246 PROCEEDINGS OF THE GEOLOGICAL society. [Feb. 23, 
base and apex of Ridgway Hill. I simply stated the new features 
in its geology, reserving a fuller statement until I had received my 
fossils from Dorsetshire. These new features were— 
Ist. The existence of another member of the Wealden formation. 
2ndly. The apparently anomalous position of what I deemed to be 
the Oxford clay ; and 
3rdly. The existence of the Tertiary system. 
The section, which I was not then prepared to send to Cambridge, 
but which is now appended to this paper, shows also what may be 
considered as another new feature,—I mean the fact that the Purbeck 
beds really dip in their natural order between the Portland stone and 
the Hastings sands. 
It will now devolve upon me to detail more fully those facts from 
which I have considered myself authorized to draw the conclusions 
I have thus briefly stated. But im doing this it will be expedient 
previously to pomt out the geological character of the district gene- 
rally, and then to state in particular those views which have hitherto 
been held with respect to the locality. 
Ridgway Hill is situate about midway between Dorchester and 
Weymouth. The high road passes over it, and the railway now in 
progress is to go right through it by tunneling the upper and deeply 
cutting the lower parts. The hill must attain the average height of - 
about 500 feet above the level of the sea, and is a portion of the 
escarpment of chalk, which ranging from the fine bluff and wave-worn 
cliff of White Nore on the east to its inland termmation at Chilcombe 
on the west, forms a very important feature in the geology of the 
Weymouth district. 
From Messrs. Conybeare and Phillips (pp. 182 and 192), and the 
elaborate paper of the present Dean of Westminster and Sir H. de la 
Beche in the Geological Transactions (vol. iv. 2nd series, part 1.), we 
learn the general structure of the country between Ridgway Hill and 
the Isle of Portland, and the great faults which in times long ante- 
rior to the present have taken place in this part of the coast. Both 
these characters must be borne in mind whenever we are considermg 
the geological phenomena of this locality. 
Respecting the general structure, it will be remembered that this 
arises from the protrusion of the forest marble on the north-west of 
Weymouth. Its anticlinal lime ranges about east and west, and the 
several superior strata, up to the Purbeck formation inclusive, lie on 
its inclined sides and conformable to them in regular succession. 
The importance of the great Ridgway fault will appear when we 
state, in the words of the authors of the paper referred to, that it ex- 
tends ‘“‘without interruption nearly fifteen miles, passmg along the 
great escarpment of chalk at various elevations from the top to the 
bottom of it*.” . . 
The geological views hitherto entertained respecting this district 
* This paper must be the manual of every student of the geology of the neigh- 
bourhood of Weymouth. It takes enlarged views of the whole subject. For my- 
self, 1 am bound to acknowledge deep obligation to its authors. 
