Moritz Hermann von Jacobi (1801-1874), German physicist and engineer. Jacobi invented some of the first full-scale, practical electric motors, carrying out this work from 1834. Jacobi moved to St Petersburg, Russia, in 1837. Financed by Tsar Nicholas I, he built a boat that used electric batteries to power an electric motor to drive paddlewheels. Jacobi also worked on galvanoplastics and wire telegraphy. He proposed a form of the maximum power theorem, also called Jacobi's Law. Artwork from 'Electricite' (1911) by French civil engineer Max de Nansouty (1854-1913), part of the 'Les merveilles de la science' series of 1867-1891 by Louis Figuier.