Pound (unit of mass)

Countries (red) where the pound is official and has not been replaced by the kilogram

The pound (lb) is currently a unit of mass, used since Ancient Rome as a unit of weight. The word (derived from Latin) means "scale or balance", and is still the name of the main unit of mass used in the United States and in some Spanish-speaking countries.

The pound has had very different values throughout history, especially in antiquity, and the pound that is still used is the libra avoirdupois, so if the word « pound" referring to the mass, it is understood that one is talking about this avoirdupois pound.

A current pound is equal to 0.453 592 37 kilograms and in turn a kilogram is equal to 2.204 622 62 pounds avoirdupois.

History

Long after the fall of the Western Roman Empire, the various regions of the ancient empire took their own particular way of estimating the value of a pound, and numerous units of weight also called pound arose.

The Roman pound was equivalent to 273 grams.^{[citation needed]} Although the Greek pound was used as the monetary unit of account, with 327.4 grams.

A long time later there were problems when weighing merchandise in different units called pounds. To end this problem, Antoine Lavoisier proposed to replace the pounds and other old units throughout Europe, by a new unit of weight, the grave (of gravity), divided in 1000 grams.

Over time, all European nations, except the United Kingdom, abandoned the use of their pounds in favor of the kilogram. The United States, as well as some Latin American countries, which still used the Castilian pound (460 grams), but whose cultures were largely influenced by the American culture during the XX (such as Puerto Rico, El Salvador, Guatemala, Cuba, Ecuador, and Panama), changing the value to the pound avoirdupoids continue to use it.

Current use

The United States and countries of the Commonwealth of Nations agreed on common definitions for the pound and the yard. Since July 1, 1959, the International Pound avoirdupois (symbol lb) has been defined as exactly 0.453 592 37 kg.

In the UK, the use of the international pound was implemented in the Weights and Measures Act 1963:

The yard or meter shall be the units of measurement of length and the pound or kilogram shall be the unit of measurement of mass by reference to which any measurement involving a measurement of length or mass shall be made in the UK, and

(a) the yard will be 0.9144 meters, exactly,

(b) the pound will be 0.453 592 37 kilograms, exactly.

- Weights and Measures Act, 1963, Section 1(1) -

One avoirdupois pound is equal to 16 avoirdupois ounces and exactly 7,000 grains. The conversion factor between the kilogram and the international pound was therefore chosen to be divisible by 7 with a final decimal representation, and one (international) grain is thus equal to exactly 64.798 91 milligrams.

In the UK, the metricing process and European units of measurement directives were expected to eliminate the use of the pound and ounce, but in 2007, the European Commission abandoned the requirement for metric-only labeling on food packaging there. goods, and allowed the dual marking of metric-imperial to continue indefinitely. When used in measurement of body weight, UK common practice, outside of medical settings, remains to use the 14 pound stone as the primary measurement, for example "11 stone 4 lbs", instead "158 lbs" (as in the US), or "72 kilograms" as it is used elsewhere.

In the United States, the "Metric Conversion Act of 1975" declared the metric system to be the "preferred system of weights and measures" but did not discontinue the use of the 'United States customary units', and the United States is the only industrialized country where business does not predominantly use the metric system, despite many efforts to do so, and the pound remains widely used as one of the key customary units.

Due to the influence of the United States, countries such as Colombia use the word libra to refer to ½ kg, or 500 g. However, Colombian law prohibits labeling in pounds, as it is wrong and varied.

Historical usage

Roman Pound

The Roman pound (from the Latin scale / balance) is an ancient unit of mass that was approximately 328.9 grams. It was divided into 12 uciae (ounces). The Roman pound is the origin of the abbreviation "lb".

In Great Britain

Historically, a number of different definitions for the pound have been used in Great Britain. Among these were the Libra avoirdupois (eng. avoirdupois pound) and the obsolete Libra de la Torre (eng. Tower pound), Merchant's pound (eng. merchant's pound), London pound (eng. London pound). Troy pounds and ounces remain in use, only for the weighing of certain precious metals, especially in trade, these are normally quoted in ounces (example "500 ounces") and, when the type of ounce is not explicitly specified, the Troy system is assumed.

