Open Access Articles- Top Results for Acre
Journal of Clinical TrialsSurvival Rate of Breast Cancer Patients who Participated in Clinicals Trials Versus those who did not
Global Media JournalKilling US Softly With Their Story: New York Times Coverage of the My Lai and El Mozote Military Massacres
International Journal of NeurorehabilitationChanges in Density Spectral Array of BIS VISTA Monitoring System in Epilepsy Surgery
Trauma & TreatmentAcute-on-Chronic Osteomyelitis of the Scapula Treated via Trephination
The acre is a unit of land area used in the imperial and U.S. customary systems. It is defined as the area of Script error: No such module "convert". by Script error: No such module "convert". which is equal to Script error: No such module "convert"., 1⁄640 of a square mile or about 40% of a hectare.
The acre is commonly used in Antigua and Barbuda American Samoa, The Bahamas, Belize, the British Virgin Islands, the Cayman Islands, Dominica, the Falkland Islands, Grenada, Guam, the Northern Mariana Islands, India, Jamaica, Montserrat, Myanmar, Pakistan, Samoa, St. Lucia, St. Helena, St. Kitts and Nevis, St. Vincent and the Grenadines, Turks and Caicos, the United Kingdom, the United States and the US Virgin Islands.
The international symbol of the acre is ac. The most commonly used acre today is the international acre. In the United States both the international acre and the slightly different US survey acre are in use. The most common use of the acre is to measure tracts of land. One international acre is defined as exactly 4046.8564224 square metres.
One acre equals 0.0015625 square miles, 4,840 square yards, 43,560 square feet or about Script error: No such module "convert". (see below). While all modern variants of the acre contain 4,840 square yards, there are alternative definitions of a yard, so the exact size of an acre depends on which yard it is based. Originally, an acre was understood as a selion of land sized at forty perches (660 ft or 1 furlong) long and four perches (66 ft or 1 chain) wide; this may have also been understood as an approximation of the amount of land a yoke of oxen could plough in one day. A square enclosing one acre is approximately 69.57 yards, or Script error: No such module "convert". on a side. As a unit of measure, an acre has no prescribed shape; any area of 43,560 square feet is an acre.
Differences between international and U.S. survey acres
In the international yard and pound agreement of 1959 the United States and five countries of the Commonwealth of Nations defined the length of the international yard to be exactly 0.9144 metres. Consequently, the international acre is exactly 4,046.8564224 square metres.
Both the international acre and the U.S. survey acre contain 1/640 of a square mile or 4,840 square yards, but there are alternative definitions of a yard (see survey foot and survey yard), so the exact size of an acre depends on which yard it is based. The U.S. survey acre is about 4,046.872609874252 square metres; its exact value (4046 13,525,426/ m2) is based on an inch defined by 1 metre = 39.37 inches exactly, as established by the Mendenhall Order. Surveyors in the United States use both international and survey feet, and consequently, both varieties of acre.
Since the difference between the U.S. survey acre and international acre is only about a quarter of the size of an A4 sheet of paper (0.016 square metres, 160 square centimetres or 24.8 square inches), it is usually not important which one is being discussed. Areas are seldom measured with sufficient accuracy for the different definitions to be detectable.
In India, residential plots are measured in cents or decimel, which is one hundredth of an acre, or Script error: No such module "convert".. In Sri Lanka the division of an acre into 160 perches or 4 roods is common.
Equivalence to other units of area
1 international acre is equal to the following metric units:
- 4,046.8564224 square metres
- 0.40468564224 hectare (A square with 100 m sides has an area of 1 hectare.)
