ef Hampshire and Dorsetshire, 253 



grotesque cliffs, remarkable both for their variety of colour and the 

 multiplicity of short pyramids implanted one upon the other. 



This loose sand is also the matter which fills up for the most part 

 the Inclined semi-trough, which from the shallow inner harbour of 

 Poole extends to the northern acclivities of the chalk hills by Corfe 

 Castle. It is there of a whitish-grey colour, covered with heath 

 reduced in some places to the state of turf. To this formation of 

 sand belong the following mineral substances i 



(a) Coarse hard ferruginous sandstone^ passing to a conglomerate, 

 composed of rolled quartzose pebbles of different sizes, united by a 

 ferruginous cement which does not effervesce with acids. This 

 rock strikes fire, and has at first the appearance of slag, being rough, 

 hollowed out, and covered externally with a crust of an earthy 

 brown colour, arising from the oxidation of the iron. It has no- 

 action whatsoever on the magnet. It occurs in the form of flat 

 scattered masses at the depth of a few feet from the surface of the 

 sandy soil ; the upper strata of loose sand being sometimes washed 

 away, these pieces project, making a sort of cornices, and protecting 

 the inferior strata of sand. I suspect this conglomerate to be of a 

 very late origin, and indeed, daily forming by a process somewhat 

 like that of cementation^ viz. the percolation of water strongly im- 

 pregnated with iron coming from the upper strata, and thus agglu- 

 tinating the loose sand. 



This rock is to be seen plentifully on the road from Shorwell to 

 Chale in the Isle of Wight, and in the sandy trough of Poole, 

 (b) Potters'' clay. 



It alternates with the loose sand in the trough of Poole, where it 

 is found in beds of various thickness at different depths. It does not 

 effervesce with acids, and from a cursory chemical examination 

 which Dr. Marcet had the kindness to make at my request, we 



