172 
SUB-AEEIAL DENUDATION 
knowledge of the geology of our district, and to indicate to his 
brethren of the hammer what seem to be the most promising 
fields of research. 
Now there is one branch of Geology that has always had for 
me a special charm, probably through the influence of my 
esteemed master, Sir A. C. Eamsay, and that is the dependence 
of scenery on geological structure. And it so happens that this 
point is admirably exemplified in many parts of our own district. 
It seemed to me therefore, that it would be worth while trying 
to work out this subject in some detail for the country in the 
neighbourhood of Bristol. For I felt that assuredly there is 
nothing like such detailed examination for proving or disproving 
the truth of those principles of Denudation which are now so 
generally accepted among geologists. Such work would more- 
over afford opportunities of verifying that most admirable 
map which Mr. Wm. Sanders has bequeathed to us — a piece of 
work of which Bristol may w’ell be proud. The task I set 
myself, then, was the investigation, in some detail, of the 
influence of geological structure on the scenery of the Avon 
basin, and at the same time the verification of the recognized 
geological map of the district. But the subject is a large one, 
and I hereby call upon the members of the Bristol Naturalists’^ 
Society in general, and upon those of the Geological Section in 
particular, to co-operate with me in this work. 
In this paper I propose to deal with the Sub-aerial Denuda- 
tion of that section of the Avon Basin which lies between 
Bristol and the Channel. But first I must say somewhat by 
way of introduction. 
The errors of geologists of the past are apt to live on in 
the popular notions of to-day. Two such cardinal errors there 
are in connection with my present subject. They may be 
termed the Diluvial error and the Volcanic error. Looking out 
on the diversified surface of the land, and impressed with the 
