Rod (unit)

's 1551 painting A Meat Stall with the Holy Family Giving Alms reads in Flemish: "behind here are 154 rods of land for sale immediately, either by the rod according to your convenience or all at once". In England, the perch was officially discouraged in favour of the rod as early as the 15th century; however, local customs maintained its use. In the 13th century, perches were variously recorded in lengths of , , and ; and even as late as 1820, a House of Commons report notes lengths of , , , , and even . In Ireland, a perch was standardized at , making an Irish chain, furlong and mile proportionately longer by 27.27% than the "standard" English measure. Until English King Henry VIII seized the lands of the Roman Catholic Church in 1536, modern land measures were essentially unknown. The practice of using surveyor's chains, and perch-length rods made into a detachable stiff chain, came about a century later when iron was a more plentiful and common material. A chain is a larger unit of length measuring , or 22 yards, or 100 links, or 4 rods (20.1168 meters). There are 10 chains or 40 rods in a furlong (eighth-mile), and so 80 chains or 320 rods in one statute mile (1760 yards, 1609.344 m, 1.609344 km); the definition of which was legally set in 1593 and popularized by Royal surveyor (called the 'sworn viewer') John Ogilby only after the Great Fire of London (1666). An acre is defined as the area of 10 square chains (that is, an area of one chain by one furlong), and derives from the shapes of new-tech plows and the desire to quickly survey seized church lands into a quantity of squares for quick sales The length of the chain was standardized in 1620 by Edmund Gunter at exactly four rods. ==Modern use and definition==

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. In Vermont, the default right-of-way width of state and town highways and trails is three rods (49 ft 6 in, 15.09 m). In the United States until 1 January 2023, the rod was defined in terms of 'survey' feet: it was 16.5 US survey feet which equalled approximately 5.029 210 058 meters; since 1 January 2023 survey feet have been deprecated and the rod formally is defined as exactly 16.5 feet (international feet) or exactly 5.0292 meters. ==Area and volume==

The terms pole, perch, rod and rood have been used as units of area, and perch is also used as a unit of volume. As a unit of area, a square perch (the perch being standardized to equal feet, or yards) is equal to a square rod, or acre. There are 40 square perches to a rood (for example a rectangular area of 40 rods times one rod), and 160 square perches to an acre (for example a rectangular area of 40 rods times 4 rods). This unit is usually referred to as a perch or pole even though square perch and square pole were the more precise terms. Rod was also sometimes used as a unit of area to refer to a rood. However, in the traditional French-based system in some countries, 1 square perche is 42.21 square metres. As of August 2013, perches and roods are used as government survey units in Jamaica. They appear on most property title documents. The perch is also in extensive use in Sri Lanka, being favored even over the rood and acre in real estate listings there. Perches were informally used as a measure in Queensland real estate until the early 21st century, mostly for historical gazetted properties in older suburbs. Volume A traditional unit of volume for stone and other masonry. A perch of masonry is the volume of a stone wall one perch () long, high, and thick. This is equivalent to exactly . There are two different measurements for a perch depending on the type of masonry that is being built: • A dressed stone work is measured by the -cubic foot perch () long, high, and thick. This is equivalent to exactly . • a brick work or rubble wall made of broken stone of irregular size, shape and texture, made of undressed stone, is measured by the () long, high, and thick. This is equivalent to exactly . ==See also==