158 PROF. K. HULL, LL.D., F.R.S., P.G.S., ON THE SUB-OCEANIC 



order to give time for the natural (or physical) operations 

 involved, namely, the erosion of wide and deep valleys, the 

 sculpturing of extensive lines of coast rising several thousands 

 of feet above their base, and the levelling down of a con- 

 tinental platform sometimes one hundred miles broad, from 

 which the existing continents and islands spring — all these 

 operations necessarily involve a lapse of time of long 

 extended duration ; — much longer than that which many of 

 us were disposed to grant to the period succeeding the 

 Pliocene,* Such a prolonged period, however, gives time 

 for the great extension of glacial conditions which necessarily- 

 accompanied the elevation of the land, together with the 

 subsequent submergence which characterised the Inter-Glacial 

 epoch — during which portions of the British Isles Avere sub- 

 merged to the extent of 1,200 feet, and the ultimate emer- 

 gence which resulted in bringing about (approximately) the 

 existing distribution of land and sea. Movement is still 

 going on, but apparently on a less stupendous scale than in 

 Post-Tertiary times. But to this subject I may probably 

 return on a future occasion. 



The Chairman (Rev. Canon Girdlestoxe, M.A.). — I am sure all 

 will be glad to pass a vote of thanks to the able anther of this- 

 paper. (Cheers.) I will now ask the Honorary Secretary to. 

 read some correspondence Avhieh has been received. 



Captain F. Petrik, F.G.S. — The first letter is from Professor- 

 T. Rupert Jones, F.R.S. He says :— 



This is a well considered and highly cymmendable contiimatioi* 

 of Professor E. Hull's former conclusions as to the extent a,n^ 

 character of the submarine extensions of the rivers, from the 

 western coast of Europe, across the contiuental plateau iind ancient 

 coast line iuto the abys.sal region. The work is now carefully 

 continued along tlie west coast of Africa and within the INledi- 

 teri-anean area, partly by the application of the soundings given 

 in the Admiralty charts ; partly by tlie hydrographic map,. 



* Professor J. W. Spencer, in a recent letter to the author, has suggested 

 this view of a prolonged j)eriod in Post-Tertiarv times. 



