52 THE DALES OF DERBYSHIRE. 
to the right and north, Crich is reached, where grey rock 
in massive undulating layers forms the hill. The grey rock 
here goes down into the river bed, where it is gradually 
being washed away, and is, consequently, producing a gradual 
widening of the valley. The rock bends round to the 
north and left, seeming to join the hills round and beyond 
Matlock. Descending to Cromford Station we strike the 
river again, and as we proceed along its bank, the grey 
rock soon asserts itself, and approaching Matlock, we have 
high walls on either side, and as the view becomes more 
extended, the same material occupies the precipitous Tors 
or cliffs, right and left. High Tor stands before us. The 
general appearance of things through Matlock Bath need 
not be described, until having passed through the steep 
wall at either side we arrive at Matlock Bridge, this exit 
being precisely similar to the gorge entered near Cromford. 
If we ascend to any of the high ground on either side of 
the river, and look towards that point where the Derwent 
enters Matlock Dale, it is not difficult io imagine the gorge 
filled up with grey rock, the beds on either side being 
continuous, and the water of the river backed up by the 
obstruction to form a deep and extensive lake occupying the 
whole valley as far as and beyond Rowsley, and filling up 
the valley of the Wye up to and beyond Bakewell. Under 
such conditions it is a comparatively simple matter to 
imagine the overflow from the lake traversing the high 
ground which then occupied the present gorge, and finally 
escaping over a magnificent fall somewhere near Cromford. 
The above conditions of affairs is possible, but as valley 
formation by means of waterfalls is practically absent in 
Derbyshire, I do not consider the above hypothesis probable. 
A much more likely explanation is that the river disappeared 
into a cavern, and pursuing an underground course, came 
to light again near Cromford. In this case, however, I am 
not disinclined to think that the Derwent at one time 
