the hills, and the softer portions, the most easily denuded, 

 forminjr llie valleys. 



Rising as vapour, mist, and cloud, and falling again on 

 the earth, rain is the source of all our lakes, springs, and 

 rivers; and, through rivers, the source of continents also, by the 

 deposition of sediment on the floors of oceans and seas, and 

 by the silting up of shallow bays and estuaries. 



Its work never ceases, and, aided by frost and the 

 chemical components of the air, it penetrates and dissolves the 

 hardest rocks, and nothing is free from its action. Rivers 

 can cut only narrow channels, and it is left to rain to widen 

 them into valleys. No drop of rain runs an inch on the 

 surface without setting some soil in .motion towards a lower level. 



The amount of erosion depends, of course, greatly on 

 the soil on which the rain falls. On clays, like those of the 



Lias, it works far greater havoc than on sandy or gravelly 

 soils ; though, without due thought, the reverse might appear to 

 be the case. Mr. \V. \\'hitaker, of the Geological survey, 



in discussing the age of man at the recent British Association 

 Meeting, well observed this, when he said, " When rain falls 

 on gravel and sand, which are open and porous, they say 

 'Oh! come in, there"s plenty of room,' and in it goes, and 

 comes out again as a clear spring of water at the base ; 

 whereas, v.hen it falls on clays and stiff soils, they say, ' We 

 don't want you and we won't have you,' and the ram, in 

 response, washes hundreds of tons away from the surface;" 

 showin;; that resistance is not always the best policy. 



A good illustration of this may be seen in the district I 

 am sptaking of, or, Hardwick Hill, which stands out, as a land 

 mark, at :he far end of Scotton Common, is mainly composed 

 of gravel and said, while the unyielding clays of the Lias are 

 worn awa^' to their present depth below the Lincoln Chff. 



I 



