 He speculated that in geologically recent times a lava flow had covered this shell sand on the sea bed, and then the strata had slowly risen to their present level.Charles Lyell's "Principles of Geology" presented a thesis of gradual rising and falling of the Earth's crust illustrated by the changing levels of the Temple of Serapis.Darwin implicitly supported Lyell by remarking that "Dr. Daubeny when mentioning the present state of the temple of Serapis.