Борис Семёнович Якоби — physicist / engineer с корнями из Russian Empire
Moritz Hermann von Jacobi was born in Potsdam in 1801, the elder brother of the mathematician Carl Gustav Jacob Jacobi. He trained and worked as a builder in Konigsberg, and in 1835 took a chair in civil architecture at Dorpat, in the Baltic provinces of the Russian Empire. In 1837 he was called to Saint Petersburg to pursue the use of electromagnetic force for driving machinery, and he stayed for the rest of his life, becoming a full member of the Academy of Sciences in 1847 and a Russian state councillor. In Russia he was known as Boris Semyonovich Yakobi.
He had built one of the first practical electric motors in 1834, testing its output by measuring how much zinc the battery consumed. Working in Saint Petersburg on the relationship between an electromagnet's power and the current, the gauge of wire, the turns of the helix and the iron core, he arrived at what is now called the maximum power transfer theorem — the rule that most power reaches a load when its resistance matches that of the source. Henry Rowland and John Hopkinson took the same ground up again nearly half a century later.
On 13 September 1838, with money from Nicholas I, he ran an eight-metre paddle boat on the Neva driven by his motor. The batteries were 320 pairs of zinc plates weighing some 200 kilograms, ranged along both sides of the hull; the motor produced roughly 300 watts; the boat carried a dozen passengers about seven and a half kilometres at around 2.5 kilometres an hour. He improved it the following year to roughly a kilowatt. The electric boat was demonstrated on the Neva in 1838 — before the first commercial telegraph line in Britain had gone into regular service. His hope of a fleet of such craft was defeated by the cost of batteries and the fumes they gave off.
In the same year he announced galvanoplasty, now called electrotyping: the exact reproduction of a form in metal by electrodeposition. It was adopted almost immediately, printing Russian government documents by 1839 and allowing metal statuary to be made without casting. Priority was contested at the time by Thomas Spencer and C. J. Jordan in England and Joseph Adams in the United States, all of whom published the following year; the controversy was examined in detail at the process's centenary in 1938.
He also took over the electric telegraph work of Baron Schilling, who died in 1837, and between 1842 and 1845 laid an underground line from Saint Petersburg to Tsarskoye Selo, building what is generally described as the first letter-printing telegraph. He received the Demidov Prize in 1840 and died in Saint Petersburg in March 1874.
"Prussia to Russia, 1835"
История миграцииПрослеживая корни — Saint Petersburg (Russia)
Brother of the mathematician Carl Gustav Jacob Jacobi, who stayed in Germany.
German-born physicist who spent his career in Russia, known there as Boris Semyonovich Jacobi. Invented galvanoplasty (electrotyping) and in 1838 demonstrated an electrically powered boat on the Neva.
.svg?width=900)
Saint Petersburg (Russia). At the time, this region lay within the Russian Empire, which spanned from Poland to the Pacific.