The rod, perch, or pole (sometimes also lug) is a
surveyor's tool
and
unit of length
A unit of length refers to any arbitrarily chosen and accepted reference standard for measurement of length. The most common units in modern use are the metric units, used in every country globally. In the United States the U.S. customary uni ...
of various historical definitions, often between approximately 3 and 8
meter
The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its pref ...
s (9 ft 10 in and 26 ft 2 in). In modern
US customary units
United States customary units form a system of measurement units commonly used in the United States and U.S. territories since being standardized and adopted in 1832. The United States customary system (USCS or USC) developed from English uni ...
it is defined as
US survey feet, equal to exactly of a
surveyor's mile, or a quarter of a
surveyor's chain (
yard
The yard (symbol: yd) is an English unit of length in both the British imperial and US customary systems of measurement equalling 3 feet or 36 inches. Since 1959 it has been by international agreement standardized as exactly ...
s), and is approximately 5.0292 meters. The rod is useful as a unit of length because whole number multiples of it can form one
acre of square measure (area). The 'perfect acre'
is a rectangular area of 43,560 square feet, bounded by sides 660 feet (a
furlong
A furlong is a measure of distance in imperial units and United States customary units equal to one eighth of a mile, equivalent to 660 feet, 220 yards, 40 rods, 10 chains or approximately 201 metres. It is now mostly confined to use in hor ...
) long and 66 feet wide (220 yards by 22 yards) or, equivalently, 40 rods and 4 rods. An acre is therefore 160 square rods or 10 square chains.
The name ''perch'' derives from the
Ancient Roman unit, the ''pertica''.
The measure also has a relationship with the military
pike
Pike, Pikes or The Pike may refer to:
Fish
* Blue pike or blue walleye, an extinct color morph of the yellow walleye ''Sander vitreus''
* Ctenoluciidae, the "pike characins", some species of which are commonly known as pikes
* ''Esox'', genus of ...
of about the same size. Both measures
date from the sixteenth century,
when the pike was still utilized in national armies. The tool has largely been supplanted by electronic tools such as surveyor lasers (
lidar) and optical target devices for surveying lands. Surveyors rods and chains are still used in rough terrains with heavy overgrowth where laser or other optical measurements are difficult or impossible. In dialectal English the term ''lug'' has also been used, although the ''
Oxford English Dictionary
The ''Oxford English Dictionary'' (''OED'') is the first and foundational historical dictionary of the English language, published by Oxford University Press (OUP). It traces the historical development of the English language, providing a co ...
'' states that this unit, while usually of feet, may also be of 15, 18, 20, or 21 feet.
History
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
The House of Commons is the name for the elected lower house of the bicameral parliaments of the United Kingdom and Canada. In both of these countries, the Commons holds much more legislative power than the nominally upper house of parliament. T ...
report notes lengths of , , , , and even . In Ireland
Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...
, a perch was standardized at , making an Irish chain, furlong
A furlong is a measure of distance in imperial units and United States customary units equal to one eighth of a mile, equivalent to 660 feet, 220 yards, 40 rods, 10 chains or approximately 201 metres. It is now mostly confined to use in hor ...
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
The Catholic Church, also known as the Roman Catholic Church, is the largest Christian church, with 1.3 billion baptized Catholics worldwide . It is among the world's oldest and largest international institutions, and has played a ...
in 1536, land measures as we now know them were essentially unknown. Instead a narrative system of landmarks and lists was used. Henry wanted to raise even more funds for his wars than he'd seized directly from church property (he'd also assumed the debts of the monasteries), and as James Burke writes and quotes in the book '' Connections'' that the English monk Richard Benese
Richard Benese (died 1546), was a canon of the Augustinian priory of Merton.
Career
Benese supplicated for the degree of B.C.L. at Oxford University 6 July 1519. He signed the surrender of the Augustinian priory of Merton to Henry VIII on 16 A ...
"produced a book on how to survey land using the simple tools of the time, a rod with cord carrying knots at certain intervals, waxed and resined against wet weather." Benese poetically described the measure of an acre in terms of a perch:[''Connections'', pbk. p.263]
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
Unit may refer to:
Arts and entertainment
* UNIT, a fictional military organization in the science fiction television series ''Doctor Who''
* Unit of action, a discrete piece of action (or beat) in a theatrical presentation
Music
* ''Unit'' (a ...
of length measuring , or 22 yards
The yard (symbol: yd) is an English unit of length in both the British imperial and US customary systems of measurement equalling 3 feet or 36 inches. Since 1959 it has been by international agreement standardized as exactly ...
