284 Mr. P. J. Martin on the Anticlinal Line of 



present, though in a lesser degree, the same dislocation as the 

 Pithingden Hill. 



The transverse fissure-valleys which transmit the affluents of 

 that branch of the Arun called the Western llother by Pet- 

 worth and Lodsworth*, present the same downcast of stony beds. 

 A quarry opened in the Petworth Rectory grounds some years 

 ago was just the counterpart of the one at Pithingden. In other 

 less angular parts of the greensand escarpment, wide fissures, 

 open joints filled with rubble, and other signs of violence, abound 

 where the intersections of hollow ways or stone quarries expose 

 their basset edges to observation. On the north side of the 

 Weald, again, the Kentish-rag country is not without these 

 signs of violent disruption, — the escarpments of Boughton- 

 Malerbe, Bougbton-Monchelsea, and Sutton-Vallance, for in- 

 stance; and I strongly suspect that the dislocation at Tilbur- 

 stow or Tilvester Hill, described by Dr. Mantellf, is a slide of 

 this kind. 



Much more might be said, and many more localities pointed 

 out, to show the effects of violent watery abrasion in these escarp- 

 ments; but I pass on to the equally important subject of dilu- 

 vium or drift. 



4. I should have preferred the use of the foraier word to de- 

 signate the transported materials of the area under review; because 

 I abjure for them every idea of other means of transport than a 

 diluvial action, — be it short and transient, or be it longer, and 

 frequently repeated till the denudation was complete. But since 

 the repudiation of the theoretical views on which that term was 

 founded by its author, and the general adoption of the word 

 drift, gives latitude to the use of the phrase, I shall use both 

 words indififerently, with the understanding that if diluvium is 

 used, I mean (as I believe is everywhere meant now) the drift of 

 a deluge, and not of the deluge. 



To those who are familiar only with the confused masses of 

 gravel, loam, sand, rounded and angular flints and rolled clays 

 of the London district, or indeed of the greater part of the south 

 of England, it will seem rather sui-prising to be told that the 

 drift of the district under review admits of a division into four 

 distinct natural zones, which occupy as many lines of country, — 

 mantling round the nucleus of the Weald. It is not pretended 

 that the hues of demarcation of these zones are so hard and well- 

 defined as some other boundary lines in this branch of natural 

 history. But they are strict enough to be very remarkable ; and 

 such as I could not myself have predicated, and could hardly 

 have believed to be in existence, if repeated and extended obser- 

 vations had not convinced me of the truth. 



* Sussex. t Geol. of S.E. of England, p. 177- 



