Rod (unit)
 |
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| SI units | |
|---|---|
| 5.0292 m | 502.92 cm |
| US customary / Imperial units | |
| 5.5000 yd | 16.500 ft |
The rod is a unit of length equal to 5½ yards, or 16½ feet (5.0292 metres) and is ⅟320th of a statute mile. A rod is the same length as a perch or a pole. In old English, the term lug is also used.[1][2]
Contents |
[edit] History
The early Anglo-Saxon rod was based on the North German foot of 335 mm. The rod, used for land measurement, was equal to fifteen of these North German or Anglo-Saxon feet. By about 1300, England had switched over to the foot and yard of today, but kept the rod at its original length because much English land had already been surveyed and measured using the older unit. The rod thus became 16½ new feet, which equalled 15 old feet.[3]
The length of the chain was standardized in 1620 by Edmund Gunter at exactly 4 rods.[4][5] Fields were measured in acres, which were one chain (four rods) by one furlong (in the United Kingdom, ten chains).[6]
Bars of metal one rod long were used as standards of length when surveying land. The rod was still in use as a common unit of measurement in the mid-19th century, when Henry David Thoreau used it frequently when describing distances in his work Walden.[7]
[edit] Modern use
The rod was phased out as a legal unit of measurement in the United Kingdom as part of a ten-year metrication process that began on 24 May 1965.[8]
In the USA, the rod, along with the chain, furlong, and statute mile (as well as the survey inch and survey foot) are based on the pre-1959 values for United States customary units of linear measurement. The Mendenhall Order of 1893 defined the yard as exactly 3600/3937 meters, with all other units of linear measurement, including the rod, based on the yard. In the post-1959 system, the fundamental unit of length is the inch, defined as exactly 2.54 centimeters. The above-noted units, used in surveying, retain their pre-1959 values. [9]
Despite no longer being in widespread use, the rod is still employed in certain specialized fields. In recreational canoeing, maps measure portages (overland paths where canoes must be carried) in rods; typical canoes are approximately one rod long.[10] In the United Kingdom, the sizes of allotment gardens continue to be measured in square poles in some areas, sometimes being referred to simply as poles rather than square poles.[11]
In Vermont, the default right-of-way width of state and town highways and trails is three rods (15.0876 m).[12] Rods can also be sometimes found on the legal descriptions of tracts of land in the United States, following the "metes and bounds" method of land survey;[13] as shown in this actual legal description of rural real estate:
LEGAL DESCRIPTION: Commencing 45 rods East and 44 rods North of Southwest corner of Southwest 1/4 of Southwest 1/4; thence North 36 rods; thence East 35 rods; thence South 36 rods; thence West 35 rods to the place of beginning, Manistique Township, Schoolcraft County, Michigan.[14]
[edit] Area and volume
The terms pole, perch and rod have been used as units of area, and perch is also used as a unit of volume. See square perch and rood.
[edit] See also
- Perch
- Chain (unit)
- Furlong
- Imperial units
- English units
- United States customary units
- anthropic units
[edit] References
- ^ Bonten, JHM (2007-01-19). "Anglo-Saxon and Biblical to Metrics Conversions". Surveyor + Chain + British-Nautical. http://home.kpn.nl/jhm.bonten/tables/anglosaxon/napolangsax.html#linsur. Retrieved 2010-11-01.
- ^ Rowlett, Russ (2008-12-15). "lug [1]". How Many? A Dictionary of Units of Measurement. University of North Carolina at Chapel Hill. http://www.unc.edu/~rowlett/units/dictL.html. Retrieved 2010-11-01.
- ^ Zupko, Ronald Edward (1977). British Weights and Measures: A History from Antiquity to the Seventeenth Century. University of Wisconsin Press. pp. 10-11, 20-21. ISBN 978-0299073404.
- ^ Thomas Ulvan Taylor (1908). "1". Surveyor's hand book. McGraw-Hill. p. 1. http://books.google.com/books?id=swsEAAAAMAAJ&pg=PA1. Retrieved 28 November 2011.
- ^ Russell, Jeffrey S.; American Society of Civil Engineers (1 August 2003). Perspectives in civil engineering: commemorating the 150th anniversary of the American Society of Civil Engineers. ASCE Publications. p. 167. ISBN 978-0-7844-0686-1. http://books.google.com/books?id=rOg6B38bunIC&pg=PA167. Retrieved 28 November 2011.
- ^ Rowlett, Russ (2008-12-03). "acre (ac or A)". How Many? A Dictionary of Units of Measurement. University of North Carolina at Chapel Hill. http://www.unc.edu/~rowlett/units/dictA.html. Retrieved 2010-11-01.
- ^ Thoreau, Henry David (1899). Walden: or, Life in the woods. H. Altemus. pp. 67, 113, 203, 204, 208, 290, 300, 309, 319, 339, 341, 356. http://books.google.com/books?id=jiE6AQAAIAAJ&printsec=frontcover&dq=thoreau+walden&hl=en&ei=xIHSTqG5H6ieiALP-qSADA&sa=X&oi=book_result&ct=result&resnum=2&ved=0CE4Q6AEwAQ#v=onepage&q=rod&f=false. Retrieved 27 November 2011.
- ^ Consumer and Competition Policy Directorate (1968). Report (1968) by the Standing Joint Committee on Metrication (PDF). Department of Trade and Industry (United Kingdom). http://www.metric.org.uk/Docs/DTI/met1968.pdf. Retrieved 2010-11-01.
- ^ Handbook 44 - 2012, Appendix C - General Tables of Units of Measurement
- ^ "Canoe Glossary and Clickable Canoe". OutdoorPlaces.com. Michael Thiessen. http://www.outdoorplaces.com/Features/Paddle/pickcanoe/newcanoe7.htm#rod. Retrieved 2010-11-01.
- ^ "Allotments". Watford Borough Council. http://www.watford.gov.uk/ccm/navigation/environment-and-planning/parks-and-open-spaces/allotments/. Retrieved 2009-10-05.
- ^ Width of highways and trails. 19 V.S.A. § 702 (Vermont Statutes Online) (Added 1985, No. 269 [Adj. Sess.], § 1.).
- ^ Shelton, Neil. "How to Read Land Descriptions". homestead.org. p. 5. http://www.homestead.org/NeilShelton/Legals/HowToReadLandDescriptions.htm. Retrieved 2008-05-07.
- ^ "Lake View Parcel $198 Down $198 Month Incredible 8 Acre Parcel!". EagleStar. American Eagle Star. http://www.eaglestar.net/ndu.html. Retrieved 2010-11-01.
