THE WEALD 607 



11 It is a matter of much satisfaction to me that Prof. 

 Gosselet's creuses should occur in a chalk area, as I have long 

 held that the dry chalk valleys are largely due to subsidence 

 from underground erosion, and have tried to get this opinion 

 officially recognised, but without success. 



" The solution of the problem afforded by these creuses 

 has, as he states in his paper, occupied Prof. Gosselet during 

 the ten years that he has been making the geological map of 

 Artois ; and, after much hesitation, he has always come back 

 to the idea that they are due to subsidence arising from com- 

 bined surface and underground erosion, but more especially 

 to the latter, which he considers hitherto to have been under- 

 rated." 



As regards the sinuous valleys, we have this opinion ex- 

 pressed by Prof. Prestwich which has a bearing on the ques- 

 tion, in his Water-bearing Strata of the Country round London. 

 He says " that streams and rivers may be considered as repre- 

 senting (but only in porous strata) in definite lines on the 

 surface, a water-flow agreeing in its general direction with that 

 which takes place, bodily, in the strata below." 



A still more definite conclusion was formed by M. D'Archiac 

 in his Memoires de la Societe Geologique de France. This 

 geologist paid great attention to the subject of the water-bear- 

 ing strata of the Tertiary and Cretaceous series of France, 

 and confirmed, as the result of his experience, the rule laid 

 down by the Abbe" Paramelle, on perfectly independent grounds, 

 in his observations on springs, viz. : that the subterranean 

 currents of water follow the same law, with reference to their 

 course, as those which flow on their surface. 



The Durability of Chalk Earthworks 



Many archaeologists have remarked on the permanence of 

 outline of tumuli and earthworks made in the chalk. The 

 resistance of the chalk to sub-aerial erosion is well illustrated 

 by the permanence of the huge figures outlined on the chalk 

 slopes, such as " The Long Man " of Wilmington, Sussex, 

 and " The Giant " of Cerne Abbas in Dorsetshire. 



Both these figures, which have no depth, but merely out- 

 line, take us back most probably to the Druidic cult of Bel 

 (Baal), the Sun God. 



In spite of their exposed position to the elements and on 

 steeply inclined slopes of chalk upland, they have not been 

 eroded, but have remained, but for the growth of herbage, 

 as definite as when made. 



The ramparts also of Maiden Castle (near Dorchester), be- 



