ITALY COVER with stamp GIOVANNI GIORGI
Giovanni Giorgi (27 November 1871 - 19 August 1950) was an Italian
electrical engineer who invented the Giorgi system of measurement, the precursor to the International System (
SI).
Giorgi was born in
Lucca and studied engineering at the Institute of Technology of Rome, he worked at Fornaci Giorgi in
Ferentino, then was the director of the Technology Office of Rome between 1906 and 1923. He also taught at the
University of Rome between 1913 and 1939.
Toward the end of the 19th century, after
James Clerk Maxwell's
discoveries, it was clear that electric measurements could not be
explained in terms of the three fundamental units of length, mass and
time. Therefore, in 1901, Giorgi proposed to the AEI (Associazione
Elettrotecnica Italiana) a new system that had as fundamental units the
metre, the
kilogram, the
second and a fourth unit to be chosen from the units of electrotechnology.
In 1935 this was adopted by the
IEC as the
Giorgi system, also known as MKSΩ, because the fourth fundamental unit was that of
electrical resistance, the
ohm. In 1960, at the 11th
General Conference of Weights and Measures, the
SI (International System) was adopted, which was based on seven fundamental units: metre, kilogram,
second,
ampere,
kelvin,
mole and
candela.
Giorgi died in
Castiglioncello,
Livorno at the age of 79.