The lines are closest at the poles, which is where the field is strongest. So the direction of a magnetic field at any point is the direction of the force on the north pole of the magnet at that ...
He hypothesized that invisible fields of electricity and magnetism carried these forces through space, and that these "lines of force" need not always move in straight lines as Newton would have ...
In this except, he explains how magnetism, the most tangible fundamental forces, was discovered, where it comes from and how it got its name. Magnetism is a manifestation of electricity ...