III. 



THE STONES IN THE WALL. 



THIS is a large subject. For in the different towns 

 of these islands, the walls are built of stones of almost 

 every age, from the earliest to the latest ; and the 

 town-geologist may find a quite different problem to 

 solve in the nearest wall, on moving from one town to 

 another twenty miles off. All I can do, therefore, is 

 to take one set of towns, in the walls of which one 

 sort of stones is commonly found, and talk of them ; 

 taking care, of course, to choose a stone which is 

 widely distributed. And such, I think, we can find in 

 the so-called New Red sandstone, which, with its 

 attendant marls, covers a vast tract and that a rich 

 and busy one of England. From Hartlepool and the 

 mouth of the Tees, down through Yorkshire and 

 Nottinghamshire ; over the manufacturing districts of 

 central England ; down the valley of the Severn ; past 

 Bristol and the Somersetshire flats to Torquay in 

 South Devon; up north-westward through Shrop- 

 shire and Cheshire ; past Liverpool and northward 

 through Lancashire ; reappearing again, north of the 



