Inventions of the 19th century make electricity and magnetism controllable. They become topics of scientific exploration and industrial utilization. The flourishing electric industry produces a multitude of instruments for the production, storage, transportation and transformation of electricity.

The discovery of induction is especially significant: an electrical current through a conductor generates a magnetic field, and a moving magnetic field generates an electrical current in a conductor. The attempt to coherently interpret induction as an effect of the relative motion between conductors and magnets led Einstein to the Special Theory of Relativity.