I. GEOLOGY. 837 



32 7O. Illustrations of the Sub-Wealden Boring, at Ne- 

 therfield, near Battle, Sussex. 



Contributed, on behalf of the Sub-Wealden Exploration 

 Committee^ by Henry Willett and W. Topley. 



The Sub-Wealden boring was commenced in 1872, with the 

 view of ascertaining the order and thickness of the secondary 

 rocks beneath the south-east of England, and of determining, if 

 possible, the depth and age of the Paleozoic rocks which are 

 believed to underlie them. Geologists have for some years believed, 

 chiefly in consequence of a paper published by Mr. R. God win - 

 Austen in 1856, that beneath the secondary strata of the south- 

 east of England there exists a floor of Palaeozoic rocks, prolonged 

 from South Wales, Gloucestershire, and Somersetshire on the 

 west, and from Belgium and the north of France on the east. 

 Amongst these Palaeozoic rocks there is a possibility that coal- 

 measures may occur ; coal, in fact, is now worked beneath the 

 Oolites in Somersetshire, and beneath the Cretaceous rocks in the 

 north of France. It is only in this subordinate sense that the 

 Sub-Wealden boring can be described, as it sometimes has been, as 

 a " search for coal." The primary object is to learn what rocks 

 underlie the Weald, this being a point of high scientific interest. 



Such were the problems presented for solution. The methods 

 employed and the results obtained are as follows : A committee 

 of reference was formed in London, with Prof. A. C. Ramsay as 

 chairman ; Mr. H. Willett, of Brighton, has throughout acted as 

 hon. sec. and treasurer. The money has been mainly raised by 

 private subscription, aided by grants from the Government, the 

 Royal Society, and the British Association. Two borings have 

 been made ; the first was abandoned at a depth of 1,030 feet, owing 

 to an accident to the rods. The second boring was commenced 

 in Feb. 1875, and is now (in March 1876) 1,903 feet from the 

 surface. 



The specimens exhibited are arranged in two series ; those on 

 the top and second shelves are examples of fossils from the 

 Kimeridge Clay, named by Mr. Etheridge. Those on the lower 

 shelves are arranged in order of depth, the ends nearest the surface 

 being placed on the left hand side of the bottom shelf ; the examples 

 in this series are mainly from the second boring, but a few speci- 

 mens are added from the first boring these are marked as such. 



The work is performed by the Diamond Rock-boring Company. 

 The rock is bored by a rapidly revolving " crown " set with dia- 

 monds ; the debris are carried up to the surface by a stream of 

 water which is forced down the hollow boring-rod. The " core " 

 of rock rises within the enlarged space, or " core-tube, at the 

 bottom of the rods ; it is thus preserved, and is afterwards drawn 

 to the surface. The machinery employed is shown in the photo- 



