THE AGE OF THE WYE. 
191 
inshore is, of course, still more quiet, but it is almost clear, 
having deposited already the great bulk of the sediment, and 
only carried over with it the very fine particles which are there 
deposited, but only amount to a very small quantit 3 ^ The 
water there is also nearly stationary, so that few fresh particles 
are brought there from the adjacent stream. This is evidently 
why the ridges are formed in such places. 
These ridges and hollows are to be seen in many places 
now, though the hollows have, of course, been considerably 
raised by a slow deposit from the greater floods which cover all 
the alluvium occasionally. The Ross Oak itself growing on 
one such ridge, as shown on the wall map, which shows distinctly 
the course of the river channel when the tree first grew there. 
It should be noted here that in modern days the regular 
course of the wearing away .of the river bank is in some places 
considerably interfered with by the erection of cribbs or walls 
for the purpose of stopping the encroachment of the stream. 
This is now the case at the Ross bend, where the stream has 
been kept from getting nearer the town, at which point it 
would otherwise have been hard up against its marginal clilf 
without that protection. But these cribbs are not numerous, 
for they are costly to build, having to be founded under water 
on the rock bottom. 
To proceed now with the consideration of the process by 
which the river wears away its marginal cliffs : — 
It has been shown that after the stream has struck the cliff 
on one side, say the west for example, it rebounds, as it were, 
across the alluvium to strike the east cliff, and again returns 
from that to the west cliff, forming thus one of the “ bends ” of 
the river. The length of one of these bends has been shown 
to average at present 1690 yards. In a bend of this description 
I find from many measurements that the actual length of cliff 
I 
