588 Strata near SiaaivwicJi, 



represents the chalk from Ballard Head to Old Harry Point, 

 forming the southern horn of Studland Bay. 



" It will be seen that the older formations rise from under 

 each other at an angle continually increasing, till it becomes 

 90° under Ballard Down ; and that at Ballard Head the 

 vertical strata are in contact with curved strata ; which latter 

 gradually approach towards a horizontally direction, as repre- 

 sented in^y^. 37. (taken from Mr. Webster's drawing in Sir 

 H. Englefield's splendid work on the Isle of Wight) ; and in 

 Jig. 38., which represents the inclination at Old Harry on a 

 larger scale, showing that the beds there dip under the sea at 

 about 19° to the north ; so that the range of the curve from 

 Ballard Head to Old Harry is about 71°. The cliff at Ballard 

 Head is about 352 ft. ; at Old Harry, about 100 ft. high. 



" It will be seen, also, that the cliffs toward the north are 

 buttressed, as it were, by a number of perpendicular masses, 

 which the action of the sea and the atmosphere have worn 

 out of the chalk; and that at the extremity, as represented in 

 Jig. 39., there are four insulated masses, two of which are 

 designated the Pinnacles, or, in a nautical phrase, Old Harry 

 and his W T ife. The elemental agencies have nearly produced 

 two other and larger pinnacles, which cannot remain many 

 years uncompleted. The beds in Studland Bay appear nearly 

 horizontal, which they must do, being merely the ends of 

 those which are along the eastern section, represented as 

 curved ; but it will instantly occur, that these horizontal 

 beds, in the upper part of the cliffs are the remains of beds 

 whose continuation on the top of the down has been partly 

 destroyed. It is also clear that the termination of the beds 

 injunction with the vertical ones does not appear in Studland 

 Bay." 



I first observe, that he states that Durlstone Head is com- 

 posed of curved strata and breccia of Purbeck stone. 



The stone is a coarse sort, known at Swanwich by the name 

 of Purbeck Portland. It is a kind of grit, or sandstone, rather 

 than an oolite, but more nearly resembles the oolite of Port- 

 land than the Purbeck stone. 



The strata of stone are not curved, but are in long parallel 

 lines, separated from each other by intermediate masses of 

 clay. 



Throughout the coast, for many miles, beginning at Swan- 

 wich, the strata, though dipping a little, approach to horizon- 

 tality of position. 



I give two sections observed at Durlstone Head in 1833; 

 only remarking that the measurements were taken by the eye. 