, or 100 links, or 4 rods (20.1168 meter
The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its pref ...
s). There are 10 chains or 40 rods in a furlong
A furlong is a measure of distance in imperial units and United States customary units equal to one eighth of a mile, equivalent to 660 feet, 220 yards, 40 rods, 10 chains or approximately 201 metres. It is now mostly confined to use in hor ...
(eighth-mile), and so 80 chains or 320 rods in one statute mile
The mile, sometimes the international mile or statute mile to distinguish it from other miles, is a British imperial unit and United States customary unit of distance; both are based on the older English unit of length equal to 5,280 Engli ...
(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'["Connections", pbk. p.265]) 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[Connections, pbk. p.63] and the desire to quickly survey seized church lands into a quantity of squares for quick sales by Henry VIII's agents; buyers simply wanted to know what they were buying whereas Henry was raising cash for wars against Scotland and France. Consequently, the surveyor's chain and surveyor rods or poles (the perch) have been used for several centuries in Britain and in many other countries influenced by British practices such as North America and Australia. By the time of the industrial revolution and the quickening of land sales, canal and railway surveys, et al. Surveyor rods such as used by George Washington
George Washington (February 22, 1732, 1799) was an American military officer, statesman, and Founding Father who served as the first president of the United States from 1789 to 1797. Appointed by the Continental Congress as commander of ...
were generally made of dimensionally stable metal—semi-flexible drawn wrought iron linkable bar stock (not steel), such that the four folded elements of a chain were easily transportable through brush and branches when carried by a single man of a surveyor's crew. With a direct ratio to the length of a surveyor's chain and the sides of both an acre and a square (mile), they were common tools used by surveyors, if only to lay out a known plottable baseline in rough terrain thereafter serving as the reference line for instrumental (theodolite
A theodolite () is a precision optical instrument for measuring angles between designated visible points in the horizontal and vertical planes. The traditional use has been for land surveying, but it is also used extensively for building an ...
) triangulation
In trigonometry and geometry, triangulation is the process of determining the location of a point by forming triangles to the point from known points.
Applications
In surveying
Specifically in surveying, triangulation involves only angle me ...
s.
The rod as a survey
Survey may refer to:
Statistics and human research
* Statistical survey, a method for collecting quantitative information about items in a population
* Survey (human research), including opinion polls
Spatial measurement
* Surveying, the techniq ...
measure was standardized by Edmund Gunter
Edmund Gunter (158110 December 1626), was an English clergyman, mathematician, geometer and astronomer of Welsh descent. He is best remembered for his mathematical contributions which include the invention of the Gunter's chain, the Gunter's q ...
in England in 1607 as a quarter of a chain (of ), or long.
In ancient cultures
The perch as a lineal measure in Rome (also ''decempeda'') was 10 Roman feet (2.96 metres), and in France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
varied from 10 feet (''perche romanie'') to 22 feet (''perche d'arpent''—apparently of "the range of an arrow"—about 220 feet). To confuse matters further, by ancient Roman definition, an arpent equalled 120 Roman feet. The related unit of square measure was the ''scrupulum'' or ''decempeda quadrata'', equivalent to about .[
]
In continental Europe
Units comparable to the perch, pole or rod were used in many European countries, with names that include french: perche and ''canne'', german: Ruthe, it, canna and ''pertica'', pl, pręt and es, canna. They were subdivided in many different ways, and were of many different lengths.
Based on data from the following:
*N - Niemann (Quedlinburg
Quedlinburg () is a town situated just north of the Harz mountains, in the district of Harz in the west of Saxony-Anhalt, Germany. As an influential and prosperous trading centre during the early Middle Ages, Quedlinburg became a center of in ...
and Leipzig
Leipzig ( , ; Upper Saxon: ) is the most populous city in the German state of Saxony. Leipzig's population of 605,407 inhabitants (1.1 million in the larger urban zone) as of 2021 places the city as Germany's eighth most populous, as wel ...
- 1830).[
]
In Britain
In England, the rod or perch was first defined in law by the Composition of Yards and Perches
The Composition of Yards and Perches ( la, Compositio Ulnarum et Perticarum) or the Statute of Ells and Perches was a medieval English statute defining the length of the barleycorn, inch, foot, yard, and perch, as well as the area of the acre. Its ...