1 United States survey acre is equal to:
- 4,046.87261 square metres (1 square kilometer is equal to 247.105 acres)
- 0.404687261 hectare
1 acre (both variants) is equal to the following customary units:
- 66 feet × 660 feet (43,560 square feet)
- 10 square chains (1 chain = 66 feet = 22 yards = 4 rods = 100 links)
- 1 acre is approximately 208.71 feet × 208.71 feet (a square)
- 4,840 square yards
- 43,560 square feet
- 160 perches. A perch is equal to a square rod (1 square rod is 0.00625 acre)
- 4 roods
- A furlong by a chain (furlong 220 yards, chain 22 yards)
- 40 rods by 4 rods, 160 rods2 (historically fencing was often sold in 40 rod lengths)
- 1⁄640 (0.0015625) square mile (1 square mile is equal to 640 acres)
For residents of other countries, the acre might be envisaged as approximately 56.68 percent of a Script error: No such module "convert". long by Script error: No such module "convert". wide association football (soccer) pitch.
It may also be remembered as 44,000 square feet, less 1%.
The word acre is derived from Old English æcer originally meaning "open field", cognate to west coast Norwegian ækre and Swedish åker, German Acker, Dutch akker, Latin ager, Sanskrit ajr, and Greek αγρός (agros). In English it was historically spelled aker.
The acre was approximately the amount of land tillable by a yoke of oxen in one day. This explains one definition as the area of a rectangle with sides of length one chain and one furlong. A long narrow strip of land is more efficient to plough than a square plot, since the plough does not have to be turned so often. The word "furlong" itself derives from the fact that it is one furrow long.
Before the enactment of the metric system, many countries in Europe used their own official acres. These were differently sized in different countries, for instance, the historical French acre was 4,221 square metres, whereas in Germany as many variants of "acre" existed as there were German states.
Statutory values for the acre were enacted in England, and, subsequently, the United Kingdom, by acts of:
- Edward I,
- Edward III,
- Henry VIII,
- George IV and
- Queen Victoria – the British Weights and Measures Act of 1878 defined it as containing 4,840 square yards.
Historically, the size of farms and landed estates in the United Kingdom was usually expressed in acres (or acres, roods, and perches), even if the number of acres was so large that it might conveniently have been expressed in square miles. For example, a certain landowner might have been said to own 32,000 acres of land, not 50 square miles of land.
The acre is related to the square mile, with 640 acres making up one square mile. One mile is 5280 feet (1760 yards). In western Canada and the western United States, divisions of land area were typically based on the square mile, and fractions thereof. If the square mile is divided into quarters, each quarter has a side length of 1⁄2 mile (880 yards) and is 1⁄4 square mile in area, or 160 acres. These subunits would typically then again be divided into quarters, with each side being 1⁄4 mile long, and being 1⁄16 of a square mile in area, or 40 acres. In the United States, farmland was typically divided as such, and the phrase "the back 40" would refer to the 40 acre parcel to the back of the farm. Most of the Canadian Prairie Provinces and the US midwest are on square mile grids for surveying purposes.
- Customary acre – The customary acre was a measure of roughly similar size to the acre described above, but it was subject to considerable local variation similar to the variation found in carucates, virgates, bovates, nooks, and farundels. However, there were more ancient measures that were also farthingales. These may have been multiples of the customary acre, rather than the statute acre.
- Builder's acre – In U.S. construction and real estate development, an area of 40,000 square feet. Used to simplify math and for marketing, it is nearly 10% smaller than a survey acre.
- Scottish acre, one of a number of obsolete Scottish units of measurement
- Irish acre = 7,840 square yards
- Cheshire acre = 10,240 square yards
- stremma or Greek acre ≈ 10,000 square Greek feet, but now set at exactly 1,000 square metres (a similar unit was the zeugarion)
- dunam or Turkish acre ≈ 1,600 square Turkish paces, but now set at exactly 1,000 square metres (a similar unit was the çift)
- actus quadratus or Roman acre ≈ 14,400 square Roman feet (about 1,260 square metres)
- God's Acre – a synonym for a churchyard.
- Anthropic units
- Conversion of units
- French arpent – also used in Louisiana as length and area unit of measure
- a Morgen ("morning") of land is usually set at 2⁄3 of a Tagwerk ("day work") of ploughing with an ox
- Public Land Survey System
- Quarter acre
- Section (United States land surveying)
- Spanish customary units
- "Gov’t Gifts ‘Bakka’ With Half-Acre Land | Antigua Observer Newspaper". web.archive.org. Retrieved 2014-02-14.
