Editing British Science Association (section)

===Electrical standards===
One of the most important contributions of the British Association was the establishment of standards for electrical usage: the [[ohm]] as the unit of [[electrical resistance]], the [[volt]] as the unit of [[electrical potential]], and the [[ampere]] as the unit of [[electrical current]].<ref name=Hunt1994>[https://www.jstor.org/stable/301998?seq=1#page_scan_tab_contents "The Ohm is where the Art is: British Telegraph Engineers and the Development of Electrical Standards" Bruce J. Hunt (1994)] {{Webarchive|url=https://web.archive.org/web/20151126054156/http://www.jstor.org/stable/301998?seq=1#page_scan_tab_contents |date=26 November 2015 }}, ''[[Osiris (journal)|Osiris]]'' 9: 48 to 63</ref> A need for standards arose with the [[submarine communications cable|submarine telegraph]] industry. Practitioners came to use their own standards established by wire coils: "By the late 1850s, Clark, [[C. F. Varley|Varley]], [[Charles Tilston Bright|Bright]], [[Willoughby Smith|Smith]] and other leading British cable engineers were using calibrated resistance coils on a regular basis and were beginning to use calibrated condensers as well."<ref name=Hunt1994/>{{rp|52}}

The undertaking was suggested to the BA by [[William Thomson, Baron Kelvin|William Thomson]], and its success was due to the use of Thomson's [[mirror galvanometer]]. [[Josiah Latimer Clark]] and [[Fleeming Jenkin]] made preparations. Thomson, with his students, found that impure [[copper]], contaminated with [[arsenic]], introduced significant extra resistance. The chemist [[Augustus Matthiessen]] contributed an appendix (A) to the final 1873 report<ref>[[Fleeming Jenkin]] (1873) [http://babel.hathitrust.org/cgi/pt?id=mdp.39015067305402;view=1up;seq=5 Reports of the Committee on Electrical Standards appointed by the British Association for the Advancement of Science] {{Webarchive|url=https://archive.today/20150317024058/http://babel.hathitrust.org/cgi/pt?id=mdp.39015067305402;view=1up;seq=5 |date=17 March 2015 }}, link from [[HathiTrust]].</ref> that showed temperature-dependence of alloys.
:The natural relation between these units are clearly, that a unit of electromotive force between two points of a conductor separated by a unit of resistance shall produce unit current, and that this current in a unit of time convey a unit quantity of electricity.
The unit system was "absolute" since it agreed with previously accepted units of work, or energy:
:The unit current of electricity, in passing through a conductor of unit resistance, does a unit of work or its equivalent in a unit of time.