Giovanni Giorgi - MKSA
Giovanni Giorgi was born in Lucca on November 27, 1871, and he became a physicist and electrical engineer. He studied engineering at the Institute of Technology of Rome, directed Rome’s Technology Office from 1905 to 1924 and taught at the University of Rome from 1913 to 1939. He was not a mathematician by profession, though he was an invited speaker at the International Congress of Mathematicians in 1924, 1928 and 1932. He died in Castiglioncello, near Livorno, on August 19, 1950.
The MKSA System
Around 1900, after Maxwell’s work, electrical measurements could not be fully explained with only three base units (metre, kilogram and second), and some equations contained unexplained irrational coefficients. In 1901 Giorgi proposed adding a fourth base unit taken from electromagnetism, which would also remove those coefficients. The fourth unit could have been electric current, voltage or electrical resistance, and electric current was chosen, with the ampere as its unit. Adding it to the three base units produced the MKSA system (metre, kilogram, second and ampere), approved in 1946. The International Electrotechnical Commission is said to have adopted Giorgi’s system as early as 1935, though it did not name the fourth unit yet. In 1954 the system was extended to six base units, and in 1960 it became the International System of Units (SI). The mole was added in 1971 as the seventh.
Note
The bright green stamp at the start of the second row on this album page is meant to commemorate Giovanni Giorgi and his measurement system.
Contains 9 spots: own 9 – 9 unused, 0 used.
Page is finished.
Album or Web Page Last changed Sep 7, 2023
Stamp Details
The table below lists information about the stamps shown on this page of Lighthouse’s stamp album. For more details about a particular stamp, click on its description. That will take you to the related web page of Colnect.
spot |
own |
catalog |
subject |
description |
comment |
|---|---|---|---|---|---|
✓ |
1935 |
Piazza San Silvestro Post Office - Rome |
700₤ (may 1990) |
||
✓ |
1936 |
Fondaco Tedeschi Post Office - Venice |
800₤ (may 1990) |
||
✓ |
1932 |
600₤ (apr 1990) |
|||
✓ |
1937 |
450₤ (may 1990) |
|||
✓ |
1938 |
700₤ (may 1990) |
|||
✓ |
1933 |
600₤ (apr 1990) |
|||
✓ |
1941 |
600₤ (jun 1990) |
|||
✓ |
1934 |
700₤ (apr 1990) |
|||
✓ |
1944 |
3200₤ (oct 1990) |
Footnotes
Spot refers to the postion of the stamp on the album page (e.g., 3.2 indicates row 3, position 2).
Amt. is an abbreviation for the face amount of the stamp.
Own indicates the stamp status: ✓ for unused; ✗ for used or canceled; ⭑ signifies I ordered one; ; ✨ indicates it was bought recently; ✠ means an auction bid is pending; and ◎ is used, and it costs too much for unused.
To search by catalog number, go to the search box and enter it in the catalog number box. However, it’s a bit broken; I need to fix it.
