Giovanni Giorgi

Born on 27 November 1871 in Lucca, Italy, Giovanni Giorgi was a physicist and electrical engineer who proposed a system of measurement that was the precursor of the modern International System of Units (SI). Giorgi studied civil engineering at the Institute of Technology in Rome, graduating in 1893. From 1906 to 1921 he served as director of the Technology Office of Rome. He also taught at the University of Rome and several other universities from 1913 to 1939. Giorgi is best known for his development in 1901 of the Giorgi International System of Measurement, which proposed that the MKS (meter, kilogram, second) system be extended with a fourth unit to standardize electric measurements. In 1960 a similar system was endorsed by the General Conference of Weights and Measures, with the ampere (as well as the kelvin and candela) joining the meter, kilogram, and second as base units. Among Giorgi’s other contributions were the development of hydroelectric installations, electric distribution networks, and urban trolley systems. Over his career, he authored some 350 scientific papers and was the author or coauthor of several textbooks on science and engineering. Giorgi died at age 79 in 1950. (Photo credit: ‘Voltiana,’ Como, Italy – 10 September 1927 issue, courtesy AIP Emilio Segrè Visual Archives)

Date in History: 27 November 1871