THE OLD RED SANDSTONE. 103 
is mottled by layers of semi-aluminous, semi-calcareous nodules, 
arranged like layers of flint in the upper Chalk. These nodules, 
when cut up and polished, present very agreeable combinations 
of color; there is generally an outer ring of reddish brown, an 
inner ring of pale yellow, and a central patch of red, and the 
whole is prettily veined with dark-colored carbonate of lime.* 
Passing onwards and upwards in the line of the strata, I next 
crossed over a series of alternate beds of coarse sandstone 
and stratified clay, and then lost sight of the rock altogether, 
in a wide waste of shingle and boulder-stones, resting on a 
dark blue argillaceous diluvium, sometimes employed in that 
part of the country, from its tenacious and impermeable char- 
acter, for lining ponds and dams, and as mortar for the 
foundations of low-lying houses, exposed in wet weather to 
the sudden rise of water. The numerous boulders of this 
tract have their story to tell, and it is a curious one. The 
Southern Sutor, with its multitudinous fragments of gneiss, 
torn from its sides by the sea, or loosened by the action of 
frosts and storms, and rolled down its precipices, is only a 
few hundred yards away ;—its base, where these lie thick- 
est, has been swept by tempests, chiefly from the east, for 
thousands and thousands of years; and the direct effect of 
these tempests, regarded as transporting agents, would have 
been to strew this stony tract with those detached fragments, 
The same billow that sends its long roll from the German 
Ocean to sweep the base of the Sutor, and to leap up against 
its precipices to the height of eighty and a hundred feet, 
breaks in foam, only a minute after, over this stony tract; 
* A concretionary limestone of the Old Red system in England, 
variegated with purple and green, was at one time wrought as a mar- 
ble. — Silurian System, Part I. p. 176. 
