Moritz Hermann von Jacobi

Portrait of Moritz Hermann von Jacobi

Physicist, inventor
Born: Potsdam, Prussia - 9 September 1801
Died: St. Petersburg - 10 March 1874

The inventor of the first electric motor, Moritz von Jacobi came from an Ashkenazi Jewish family in Potsdam. His father, Simon Jakobi, was personal banker to King Friedrich Wilhelm III of Prussia, and his younger brother was the renowned mathematician, Carl Gustav Jacobi.

Jacobi studied at Berlin and Gottingen Universities, and began his career as a government architect. In 1833, he moved to Konigsberg (Kaliningrad) and began to experiment with electromagnets. In May of the following year, he developed the first working electric motor. He described his motor in precise detail in a memorandum the following year, and was awarded an honorary doctorate by Konigsberg University. He also moved to the Duchy of Livonia, where he taught civil architecture at the University of Dorpat. Two years later, he was invited by Nicholas I to continue developing his electrical motor at the Imperial Academy of Sciences in St. Petersburg.

His investigation delved into the power of electromagnetism in motors and generators. During these studies he deduced the maximum power theorem (Jacobi's law). With the financial support of Tsar Nicholas, Jacobi built a 28-foot paddle boat powered with an improved version of his motor, which carried up to 14 passengers on the Neva River, as demonstrated in September 1838.

Also in 1838, Jacobi discovered the ability to make printing plates through the process of electrotyping, the chemical reproduction of exact forms in metal. By the following year, electrotyping was already being used to print government documents. This technology was also used to create metal statues without having to cast them. Jacobi was also involved in the development of the electric telegraph. From 1842-1845 he built a telegraph line between St. Petersburg and Tsarskoe Selo using underground cables, and produced the first letter-typing telegraph machine.

In 1840, Jacobi was awarded the recently instigated Demidov Prize for his achievements. He became a naturalized Russian citizen, and spent the last years of his life as the head of the Physics Office at the Russian Academy of Sciences. He died of a heart attack at the age of 72, and was buried in the Smolenskoye Lutheran Cemetery.

Addresses: 1, Nikolaevskaya Naberezhnaya (Naberezhnaya Leytenanta Shmidta) (1839-1874)

Connected with: Heinrich Friedrich Emil Lenz