Page:Cornwall; Cambridge county geographies.djvu/42

 26 CORNWALL dulated through enormous lateral pressure. The granite, the lowest and most ancient formation of all, was itself consolidated under vast pressure from above, and was not in a molten condition when forced to the surface. Had it been so, it would have resolved itself into lava. It was cold when upheaved, tearing apart the superincumbent stratified sedimentary rocks, which disappeared from the summits, and on all sides about these upheavals were twisted, contorted, thrown back, and fissured. Atmospheric effect and natural gravitation is con- stantly carrying the soil from the upper land, from the hills into the bottoms, and consequently it is in the latter that we find the richest land, best calculated to repay the toil of the agriculturist. On the high moors there is little depth of so called "meat earth," below which is clay and grit, hard and unprofitable, commonly called the u calm " or the "deads." But adjoining the granite is the wash from it of its dissolved felspar, the china-clay that furnishes the inhabitants of the St Austell district with a remunerative and ever-growing industry, of which more presently. 7. Natural History. Various facts, which can only shortly be mentioned here, go to show that the British Isles have not existed as such, and separated from the Continent, for any great length of geological time. Around our coasts, for instance, and specially in Cornwall, are in several places remains of forests now sunk beneath the sea, and only to be seen at