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As a unit of measurement within the Imperial system, the chain (surveyor's chain, Gunter's chain) is defined as 22 yards, 66 feet, or four rods. Ten chains made one furlong, and eight furlongs to a mile means there are 80 chains to a mile. In metric units, a chain equals exactly 20.1168 metres. A chain is divided into 100 links. The Imperial units are an irregularly standardized system of units that have been used in the United Kingdom and its former colonies, including the Commonwealth countries. ...
This article is about the unit of measure known as the yard. ...
A foot (plural: feet) is a non-SI unit of distance or length, measuring around a third of a metre. ...
A pole (more commonly called a perch or a rod) is a unit of length, equal to 5. ...
The 5 furlong post on Epsom Downs A furlong is a measure of distance within Imperial units and U.S. customary units. ...
The International System of Units (symbol: SI) (for the French phrase Syst me International dUnit s) is the most widely used system of units. ...
The metre is the basic unit of length in the International System of Units (SI: Système International dUnités). ...
A Link, also called a Gunter’s link, is a unit of length in the Imperial system. ...
 A Gunter's chain that belonged to John Johnson (1771–1841), Surveyor General of Vermont. Source: Smithsonian Institution The term chain derives from the device commonly used for measurement of land in the past — a chain of 100 links, the Gunter's chain being the most common. The links were about eight inches long, made of heavy gauge wire, with a loop at each end. The links were joined end to end to create the chain by three rings between the links. This enabled the chain to be folded up, link by link, until all 100 were in a bundle which could be held in the hand. At each end were brass handles and the full chain measurement was between the outside extremities of the brass handles with the chain at full stretch on flat ground. If the chain had been folded correctly, an experienced chainman (surveyor's assistant) could fling the bundle out and it would unfold neatly with no snags. Another chainman would grab the handle, flick the chain to get it straight and then be ready to take the measurement. Long distances would be measured in bays of one chain, the actual chain being dragged forward for each bay. Image File history File links Gunters chain [belonged to John Johnson (1771-1841), Surveyor General of Vermont] Steel and brass Courtesy of Smithsonian Institution, National Museum of American History, Behring Center, Washington, D.C. (9B) Found at the Library of Congress site for the Rivers, Edens, Empires: Lewis & Clark...
Image File history File links Gunters chain [belonged to John Johnson (1771-1841), Surveyor General of Vermont] Steel and brass Courtesy of Smithsonian Institution, National Museum of American History, Behring Center, Washington, D.C. (9B) Found at the Library of Congress site for the Rivers, Edens, Empires: Lewis & Clark...
The Castle The Smithsonian Institution is a museum complex with most of its facilities in Washington D.C.. It consists of 16 museums, 7 research centers and 142 million items in its collections. ...
A Gunters chain that belonged to John Johnson (1771-1841), Surveyor General of Vermont. ...
With so many links in the chain there were many wearing surfaces and chains commonly were longer than the designated length. Also some surveyors added an extra link, so that their surveys always included a greater physical area than the actual measurements indicated (the landowners weren't going to complain!). When retracing old surveys with modern equipment a surveyor will almost always find his measurements between monuments are longer than the originals.
The unit was once important in everyday life, being one of the fundamental units of Imperial system in the United Kingdom and its colonies, and was used to some extent in engineering and surveying in the U.S. Licensure and Qualifications for the Practice of Engineering The Engineers Ring The origin of then Engineers Ring Engineering Disasters and Learning from Failure American Society of Engineering Education (ASEE) ASEE engineering profile (2003) PDF EngineersEdge GlobalSpec Categories: Architecture and engineering occupations | Engineering ...
Surveyor at work Surveying is the art and science of accurately determining the position of points and the distances between them. ...
In Britain, it was commonly used in the railway industry (where the measure is still in widespread use). Mapping by the Ordinance Survey (Britain's national mapping organisation) began in the early 19th century using the chain as the basic unit of measurement. All map scales at that time were expressed as a relative fraction of a chain or a mile (e.g. a one inch to ten chain scale was equivalent to 1:7920).
The use of the chain was once very common in laying out townships and mapping the U.S. along the train routes in the 19th century. In the U.S. a federal law was passed in 1785 (the Public Land Survey Ordinance) that all official government surveys must be done with a Gunter's chain (also referred to as the "surveyor's chain"). This General Land Office map shows the theoretical sectioning of a standard survey township. ...
American surveyors sometimes used a longer chain of 100 feet (30.48 m), known as the engineer's chain or Ramsden's chain. In Texas, the vara chain of 20 varas (55.556 ft) was used in surveying Spanish land grants. Jesse Ramsden (October 6, 1735 - November 5, 1800) was an English astronomical instrument maker. ...
State nickname: Lone Star State Other U.S. States Capital Austin Largest city Houston Governor Rick Perry (R) Official languages None. ...
In agriculture, measuring wheels with a circumference of 0.1 chain are still common and readily available in the United States and Canada, at least. For a rectangular tract, multiply the number of turns of one of these wheels for each side, then divide by 1000 to get the area in acres.
The chain also survives, in fact if not always in name, in two other specific contexts.
- It is the length of the pitch, between the wickets, in cricket.
- It lies at the origin of the definition of an acre as 4840 square yards. The original acre was an area of land suitable for ploughing in a defined time, and was therefore not square; it measured one chain by one furlong (10 square chains).
In the laying out of towns in Australia and New Zealand, most building lots in the past were a quarter of an acre, measuring one chain by two and a half chains, and other lots would be multiples or fractions of a chain. As a consequence, the street frontages of many houses in these countries are one chain wide — roads were almost always one chain wide (20.117 m) in urban areas, sometimes one and a half (30.175 m) or two chains (40.234 m). Laneways would be half a chain (10.058 m). In rural areas the roads were wider, up to 10 chains (201.17 m) where a stock route was required. For more coverage of cricket, go to the Cricket portal. ...
An acre is a measure of land area in Imperial units or U.S. customary units. ...
The 5 furlong post on Epsom Downs A furlong is a measure of distance within Imperial units and U.S. customary units. ...
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