by William Gilbert, On the Magnet — Book III. Chap… (1900)
“ But if a thin straight rod be bent into a ring without any welding or union of the ends, and be touched in the middle by a loadstone, both ends will be of the same verticity. Let a ring be taken which is whole and continuous, and which has been * touched by a loadstone at one place, and let it be divided afterward at the opposite point and straightened out, both ends will also be * of the same verticity, no otherwise than a thin rod touched in the middle or a ring not cohærent at the joint. ”
