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 length; both are based on the older English unit of length equal to 5,280 English feet, or 1,760 yards. The statute mile was standardised as a unit of length between the Commonwealth of Nations and the United States by an international agreement in 1959, when the yard was formally redefined with respect to SI units as 0.9144metres, making the mile exactly . For everyday use, five miles equates roughly to eight kilometres.
With qualifiers, mile is also used to describe or translate a wide range of units derived from or roughly equivalent to the Roman mile, such as the [|nautical mile], the Italian mile, and the Chinese mile. The Romans divided their mile into 5,000 Ancient Roman units of measurement#Length, but the greater importance of furlongs in the Elizabethan-era England meant that the statute mile was made equivalent to or in 1593. This form of the mile then spread across the British Empire, some successor states of which continue to employ the mile. The US Geological Survey now employs the metre for official purposes, but legacy data from its 1927 geodetic datum has meant that a separate US survey mile continues to see some use, although it was officially phased out in 2022. While most countries replaced the mile with the kilometre when switching to the International System of Units, the international mile continues to be used in some countries, such as the United Kingdom, the United States, and a number of countries with fewer than one million inhabitants, most of which are UK or US territories or have close historical ties with the UK or US.
Name
The modern English word mile derives from Middle English myle and Old English mīl, which was cognate with all other Germanic terms for miles. These derived from the nominal ellipsis form of mīlle passus 'mile' or mīlia passuum 'miles', the Roman mile of one thousand paces.The present international mile is usually what is understood by the unqualified term mile. When this distance needs to be distinguished from the nautical mile, the international mile may also be described as a land mile or statute mile. In British English, statute mile may refer to the present international mile or to any other form of English mile since an act of Parliament, the Restriction on Building Act 1592 was passed in 1593, which set it as a distance of. Under American law, however, statute mile refers to the US survey mile. Foreign and historical units translated into English as miles usually employ a qualifier to describe the kind of mile being used but this may be omitted if it is obvious from the context, such as a discussion of the 2nd-century Antonine Itinerary describing its distances in terms of miles rather than Roman miles.
Abbreviation
The mile has been variously abbreviated in English—with and without a trailing period—as "mi", "M", "ml", and "m". The American National Institute of Standards and Technology now uses and recommends "mi" to avoid confusion with the SI metre and millilitre. However, derived units such as miles per hour or miles per gallon continue to be abbreviated as an initialism as in "mph" and "mpg", rather than "mi/h" and "mi/gal". In the United Kingdom, road signs use "m" as the abbreviation for mile though height and width restrictions also use "m" as the symbol for the metre, which may be displayed alongside feet and inches. The BBC style holds that "there is no acceptable abbreviation for 'miles and so it should be spelled out when used in describing areas.Historical
Roman
The Roman mile consisted of a thousand paces as measured by every other step—as in the total distance of the left foot hitting the ground 1,000 times. The distance was indirectly standardised by Agrippa's establishment of a standard Roman foot in 29 BC, and the definition of a pace as 5 feet. An Imperial Roman mile thus denoted 5,000 Roman feet. Surveyors and specialised equipment such as the decempeda and dioptra then spread its use.In modern times, Agrippa's Imperial Roman mile was empirically estimated to have been about in length, slightly less than the of the modern international mile.
In Hellenic areas of the Empire, the Roman mile was used beside the native Greek units as equivalent to 8 stadia of 600 Greek feet. The mílion continued to be used as a Byzantine unit and was also used as the name of the zero mile marker for the Byzantine Empire, the Milion, located at the head of the Mese near Hagia Sophia.
The Roman mile spread throughout Europe, with its local variations giving rise to the different units. Also arising from the Roman mile is the milestone. All roads radiated out from the Roman Forum throughout the Empire – 50,000 miles of stone-paved roads. At every mile was placed a shaped stone. Originally, these were obelisks made from granite, marble, or whatever local stone was available. On these was carved a Roman numeral, indicating the number of miles from the centre of Rome – the Forum. Hence, one can know how far one is from Rome.
