TERRACES AND RIVER VALLEYS OF WKSTERN EUROPE. 289 



Plate III. 



Little need be said in explanation of Plate III, except that ihe 

 horizontal and vertical scales are unequal, the latter being (for obvious 

 reasons) exaggerated ; but as the soundings are given in fathoms, and 

 may be read by aid of a lens— the detei^mination of the form can be made 

 in each case. These cross sections bring out in a marked manner the 

 forms of the ancient river channels or canons as they trench deep into the 

 gently slojiing plain of the Continental Platform. 



Discussion. 



Tlie Chairman (Sir C. Gordon, K.C.B.). — Like myself, all must 

 have followed the author's arguments with great interest and 

 desire to join in according him a vote of thanks. (Cheers.) 



Professor Etheridge, F.R.S.- — I need hardly say that I am 

 pleased to hear this paper by Dr. Hull, but it is one not easily 

 discussed. Its statements are not even easily questioned ; few 

 are aware of the amount of labour involved in tracing and 

 determining these great depths, and the involved results placed 

 in that form, for popular exhibition and with scientific descrip- 

 tion. Few are aw^are of the labour and patience required to 

 examine and plot out over the Admiralty sheets and Mie sound- 

 ings which occur by thousands along our shores and over 

 the deep sea bottom, both British and Continental, then esti- 

 mating the varying depths to the old and now submerged con- 

 dition of the river channels ranging from Cape Finistere to 

 near Gibraltar or the entrance to the Mediterranean. These 

 river channels and tlie " continental platforms " from which the 

 numerous rivers take their rise were discussed by Professor Hull, 

 and compared with the remarkable researches carried on along 

 the eastern side of North and South America as far as the 

 Mexican Gulf, and so ably discussed in his paper read before 

 this Society in 1898 (see p. 141). It would be difficult to name 

 or point out along the extended French and Spanish coast-line 

 any special point of more interest than another, but the case of 

 the remarkable River Adour, north of the Pyrenees, with its 

 deep canon, is one of many described by Dr. Hull, illustrating 

 the great depression and physical condition of the submarine 

 area some 8,000 or 9,000 feet deep. These great river courses 

 and changes are not depicted as they should be either on oar 