Historically, the Sterling Pound was a silver Tower Pound. In 1528, the standard was changed to the Troy Pound.

Avoirdupois pound (eng. avoirdupois pound)

The Libra avoirdupois, also known as the Libra de la lana (Eng. wool pound), first came into general use c. 1300. It was initially equal to 6992 Troy grains. The Pound avoirdupois was divided into 16 ounces. During the reign of Queen Elizabeth I, the Avoirdupois pound was redefined as 7,000 troy grains. Since then, the grain has been an integral part of the avoirdupois system. By 1758, there were two Elizabethan Treasury weight standards for the Pound avoirdupois, and when measured in Troy grains, they were found to be 7,002 grains > and 6,999 grains.

Imperial Standard Pound (eng. Imperial Standard Pound)

In the United Kingdom, weights and measures have been defined by a long series of Acts of Parliament, the intention of which has been to regulate the sale of goods. The materials traded in the markets are quantified according to accepted units and standards in order to avoid fraud. The standards themselves are legally defined to facilitate the resolution of disputes brought to court, only legally defined measures will be recognized by the courts. Quantification instruments used by merchants (weights, weighing machines, volume containers, length meters) are subject to official inspection, and penalties applied, if they are fraudulent.

The "Weights and Measures Act 1878", marked a major revision of the British system of weights and measures, and the definition of pound given therein remained in force until the 1960s. The pound was defined, thus (Section 4):

"The... platinum weight... deposited with the standards department of the Board of Trade... will continue to be the imperial standard of... weight... and the aforementioned platinum weight will continue to be the standard imperial to determine the Imperial Standard Pound for the United Kingdom".

Paragraph 13 says that the weight in vacuo of this standard will be called the Imperial Standard Pound, and all other weights mentioned in the act and allowed for trade they must be verified only with him. The first program of the minutes gave more details of the Standard Pound: it is a platinum cylinder about 1.35 inches (34 mm) high, and 1.15 inches (29 mm) in diameter, and the edges are carefully rounded. It is notched about 0.34 inches (6.6 mm) from the top, to allow the cylinder to be lifted using an ivory fork. It was built after the destruction of Parliament House by fire in 1834, and is stamped "P.S. 1844, 1 lb" (P.S. for "Parliamentary Standard", parliamentary standard).

Redefinition in terms of kilograms

The British Act of 1878 said that contracts drawn up in terms of metric units would be considered by courts to be made according to the imperial units defined in the act, and a table of metric equivalences was provided, so imperial equivalences can be legally calculated. This defined, in UK Law, metric units in terms of imperial ones. The equivalence for the pound was given as 1 lb = 453.592 65 g or 0.4359 kg, which makes the kilogram equivalent to about 2.204 6213 lb.

In 1883, it was determined jointly by the standards department of the British Board of Trade and the International Board that 0.453 592 4277 kg was a better approximation, and this figure, rounded to 0.453 592 43 kg, was given legal status by an order in council in May 1898.

In 1959, based on further international measurement and coordination, the international yard and pound agreement defined an "International Pound" being exactly equivalent to 0.453 592 37 kg. This means the existing legal definition of the UK Pound differs from the International Standard Pound by 0.06 milligrams. To remedy this, the pound was again redefined in the UK by the "Weights and Measures Act 1963" to equate the international pound, stating: "the pound must be exactly 0.453 592 37 kilograms", a definition that remains valid to this day.

The 2019 redefinition of the SI base units means that the pound is now precisely redefined in terms of fundamental constants, ending the era of its definition in terms of physical prototypes.

Troy Pound

A Troy Pound (abbreviated lb t) is equal to 12 Troy ounces and 5760 grains, which is exactly 373.241 7216 grams. Troy weights were used in England by jewelers. Apothecaries also used the Pound and Troy ounce, but added the units drachmas (eng. drachms) and scruples to the Apothecary system of weights.

Troy weights should take their name from the Troyes market in France, where English merchants traded until at least as early as the turn of the century IX.

