Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/160

 148 them.─If we are to attribute the origin of these veins, according to the Huttonian Theory, to the action of a force from below, and which has caused them to intersect the grauwacke posterior to its formation, how comes it that along the whole line of the superposition of the grauwacke on the granite, they occur in so few places? and how comes it that the grauwacke, without any exception, forms a covering upon the granite, which, as it approaches the junction between it and the primitive rock, continues diminishing in thickness?

From Mousehole to St. Burien, the road continues to ascend, and is now completely in the granite formation. Several projections or hillocks may be seen in the horizon as we advance into the interior of the country; they are all of little height, and to their partial disintegration may be attributed the great number of blocks which are spread over the surface of this plain; it extends to the west, and has that uneven rugged appearance peculiar to a low primitive country.

St. Burien stands, I believe, on the highest point in that part of the country; its height is four hundred and sixty-seven feet above the level of the sea. There is a very extensive view from the top of the church tower, commanding the whole range of the surrounding country, and it is even said, that in clear weather, the Scilly Islands may be seen in the horizon. The soil in the neighbourhood of St. Burien is mossy, and characterized by that sterility which usually accompanies a granitic country, but it becomes more fertile in approaching the sea. There are two or three druidical barrows, in very good preservation, at a short distance from the town.

The plain on which St. Burien is situated preserves its height