XXVIU PKOCEEDIXGS, 



and also two lime-trees which give a welcome shade dnriTio; the 

 summer, their branches spreading out over a large area. The 

 Japanese arbor- vitse {Thimpns dolabrata) is believed to be the 

 best example in this country. Well-grown trees of Wellingtonia 

 gigantea form an avenue 500 yards long. 



Rhododendrons thrive well, and they are grown on a very large 

 scale, all the leading varieties being included. And here are abo 

 to be found the largest sweet-scented verbenas [Aloysia) in this 

 country.* 



The finest trees in the park are beeches, for which the calcareous 

 soil is most favourable. In fact, there are so many noble examples 

 of the erect-growing beech that the park is celebrated for them. 



On leaving the gardens the party proceeded to Frithsden, 

 a distance of two miles through the park, and, after having tea 

 there, on the hill-side just under Frithsden Copse, dispersed. 



Field Meeting, Hth Mat, 1898. 

 AYOT GREEN AND HATFIELD HYDE. 



This was a joint meeting with the Geologists' Association under 

 the direction of Mr. Hopkinson and Mr. A. K. Salter. Most of the 

 members of the Herts Soci^^ty cycled, while the members of the 

 Geologists' Association came by train to Ayot Station. 



The brickfields near the station were first visited, and here 

 !Mr. Salter gave an account of the physiography of the disti'ict. 

 He stated that Ayot Green was situated on high ground — from 

 380 to 406 feet above sea-level — between the valley of the Lea 

 and that of its afiiuent the Mimram, the Lea rising near Houghton 

 Regis, over 400 feet above the sea, and flowing through Luton 

 before it enters Hertfordshire, and the Mimram first appearing as 

 a pond at Whitwell near St. Paul's Walden, scarcely 300 feet 

 above the sea, and flowing through Welwyn, past Tewin, and into 

 the Lea at Hertford. He then referred to the various gaps in the 

 Chalk downs — the Luton Gap through which the Lea flows, 

 the Hitchin Gap (305 feet), and tlie Bishop's Stortford Gap 

 (230 feet), the position of these gaps being regarded by him as of 

 great importance in all questions relating to the origin of the drift 

 deposits in the Thames Basin. 



He next described the geological structure of the district, stating 

 that Ayot brickfield is situated on one of the many Tertiary 

 outliers, resting on the Chalk, which fringe the Thames Basin on 

 the north and on the south. In most cases, if not all, they are 

 capped by beds of gravel, to the presence of which their preservation 

 may mostly be ascribed. The outlieis at Penn and Coleshill 

 between High Wycombe and Amersham, Tyler's Hill or Cowcroft 

 near Chesham, Bennett's End, and Bernard's Heath, St. Albans, 

 on the north-west of the London Basin, are similar examples, and 

 Well Hill is an example of such an outlier occurring on the south. 



* For information on these trees and shrubs the Editor is indebted to Mr. Lowe. 



