User:Milton Beychok/Sandbox: Difference between revisions

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A '''gallon''' is a measure of [[volume]] of approximately four [[litre]]s in the United States, and approximately five [[litre]]s in the United Kingdom.  Historically it has had many different definitions, but there are three definitions in current use.  These are the [[U.S. liquid gallon]] (≈&nbsp;3.78&nbsp;L) and the lesser used [[U.S. dry gallon]] (≈&nbsp;4.4&nbsp;L) which are in use in the [[United States]], and the [[Imperial (UK) gallon]] (≈&nbsp;4.5&nbsp;L) which is in unofficial use within the [[United Kingdom]] and [[Ireland]] and is in semi-official use within [[Canada]] (See [[Canadian units]]).<ref>{{cite web|url=http://laws.justice.gc.ca/en/showdoc/cs/W-6/sc:2//en#anchorsc:2|title=Weights and Measures Act: Canadian units of measure|publisher=Department of Justice|accessdate=2007-11-14}}</ref>  The gallon, be it the Imperial or U.S. gallon, is sometimes found in other [[English language|English]]-speaking countries.


==Definitions==
[[Image:GasCan.jpg|thumb|200px|A one U.S. gallon gas can purchased near the U.S.-Canada border. It shows equivalences in Imperial gallons and litres.]]
* The '''U.S. liquid gallon''' is legally defined as 231 [[cubic inch]]es,<ref name="15USC205">[http://www.law.cornell.edu/uscode/search/display.html?terms=unit%20measure&url=/uscode/html/uscode15/usc_sec_15_00000205----000-notes.html ''Authorized tables'']'', U.S. Code'', Title 15, ch. 6, subchapter I, sec. 205, accessed 19 July 2008.</ref> and is equal to exactly {{val|3.785411784|u=[[litre]]s}} or about {{val|0.133680555|u=[[cubic foot|cubic feet]]}}. This is the most common definition of a gallon in the United States. The U.S. [[fluid ounce]] is defined as {{frac|128}} of a U.S. gallon.
* The '''U.S. dry gallon''' is one-eighth of a U.S. ''[[Winchester measure|Winchester]]'' [[bushel]] of 2150.42 cubic inches, thus it is equal to exactly 268.8025 cubic inches or {{val|4.40488377086|u=litres}}.  The U.S. dry gallon is less commonly used, and is not listed in the relevant statute, which jumps from the dry quart to the [[peck]].<ref name="15USC205"/>
* The '''imperial (UK) gallon''' was legally defined as {{val|4.54609|u=litres}}. This definition is used in some [[Commonwealth of Nations|Commonwealth]] countries and [[Ireland]], and is based on the volume of 10 [[pound (mass)|pound]]s of water at 62&nbsp;[[degree Fahrenheit|°F]]. (A U.S. liquid gallon of water weighs about 8.33 pounds at the same temperature.) The imperial fluid ounce is defined as {{frac|160}} of an imperial gallon.
On 1 January 2000, it ceased to be a legal unit of measure within the United Kingdom for economic, health, safety or administrative purposes.<ref>{{cite web
          |url=http://www.opsi.gov.uk/si/si1995/Uksi_19951804_en_1.htm
          |title=The Units of Measurement Regulations 1995 (Article 4)
          |date=2000-09-20
          |accessdate=2009-01-28}}</ref>
In 2005 a major step in metrication i.e. kilometres and litres, was taken in Ireland, only excluding draught beer.<ref>{{cite web
          |url=http://lamar.colostate.edu/~hillger/internat.htm
          |title=Metric usage and metrication in other countries
          |date=2009-02-13
          |accessdate=2009-07-03}}</ref>

Revision as of 17:51, 5 June 2010

A gallon is a measure of volume of approximately four litres in the United States, and approximately five litres in the United Kingdom. Historically it has had many different definitions, but there are three definitions in current use. These are the U.S. liquid gallon (≈ 3.78 L) and the lesser used U.S. dry gallon (≈ 4.4 L) which are in use in the United States, and the Imperial (UK) gallon (≈ 4.5 L) which is in unofficial use within the United Kingdom and Ireland and is in semi-official use within Canada (See Canadian units).[1] The gallon, be it the Imperial or U.S. gallon, is sometimes found in other English-speaking countries.

Definitions

A one U.S. gallon gas can purchased near the U.S.-Canada border. It shows equivalences in Imperial gallons and litres.
  • The U.S. liquid gallon is legally defined as 231 cubic inches,[2] and is equal to exactly Template:Val or about Template:Val. This is the most common definition of a gallon in the United States. The U.S. fluid ounce is defined as Template:Frac of a U.S. gallon.
  • The U.S. dry gallon is one-eighth of a U.S. Winchester bushel of 2150.42 cubic inches, thus it is equal to exactly 268.8025 cubic inches or Template:Val. The U.S. dry gallon is less commonly used, and is not listed in the relevant statute, which jumps from the dry quart to the peck.[2]
  • The imperial (UK) gallon was legally defined as Template:Val. This definition is used in some Commonwealth countries and Ireland, and is based on the volume of 10 pounds of water at 62 °F. (A U.S. liquid gallon of water weighs about 8.33 pounds at the same temperature.) The imperial fluid ounce is defined as Template:Frac of an imperial gallon.

On 1 January 2000, it ceased to be a legal unit of measure within the United Kingdom for economic, health, safety or administrative purposes.[3] In 2005 a major step in metrication i.e. kilometres and litres, was taken in Ireland, only excluding draught beer.[4]

  1. Weights and Measures Act: Canadian units of measure. Department of Justice. Retrieved on 2007-11-14.
  2. 2.0 2.1 Authorized tables, U.S. Code, Title 15, ch. 6, subchapter I, sec. 205, accessed 19 July 2008.
  3. The Units of Measurement Regulations 1995 (Article 4) (2000-09-20). Retrieved on 2009-01-28.
  4. Metric usage and metrication in other countries (2009-02-13). Retrieved on 2009-07-03.