Hundredweight
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The hundredweight or centum weight (abbreviated cwt) is a unit of mass defined in terms of the pound avoirdupois (lb). The Imperial and U.S. customary definitions differ :
- In Imperial units, British legislation defined the (long) hundredweight as 50.80234544 kg.[1] This is so close to 50 kg that the transition to its 50 kg metric equivalent of quintal aka centner (Zentner in German) has been easy. Earlier British legislation[2] had defined it as being a weight or mass [sic] equal to 112 [avoirdupois] pounds or 8 stone.
- In U.S. customary units, a (short) hundredweight is defined as 100 lb; equivalent to 45.35924 kg.[3] This is also the normal hundredweight in Canada. The short hundredweight is also called a cental, especially in places which normally use the long hundredweight.
In both systems, there are twenty hundredweights to a ton: respectively, the long ton of 2240 lb—approximately equal to a metric tonne of 1,000 kilograms (2,205 lb))— and the short ton of 2000 lb.
[edit] History
Before the 15th century in England, a hundredweight used the old hundred of 108 lb[4], giving a ton of 2160 pounds. In some industries (notably forges) this old hundred was retained somewhat longer. The London hundredweight of 112 pounds eventually replaced the old hundred.
The short hundredweight is commonly used in the sale of livestock and some cereal grains and oilseeds and concrete additives and on futures exchanges:[citation needed]. The long hundredweight is now little used in any country; one exception is for measuring the weight of ringable bells used for change ringing.[5]
[edit] See also
William J. Murphy. "Tables for Weights and Measurement: Crops". University of Missouri Extension. http://extension.missouri.edu/xplor/agguides/crops/g04020.htm
[edit] References
- ^ UK Units of Measurement Regulations
- ^ "Weights and Measures Act 1985". Her Majesty's Stationery Office. 1985-10-30. http://www.opsi.gov.uk/acts/acts1985/pdf/ukpga_19850072_en.pdf. Retrieved 2009-08-14.
- ^ NIST Guide to the SI
- ^ "Tractatus de Ponderibus et Mensuris". Statutes of the Realm. http://www.sizes.com/library/British_law/ponderibus.htm. Retrieved 3 Sep 2009.
- ^ Central Council of Church Bell Ringers. "Scope, Conventions, Abbreviations, etc". Dove's Guide for Church Bell Ringers. http://www.dove.cccbr.org.uk/doveDesc.php. Retrieved 15 Dec 2008.
