28o Fifth Conference 



field become bewildered in masses of detail without 

 gaining a thorough mastery of any. 



My lecture passes quickly under review the various 

 obvious denuding forces at work carving out the 

 features recognized as river-bed, valley, hill range, 

 &c. In fuller detail an attempt is then made to show 

 the effects of earth movement in producing — 



(i) Basin -shaped areas (synclinals). This is as- 

 sumed as the structure of the London basin. 



(2) Dome-shaped areas (anticlinals). The upper 

 portion of the dome having disappeared, there are 

 left the exposed edges of a large number of different 

 formations, and these different formations coming suc- 

 cessively into view during the school journey, give 

 variety to the surface aspects, and thus make the 

 selected area a very fruitful one for study. 



(3) In order to make these curves appear more 

 than mere speculation, a number of well sections 

 are shown, establishing the fact that the rocks pierced 

 by these vertical shafts appear in the same order at 

 the surface at different stages of the journey.* 



A comparison is now instituted between the map 

 and plan of the area to be traversed. The plan 

 is intended to show the different rock -formations 

 crossed, beginning with the river deposits as far as 

 New Cross, the London Clay from New Cross to 

 Croydon, the sands and gravels of the Lower London 

 Tertiaries at South Croydon, and the Chalk as far 

 as Caterham. The attention of the students is then 



* Diagrams illustrating the above paragraphs were printed on a separate 

 sheet and distributed amongst the audience. They were reproduced from 

 a work entitled The School Journey, by J. H. Cowham, and published by 

 Simpkin, Marshall, & Co. 



