270 PEOF, E. HULL^ LL.D.^ ETC., ON THE SUB-OCEANIC 



represented at the Little Sole Bank and the Nymph Bank 

 in lat. 49° N. and long. 10° E.* 



In 1853 the late Sir H. T. de la Beche in his Geological 

 Observer shows by a map the expanse of the area within the 

 100-fathom line, Avhich if raised to the level of the sea, as he 

 believed it had been, would represent to the eye little else 

 than a vast plain ; and he adds, " if we extend the area to 

 the 200-fathom line it would not be much increased owing 

 to the steep descent of the slope."! Tliis able exponent of 

 geological phenomena indicates also the process of formation 

 of this but very gently sloping shelf, by attributing it to the 

 eroding efi'ects of wave action, and the distributing power of 

 the tides during a period of gradual submergence. The 

 existence of this remarkable platform — established by these 

 early observers — has since been recognised byseveral writers,^ 

 and its extension southwards along the coasts of France, 

 Spain and Portugal is thoroughly established. But the real 

 j^hysical base of the declivity forming the margin of the 

 British-Continental shelf has not been indicated by these 

 authors, nor the fact that the shelf is intersected by river 

 channels reaching down to its very base at depths varying 

 from 6,000 to 9,000 feet below the level of the ocean, as I 

 hope to show by means of the soundings on the Admiralty 

 charts of the British Isles and Western Europe. Nor is this 

 at all surprising, seeing that the existence of such physical 

 features at such great depths demands the admission of 

 stupendous changes in the regions here contemplated as 

 regards elevation and depression, such as naturalists might 

 well hesitate to accept unless demonstrated by evidence of 

 the most convincing kind. And, for myself, I full}^ admit 

 that had it not been for the clear demonstration by several 

 American geologists, but especially by that of the Professor 

 J. W. Spencer, that the bed of the ocean along its Avestern 

 margin has been worn into terraces traversed by old river 



* " The Valley of the English Channel," Quart. Joitrn. Geol. Soc, 

 vol. vi (1849). Prestwich concurs in this view, Geology, vol. i, p. 118. 



t Geological Observer, 2 Edit., pp. 91-92. 



\ Amongst these may be mentioned Dr. G. C. Wallich, TJie North 

 Atlantic Sea-Bed (1862), Plate XII, Professor Boyd-Dawkins, Popular 

 Science Reviexv, October, 1871 ; Professor T. Rupert Jones, Rep. Croydon 

 Microscopic Club, 1877 ; Professor J. Geikie, Address Brit. Assoc, 1892, 

 and Proc. Roy. Geog. Soc, Sept., 1892 ; Professor T. McK. Hughes, 

 Trans. Victoria Inst., 1879 ; A. J. Jukes-Browne, Building of the 

 British Isles, 2 Edit. 