- "National Park of American Samoa completes two successful forest projects | Samoa News". samoanews.com. Retrieved 2014-02-14.
- "The Nassau Guardian". thenassauguardian.com. Retrieved 2014-02-14.
- "2,225-acre Cobia farm proposed near Lark and Bugle Cayes | Amandala Newspaper". amandala.com.bz. Retrieved 2014-02-14.
- "Work continues on development". bvibeacon.com. Retrieved 2014-02-14.
- "Kai drama over 50-acre development :: cayCompass.com". compasscayman.com. Retrieved 2014-02-14.
- "Dominica not meeting quota for international banana markets | Dominica News Online". dominicanewsonline.com. Retrieved 2014-02-14.
- "Farm Yarns with Elaine - Farm yarns with Elaine Turner - Part 13". penguin-news.com. Retrieved 2014-02-14.
- "Grenada Broadcast - George Grant - THE GRENADA SPICES INDUSTRY". grenadabroadcast.com. Retrieved 2014-02-14.
- "Local News | Pacific Daily News | guampdn.com". guampdn.com. Retrieved 2014-02-14.
- "Saipan Tribune.". saipantribune.com. Retrieved 2014-02-14.
- "Beresford Allen of St. Peters Montserrat is a Wanted Man! | The Montserrat Reporter". themontserratreporter.com. Retrieved 2014-02-14.
- "Conflicting stories about Nu’u estate". samoaobserver.ws. Retrieved 2014-02-14.
- "The Voice - The national newspaper of St. Lucia since 1885". thevoiceslu.com. Retrieved 2014-02-14.
- "FEATURE: We built an island dream on our own St Helena | St Helena Online". sthelenaonline.org. Retrieved 2014-02-14.
- "SIDF Sinks SKN Passport Money into Christophe Harbour :: The St. Kitts-Nevis Observer". thestkittsnevisobserver.com. Retrieved 2014-02-14.
- "PM vows to spend rest of life seeking reparations – I-Witness News". iwnsvg.com. Retrieved 2014-02-14.
- "Government gets $8million from Emerald Cay sale". suntci.com. Retrieved 2014-02-14.
- "Proposed dolphin facility will enclose about 2 acres of Water Bay - News - Virgin Islands Daily News". m.virginislandsdailynews.com. Retrieved 2014-02-14.
- National Institute of Standards and Technology (n.d.) General Tables of Units of Measurement
- Klein, Herbert Arthur. The Science of Measurement: A Historical Survey. Dover Publications, 1988. Print. p. 76
- National Bureau of Standards. (1959). Refinement of Values for the Yard and the Pound.
- National Geodetic Survey, (January 1991), "Policy of the National Geodetic Survey Concerning Units of Measure for the State Plane Coordinate System of 1983.
- Minimum Standard Detail Requirements For ALTA/ACSM Land Title Surveys. Federick, MD: American Congress on Surveying and Mapping. 2011. [The standard uses "precision" in a sense more typically used for "accuracy"; the stated maximum allowable "precision" (page 3) is 2 cm and 50 parts per million. An instrument consistently measuring 2 cm short would measure the area of a one international acre square, 63.614907 m on a side, as 4044.3 square metres, 2.6 square metres less than the true value, a far greater discrepancy than the difference between the international and survey acres.]
- "SRI LANKA". webcache.googleusercontent.com. Retrieved 2014-02-14.
- "acre, n.2". OED Online. September 2011. Oxford University Press. (accessed November 15, 2012).
- Holland, Robert. (1886). A glossary of words used in the County of Chester. London: Trübner for the English Dialect Society. p. 3.
- Malcolm, Noel (1999). Kosovo: A Short History. Harper Perennial. ISBN 978-0-06-097775-7.
- The Merriam-Webster Online Dictionary
|40x40px||Wikisource has the text of the 1911 Encyclopædia Britannica article Acre (land measure).|