Rod (unit)

# Rod (unit)

Discussion

Encyclopedia
The rod is a unit of length
Length
In geometric measurements, length most commonly refers to the longest dimension of an object.In certain contexts, the term "length" is reserved for a certain dimension of an object along which the length is measured. For example it is possible to cut a length of a wire which is shorter than wire...

equal to 5.5 yard
Yard
A yard is a unit of length in several different systems including English units, Imperial units and United States customary units. It is equal to 3 feet or 36 inches...

s, 5.0292 metre
Metre
The metre , symbol m, is the base unit of length in the International System of Units . Originally intended to be one ten-millionth of the distance from the Earth's equator to the North Pole , its definition has been periodically refined to reflect growing knowledge of metrology...

s, 16.5 feet, or of a statute mile. A rod is the same length as a perch
Perch (unit of measure)
A perch is as a unit of measurement used for length, area, and volume in a number of systems of measurement. Its name derives from the Ancient Roman unit, the pertica.-Origin:...

or a pole. In old English, the term lug is also used.

## 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 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 because 16 1/2 new feet = 15 old feet.

The length of the chain
Chain (unit)
A chain is a unit of length; it measures 66 feet or 22 yards or 100 links . There are 10 chains in a furlong, and 80 chains in one statute mile. An acre is the area of 10 square chains...

was standardized in 1620 by Edmund Gunter
Edmund Gunter
Edmund Gunter , English mathematician, of Welsh descent, was born in Hertfordshire in 1581.He was educated at Westminster School, and in 1599 was elected a student of Christ Church, Oxford. He took orders, became a preacher in 1614, and in 1615 proceeded to the degree of bachelor in divinity...

at exactly 4 rods. Fields were measured in acres, which were one chain (four rods) by one furlong
Furlong
A furlong is a measure of distance in imperial units and U.S. customary units equal to one-eighth of a mile, equivalent to 220 yards, 660 feet, 40 rods, or 10 chains. The exact value of the furlong varies slightly among English-speaking countries....

(in the United Kingdom, ten chains).
Bars of metal one rod long were used as standards of length when surveying
Surveying
See Also: Public Land Survey SystemSurveying or land surveying is the technique, profession, and science of accurately determining the terrestrial or three-dimensional position of points and the distances and angles between them...

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
Henry David Thoreau was an American author, poet, philosopher, abolitionist, naturalist, tax resister, development critic, surveyor, historian, and leading transcendentalist...

used it frequently when describing distances in his work Walden
Walden
Walden is an American book written by noted Transcendentalist Henry David Thoreau...

.

## 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.

Despite no longer being in widespread use, the rod is still employed in certain specialized fields. In recreational canoe
Canoe
A canoe or Canadian canoe is a small narrow boat, typically human-powered, though it may also be powered by sails or small electric or gas motors. Canoes are usually pointed at both bow and stern and are normally open on top, but can be decked over A canoe (North American English) or Canadian...

ing, maps measure portage
Portage
Portage or portaging refers to the practice of carrying watercraft or cargo over land to avoid river obstacles, or between two bodies of water. A place where this carrying occurs is also called a portage; a person doing the carrying is called a porter.The English word portage is derived from the...

s (overland paths where canoes must be carried) in rods; typical canoes are approximately one rod long. In the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, the sizes of allotment
Allotment (gardening)
An allotment garden, often called simply an allotment, is a plot of land made available for individual, non-professional gardening. Such plots are formed by subdividing a piece of land into a few or up to several hundreds of land parcels that are assigned to individuals or families...

garden
Garden
A garden is a planned space, usually outdoors, set aside for the display, cultivation, and enjoyment of plants and other forms of nature. The garden can incorporate both natural and man-made materials. The most common form today is known as a residential garden, but the term garden has...

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
Vermont is a state in the New England region of the northeastern United States of America. The state ranks 43rd in land area, , and 45th in total area. Its population according to the 2010 census, 630,337, is the second smallest in the country, larger only than Wyoming. It is the only New England...

, the default right-of-way width of state and town highways and trails is three rods (15.0876 m). Rods can also be sometimes found on the legal descriptions of tracts of land in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, following the "metes and bounds
Metes and bounds
Metes and bounds is a system or method of describing land, real 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...

" method of land survey; as shown in this actual legal description of rural real estate:

## 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
Rood (measurement)
Rood has several distinct meanings, all derived from the same basic etymology. The most significant are an obsolete English measure of area, an obsolete English measure of length, and a term for a cross or crucifix, especially a large one displayed in a church....

.

• Perch
Perch (unit of measure)
A perch is as a unit of measurement used for length, area, and volume in a number of systems of measurement. Its name derives from the Ancient Roman unit, the pertica.-Origin:...

• Furlong
Furlong
A furlong is a measure of distance in imperial units and U.S. customary units equal to one-eighth of a mile, equivalent to 220 yards, 660 feet, 40 rods, or 10 chains. The exact value of the furlong varies slightly among English-speaking countries....

• anthropic units
Anthropic units
Anthropic units are units of measurement which explicitly arose from human physiology or behavior. Some were derived directly from the dimensions of the human body, and as such, are commonly referred to as anthropomorphic...

• Imperial units