370 



8. S. Buckman — River Development. 



angles, as it would if the axis were level, but in a direction 

 intermediate between the dip of the longitudinal axis and the dip 

 from the crown to the gutter (Fig. 1). 



The same thing is shown even better in a courtyard as regards 

 synclinic drainage. I have in mind the Close at Gloucester, where 

 there is a dipping syncline such as B, with oblique lateral channels 

 like D', D". These artificial cases would have shown Mr. Strahan 

 that his river drainage should be on the same plan. But he could 

 have verified them by actual examples of river drainage ; as regards 

 the anticline, how off the north side of the Mendip axis, which runs 

 approximately west to east with east dip, the streams flow north- 

 eastward,^ or how off the east side of the Pennine axis the streams 

 like the Swale, Ure, Nidd, Wharfe, and Aire drain approximately 

 south-eastward. Or, as regards a syncline, how, in that to the north 

 of the Pevvsey axis, the streams from north and south run obliquely 

 to meet in the synclinal trough of the Kennet-Thames. 



Fig-1 



Fig. 1. — Drainage of a road and path. A, the crown of the road — ^the anticlinal 

 axis, dipping south-east ; B, the syncline — the gutter between the road A and 

 the path C ; D, D', streams draining off the dipping axis at oblique angles ; 

 D', D", streams obliquely joining the synclinal or trough stream of the gutter. 



Fig. 2. — Direction of tributaries on the left bank of Severn -Avon, to fulfil 

 Mr. Strahan' s hypothesis. 



Examples of drainage show conclusively, then, that Mr. Strahan's 

 river-system should have been after the manner depicted in Fig. 2 ; 

 the tributaries draining his supposed anticline should have flowed 

 obliquely. But the facts are against him : the tributaries on the 

 left bank of the Severn-Avon have not the direction which his 

 hypothesis requires ; but they flow in a peculiar manner, more or 

 less against the direction of the Severn and Avon (Fig. 3). 



Now these tributaries diverge more or less from a central point ; 



1 S. S. Buckman, " Excursion to Dundry " : Proc. Geol. Assoc, 1901, vol. xviii, 

 pt. 4, p. 157, fig. 9. 



