III.—On Changes of Level and the Production of Raised Beaches

Extract

I have occasionally drawn attention to the effect produced on the relative level of sea and land by variations of pressure on the surface, such as would be occasioned, for example, by the increase or diminution of the loads of ice which existed during the Glacial period. I argued that the position of the surface must be always tending to an exact equilibrium between the upward and the downward pressure, and that any variation in the superincumbent load must result in some change, however small, in order to rectify the balance. For if the balance was not perfert, motion must necessarily ensue, either up or down as the case might require.