Physicist and engineer — Moritz Hermann von Jacobi (1801–1874) was a German physicist and engineer who spent most of his life in Russia, a member of the St Petersburg Academy of Sciences; he was the brother of the great mathematician Carl Gustav Jacob Jacobi. In 1838 he invented electrotyping, that is, the reproduction of objects by electrolytic deposition of metal, a technique later used for coins, statues and decorations. He built one of the first practical rotary electric motors and, also in 1838, launched on the Neva a boat driven by a battery-powered electric motor, capable of carrying passengers. In his studies on power delivery from generators he stated the principle of maximum power transfer to the load, known as Jacobi’s law.

Theories and contributions

  • Electrotyping — Reproduction of objects by electrolytic deposition of metal onto a mould (1838).
  • Jacobi’s law (maximum power transfer) — The power delivered to the load is maximum when its resistance equals the internal resistance of the generator.
  • Electric motor and electric boat — Built a rotating electromagnetic motor and the first electrically propelled boat on the Neva.

Linked atoms

1 linked atom.

17 Il campo magnetico