Giovanni Giorgi

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For the Italian priest and composer, see Giovanni Giorgi (composer).
Giovanni Giorgi
Born (1871-11-27)27 November 1871
Died 19 August 1950(1950-08-19) (aged 78)
Castiglioncello, Livorno
Nationality Italian
Engineering career
Institution memberships University of Rome
Significant projects SI

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. During World War II he moved to Ferentino.

Giorgi died in Castiglioncello, Livorno at the age of 79.

The "Giorgi" system[edit]

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. 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.[1][2]

In 1935 this was adopted by the IEC as the Giorgi system, also known as MKS system.[3]

In 1946 the CIPM approved a proposal to adopt a four-dimensional system based on the metre, kilogram, second and ampere, the MKSA system.[4]

The Giorgi system is considered the precursor to the SI. 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.[4]


  1. ^ Giovanni Giorgi (1901), "Unità Razionali di Elettromagnetismo", Atti della Associazione Elettrotecnica Italiana (in Italian) (Torino) 
  2. ^ Giovanni Giorgi (1902), Rational Units of Electromagnetism  Original manuscript with handwritten notes by Oliver Heaviside
  3. ^ Arthur E. Kennelly (1935), "Adoption of the Meter-Kilogram-Mass-Second (M.K.S.) Absolute System of Practical Units by the International Electrotechnical Commission (I.E.C.), Bruxelles, June, 1935", Proceedings of the National Academy of Sciences of the United States of America 21 (10): 579–583, Bibcode:1935PNAS...21..579K, doi:10.1073/pnas.21.10.579 
  4. ^ a b International Bureau of Weights and Measures (2006), The International System of Units (SI) (8th ed.), pp. 109,110, ISBN 92-822-2213-6 


  1. International Electrotechnical Commission. "IEC Historical Figures - Giovanni Giorgi". Retrieved 2014-02-21. 
  2. Giovanni Giorgi (1905), "Proposals Concerning Electrical and Physical Units", Transactions of the International Electrical Congress, St. Louis, 1904: 136–141, OCLC 3395740