182 



Professor W. Boyd DaicJcins 



[June 6 



Tlie coal-measures were struck at a depth of 1204 feet from the 

 surface, or 1160 feet from the top of the bore-hole, and a seam of 

 good blazing coal was met with 20 feet lower. 



12. This discovery proves up to the hilt the truth of Godwin- 

 Austen's views as to the range of the coal-measures along the line of 

 the North Downs, and as to the thinning off of the Oolitic and 

 Wealden strata against the buried ridge. The former are less than 

 one-third of their thickness at Netherfield, and the latter are wholly 

 unrei^resented. It establishes the existence of a coal-field in South- 

 eastern England, at a depth well within the limits of working at a 

 profit. The principal coal-j^its in this country are worked at depths 

 ranging from over 1000 to 2800 feet, and one at Charleroi, in Belgium, 

 is worked to a depth of 3412 feet. 



The Dover coal-field probably forms part of the same narrow 

 trough as the Calais measures, prolonged westward under the 

 Channel further to the south than Godwin-Austen drew it in 1858. 

 Whether it is a trough similar to that which extends through 

 Northern France for more than 100 miles from east to west, as 

 God win- Austen has drawn it in the diagram on the wall, reaching 

 as far to the west as Reading, or whether it is a small, faulted, 

 insignificant fragment of a field, such as that of Marquise and 



Fig. 2. 



Cham 

 Gau 

 Greensand 



Measures 





Probable Kange of Coal Measures between Doveb and Calais. 



Hardinghen, remains to be proved. It is, however, one of a chain of 

 coal-fields, which will, in my opinion, ultimately be proved to extend 

 under the newer rocks between Dover and Somerset, along the line of 

 the North Downs, in long narrow east and west troughs. It is 

 probably a continuation beneath the Straits of Dover of the coal 

 measures struck at Calais. (See Fig. 2.) 



The further question as to the value of these fields may be 

 answered by the amount of coal in the fields which are now being 



