the London and Hampshire Basins, 473 



the Sevenoaks and Maidstone countries, we find that the flexures 

 which rule the Hne of the escarpment of the North Downs run 

 longitudinally south of the greensand escarpment ; so that the 

 infiltration of the Reigate, Nutfield and Westerham Hills, is 

 turned toward London. But further east in the Sevenoaks 

 district, the flexure at Montreal, first noticed by Dr. Fitton and 

 afterwards spoken of by Mr. Hopkins as the " Sevenoaks anti- 

 clinal,'' and then another in the Maidstone district, which, as 

 Dr. Fitton informs me, brings the Weald clay up at Tenterden 

 Heath, must produce a strong diversion, and throw much of the 

 rainfall of these districts severally into the Medway and the 

 Darent. 



But if I may venture an opinion on such a subject, neither 

 these nor any of the minor flexures and faults that can be traced 

 through the districts, the subject of Mr. Prestwich's research^ 

 should militate against a trial of the efficacy of Artesian wells 

 carried through the superincumbent strata into the greensand 

 under London. The faults and flexures that run east and west 

 within the great synclinal cannot be of much moment as ob- 

 structive agencies. In my earliest publication I have spoken of 

 Windsor as a chalk " outlier-by-protrusion,'' and of the Isle of 

 Thanet as another, and it is probable that the Deptford chalk is 

 intermediate in the same parallel of elevation ; but these, and 

 such as these, would not be likely to off'er any serious obstruc- 

 tion to the constant infiltration from higher levels. Borings 

 through the chalk to the level of the gault would probably absorb 

 the supply of the springs which now issue from that stratum round 

 London, and especially those which take their rise only during 

 great engorgements of it. Such are the ^^ winter-bournes " of 

 Hampshire and Wiltshire, and such intermitting streams as the 

 Lavant and the Bourne, which do not fill till the ordinary issues 

 are insufficient for the transmission of the superabundant supply. 

 I reside in the synclinal of the great anticlinal flexure of Green- 

 hurst, and I have an Artesian well in my garden, which soon 

 after it began to operate, dried up a perennial spring about two 

 hundred yards off and about twenty feet above me. And so it 

 continues to do, except in long- continued rainy seasons, when the 

 natural spring discharges again for a short time. What I have 

 said of the waters of the chalk, as they are stopped by the gault, 

 may apply to those of the greensand, which is constrained to throw 

 them out because they do not find issue at a lower level ;. and 

 such issue the Artesian wells would afibrd them. ^ (iii>] ^-r; »iir 



Nomenclature. — I share in Mr. Prestwich's objection' t6 the 

 name of " plastic clay," and I only use it in submission to the 

 tyranny of prescription. Mr. Prestwich's ^^ lower tertiary " is a 

 better phrase. The imposition of names is seldom well-consi- 



