52 
In proceeding eastwards these rocks are in their turn overlaid: 
by other newer formations, which taken in ascending order 
consist of Inferior Oolite, Fuller’s Earth and rock, and the Great, 
or Bath Oolite, of Combe Down, which is the highest rock within 
the probable limits of the Somersetshire Coalfield. Many of the 
pits have been sunk through the Lias, Rhetic and New Red Sand- 
stone before reaching the Coal Measures, and in some instances, as 
at Braysdown, the shaft begins as high up as the Inferior Oolite, 
which is the highest formation that any pit in the district has yet 
passed through, the section of strata, as proved in that pit, being 
as follows :— 
Feet. 
Inferior Oolite <a oe ass ae ee 
Lias and Rhetic ws , “an woe) LG 
New Red Sandstone and Conglomerate ... ce HG 
Total depth to Coal Measures sae oua'g oka 
Leaving the probable limits of the Somerset Coalfield under the 
Great Oolite of Combe Down, and tracing our way, with the aid 
of a geological map, across the south-eastern counties of England, 
we find the following strata appearing at the surface in ascending 
order, viz., the Forest Marble with Bradford Clay, the 
Cornbrash, Oxford Clay, Coral Rag, Kimmeridge Clay, Purbeck 
and Portland beds, Weald Clay and Hastings Sands, Lower 
Greensand, Gault, Upper Greensand and Chalk, above which lie 
the Tertiary formations. 
Although a survey of the South of England has enabled 
Geologists thus to trace the out crops of the various formations 
which appear on the surface in regular succession, it must not be 
supposed that they are absolutely cumulative, otherwise any 
sinkings or borings towards the South East coast would present 
insuperable difficulties, the estimated thickness of overlying strata 
being 7,150 feet. 
On the contrary, recent borings have shown that as one 
