COAL UNDER SOUTH-EASTERN ENGLAND. 145 



in beds older or newer than the Carboniferous Series, of which the Coal Measures 

 form an upper member. Dover and Harwich are the only places in South-Eastern 

 England at which rocks belonging to the Carboniferous Series have been found. 

 But while at Dover Coal Measures were pierced, at Harwich the boring ended 

 in beds apparently older than Coal Measures. However, in the district where 

 the lower beds of a series are found, the higher are more likely to be discovered 

 than elsewhere. 



We have learned that, east of the Straits of Dover, Coal Measures have been 

 found on ihe northern flank of a ridge or plateau of older rocks. This ridget 

 though having a general east and west range, is seen, where visible, to take a 

 more or less sinuous course, like that of an ordinary mountain-chain. The lowest 

 beds 3'et reached in South-Eastern England are (as already mentioned) the Upper 

 Silurians at Ware. Between Ware and the Thames at and near London only 

 Devonian or Old or New Red Rocks have been discovered, as already stated ; 

 but we have seen that we are not justified in expecting Coal Measures on the 

 ancient plateau but on its northern flank. Assuming that the Coal Measures 

 struck at Dover are thus situated, it is evident that the range of the plateau 

 between Dover and Ware is nearly north-westerly in direction, and that the most 

 probable position of any Coalfields associated with it is on the north-eastern side 

 of a line connecting those towns. Thus a section between Harwich and Ware 

 would probably disclose a state of things more or less resembling that indicated 

 in the diagram below, the surface rocks being removed. 



■•iAIKyviCH 



.\. Silurian Rocks. C. Lower Carboniferous 



H. Devonian. D. Coal Measures. 



But the Utter want of evidence between \\'are and Harwich, and the probability 

 that any Coal Basins existing under South-Eastern England are comparatively 

 small, and detached from each other, will make a series of borings necessary before 

 the subterranean geology of Essex and Suffolk can be clearly intelligible. Every 

 boring, however, will add to our knowledge, and it matters little or nothing 

 whether the Coal Measures themselves are pierced in the first boring or only in 

 the third or fourth, as it is almost as important to know where they are not as 

 where the}- are. The accidental discovery of Coal Measures at Dover, for 

 example, tells us nothing about the size of the Coal Basin touched, or the 

 directions in which it extends. It may lie mainly between Dover and Canterbiuy or 

 Dover and the Goodwin Sands, and ma)' accordingly be either workable or almost 

 entirely out of reach. Nor does it show whether there is, or is not, any inversion 

 of the beds. In short, its interest and importance resemble that at Burford. As 

 the Burford boring proves the existence of a Coal Basin under Secondar}' rocks 

 many miles eastward of the Coalfields of Bristol and of the Forest of Dean, so the 

 Dover boring demonstrates the existence of coal under Secondary rocks about an 

 equal distance westward of the nearest continental Coalfields. 



In selecting a site for the first experimental boring in the Eastern Counties, I 

 should be inclined to favour one somewhere between Ware and Harwich, but 

 much nearer to the latter town. Probably a spot three or four miles north-east 



