399. According to some other facts stated by the same ingenious author, it appears, that on the coast of Italy the progress of the sea in ascending, or of the land in descending, has not been uniform during the period above mentioned, but that different oscillations have taken place; so that, from about the beginning of the Christian era, till some time in the middle ages, the sea rose to be sixteen feet higher than at present, from which height it has descended till it became lower than it is now, and from that state of depression it is now rising again. Breislac infers this from two facts, which he combines very ingeniously with the preceding, viz. the remains of some ancient buildings, at the foot of Monte Nuovo, five or six feet above the present level of the sea, in which are found the shells of some of those little marine animals that eat into stone: And again, the marble columns of the temple of Serapis, which are also perforated by pholades, to the height of sixteen feet above the ground. All these changes Breislac ascribes to the motion of the sea itself; a supposition which, as we have seen, cannot possibly be admitted, since nothing can permanently affect the level of the sea in one place, which does not affect it in all places whatsoever. 400. Appearances, which indicate such alternations as have just been mentioned in the level of the sea, are to be met with on some other coasts. In England, on the coast of Lincolnshire, the remains of a forest have been observed, which are now entirely covered by the sea.[207] The submarine stratum which contains the remains of this forest, can be traced into the country to a great distance, and is found throughout all the fens of Lincolnshire. The stratum itself is about four feet thick; it is covered in some places by a bed of clay sixteen feet thick, and under it for twenty feet more is a bed of soft mud, like the scourings of a ditch, mixed with shells and silt. [Footnote 207: Phil. Trans. 1799, p. 145.]