Page:Geological Evidences of the Antiquity of Man.djvu/74

56 direction not always upwards, and there may have been long stationary periods, one of which of more than usual duration seems indicated by the forty foot raised beach, which has been traced for vast distances along the western coast of Scotland.

Sir H. De la Beche has adduced several proofs of changes of level, in the course of the human period, in his 'Report on the Geology of Cornwall and Devon for 1839.' He mentions (p. 406) that several human skulls and works of art, buried in an estuary deposit, were found in mining gravel for tin, at Pertuan, the skulls lying at the depth of forty feet from the surface, and others at Carnon, at the depth of fifty-three feet. The overlying strata were marine, containing sea-shells of living species, and bones of whales, besides the remains of several living species of mammalia.

Other examples of works of art, such as stone hatchets, canoes, and ships, buried in ancient river-beds in England, and in peat and shell-marl, I have mentioned in my work before cited.

In the same work I have shown that near Stockholm, in Sweden, there occur, at slight elevations above the sea-level, horizontal beds of sand, loam, and marl, containing the same peculiar assemblage of testacea which now live in the brackish waters of the Baltic. Mingled with these, at different depths, have been detected various works of art implying a rude state of civilization, and some vessels built before the introduction of iron, and even the remains of an ancient hut, the whole marine formation having been upraised, so that the upper beds