a German Jewish and Russian engineer and physicist born in Potsdam. Jacobi worked mainly in Russia. He furthered progress in galvanoplastics, electric motors, and wire telegraphy. While studying the transfer of power from a battery to an electric motor, he deduced the maximum power theorem. Jacobi tested motors output by determining the amount of zinc consumed by the battery. With financial assistance of Czar Nicholas, Jacobi constructed in 1839 a 28-foot electric motor boat powered by battery cells. The boat carried 14 passengers on Neva river against the current. The boat fared at the speed of three miles for hour.
