On the Magnetization and Retentiveness of Nickel Wire under combined Torsional and Longitudinal Stresses

The quite unexpected results described in the preceding paper induced me to examine the magnetization of nickel wire at constant twists under the influence of gradually increasing magnetizing fields. The first series of experiments is concerned with the peculiarities of magnetization of nickel wire subject to combined torsional and longitudinal stresses. The wire under examination was first demagnetized by successive reversals of a current of gradually diminishing strengths. A definite load was then applied, and the wire twisted through a definite angle by means of the twisting apparatus. The wire was then subjected to magnetizing currents of gradually increasing strengths, and the amount of induced magnetism measured by the direct magnetometric method. The results of these experiments show that twisting produces many singular effects on the magnetic properties of nickel. The twisted wire acquires its maximum susceptibility in a particular field of force, which