, one of the statutes of uncertain date
The statutes of uncertain date, also known as ''statuta incerti temporis'' or ''Certain Statutes made during the Reigns of K. Henry 3. K. Edward 1. or K. Edward 2. but uncertain when or in which of their times'', are British (previously English) st ...
from the late 13th to early 14th centuries: ''tres pedes faciunt ulnam, quinque ulne & dimidia faciunt perticam'' (three feet make a yard, five and a half yards make a perch).
The length of the ''chain
A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A c ...
'' was standardized in 1620 by Edmund Gunter
Edmund Gunter (158110 December 1626), was an English clergyman, mathematician, geometer and astronomer of Welsh descent. He is best remembered for his mathematical contributions which include the invention of the Gunter's chain, the Gunter's q ...
at exactly four rods.[ Fields were measured in '']acres
The acre is a unit of land area used in the imperial and US customary systems. It is traditionally defined as the area of one chain by one furlong (66 by 660 feet), which is exactly equal to 10 square chains, of a square mile, 4,840 square ya ...
'', which were one chain
A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A c ...
(four rods) by one furlong
A furlong is a measure of distance in imperial units and United States customary units equal to one eighth of a mile, equivalent to 660 feet, 220 yards, 40 rods, 10 chains or approximately 201 metres. It is now mostly confined to use in hor ...
(in the United Kingdom, ten chains).
Bars of metal one rod long were used as standards of length when surveying
Surveying or land surveying is the technique, profession, art, and science of determining the terrestrial two-dimensional or three-dimensional positions of points and the distances and angles between them. A land surveying professional is ca ...
land. The rod was still in use as a common unit of measurement in the mid-19th century, when Henry David Thoreau
Henry David Thoreau (July 12, 1817May 6, 1862) was an American naturalist, essayist, poet, and philosopher. A leading Transcendentalism, transcendentalist, he is best known for his book ''Walden'', a reflection upon simple living in natural su ...
used it frequently when describing distances in his work, ''Walden
''Walden'' (; first published in 1854 as ''Walden; or, Life in the Woods'') is a book by American transcendentalist writer Henry David Thoreau. The text is a reflection upon the author's simple living in natural surroundings. The work is part ...
''.
In traditional Scottish units
Scottish or Scots units of measurement are the weights and measures peculiar to Scotland which were nominally replaced by English units in 1685 but continued to be used in unofficial contexts until at least the late 18th century. The system was ...
, a ''Scottish rood'' (''ruid'' in Lowland Scots, ''ròd'' in Scottish Gaelic
Scottish Gaelic ( gd, Gàidhlig ), also known as Scots Gaelic and Gaelic, is a Goidelic language (in the Celtic branch of the Indo-European language family) native to the Gaels of Scotland. As a Goidelic language, Scottish Gaelic, as well as ...
), also ''fall
Autumn, also known as fall in American English and Canadian English, is one of the four temperate seasons on Earth. Outside the tropics, autumn marks the transition from summer to winter, in September (Northern Hemisphere) or March ( Southe ...
'' measures 222 inches (6 ell
An ell (from Proto-Germanic *''alinō'', cognate with Latin ''ulna'') is a northwestern European unit of measurement, originally understood as a cubit (the combined length of the forearm and extended hand). The word literally means "arm", and ...
s).
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.[
In the US, 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
United States customary units form a system of measurement units commonly used in the United States and U.S. territories since being standardized and adopted in 1832. The United States customary system (USCS or USC) developed from English units ...
of linear measurement. The Mendenhall Order
The Mendenhall Order marked a decision to change the fundamental standards of length and mass of the United States from the customary standards based on those of England to metric standards. It was issued on April 5, 1893, by Thomas Corwin Mend ...
of 1893 defined the yard as exactly meters, with all other units of linear measurement, including the rod, based on the yard. In 1959, an international agreement (the International yard and pound
The international yard and pound are two units of measurement that were the subject of an agreement among representatives of six nations signed on 1 July 1959: the United States, United Kingdom, Canada, Australia, New Zealand, and South Africa. T ...
agreement), defined the yard as the fundamental unit of length in the Imperial/USCU system, defined as exactly 0.9144 metres. However, the above-noted units, when used in surveying, may retain their pre-1959 values, depending on the legislation in each state. there are plans by U.S. National Geodetic Survey
The National Geodetic Survey (NGS) is a United States federal agency that defines and manages a national coordinate system, providing the foundation for transportation and communication; mapping and charting; and a large number of applications ...
and National Institute of Standards and Technology
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical sci ...
to replace the definition for the above-mentioned units by the International 1959 definition of the foot, being exactly 0.3048 meters.
