Polarization of Armature

—The result of the rotation of a dynamo armature is to produce a number of reactions between its windings and the magnetic field, with the s result that the armature itself becomes a magnet, being constantly polarized at certain definite points in its path of rotation. According to the accepted rule of magnetic induction, the tendency is to produce poles in the armature at right angles to the lines of force, but since the neutral points, theoretically situated on the same diameter, are points of contact between the brushes and the commutator, where the current leaves and re-enters the winding of the armature, it will be found that the armature is really transformed into two separate adjacent magnets, having two north and two south poles, on either side of the diameter of commutation. These -double poles, practically operating as a single pole, at the two extremities of the given diameter, act to produce the great distortion of the lines of magnetic force, which follow the rotation of the armature,