Ptolemaic mile
In the 2nd-century, Greco-Roman polymath, Claudius Ptolemy, of Alexandria, in his Almagest and Geography, defined a mile as a geographic arcminute of longitude, of the earth's circumference, equivalent to 1:60 of a degree of longitude, or 1:21,600 of the circumference. While his estimate of the circumference of the earth, and therefore the derived length of a stade, and a mile, from third party observations, principally offered in non-normalised stadion, Egyptian schoinos, and Persian parasang were erroneous. Ptolomy's assumptions of a customary stade to be of a Roman mile, of a schoinos or parasang, of an arc-minute, or ~185 metres, his Geographical mile, is the basis of the current nautical mile, and was adopted by medieval Arab and European cartographers.Arabic
The Arabic mile, of 4,000 cubits, was not the common Arabic unit of length; instead, Arabs and Persians traditionally used the longer parasang or "Arabic league". Although the precise length of the Arabic mile remains disputed, due to the variability in cubit length, it was somewhere between 1.8 and 2.0 km; it is approximate to a 1.852 km nautical or geographical mile, and an approximation of 1 arcminute of latitude measured directly north-and-south along a meridian. The mile was used by medieval Arab geographers and scientists.Breslau
The Breslau mile, used in Breslau, and from 1630 officially in all of Silesia, is equal to 11,250 ells, or about 6,700 meters. The mile equaled the distance from the Piaskowa Gate all the way to Psie Pole. By rolling a circle with a radius of 5 ells through Piaskowa Island, Ostrów Tumski and suburban tracts, passing eight bridges on the way, the standard Breslau mile was determined.Croatian
The Croatian mile, first devised by the Jesuit Stjepan Glavač on a 1673 map, is the length of an arc of the equator subtended by ° or 11.13 km exactly. The previous Croatian mile, now known as the "ban mile", had been the Austrian mile given above.Danish
Following its standardisation by Ole Rømer in the late 17th century, the Danish mile was precisely equal to the Prussian mile and likewise divided into 24,000 feet. These were sometimes treated as equivalent to 7.5 km. Earlier values had varied: the Sjællandske miil, for instance, had been 11.13 km.Dutch
The Dutch mile has had different definitions throughout history. One of the older definitions was 5,600 ells. But the length of an ell was not standardised, so that the length of a mile could range between 3,280 m and 4,280 m. In the sixteenth century, the Dutch had three different miles: small, medium, and large. The Dutch kleine mile had the historical definition of one hour's walking, which was defined as 24 stadia, 3000 paces, or 15,000 Amsterdam or Rhineland feet. The common Dutch mile was 32 stadia, 4,000 paces, or 20,000 feet. The large mile was defined as 5000 paces. The common Dutch mile was preferred by mariners, equating with 15 to one degree of latitude or one degree of longitude on the equator. This was originally based upon Ptolemy's underestimate of the Earth's circumference. The ratio of 15 Dutch miles to a degree remained fixed while the length of the mile was changed as with improved calculations of the circumference of the Earth. In 1617, Willebrord Snellius calculated a degree of the circumference of the Earth at 28,500 Rijnlantsche Roeden, which resulted in a Dutch mile of 1900 rods. By the mid-seventeenth century, map scales assigned 2000 rods to the common Dutch mile, which equalled around 7,535 m. The metric system was introduced in the Netherlands in 1816, and the metric mile became a synonym for the kilometre, being exactly 1,000 m. Since 1870, the term mijl was replaced by the equivalent kilometer. Today, the word mijl is no longer used, except as part of certain proverbs and compound terms like mijlenver.English
The "old English mile" of the medieval and early modern periods varied but seems to have measured about 1.3 international miles. The old English mile varied over time and location within England. The old English mile has also been defined as 79,200 or 79,320 inches. The English long continued the Roman computations of the mile as 5,000 feet, 1,000 paces, or 8 longer divisions, which they equated with their "furrow's length" or furlong.The origins of English units are "extremely vague and uncertain", but seem to have been a combination of the Roman system with native and Germanic systems both derived from multiples of the barleycorn. Probably by the reign of Edgar in the 10th century, the nominal prototype physical standard of English length was an arm-length iron bar held by the king at Winchester; the foot was then one-third of its length. Henry I was said to have made a new standard in 1101 based on his own arm. Following the issuance of Magna Carta in 1215, the barons of Parliament directed John and his son to keep the king's standard measure and weight at the Exchequer, which thereafter verified local standards until its abolition in the 19th century. New brass standards are known to have been constructed under Henry VII and Elizabeth I.
Arnold's Customs of London recorded a mile shorter than previous ones, coming to 0.947 international miles or 1.524 km.