594 SCIENCE PROGRESS 



the intervention of ice, 1 though there is no direct indication 

 of either. The expert opinion seems, however, to favour a 

 combination of sea action followed by a period of ordinary 

 sub-aerial erosion, i.e. by rain, river and frost action. 



The idea of the past continuity of the chalk over the whole 

 Weald is generally illustrated by a diagram of a section of the 

 Weald, which, being contracted out of all proportion, forces 

 on one an erroneous impression as to the height of the chalk 

 escarpments as compared with the breadth of the intervening 

 area. This diagram, which shows the chalk, as supposed to 

 be once continuous, rising to a height of some 3,000 ft. sur- 

 mounting the Weald, is reproduced in most descriptions and 

 tends to act as a misleading sign-post to every subsequent in- 

 vestigation. A section to scale is on Plate I taken fromTopley's 

 Geology of the Weald, in which the true proportions are approxi- 

 mately given, and the assumption of the continuity of the 

 chalk appears far from being well founded. Had the chalk of 

 the escarpments been a little further removed from the action 

 of the anticlinal 2 upthrust, it would have been generally 

 horizontal — even now the mean dip of the South Downs is 

 very small — and the present theories would never have been 

 held ; certainly, not so firmly. 



The Weald was undoubtedly a closed area. If one con- 

 tinues the direction of the points of the horseshoe across the 

 Channel, they will join up with a small area round Boulogne 

 (the Bas boulonnais), identical in its features with the Weald, 

 showing that the whole was once entirely circumscribed by 

 the chalk (see Plate II). Afterwards, owing to changes which 

 resulted in the depression of its Channel portion in a synclinal 3 

 curve, the sea was allowed to penetrate, forming the Straits 

 of Dover. We do not know when this occurred, but on this 

 small dimpling of the earth's surface depended the whole 

 course of England's history. Incidentally, but for this, there 

 would probably have been no British Empire ! 



That is the staging. I now wish to suggest another inter- 

 pretation than that given by the current theories regarding 



1 There is no doubt, however, that once at least during the maximum intensity of 

 the Glacial Epoch (that of the Chalky Boulder Clay probably) the Coomb Rock 

 and " Head" were formed by the melting of local ice sheets covering the south 

 of England. 



' Anticlinal = convexity of strata forming a mound, while in a synclinal forma- 

 tion the strata make a basin- like curve. 