The Troy Pound is no longer in general use or as a legal unit of trade (it was abolished in the United Kingdom on January 6, 1879 by the "Weights and Measures Act of 1878), but the troy ounce, 1⁄12 of a Troy pound, is still used for the measurement of gems such as opals, and precious metals such as silver, platinum and particularly gold.

Libra de la Torre (eng. Tower pound)

The system called peso Torre (eng. Tower weight) was the more general name for the Libra del rey Offa (eng. King Offa's pound).. This dates from 757 AD. C. and was based on the silver penny (eng. silver penny).

The Pound Tower was also called the Moneyers' Pound, referring to the wealthy Saxons before the conquest; the Pound sterling (eng. Easterling pound), which refers to traders from eastern Germany, or traders from the east coast of the Baltic Sea, or Asian goods dealers who settled in the Steeland pier; and the Libra de Rochelle (eng. Rochelle Pound) by French writers, as it was also in use in Rochelle. An almost identical weight was used by the Germans for the weighing of gold and silver.

The mercantile pound (eng. mercantile pound) (1304) of 6750 Troy grains, or 9600 Tower grains, derives from this pound, as 25 shilling-weights or 15 ounces of the Tower, for general commercial use. Multiple pounds based on the same ounce were very common. In much of Europe, the Apothecary Pound and Commercial Pound were different numbers of the same ounce.

The Tower system was referenced to a standard prototype found in the Tower of London and circled concurrently with the avoirdupois and Troy systems until the reign of Henry VIII, when a royal proclamation dated 1526, required the Troy Pound to be used for minting purposes instead of the Tower Pound. No standard of the Tower Pound is known to have survived.

The Tower Pound was equivalent to about 350 grams.

Merchant's pound (eng. Merchant's pound)

The Merchant Pound, Mercantile Pound, Mercantile Pound, or Commercial Pound (eng. mercantile pound, libra mercatoria, or commercial pound) was considered to be composed of 25, rather than 20 Tower shillings or 12 pence. It was equal to 9,600 grains of wheat (eng. wheat grain) (15 ounces or 6,750 Tower grains) and was used in England until the 17th century XIV for goods other than money and medicines ("electors").

London pound (eng. London pound)

The London Pound is that of the Hansa, as used in various trading places. The London Pound is based on 16 ounces, each ounce divided as a Tower ounce. It never became a legal standard in England, the use of this pound being washed and waxed by Hansa herself. One London Pound was equal to 7,200 Troy grains (16 Troy ounces) or, equivalently, 10,240 Tower grains (16 Tower ounces).

In the United States

In the United States, the avoirdupois pound as a unit of mass has been officially defined in terms of the kilogram since the "Mendenhall Order of 1893". That order defined the pound as 2.204 62 pounds is a kilogram. The following year, this relationship was redefined as 2,204 622 34 pounds is a kilogram, following the determination of the British Pound. In 1959, the "United States National Bureau of Standards" redefined the pound (avoirdupois) to be exactly equal to 0.453 592 37 kilograms, as declared by the "International Yard and Pound Agreement" of that year. According to a 1959 NIST publication, the 1894 United States Pound differs from the International Pound by approximately one part in 10 million. The difference is so insignificant that it can be ignored for almost all practical purposes.

Byzantine Litra

The Byzantines used a series of measurements known as pounds (Latin: pound, Ancient Greek: λίτρα, romanized as litra). The most common was the logarikē litra (λογαρική λίτρα, "Pound to count"), established by Constantine the Great in 309 / 310. It formed the basis of the Byzantine monetary system, with 1 liter of gold equivalent to 72 solidi. One hundred litrai were known as one kentēnarion (κεντηνάριον, "hundreweight"). Its weight appears to have gradually decreased from the original 324 grams to 319. Due to its association with gold, it was also known as the chrysaphikē litra (χρυσαφική λίτρα,"Pound of Gold") or the thalassia litra (θαλάσσια λίτρα, "Maritime Libra"), but can also be used as a measure of land, equaling one fortieth of the thalassios modios.

