35O Grey Wethers. 



spread far across the plains which the abrupt Chalk es- 

 carpments now overlook. These have been and are still 

 being wasted back, for they are comparatively easily 

 destroyed, but the strong ( grey wethers ' remain, and as 

 the rocks on which they once lay were slowly wasted 

 away and disappeared, these masses of tough and intract- 

 able silicious stone gradually subsided to their present 

 places. 



Besides the name of ' grey wethers,' they are also 

 known as Sarsen stones, and Druid stones, and all the 

 standing masses of Avebury and Stonehenge, popularly 

 supposed to be Druidical temples, have been left, by 

 denudation, not far from the spots where they have since 

 been erected into such grand old monuments by an 

 ancient race. 1 , 



I might add many details respecting the origin of 

 the scenery of other portions of England, such as the 

 relation of the secondary rocks to the older rocks of 

 Devon, the structure of the Malvern Hills, a true 

 miniature mountain range, and of the Mendip Hills, 

 or of the beautiful Vale of Clwyd, in North Wales, 

 consisting of a bay of soft New Eed Sandstone, bounded 

 by Silurian mountains and old limestone cliffs, and of 

 the still larger Vale of Eden, in the North, where the 

 mountains of Cumberland look down on an undulating 

 ground formed of Permian and partly of New Ked 

 strata (fig. 104, p. 521). But some of these regions 

 will be dealt with when I discuss the subject of the 

 British rivers, and in the meanwhile it would not 



1 The smaller stones at Stonehenge have been brought from a 

 distance. They are mostly of igneous origin, and are believed by 

 Mr. Fergusson to have been votive offerings. See * Memoirs of the 

 Geological Survey of Great Britain ; the Geology of parts of Wilt- 

 shire and Gloucestershire.' sheet 34, 1858, pp. 41-44. Also a 

 memoir by Professor Maskelyne. 



