SOIL ANALYSIS AND ITS INTERPRETATION 325 



istics vary between a higher and a lower limit. The investi- 

 gator must be guided by the importance of the region from 

 the particular point of view in deciding how closely he is to 

 map out the country. 



Absolute uniformity cannot be expected over any con- 

 siderable area, and even such uniformity as existed has often 

 been upset by subsequent rearrangements of the soil which 

 result in the original surface being covered up with a later 

 deposit or being washed away, leaving the original subsoil to 

 become the new soil. Such changes are readily detected by 

 mechanical analysis of the surface and subsoils ; examples are 

 given in Table LXXXIII. At Merton the subsoil on the lower 

 ground appears to have been the original surface soil, because 

 of its identity with the surface soil and its marked difference 

 from the subsoil of the land higher up ; it has been covered 

 with a deposit identical with and presumably derived from the 

 higher lying soil. The same thing has happened at Hamsey 

 Green. At Woodchurch, however, it appears that the old 

 surface of 69, now the subsoil, has been covered with rather 

 a lighter soil ; it is equally possible, however, in this particular 

 case that 70 has lost its original surface soil, the present 



TABLE LXXXIII. VARIATION IN SOIL DUE TO WASHING OR FLOODING. 



