and other Valleys of the East of England. 181 



until they cease abruptly against the outcrop of the Trias. The 

 innermost of these circles is completed in England by the Dover 

 and Folkestone cliffs ; but of the others, a less and less portion 

 of the circumference falls within England, as the circles become 

 larger from emergence. The second class of inequalities is in 

 all respects, except in the degree of force by which they have 

 been produced, similar to the first ; but the circles from which 

 they result emerge from a centre lying in the sea a few miles 

 south-west of Brook Point, in the Isle of Wight. The circles 

 of both groups are broken into an irregular outline, which par- 

 takes of the form of a series of springing curves. The circles of 

 the second group are none of them completed within England, 

 not more than half their circumference falling within it. 



The third group consists of inequalities having a general paral- 

 lelism to each other, and which appear as repetitions of the scarp 

 of the North Downs between Maidstone and Ashford. I shall 

 endeavour to show that they are the result of flexures produced 

 in the strata by the pressure of the Isle of Wight circles on the 

 beds first disturbed by those from the Kentish centre. 



The circles of the second group present features differing 

 in some respects from those of the first ; for although those of 

 the first may be traced, almost unimpaired in regularity, through 

 a part of the proper area of the second group, yet in other parts 

 the latter exhibit the appearance of having operated upon the 

 strata moved by the first group, and warped them into that 

 form which characterizes the third group of inequalities in the 

 East of England. The inequalities resulting from this interference 

 become more and more minute, but yet more frequent, as the 

 distance from the two centres increases, until in Norfolk, and 

 also along the verge of the Triassic outcrop that stops them in 

 the Midland Counties, their intricacy becomes extreme. 



These three groups form all the valleys of the East of England ; 

 and, so far as I have been able to test them, these valleys are 

 entirely alike in the evidence they present as to the date of their 

 origin. They all cut through the drift wherever it occurs : that 

 is to say, where the lower drift alone has been spared by the 

 denudation, they cut through that; where the upper or clay 

 drift remains covering the lower, they alike cut through both 

 drifts ; and where the upper drift rests upon the Eocene, or the 

 Secondaries, they cut through that and the underly ingtertiary 

 or secondary bed. 



It requires a minute and careful study of the maps of the 

 General Ordnance Survey to reduce these three groups of in- 

 equalities into the harmonious outline that they actually present ; 

 and for the purpose of making them conspicuous, I have carefully 

 extracted into the Map (Plate I.) accmpanying this paper all 



