471^ Ml*. P. JF. Martin on the Anticlinal Line of 



strata & tt^tvtiter-bearing one, as Mr. Prestwich has obseiTed, is 

 the gi'eensand. The upper greensand of the Vale of Pewscy and 

 the suboixiinate valleys of that line of elevation, is satisfactorily 

 disposed of by Mr. Prestwich. Its rainfall, like that of the chalk 

 of that line of countiy, is stopped by the gault, and much of it 

 carried off southward by the Wiltshire Avon. But the inflection 

 which brings down the Kcnnet eastward, and the synclinal which 

 throws out the waters of the Basingstoke Canal, would assist in 

 filling the beds under London, and feeding any Artesian wells 

 carried deep enough there. 



Of the greater and more important exposure of the Lower 

 Greensand in the great plateaux of Wolmar Forest, Hind Head, 

 the HambledoD^ Uasscomb and E^whurst Hills^ there is more to 

 be said. ' iu;> fiiilr '^tiini\ Una ^.nji/alt -ion ski oiij. io /au -joh tmiidi 



A cursory inspection dnly of thfe map \vill show thdt tte' stlt'- 

 face-drainage of all this country, including also a part of Leith. 

 Hill, is taken off by the Wey. This river draws some water out 

 of the Malm country near Alton, and in its course by Farnham 

 takes in the Bourne and other springs thrown out by the sharp 

 flexure of the Hogsback. It then receives the sui-plus of the 

 Frensham Ponds, which are maintained on the middle argillaceous 

 beds of the lower greensand of Dr. Fittou, of which there is a 

 considerable exposure from that line of country by Pepper Har- 

 row to Godalming. It then takes in the stream that works the 

 paper-mills at Haslemere, and passing by Elsted drains Hind 

 Head, takes in other subordinate streams from the Godalming 

 and Hasscomb countries, and finally receives the large supply 

 out of the Albury and Shiere Valley at Shalford*. All these 

 watei*s are thrown out by the Weald clay ; and looking at the 

 collective stream as it is constantly flowing under Guildford 

 Bridge, one cannot but suppose that it insufficient to account for 

 all the rain that falls on the above-mentioned superficies, not lost 

 by evaporation, iniin-miin iRtns oiii to ij;i J 



The sharp flexure at the bolder 'of ^hie chalk escarpment fronf 

 Farnham eastward, and the rise of the Weald clay in all the an- 

 ticlinal of which the Peasemarsh exposure is a part, extending 

 eastward toward Albury and then resumed in the flexure at Buiy 

 Hill, must preclude the thought of much infiltration toward and 

 under the chalk of the London basin. I therefore incline to the 

 opinion, that if the rain which falls on the greensand countiy 

 north of a line drawn from Leith Hill by Hambledon to Hasle- 

 mere, and from thence to the gault under the Alton Hills, is to 

 benefit London, it must be collected from the sources of the Weijj 

 and led there by artificial means. 



H Massing eastward toward the next largest greensand exposures, 

 '' * None comes down from the Weald except in flood-times. 



