Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/161

 Rh pretty far to the west, for Sennen, the most western village in England, which is three miles distant from it in a straight line, and only half a mile from the Land's-end, is, according to my observations, but seventy-six feet lower than St. Burien, that is, three hundred and ninety-one feet above the level of the sea.

The cliffs which bound this western shore of England, are nevertheless of small elevation. They are rather more abrupt and more lofty towards the north than towards the south. Mean Cliff and Cape Cornwall are higher than the Land's-end and the Logan rock.

The Logan rocks, or rocking stones, are a heap of blocks of granite on the sea-coast, beyond the village of Traen or Trereen, a little to the south of the road from St. Burien to Sennen, forming a kind of cliff more inclined than abrupt towards the sea. Though there may be to the south of these rocks, near the ancient castle of Trereen, some remains of fortifications, I am satisfied that the logan stones formed at one time only one complete mass of granite, which by the action of the atmosphere and other external agents, has split into irregular blocks: the greater part of these, though separated on all sides from each other, have remained in their original position, but now appear as if they had been placed one above another. It appears to me, that it is in this way granite disintegrates in low primitive countries, and this appearance has, I believe, been often mistaken for strata, and has given rise to the idea that true granite is stratified, an opinion which I cannot adopt, even after having visited those places where Saussure thought he had discovered the strongest proofs in favour of the fact. Among these logan rocks, there is one which rests upon another by only one