HOW IT WORKS.

how to decide in which direction the current flows. The armature is revolving in a clockwise direction, and y z, therefore, is moving downwards. Now, suppose that you rest your left hand on the N. pole of the magnet so that the arm lies in a line with the magnet. Point your forefinger towards the S. pole. It will indicate the direction of the lines of force. Bend your other three fingers downwards over the edge of the N. pole. They will indicate the direction in which the conductor is moving across the magnetic field. Stick out the thumb at right angles to the forefinger. It points in the direction in which the induced current is moving through the nearer half of the coil. Therefore lines of force, conductor, and induced current travel in planes which, like the top and two adjacent sides of a box, are