Editing Metric system (section)

=== 20th century ===
In 1901, [[Giovanni Giorgi]] showed that by adding an electrical unit as a fourth base unit, the various anomalies in electromagnetic systems could be resolved. The metre–kilogram–second–[[coulomb]] (MKSC) and metre–kilogram–second–[[ampere]] (MKSA) systems are examples of such systems.<ref name=IECGiorgi>{{cite web|url = http://www.iec.ch/about/history/beginning/giovanni_giorgi.htm|title = In the beginning... Giovanni Giorgi|year = 2011
|publisher = [[International Electrotechnical Commission]]|access-date = 5 April 2011|archive-date = 15 May 2011|archive-url = https://web.archive.org/web/20110515134553/http://www.iec.ch/about/history/beginning/giovanni_giorgi.htm|url-status = dead}}</ref><ref name=":1">{{Cite journal |last=Jayson |first=Joel S. |date=January 2014 |title=The Daniell cell, Ohm's law, and the emergence of the International System of Units |url=https://pubs.aip.org/aapt/ajp/article/82/1/60-65/1058039 |journal=American Journal of Physics |language=en |volume=82 |issue=1 |pages=60–65 |arxiv=1512.07306 |doi=10.1119/1.4826445 |bibcode=2014AmJPh..82...60J |s2cid=119278961 |issn=0002-9505}}</ref>

The [[metre–tonne–second system of units]] (MTS) was based on the metre, [[tonne]] and second – the unit of force was the [[sthène]] and the unit of pressure was the [[pièze]]. It was invented in France for industrial use and from 1933 to 1955 was used both in France and in the [[Soviet Union]].<ref name=ieeeghn>{{cite web |url=http://www.ieeeghn.org/wiki/index.php/System_of_Measurement_Units |title = System of Measurement Units |work = IEEE Global History Network |publisher= [[Institute of Electrical and Electronics Engineers]] (IEEE) |access-date = 21 March 2011}}</ref><ref>{{cite web |url = http://www.hydrelect.info/articles.php?lng=fr&pg=3 |title = Notions de physique – Systèmes d'unités |language = fr |trans-title=Symbols used in physics – units of measure |access-date = 21 March 2011 |publisher = Hydrelect.info}}</ref> [[Gravitational metric system]]s use the [[kilogram-force]] (kilopond) as a base unit of force, with mass measured in a unit known as the [[Gravitational metric system|hyl]], ''Technische Masseneinheit'' (TME), mug or [[slug (unit)|metric slug]].<ref>
{{cite web
 |url = http://www.numericana.com/answer/units.htm#slug
 |title = Final Answers
 |first1 = Gérard P
 |last1 = Michon
 |publisher = Numericana.com
 |date = 9 September 2000
 |access-date = 11 October 2012
}}</ref> Although the CGPM passed a resolution in 1901 defining the standard value of [[Standard gravity|acceleration due to gravity]] to be 980.665&nbsp;cm/s<sup>2</sup>, gravitational units are not part of the [[International System of Units]] (SI).<ref>{{cite web
|url = http://www.bipm.org/en/CGPM/db/3/2/
|title = Resolution of the 3rd meeting of the CGPM (1901)
|publisher = General Conference on Weights and Measures
|access-date = 11 October 2012}}</ref>