328 Landslips. 



give them to show that even on the top of the table-land, 

 where of running water there is almost none, degrad- 

 ation and lowering of the surface does not absolutely 



FIG. 65. 



cease. This work is aided by the easy decomposition of 

 the felspar, which forms an important ingredient in this 

 coarse-grained sandstone, and during heavy gales that 

 sweep across the high bare plateau, the sand is driven 

 along the surface, and grating along the bases of the 

 projecting masses of rock, these become undercut, and 

 eventually must topple over. In this way, Brimham 

 rocks, and rocking-stones, and other isolated rock-masses 

 have been formed in other districts, as, for example, 

 such a grand mass of granite as the Mainstone of Dart- 

 moor, now unhappily blasted away and sold by its 

 proprietor. 



There is no area that shows better than this part of 

 Derbyshire how valleys have been formed in a high 

 tableland composed of Carboniferous sandstones and 

 shales. There are landslips everywhere. Groin g up the 

 valley from Hathersage a notable landslip is to be seen on 

 the hill-side west of the Derwent and south of Yorkshire 

 Bridge. Between that and the twenty-fifth milestone, 

 on the road to Glossop, there are several on either side of 

 the valley. On the north side of the valley of the Ashop, 

 the shattered masses cumber the hill-side for at least 

 three miles, and on the east side of Alport Dale, there 

 is one vast landslip a mile in length. The whole hill- 



