74. Mr. Fohn Flower. 
the Merstham valley near Caterham Junction, where the Cater- 
ham valley joins it, is only about 210 feet, so that here, in about 
six miles, we have a fall of about 670 feet, and which from the 
lower hills is about 500 feet. The highest point in the main’ 
Caterham valley is 560 feet, and inthe Marden Park valley 
623 feet. Probably the Caterham valley is an old river valley, 
which had its own stream before its connection with the 
Weald was severed. Like all the other valleys of the dis- 
trict, the valleys which run into the Caterham valley are 
now perfectly dry. 
The high ground which lies between the Merstham valley 
and the Caterham valley has three large valleys which have 
been formed in it,’ and which originate in ground which is 
over 700 feet above the sea level. One of these runs up 
to and passes on either side of Chaidon Church, another 
passes to the east of Coulsdon Church, and a third runs up 
between the other two. All of these valleys run into the 
Merstham valley, one close to the Red Lion Inn, and the 
other two, one a little to the north, and the other a little to the 
south of it. If to the above-mentioned valleys we add one 
or two smaller ones which run into the Merstham valley 
from the high ground about Sanderstead, we shall have before 
us all the valleys which it is important for us now to consider. 
Taken as a whole, all the valleys which are comprised in 
the Wandle basin have exactly the same relation to one 
another that the branches of a stream would have. The 
smaller branches run into and coalesce with the larger ones, 
and all ultimately flow into and join the Merstham valley, 
in which valley our town stands. Like branches of a stream 
too, they have a gradual and continuous fall. If you trace 
any one of them down from its origin in the high ground 
to the Merstham valley you will find no ups and downs in it, 
no hills and valleys. The bottom of the valley is a complete 
trough, with a steady and gradual slope down to Croydon. 
How then were these valleys formed? To answer this ques- 
tion satisfactorily it would be necessary to take each valley in 
succession, and subject it to a minute and exhaustive 
examination. This is of course impossible this evening. 
It would moreover require a great deal more time and 
attention than as yet I have been able to give to the 
subject. But stated generally it seems probable that 
more than one of the main valleys were, in the first 
instance, cut out by streams, lateral branches of the ancient 
Wandle, which flowed out of the Weald, but which one by one » 
were converted into dry valleys by the deepening of the valley 
of the Gault, as already pointed out. Since that time they have 
been greatly deepened and enlarged, and smaller lateral valleys 
