But while this conclusion falls in most happily with our present argument, it would seem on further examination to bring with it a very serious difficulty. For, while those ancient monuments testify that the Crust of the Earth in this locality has _subsided_, the structure of the sea-coast, interpreted according to Geological principles, would indicate, on the contrary, that the Crust of the Earth has been _upheaved_. Close to the sea, at the present day, on the bay of Baiæ, there is a low, level tract of fertile land, and at a little distance inland, a lofty range of precipitous cliffs, eighty feet high, parallel to the line of the coast. This fertile tract, lying between the sea-beach and the perpendicular cliffs, is about twenty feet above the sea level, and is composed of regularly stratified deposits abounding in marine shells of recent species, together with works of human art, such as tiles, squares of mosaic pavement, fragments of bricks, and sculptured ornaments. Upon these facts a Geologist would pronounce without hesitation:--First, that at some period since the district around Naples was first inhabited by man, the waters of the sea washed the base of the perpendicular cliffs; secondly, that the strata in which we now find the recent marine shells, and the remains of man’s workmanship, were formed during that period by the process of deposition at the bottom of the sea; and thirdly, that at some subsequent time, by an upheaval of the Earth’s Crust, these strata were lifted up so as to form a pretty considerable area of dry land, fit for agriculture and the arts of life. Does it not seem, therefore, that we have here a direct contradiction between the evidence of ancient Roman buildings and the inferences of modern Geology? Doubtless, they both agree in the main point about which we are concerned just now, that the Crust of the Earth has been moved in recent times on the shores of the bay of Naples; but according to the testimony of the Roman temples, now covered by water, this movement has been one of _subsidence_, while, according to the inferences of Geological theory, it has been one of _upheaval_. This apparent contradiction seems to call for some elucidation.