio into figures, for the sake of 
illustration, we might say with regard to the rocks of the basin of 
the Eden, that the (now vanished) Cretaceous and Tertiary rocks 
wasted in a thousand years at the rate of one foot; the New Red 
at nine inches; the Carboniferous six inches; and the Siluro- 
Cambrian rocks generally at shee inches during the same time. 
(In regard to the last mentioned rocks, the Skidda Slates weathered 
at a higher-, and the Coniston Grits at a lower rate than the general 
average of the whole.) 
