The Molecular Condition of Iron demagnetised by various Methods

Extract

The demagnetisation of iron by decreasing reversals secures a molecular condition such that there is perfect symmetry to subsequent applications of either a positive or negative magnetising force (H). In a former communication it was shown that this symmetry is uni-directional. It is symmetry to the directional force (ab) used in the demagnetising process. During the early stages of induction iron is more permeable to a reapplication of a magnetising force in the same direction (+ or − ) as that used in the immediately preceding demagnetising process, than it is to a force (+ or − ) at right angles to that used in the immediately preceding demagnetising process. The hypothesis was advanced that on the completion of this process, a preponderance of the molecules would point towards an equatorial belt at right angles to ab. If H makes an angle other than zero with ab, the number of molecules lying in the most advantageous position, i.e., equatorially, is reduced, and the pull becomes less and less as the angle approximates to 90°.