text:  Three pillars forty-two feet in height up to about twelve feet above their pedestals have the surface of the marble as smooth as any in the Forum; then comes a portion of nine or ten feet of which the marble has been bored drilled in all directions by that persevering bivalve the _Lithodomus;_ the perforations are so considerable and go so deep as to prove "the long-continued abode" of these animals within the stone and by consequence as Mr Lyell observes "a long-continued immersion of the columns in the sea at some period recent comparatively with that of its erection