NOTES AND QUERIES. 



259 



tions of the pipes have fallen down, giving the patched appearances seen in the 

 illustration. I could not trace the pipes lower than the depths given above, 

 owing to their disappearance in the talus and rubbish at the base of the chalk- 

 platform, which has been left to support the planks on which the workmen 

 wheel the barrows to the lime-kilns. I have preserved a specimen of the sandy 

 clay taken from the lowest attainable depth in one of the pipes (fig. 1, c), with 

 a flint that was embedded in it. This mass seems to be a mixture of clay from 



4 inches. 



Vegetable mould. 

 Angular flint gravel. 



Coloured sands, finely laminated. 

 Band of small pebbles. 



White or grey quartzite sands, rather darker 

 than those seen at Charlton. 



Band of red ochreous sand and clay containing 

 green-coated flints. 



— Chalk. 



Fig 2.— Section above the sandpipes, showing the strata through which the water 

 percolates. 



No. 6, and sand from the superincumbent strata No. 5 (fig. 2) ; but the white 

 grains of the sand are much discoloured by the oxide of iron contained in the clay 

 No. 6. The flint is not in the least degree water- worn, but has one of its pro- 

 jecting portions broken off, showing the fracture dear and distinct : it is not 

 tinged by the red clay which surrounded it, and still preserves the outer white 

 coating characteristic of chalk-flints. The chalk forming the sides of the 

 pipes is invariably disintegrated for about two inches into the solid mass of 

 chalk forming a cellular or spongy substance, and may by slight pressure be 

 reduced to fine powder. 



The extreme depth and uniform width of these pipes, although frequent 

 examples are met with, are not the common characteristics of sandpipes 

 occurring in cretaceous stiata, which are generally more or less triangular or 

 funnel-shaped (fig. 3), and this led me for the moment to imagine that they might 

 be fissures into which the clay and sand had been washed or had fallen ; but the 

 stratification of the chalk in their neighbourhood being nearly level and quite 



