The rod is a unit of length equal to 5.5 yards, 5.0292 metres, 16.5 feet, or 1⁄320 of a statute mile. A rod is the same length as a perch and a pole. The lengths of the perch (one rod) and chain (four rods) were standardized in 1607 by Edmund Gunter. In old English, the term lug is also used.12
The length is equal to the standardized length of the ox goad used by medieval English ploughmen;citation needed fields were measured in acres which were one chain (four rods) by one furlong (in the United Kingdom, ten chains).citation needed
Because the furlong was "one plough's furrow long" and a furrow was the length a plough team was to be driven without resting, the length of the furlong and the area of the acre vary regionally, nominally due to differing soil types (causing differences in how far a team could be driven until it needed to rest). In England the acre was 4,840 square yards, but in Scotland it was 6,150 square yards and in Ireland 7,840 square yards.citation needed In all three countries, fields were divided in acres and thus the furlong became a measure commonly used in horse racing, archery, and civic planning.citation needed
A sign at the City Hall in Münster, Germany noting that the bar shown is one "Prussian Half Rod" (1.883 m) longBars of metal one rod (16.5 feet) long were used as standards of length in surveying land in the past. One example of a surveyor's rod is a one piece metal bar encased in a cylindrical canvas tube (to keep the sun from heating it and making it increase in length) with a piece of the semiprecious gemstone jasper at each end of the rod (to prevent wear of the metal bar).citation needed The rod was still in use as a common unit of measurement in the mid-1800s, when Henry David Thoreau used it frequently when describing distances in his work Walden.citation needed
The rod was phased out as a unit of measurement that could legally be used in the United Kingdom as part of a ten year metrication process that began on 24 May 19653.
Despite no longer being in widespread use, the rod is still used in certain specialized fields. In recreational canoeing, maps measure portages (overland paths where canoes must be carried) in rods4. This is thought to persist due to the rod approximating the length of a typical canoe. In the United Kingdom, the sizes of allotment gardens continue to be measured in square poles in some areas, being referred to simply as poles rather than square poles.5 In Vermont, the default width of state and town highways and trails is three rods (15.0876 m).6 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;7 as shown in this actual legal description of rural real estate:
citation needed
Area and volumeThe 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.
Notes ^ Anglo-Saxon And Roman To Metrics Conversion Dead link - 2009-07-31 ^ Units: P ^ Department of Trade and Industry ^ Voyaguer Maps BWCA map downloads ^ "Allotments". Watford Borough Council. http://www.watford.gov.uk/ccm/navigation/environment-and-planning/parks-and-open-spaces/allotments/. Retrieved 5 October 2009. ^ VSA Title 17 §702 (published 2009). ^ Shelton, Neil. "How to Read Land Descriptions". homestead.org. http://www.homestead.org/land/Legals/HowtoReadYourDeed.htm. Retrieved 2008-05-07. See also Perch Furlong anthropic units Imperial units
