Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/139

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of Devonshire and Cornwall.
127

feet above the level of the sea, six miles east of Varalla, at the entrance of the vallies of Sesia Grande and Piccola.

From Grampound to Falmouth, by Creed, Tregony, Tregear, and St. Mawes, grauwacke slate continues the whole way, and the fertility of the country sufficiently indicates it, as that kind of rock is very abundant in springs. The granite ridge begins sensibly to lower, and consequently the grauwacke formation occupies less extent. It is found on the sea-shore, traversed by quartz veins, although it is stratified. I observed this, among other things, in crossing from St. Mawes to Falmouth, near a strong fort on the right, facing Pendennis Castle.

There is something very romantic in the view of the port of Falmouth from the heights of St. Just: it resembles very much the situation of Loch Long and Loch Fine in Argyleshire. There is at first some difficulty in believing that all those creeks which penetrate so far into the interior of the country, are basins of salt water.

I observed on this road, that near Pennare Point, a small promontory a few miles E.N.E. of Falmouth, the cliffs were high and precipitous.

The grauwacke slate still prevails from Falmouth to Menaccan: there is a fine quarry of it from Falmouth to Penryn, which skirts the bottom of the hill on one side, and the King's Road on the other. The beautiful river called the Hel flows over the same rock, at the ferry, near its mouth, from Mawnan to Helford. It is intersected there by a great number of quartz veins, and blocks of it of different sizes are found on the road from Penryn to Mawnan Smith. This very extensive formation at length terminates near a small sea-port called Port-hallo, or as the inhabitants pronounce it, Pralo, which is three miles S. S. E. of Menaccan, across the Dinnis. This river runs in the bottom of a valley, where the substance named