Inch: Difference between revisions

| image    = Inch tape.jpg

In many other European languages, the word for "inch" is the same as or derived from the word for "thumb", as a man's thumb is about an inch wide (and this was even sometimes used to define the inch<ref>{{Cite web|url=https://www.britannica.com/science/inch|title=Inch {{!}} unit of measurement|website=Encyclopedia Britannica|language=en|access-date=28 March 2019}}</ref>). In the [[Dutch language]] a term for inch is ''engelse duim'' (english thumb).<ref>{{cite web |url=https://onzetaal.nl/taalloket/duim-lengtemaat |title=duim - lengtemaat |publisher=Genootschap Onze Taal|access-date=22 October 2022}}</ref><ref>{{cite web |url=https://www.omrekenen.nl/duim/ |title=duim |date=24 May 2020 |access-date=22 October 2022}}</ref> Examples include {{langx|ca|polzada}} ("inch") and ''{{lang|ca|polze}}'' ("thumb"); {{langx|cs|palec}} ("thumb"); Danish and {{langx|no|tomme}} ("inch") ''{{lang|no|tommel}}'' ("thumb"); {{langx|nl|duim}} (whence {{langx|af|duim}} and {{langx|ru|дюйм}}); {{langx|fr|pouce}}; {{lang-ka|დუიმი}}, {{langx|hu|hüvelyk}}; {{langx|it|pollice}}; {{langx|pt|polegada}} ("inch") and ''{{lang|pt|polegar}}'' ("thumb"); ("duim"); {{langx|sk|palec}} ("thumb"); {{langx|es|pulgada}} ("inch") and ''{{lang|es|pulgar}}'' ("thumb"); and {{langx|sv|tum}} ("inch") and ''tumme'' ("thumb").

The inch is a commonly used customary unit of length in the United States,<ref>{{cite web |url=http://corpus.byu.edu/coca/ |title=Corpus of Contemporary American English |website=Brigham Young University |location=US |access-date=5 December 2011}} lists 24,302 instances of inch(es) compared to 1548 instances of centimeter(s) and 1343 instances of millimeter(s).</ref> Canada,<ref>{{cite web |url=http://laws-lois.justice.gc.ca/PDF/W-6.pdf |title=Weights and Measures Act |page=37 |via=Justice Laws Website |location=Canada |year=1985 |access-date=11 January 2018}}</ref><ref>{{cite web |url=http://laws-lois.justice.gc.ca/eng/acts/W-6/page-2.html#h-4/ |title=Weights and Measures Act |page=2 |via=Justice Laws Website |location=Canada |date=1 August 2014 |access-date=18 December 2014}} Canadian units (5) The Canadian units of measurement are as set out and defined in Schedule II, and the symbols and abbreviations therefore are as added pursuant to subparagraph 6(1)(b)(ii).</ref> and the United Kingdom.<ref name=bis/> For the United Kingdom, guidance on public sector use states that, since 1 October 1995, without time limit, the inch (along with the foot) is to be used as a primary unit for road signs and related measurements of distance (with the possible exception of clearance heights and widths)<ref>{{cite web |url=http://www.legislation.gov.uk/uksi/2002/3113/schedule/2/made |title=The Traffic Signs Regulations and General Directions 2002 - No. 3113 - Schedule 2 - Regulatory Signs |publisher=The National Archives |location=UK |year=2002 |access-date=25 April 2013}}</ref> and may continue to be used as a secondary or supplementary indication following a metric measurement for other purposes.<ref name=bis>{{cite web |url=http://www.bis.gov.uk/assets/bispartners/nmo/docs/legislation/legislation/units-of-measurement/gnotes-for-public-sector-on-use-of-metric.pdf |archive-url=https://web.archive.org/web/20110704232045/http://www.bis.gov.uk/assets/bispartners/nmo/docs/legislation/legislation/units-of-measurement/gnotes-for-public-sector-on-use-of-metric.pdf |url-status=dead |archive-date=4 July 2011 |title=Guidance Note on the use of Metric Units of Measurement by the Public Sector |publisher=Department for Business Innovation and Skills |location=UK |year=2007 |access-date=12 December 2014}}</ref>

Inches are used for display screens (e.g. [[television]]s and computer monitors) worldwide. It is the official [[Japanese units of measurement#Imperial units|Japanese standard]] for electronic parts, especially display screens, and is the industry standard throughout continental Europe for display screens ([[Germany]] being one of few countries to supplement it with centimetres in most stores<ref>{{Cite web|url=https://www.otto.de/technik/fernseher/|title=Fernseher|publisher=[[Otto GmbH]]|language=de|access-date=28 December 2023}}</ref>).

