See Hodsons Letters from North America, Vol. Pliny는 여러 가지에 대해 이야기합니다 아시아 역사. Nat. Lib. I., c. and Apollonius Rhodius expatiates on the rocking stones, and says that they are stones placed on the apex of a tumulus, and so sensitive as to be movable by the mind Ackermans Arth.