THE EVOLUTION OF DERBYSHIRE SCENERY. 215 



on which the berg is being floated out. This mass being thus 

 detached, and its lateral support withdrawn from the parent rock, 

 the compression proceeds apace, and another block parts and 

 floats off at the rate of probably only a few feet per century, to be 

 followed by other blocks, whose downward path, though by no 

 means rapid, is certainly sure, and does not cease until the hillock 

 is brought to the brookside, and there exposed to the rapid 

 disintegration of the stream. But so slow are these movements — 

 so apparently earth-fixed are the hillocks — that upon one of these 

 slipped masses lower down the valley is an old cottage with its 

 outbuildings and gardens. It will be seen that the earliest removed 

 masses will have been for a longer period subjected to the wear 

 and tear of sub-aerial denudation ; hence we find such more 

 disintegrated, possessing gentler slopes, and more completely 

 clad with the verdure which only time can bestow. The newer 

 ones — near the mainland, so to speak — are steeper and barer ; 

 while right back on the slope of the parent mass higher up the 

 valley, can be perceived — particularly from a distance — peculiar 

 A shaped ^depressions marking the lines along which further 

 separation is taking place. There is no actual fissure in these cases, 

 for it would be filled up as formed with material from above and 

 below, but they are interesting as marking the line of parting 

 for the next mass. Sufficient has been said to shew that this 

 ingenious theory is fully borne out by the observed facts, and 

 certainly has, so far as the writer is aware, the merit of novelty. 

 And here must end the present article; not because the subject 

 is exhausted but because the space is limited. One word may 

 be said in conclusion. It is sometimes thought that the scientific 

 investigation and explanation of these natural phenomena will 

 detract from the pleasure to be derived from them. One friendly 

 critic wrote as much in reference to my article bearing a similar 

 title in last year's Journal. Surely the opposite is the case. To 

 the geologist every detail in the outline of hill and valley conveys 



* This refers not to the section of the depression, but to its outline on the 

 hill side. 