Despite no longer being in widespread use, the rod is still employed in certain specialized fields. In recreational canoe
A canoe is a lightweight narrow water vessel, typically pointed at both ends and open on top, propelled by one or more seated or kneeling paddlers facing the direction of travel and using a single-bladed paddle.
In British English, the term ...
ing, maps measure portage
Portage or portaging (Canada: ; ) is the practice of carrying water craft or cargo over land, either around an obstacle in a river, or between two bodies of water. A path where items are regularly carried between bodies of water is also called a ...
s (overland paths where canoes must be carried) in rods; typical canoes are approximately one rod long. The term is also in widespread use in the acquisition of pipeline
Pipeline may refer to:
Electronics, computers and computing
* Pipeline (computing), a chain of data-processing stages or a CPU optimization found on
** Instruction pipelining, a technique for implementing instruction-level parallelism within a s ...
easement
An easement is a nonpossessory right to use and/or enter onto the real property of another without possessing it. It is "best typified in the right of way which one landowner, A, may enjoy over the land of another, B". An easement is a propert ...
s, as the offers for an easement are often expressed on a "price per rod".
In the United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...
, the sizes of allotment garden
A garden is a planned space, usually outdoors, set aside for the cultivation, display, and enjoyment of plants and other forms of nature. The single feature identifying even the wildest wild garden is ''control''. The garden can incorporate both ...
s continue to be measured in square poles in some areas, sometimes being referred to simply as ''poles'' rather than ''square poles''.[
In ]Vermont
Vermont () is a state in the northeast New England region of the United States. Vermont is bordered by the states of Massachusetts to the south, New Hampshire to the east, and New York to the west, and the Canadian province of Quebec to ...
, the default right-of-way
Right of way is the legal right, established by grant from a landowner or long usage (i.e. by prescription), to pass along a specific route through property belonging to another.
A similar ''right of access'' also exists on land held by a gov ...
width of state and town highways and trails is three rods (49.5 feet or 15.0876 m).[ Rods can also be found on the older legal descriptions of tracts of land in the ]United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
, following the "metes and bounds
Metes and bounds is a system or method of describing land, real property (in contrast to personal property) or real estate. The system has been used in England for many centuries and is still used there in the definition of general boundaries. The ...
" method of land survey;[ as shown in this actual legal description of rural real estate:
]
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
Area is the quantity that expresses the extent of a region on the plane or on a curved surface. The area of a plane region or ''plane area'' refers to the area of a shape
A shape or figure is a graphics, graphical representation of an obje ...
, 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
A rood or rood cross, sometimes known as a triumphal cross, is a cross or crucifix, especially the large crucifix set above the entrance to the chancel of a medieval church.
Alternatively, it is a large sculpture or painting of the crucifixion ...
(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
Jamaica (; ) is an island country situated in the Caribbean Sea. Spanning in area, it is the third-largest island of the Greater Antilles and the Caribbean (after Cuba and Hispaniola). Jamaica lies about south of Cuba, and west of His ...
. They appear on most property title documents. The perch is also in extensive use in Sri Lanka
Sri Lanka (, ; si, ශ්රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...
, being favored even over the rood and acre in real estate listings there. Perches were informally used as a measure in Queensland
)
, nickname = Sunshine State
, image_map = Queensland in Australia.svg
, map_caption = Location of Queensland in Australia
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, established_ ...
real estate
Real estate is property consisting of land and the buildings on it, along with its natural resources such as crops, minerals or water; immovable property of this nature; an interest vested in this (also) an item of real property, (more general ...
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 ]
See also
* Anthropic units
The term anthropic unit (from Greek '' άνθρωπος'' meaning human) is used with different meanings in archaeology, in measurement and in social studies.
In archaeology
In archaeology, ''anthropic units'' are strata, or deposits of mater ...
* English units
English units are the units of measurement used in England up to 1826 (when they were replaced by Imperial units), which evolved as a combination of the Anglo-Saxon and Roman systems of units. Various standards have applied to English units at ...
References
{{DEFAULTSORT:Rod (Unit)
Imperial units
Units of length
Customary units of measurement in the United States
Obsolete units of measurement
Units of measurement
Area