Near Swanage also, in the middle of an open heath, is the celebrated Aggie Stone, or holy stone, though it is more generally known at present as the Devil's Nightcap.  It is a long stone poised on a single point. We agreed that it was something like a giant mushroom.  The country people say it was thrown from the Isle of Wight, with the intention of destroying Corfe Castle, but that, falling short, it descended where we found it, on the top of the hill, eighty or ninety feet high.  We could not decide whether it was placed here by art or Nature, for similar stones exist in other places where water and the atmosphere have cleared away the surrounding earth.  Papa was of opinion that it was formed by natural causes.