sKssiON 1898-99. li 



then visited. Tliere is lieve a very fiue section of the Chalk, 

 lieading 13cds, aud London Chiy with its basement-bed, which has 

 been described by Mr. Whitaker in his ' Geology of the London 

 Basin' (vol. i, p. 196). 



The section is now rather clearer than when that description 

 •was drawn \ip. The mottled clays of the Heading Series are fully 

 exposed, and the grey sand and clay appear to have a considerable 

 extent. The only foreign rock seen in the bed of tlint-pebbles (at 

 the bottom) was an iron-sandstone, rather friable. Mr. Whitaker 

 remarked that this bed was much like the Hertfordshire pudding- 

 stone, except that it was not in Hertfordshire and was not 

 a pudding-stone. It was in Middlesex, but close to the Herts 

 border, and although the pebbles were not consolidated with silica, 

 there was silica present in the form of sand. Several fossils were 

 obtained in the basement-bed of the Loudon Clay. Shells chiefly 

 occur in masses, but are not in a good state of preservation. 



Passing the Asbestos Mills, formerly, as marked on the Ordnance 

 map, the " Copper Mills," the Harefield Lime Works were visited. 

 Here there is a section of the Upper Chalk nearly 100 feet in 

 height, giving a better illustration of the phenomenon of " pipes " 

 than is to be seen elsewhere within many miles of London. It was 

 quite clear, Mr, Whitaker said, that the irregular masses of loose 

 sand and gravel which extend downwards in them from the top of 

 the pit had really been let down from above. No surface-action 

 could have formed them ; the Chalk had evidently been dissolved 

 away by water percolating through fissures, and the sand and 

 gravel had gradually taken its place. The Chalk was seen to be 

 quite evenly bedded. 



Crossing the fields to the Springwell Chalk Pit, it was noticed 

 that the Chalk was veiy little fissured by pipes, this being due 

 to a bed of comparatively impervious clay on the top. Although 

 this pit has been worked for at least thirty years, it is not indicated 

 on the 6-inch Ordnance map. 



After a vote of thanks had been recorded to the Directors the 

 party separated, the cyclists leaving those who came by rail to 

 take a short walk along the towing-path of the canal to Eickmans- 

 worth Station, 



Field Meeting, 24th June, 1899. 

 SHEPHALL, ASTON, AND FROGMORE HALL. 



This was the only field meeting in the year for which hospitality 

 was offered, and the choice for it of Midsummer Day proved most 

 satisfactory. A threatening cloud passing away soon after 1 o'clock, 

 the weather henceforth was perfect, and although the meeting was 

 devoid of scientific results from a naturalist's point of view, it was 

 of considerable archaeological interest. 



The meeting was under the direction of Mr. Hopkinson, who 

 conducted a party of cyclists from St. Albans, whither a few had 



