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POPULAR SCIENCE REVIEW. 
showing that the Devonian rocks occupy this area 1,000 feet 
below the surface through a known extension northward from 
London, of twenty-four miles. 
The exposed Devonian Rocks of North Devon, on the one 
hand, and the Silurian Rocks of Wales on the other, are now 
proved, through their fossil contents, to be continuous to and 
to extend under the London Basin, striking below the German 
Ocean on to Belgium and Germany, holding, so to speak, on 
their denuded surfaces much of, if not all, the superincumbent 
strata of the south and south-eastern part of England ; had the 
sub-Wealden boring touched the Palseozoic rocks at Battle, 
nothing more would have been desired to show the palseogeo- 
graphical structure of the south-east corner of Britain and our 
relation to north France and Belgium. 
