190 PROC. COTTESWOLD CLUB vol. xiii. (3) 



Coin ; and the Chalk gorge at Upavon shows the counter- 

 part of what the OoUte gorge at Charhon Kings must 

 have been. 



So that, changing the necessary names, putting Severn 

 for Bristol Avon, Coin for Salisbury Avon, Chelt Oohte 

 gorge for Upavon Chalk gorge, Severn Vale for Pewsey 

 Vale, we get from a present day example an exact picture 

 of what a Cotteswold river system was in the past. 



Then, from analogy with what this river system of the 

 Cotteswolds is at present, we can infer the future of the 

 river system of the Pewsey Vale — the Bristol Avon will 

 invade that vale further and will behead the Salisbury 

 Avon ; and then the Salisbury Avon will rise below 

 Upavon on the slope of the Chalk escarpment as the Coin 

 does now near Andoversford, and the Upavon gorge will 

 be deepened to become the valley of an obsequent river 

 like the Chelt. 



But the success of the north-eastern part of the Bristol 

 Avon along the vale by Swindon — detailed in an earlier 

 part of this paper, p. 185 — will probably precede this event. 

 It would hasten it, perhaps. 



There was one feature noticed about the Kennet in the 

 day's excursion. Ascending the hill from Marlborough, 

 a good view of the valley was obtained ; and there could 

 be plainly seen just those diminishing curves which are 

 so characteristic of the Upper Coin — illustrated in Fig. 14. 

 There was another observation. The south-western road 

 by which we left Marlborough for Pewsey was evidently 

 a British trackway leading first to earthworks on the 

 downs overlooking the Pewsey Vale, and then perhaps 

 continuing as one of the ancient roads to Stonehenge. 



