530 ^ OF THE PHYSICAL STRUCTURE 



memoir on the Strata below the Chalk, and likewise from the more 

 recent investigations, in the same region, by Mr, Hopkins, of which 

 a summary is to be seen in the proceedings of the Geological 

 Society of London, for 1841, it would appear, that in the districts 

 of the Wealden and Bas Boulonnais, the numerous axes observe 

 a curved form, and are nevertheless parallel to one another. Mr. 

 Hopkins, after describing several of these flexures, states, that 

 " all these lines preserve a remarkable parallelism with each other, 

 and with the curved central axis of the district." It would further 

 appear, from the observations of these distinguished geologists, 

 unless we have given an eiToneous interpretation to their sections 

 and descriptions, that a great number, if not all of these axes, pre- 

 sent a much steeper dip on one side than on the other, and that 

 this stronger inflection generally occurs on the same, to Avit, the 

 northern side. Speaking of the line from Farnham to Seven-oaks, 

 Mr. Hopkins uses these words : " It is a line of flexure,* with a 

 gi'eat dip to the north, but without the corresponding dip to the 

 south, necessary to form an anticlinal arrangement, except in one 

 or two localities. Towards the west, it runs immediately at the 

 foot of the hogsback, with a dip, which, near its western extrem- 

 ity, amounts to seventy or eighty degrees." " Tracing it towards 

 the east," he adds, that, " at some points the line assumes a dis- 

 tinct anticlinal character.- 



Dr. Fitton, in describing the interior of Kent (p. 134 and 135), 

 gives several drawings of sections of this or an adjoining axis, in 

 all of which the predominance of the dip on the northern side is 

 distinctly marked. Alluding to one of these sections, he says : 

 " Both sides of the saddle are visible within a few paces ; the beds 

 on the north rising at an angle of about sixty degrees, while on 

 the south, they decline at an angle of forty-five degrees." As 

 illustrating the same law, we would more particvilarly refer to the' 

 following colored sections, appended to Dr. Fitton's memoir. 



* By the term flexure, as explained by the phrase, one-sided saddles, used in the same 

 connection, we infer the author to mean, what we denominate, oblique flexures, while he 

 restricts the term anticlinal, to those bendings which give, approximately, equal dips oa 

 the opposite sides. 



