Complex sentence: The system goes back to a proposal made in 1833 by the German mathematician Carl Friedrich Gauss and was in 1874 extended by the British physicists James Clerk Maxwell and William Thomson with a set of electromagnetic units.
Split into simpler sentences: The system goes back to a proposal made in 1833 by the German mathematician Carl Friedrich Gauss. In 1874 it was extended by the British physicists James Clerk Maxwell and William Thomson with a set of electromagnetic units.