Strata between Diirlstone Head and Old Harry. 133 



15 



Arch in the chalk off Ballard Head, formed by the removal of regular 

 fragments of chalk. 



The dotted part below the water, is pierced by myriads of 

 limpets, which have fixed their habitation between high and 

 low water mark, and superficially have honey-combed the 

 whole cliff, from Old Harry to Ballard Head, in a most sin- 

 gular manner. 



Two other points sub judice, are, the height of the cliffs, 

 and the rate of decay. I have stated the cliff at Old Harry 

 to be about 100 feet high ; (p. 418). Dr. M. says "the boat- 

 men ascertained Old Harry to be about 70 feet high, by look- 

 ing at the mast of an India/man, which came very near him? 

 Now Old Harry stands on a ledge, dry at low water, and 

 having only a depth of 6 feet over it, at high water. Old 

 Harry's wife has two feet water at the base, at low, and 8 feet 

 at high, water. There is, moreover, not a depth of water 

 equal to 4 fathoms, within half a mile ; and there is generally 

 a heavy sea running, even in moderate weather, all along the 

 ledge that runs outside the coast, and it is dangerous, even 

 for a boat, at low water, to navigate too close, owing to the 

 fragments of chalk, the ruins of former cliffs, now destroyed, 

 that form dangerous rocks below the surface. I cannot there- 

 fore imagine that the boatmen got at the height so easily, if 

 at all, without measurement. In order, however, to make cer- 

 tain, (for, of my two boatmen, one said Old Harry was 70, 

 and the other, 100 feet high), I requested Lieut. Billingsley, 

 R. N. chief officer at Studland, to have it measured. This he 

 accomplished by a hand-line, over the cliff, and his determi- 

 nation is, that Old Harry rock is not more than 70 feet, the 

 cliff being higher ; — and that Old Harry's wife is 93 feet high, 

 the cliff opposite being 130 feet. The height, therefore, of 

 100 feet which T affixed to the cliff at Old Harry, is not far 

 from the truth : it was from an old measurement, on a map 

 made several years back, and not mere tradition. I cannot 



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