Proceedings. cliii. 



Datum; mould, 2-ft. ; gravel, 9-ft. ; mouse coloured clay, 3-ft. ; 

 London clay, 6-ft. ; septaria, i-ft. ; London clay, 22-ft. ; sandy clay, 

 i-ft. ; London clay, 4-ft. ; sandy clay, 3-ft.; London clay, 6-ft.; 

 sandy clay, 3-ft. ; London clay, 2-ft.; sandy clay and septaria, i-ft. : 

 sand, * 2-ft. ; sand and pebbles, i-ft. 6-in. ; blue clay, 25-ft. *; mottled 

 clay, i6-ft. ; dark sand, r-ft. ; green sand and pebbles, 14-ft. ; light 

 sand, 43-ft.; loamy sand, lo-ft. ; flints, i-ft. ; chalk with flints at 

 281-ft. 6-in. In 1866 a well was sunk loo-ft. west from the 

 site of the present well. The vertical section in this was 

 from * to * inclusive: 2-ft. dark sandstone, 5-ft. light sand, i-ft. 

 stone, I-ft. pale sand, 4-ft. black sand, 5-ft. sand stone, 3-ft. sandy 

 clay, 4-ft. shelly beds, 6-ft. black sand, clay and pebbles. 



Park Hill Railway Section. — Sequence and greatest thickness of 

 the Lower London tertiaries in descending order : Brown and grey 

 laminated clayey sand, lo-ft. ; grey sand, 24-ft. ; hard white shell- 

 bed, lo-ft. ; blue clay with lignite, lo-ft. ; mottled clay, 21-ft. ; 

 lavender coloured sandy pebble bed, i-ft. 6-in.; green sand, 3-ft. ; 

 greenish-brown sand, 6-ft. 8-in. ; grey sand, 2-ft. ; brown clayey 

 sand, 2-ft. ; Thanet beds, 38-ft. 



Croydon Rural Sewage Works' Well, at Merton. Communicated 

 by Mr. Baldwin Latham, C.E. :— Surface ground 36-69 feet above 

 Ordnance Datum ; mould and peat, lo-ft. ; ballast [gravel] i-ft. 6-in. ; 

 blue clay with septaria, 51-ft. ; shells, i-ft. ; brown sand, 5-ft. ; blue 

 clay, 7-ft. ; shell rock, i-ft. 6-in.; dark coloured clay, 8-ft. ; dark 

 blue clay, 3-ft. ; black blue clay, 3-ft. ; yellow clay, 3-ft. ; purple 

 clay, 3-ft.; red clay, 4-ft.; brown and green sand, i-ft. 6-in.; brown 

 sand, 9-ft. 6-in. ; brown clay, 5-ft. ; pebbles, i-ft. 6-in. ; green sand, 

 6-ft. 6-in. ; grey sand, 31-ft. ; chalk with flints, 77-ft. 



Crystal Palace, Upper Norwood, Well in the lower part of the 

 ground : Surface of the ground about 190-ft. above Ordnance Datum ; 

 ferruginous sandy loam, 9-ft. ; London clay with septaria, 249-ft.; 

 pebbles, i-ft. ; Woolwich and Reading beds, 47-ft. i-in. ; Thanet 

 beds, 54-ft. 6-in. ; chalk with flints, 149-ft. 



These geological details look uninviting, but it is often necessary 

 to be acquainted with them. During a heavy rainfall, gardens, 

 resting possibly upon a thin stratum of impervious clay, may 

 become flooded ; the position of the garden may make it impossible 

 to lead the water into the main drain, and good feeling does not 

 allow us to remove a brick from the garden wall, by which the water 

 could be drained into a neighbouring field or into a neighbour's 

 garden. It is useful then to know the succession and thickness ot 

 the London tertiary beds, which are partly pervious to water, 

 namely, sandy, shelly and pebbly beds, partly clayey beds, im- 

 pervious to water. By boring or sinking to the pervious bed, 

 surface water may thus sometimes be easily disposed of. 

 Signed 



Alfred Carpenter. 



James Chisholm. 



William Topley. 



H. Turner. 



Thos. Walker. 



H. M. Klaassen, Hon. Sec. 



