112 W. WHITAKEE — ADDRESS: GEOLOGICAL 



Stanmore, are on the county-border. The Hampstead type occurs 

 at Totteridge; the High Barnet type at that place, Potter's Bar, 

 near Ayot, Sacombe Park, and Collier's End ; the Bell Bar type 

 at Bayford and Hertford Heath ; high-level glacial gravels at 

 St. Albans, Ayot, Welwyn, etc. 



I must refer the reader to the original for the differences of 

 character of the first four types of pebbly gravel and for their 

 relation to the various gaps in the high ground north-east from 

 Goring, the Hitchin and Bishop's Stortford gaps being in our 

 domain. It is in the neighbourhood of the gaps that the gravels 

 occur. The author regards them as "the first deposits of the 

 Glacial Series." ^ 



Mr. Salter showed some of these gravels to the Geologists' 

 Association in an excursion to Potter's Bar and Hatfield, f 



Mr. R. E. Middleton's paper on "The Belative Value of Per- 

 colation Gauges " is, of course, largely concerned with our county, 

 and the conclusion come to is "that percolation gauges do afford 

 a general indication of the amount of rain-water which passes into 

 the subsoil under given conditions, but that the discrepancies 

 between gauges are so marked that no one gauge can be relied on as 

 an authoritative index of what has taken place in the whole of the 

 district, ... a result obtained from the averages of all the 

 gauges is more to be relied upon"; and the gaugings of rivers 

 should also be taken into account. In the discussion Sir J. Evans 

 and Mr. B. Latham took a leading part. :j: 



In a discourse on " The Past, Present, and Future Water Supply 

 of London," Sir E. Erankland notices the supply from the Lea, 

 and advocates its extension to the amount of a hundred million 

 gallons a day, a figure which late events lead us to think much 

 too high. § 



1897. 



Mr. Hej^ry Woods has written an important paper, in two parts, 

 on " The Mollusca of the Chalk Rock," || which is largely concerned 

 with specimens from Hertfordshire and Bedfordshire, the aid of 

 our members, Mr. W. Hill, Dr. M orison, and Mr. J. Saunders, 

 being duly acknowledged. 



Some of Mr. Woods' remarks may well be quoted, as they should 

 find a place in our ' Transactions.' 



* ' Proc. Geol. Assoc ,' vol. xiv, pt. 9, pp. 389-404. 

 t Ibid., pp.420, 421. 

 X ' Trans. Soc. Eng.,' pp. 153, etc. 

 ^ ' Proc. Roy. Inst.,' vol. xv, p. 73. 



II ' Quart. Journ. Geol. Soc.,' vol. Hi, pp. 68-98, pis. ii-iv (1896) ; and 

 vol. liii, pp. 377-404, pis. xxvii, xxviii. 



