1910.] The Scouring Lands of Somerset. 



539 



Inferior Oolite, we find also an obvious difference in texture 

 between the two soils. The figures for the mechanical 

 analyses given in Table II. (Nos. 7 and 8) show that here 

 we are dealing with an actual difference in mechanical com- 

 position, i.e., there is a considerably greater proportion of 

 the coarser grades of particles in the soil of the sound land. 

 This difference in composition is quite to be expected where 

 both soils are derived from the underlying rock as in this 

 case, and accounts for the noticeable difference in texture, 

 greatly in favour of the sound field. Still, from the evidence 

 above it seems reasonable to suppose that the "teart" nature 

 of the pasture is due to its particular physical condition, and 

 not to the mechanical composition. 



A further point is that, though there is a large area of the 

 Lower Lias formation stretching right across the country, we 

 do not hear of serious scouring outside Somerset. This is 

 probably because, except in Somerset and to a slight extent 

 in parts of Gloucestershire and Lincolnshire,* this formation 

 is largely concealed beneath coverings of Boulder Clay, Sand, 

 Gravel, and extensive beds of Glacial Drift. f Thus it is to 

 be expected that the soils on the Lower Lias in Somerset will 

 be essentially different from the soils on this formation in 

 most other parts of the country, where it is covered by 

 Drift. 



Analyses Nos. 9 and 10 in Table II. illustrate this. They 

 are the figures given by two samples of soil from the Lower 

 Lias formation (Drift-covered) in Northamptonshire, where 

 scouring it quite unknown. The composition is entirely unlike 

 any of the "teart" soils given; land the comparative textures 

 reflect this difference, these Northamptonshire soils being 

 sandy loams. 



Such considerations suggest strongly that it is the particular 

 physical condition of the "teart" soils that is at the bottom 

 of the trouble, although no doubt there are other factors 

 involved at the same time. Moreover, whatever view of the 

 actual cause of the production of scouring herbage be taken, 

 it seems probable that it will be necessary to improve the 



Possibly also to some extent further North, 

 t The Jurassic Rocks of Britain. Vol. iii. By H. B. Woodward. 

 (Memoirs of the Geological Survey.) 



