ABSTRACT
Soft iron and steel exhibit the effect of magnetic viscosity strongly for a frequency of 1,000. In order to determine the hysteresis curve for soft iron and steel when the current varied very rapidly, the time of rise of the magnetizing current for soft iron and steel rings was obtained by use of the time apparatus. Not only was the time-apparatus a very simple means of determining the times of rise of currents in circuits when a steady EMF was applied, but with different connections the duration of secondary induced currents at make and break of the primary could be examined under any conditions required. The principle of the time-apparatus can be used to determine the velocity of projectiles at various points of their path. In the experiments on magnetic viscosity the times of rise of currents in circuits containing iron were determined.
