On the Weald. 77 
further progress through the Chalk, forms springs all along at 
the edge of the clay, from which originate streams which flow 
over the clay into the Thames. 
This peculiarity of the district seems to have had a very 
curious effect upon the distribution of the chief towns in our 
neighbourhood. You will see from the geological map that 
the line of the southern edge of the London Clay is a very 
irregular one, and yet along it are placed in succession 
Croydon, Beddington, Carshalton, Sutton, Cheam, Ewell, and 
Epsom, and numerous smaller towns and villages. These, 
no doubt, were placed where they are on account of the 
_ springs of which I have spoken. On the Chalk, on the other 
“ hand, owing, no doubt, to the scarcity of water, not a single 
large town is to be found, except in the immediate neighbourhood 
of one of the few streams which now flow through it from the 
Weald. 
In conclusion, I trust that I have been able to make 
intelligible to you all the facts and problems which I have 
dealt with this evening. My aim has been throughout to 
deal with general principles, rather than to go minutely 
into details, and I think I have shown that there is a 
very great deal in our immediate neighbourhood which is 
well worthy of the attention of those of our members 
who are interested in geology and physical geography. The 
amount of leisure which I am able to command is unfortu- 
nately but small, and I have not therefore been able to make 
my paper’as complete as I should have liked, or to prepare all 
the diagrams that I had intended, but if my paper has no 
other effect, it will have helped to call the attention of our 
members to some matters of great interest, and will, I hope, 
afford some assistance to those who, like myself, have striven 
to understand the very remarkable series of changes which 
have brought our district into the condition in which we now 
see it. 
