On Irregularities in Magnetization

Line patterns of iron oxide deposited from a suspension, similar to those observed by F. Bitter on large crystals of iron and nickel, have been studied on cold-drawn, polycrystalline nickel-iron wires under uniform applied stress and in a magnetic field. The patterns consisted of parallel lines but they differed from the highly regular patterns published by Bitter, in that the spacing between adjacent lines varied considerably and in that they appeared very consistently in the same places even after changes in magnitude and direction of the applied field. The spacing of the lines lay within the range 0.7 to 10×${10}^{-3\mathrm{}}$ cm. Both experiments on a wire under tension and the agreement of results on a twisted wire with conclusions from R. Becker's theory prove that the lines form perpendicular to the direction of induction in the material. No further evidence regarding the origin of the pattern could be found.