The international standard symbol for inch is '''in''' (see [[ISO 31-1]], Annex A) but traditionally the inch is denoted by a [[Prime (symbol)|double prime]], which is often approximated by a [[quotation mark|double quote]] symbol, and the [[Foot (unit)|foot]] by a [[Prime (symbol)|prime]], which is often approximated by an [[apostrophe (mark)|apostrophe]]. For example; ''{{nowrap|three feet, two inches}}'' can be written as 3{{prime}} 2{{pprime}}. (This is akin to how the [[minute|first]] and [[second]] "cuts" of the [[hour]] are likewise indicated by prime and double prime symbols, and also the [[Minute of arc|first]] and [[Second of arc|second]] cuts of the [[Degree (angle)|degree]].)

* {{calculator|id=cm|type=plain|default=2.54|formula=in*2.54|decimals=1|NaN-text=0}} [[centimeter]]s (1 inch is exactly 2.54&nbsp;cm)

* {{calculator|id=points|type=plain|default=100|formula=in*100|NaN-text=0}} points{{efn|Used by the Australian [[Bureau of Meteorology]] for measuring rainfall until 1973<ref>{{cite web |url=http://www.bom.gov.au/climate/cdo/about/definitionsrain.shtml |title=Climate Data Online – definition of rainfall statistics |publisher=[[Bureau of Meteorology]] |location=Australia |access-date=10 June 2012}}</ref>}} or gries{{efn|name=locke|Part of [[John Locke]]'s proposal for decimalization of English measures<ref>{{citation |last=Locke |first=John |author-link=John Locke |display-authors=0 |contribution=Of Human Understanding |page=[https://books.google.com/books?id=3n8PAAAAQAAJ&pg=PA293 293] |title=The Works of John Locke Esq., ''Vol. I'' |location=London |publisher=John Churchill |date=1714 |url=https://books.google.com/books?id=3n8PAAAAQAAJ }}.</ref>}}

An Anglo-Saxon unit of length was the [[English units|barleycorn]]. After 1066, 1&nbsp;inch was equal to 3 barleycorns, which continued to be its legal definition for several centuries, with the barleycorn being the base unit.<ref name=Klein>{{cite book |title=The world of measurements: masterpieces, mysteries and muddles of metrology |url=https://archive.org/details/worldofmeasureme0000klei |url-access=registration |first=H. Arthur |last=Klein |publisher=Simon and Schuster |location=New York, US |year=1974|isbn=9780671215651 }}</ref> One of the earliest such definitions is that of 1324, where the legal definition of the inch was set out in a statute of [[Edward II of England]], defining it as "three grains of [[barley]], dry and round, placed end to end, lengthwise".<ref name=Klein />

}}</ref> In 1893, [[Mendenhall Order|Mendenhall ordered]] the physical realization of the inch to be based on the international prototype metres numbers 21 and 27, which had been received from the [[CGPM]], together with the previously adopted conversion factor.<ref name="Mendenhall">{{cite web |author=T. C. Mendenhall, Superintendent of Standard Weights and Measures |author-link=Thomas Corwin Mendenhall |url=http://physics.nist.gov/Pubs/SP447/app3.pdf |date=5 April 1893 |title=Appendix&nbsp;6 to the Report for 1893 of the Coast and Geodetic Survey |url-status=dead |archive-url=https://web.archive.org/web/20120930180925/http://physics.nist.gov/Pubs/SP447/app3.pdf |archive-date=30 September 2012 }}</ref>

Before the adoption of the metric system, several European countries had customary units whose name translates into "inch". The French ''[[pouce]]'' measured roughly 27.0&nbsp;mm, at least when applied to describe the calibre of artillery [[Cannon|pieces]]. The [[Dutch units of measurement|Amsterdam foot]] (''voet'') consisted of 11 Amsterdam inches (''duim''). The Amsterdam foot is about 8% shorter than an English foot.<ref>*{{cite book

* [[English units]]