282 SCIENCE PROGRESS. 



causing the Welsh watershed to lie much east of its proper 

 position. 



The drainage established during the uplift (or uplifts) 

 consisted primarily of rivers whose sources lay along the 

 axes of uplift, with their subsequent and obsequent tribu- 

 taries, such as the Tyne, Tees, H umber and other East 

 Anglian rivers, and the great stream of which the Thames 

 is a beheaded portion (5), partly of antecedent streams which 

 continued to flow for some time across the axes of uplift (as 

 for instance the Scotch-Cornish river on the site of St. 

 George's Channel and the Irish Sea?), and partly of rivers 

 flowing along synclinal depressions, as the lower parts of the 

 Dee, the river on the site of the Severn Estuary and that 

 part of the Thames which lies in the Eocene basin. 



It is the task of the English geographer to trace the 

 modifications which have complicated this initial river system, 

 as well as to clear up the story of its initiation ; and much 

 work is being done in the direction of elucidating the sub- 

 sequent complications. I have already referred to the work 

 of Prof. Davis in this connection, and his paper is extremely 

 valuable to the physical geographer, but much similar work 

 has been done in isolated areas, especially by Ramsay, Jukes, 

 Topley, Jukes-Browne, Strahan, Green and others (6); and 

 we learn from Dr. Keltie's recent address to the Geogra- 

 phical Section of the British Association that it is proposed 

 to carry out work of this kind in a systematic manner. 

 He writes : "Taking the sheets of the Ordnance Survey 

 map as a basis, it is proposed that each district should be 

 thoroughly investigated and a complete memoir of moderate 

 dimensions systematically compiled to accompany the sheet, 

 in the same way that each sheet of the Geological Survey 

 map has its printed text. It is a stupendous undertaking, 

 that would involve many years' work, and the results of 

 which when complete would fill many volumes. But it is 

 worth doing ; it would furnish the material for an exact and 

 trustworthy account of the geography of Britain on any 

 scale, and would be invaluable to the historian as well as to 

 others dealing with subjects having any relation to the past 

 and present geography of the land. . . . Dr. H. R. Mill 



