‘i ~ Fm ONE Se al ae 
ti rs 

OS) Fea 
fee DYNAMICAL GEOLOGY. —  [Boox III. — 
- 

so complete that only a few scattered fragments remain of a once — 
extensive stratum, and where it may not be easy to realize that 
these fragments are not transported boulders. In Dorsetshire and 
Wiltshire, for example, the surface of the country is in some parts 
so thickly strewn with fragments of sandstone and conglomerate 
“that a person may almost leap from one stone to another without 

























































































































































~—_-- = - sd 
Fig. 93.—RAIN-ERODED PILLARS OF OLD RED CONGLOMERATE, FOCHABERS. 
touching the ground. The stones are frequently of considerable 
size, many being four or five yards across, and about four feet 
thick.”* They are found lying abundantly on the Chalk, suggestive 
at first of some former agent of transport by which they were 
brought from a distance. They are now, however, generally ad- 
mitted to be simply fragments of some of the sandy Tertiary strata. 
which once covered the districts where they occur. While the 
softer portions of these strata have been carried away, the harder 
parts (their hardness perhaps increasing by exposure) have remained 
behind as “Grey Wethers,” and have subsequently suffered from the 
inevitable splitting and crumbling action of the weather. Similar 
blocks of quartzite and conglomerate referable to the disintegration — 
of Lower ‘Tertiary beds zn sité, are traceable in the north-east of 
' They have been used for the huge blocks of which Stonehenge and other of the 
so-called druidical circles have been constructed, hence they have been termed Druid 
Stones. Other names are Sarsen Stones (supposed to indicate that their accumulation 
has been popularly ascribed to the Saracens), and Grey Wethers, from their resemblance 
in the distance to flocks of (wether) sheep. See Descriptive Catalogue of Rock Specimens 
in Jermyn Strect Museum, 31d ed.; Prestwich, Q. J. Geol. Soc. x. p. 128; Whitaker, 
Geological Survey Memoir on parts of Middlesex, &e. p. 71. : 