The soualia litra was specifically used for weighing olive oil or wood, and corresponds to 4/5 of the logarikē, for example 256 g. Some peripheral regions, especially in late times, adopted various local measures, based on Italian, Arab or Turkish measures. The most important of these was the 333-g argyrikē litra (αργυρική λίτρα, "Silver Pound"), found in Trebizond and Cyprus, and probably of Arab origin.

French Livre

Since the Middle Ages, various pounds (fr. livre) have been used in France. Since the 19th century, a livre has been referenced to the metric pound, as 500 g. The Livre sterlin was equivalent to about 367.1 grams (5,666 gr) and was used between the late IX and mid-century XIV.

The livre poids de marc or Livre de Paris was equivalent to about 489.5 grams (7,554 gr) and was used between the 1350s and the late 18th century. It was introduced by the government of Juan II.

The livre métrique was set equal to the kilogram by decree 13 Brumaire an IX between 1800 and 1812. This was a form of the official metric pound.

The livre usuelle (customary unit) was defined as 500 grams by the decree of March 28, 1812. It was abolished as an effective unit of mass on January 1, 1840 by a decree of 4 July 1837, but it is still used, informally.

German and Austrian Pfund

Originally derived from the Roman Libra, the definition varied throughout the Holy Roman Empire in the Middle Ages and onward. For example, the weights and measures of the Habsburg Monarchy were reformed in 1761 by Empress Maria Theresa of Austria. The extraordinarily heavy Habsburg Pound (civil) of 16 ounces was later defined in terms as 560.012 grams. The Bavarian Reforms in 1809 and 1811 essentially adopted the same standard as the Austrian Pound. In Prussia, a reform in 1816 defined a uniform civil Pound in terms of the Prussian Foot and distilled water, resulting in a Prussian Pound of 467.711 grams.

Between 1803 and 1815, all of the German regions west of the Rhine River were under French control, organized into the Roer, Sarre, Rhine-et-Moselle, and Mont-Tonnerre departments. As a result of the Congress of Vienna, again, these regions became part of several German states. However, several of these regions retained the metric system and adopted a metric pound of precisely 500 grams. In 1854, the 500-gram pound also became the official mass standard of the German Customs Union and was renamed the Zollpfund, but local pounds continued to coexist with the Zollverein for some time in some German states. Today, the term Pfund is sometimes still in use and universally refers to the 500-gram pound.

Russian Funt

The Russian Pound (Фунт, funt) is an obsolete Russian mass unit of measurement. It is equal to 409.51718 grams. In 1899, the funt was the basic unit of weight, and all other units of weight were formed from it, in particular, a zolotnik was 1⁄96 of a funt, and a pood was 40 fúnty.

Skalpund

The Skålpund was a Scandinavian measurement that varied in weight between regions. From the 17th century onwards, it was equal to 425.076 grams in Sweden but was abandoned in 1889 when Sweden switched to the metric system. In Norway, the same name was used for the weight of 498.1 grams. In Denmark, it equaled 471 grams. In the 19th century, Denmark followed Germany's lead and redefined the pound to 500 grams.

Portuguese Libra and Arrátel

The Portuguese unit that corresponds to the pound of different nations is the arrátel, equivalent to 16 ounces of Colonha, a variant of the Colonia standard. This arrátel was introduced in 1499 by Manuel I, King of Portugal. Based on an evaluation of nested bronze weight stacks distributed by Manuel I to different towns, Manuel I's arrátel has been estimated at 457.8 g. In the early 19th century, the arratel was valued at 459 g.

In the XV century, the arrátel was 14 ounces of Colonha or 400.6g. The Portuguese pound was the same as 2 arráteles. There were also arráteis of 12.5 and 13 ounces and libras of 15 and 16 ounces. The Troyes or Tria standard was also used.

Jersey Pound

A Jersey pound is an obsolete unit of mass used on the island of Jersey from the 14th century to the <XIX. It was equivalent to about 7,561 grains (490 grains). It must have been derived from the French Livre poids de marc.

Trone's Pound

The trone pound is one of a number of obsolete Scottish units of measurement. It was equivalent to between 21 and 28 avoirdupois ounces (about 600 to 800 grams).

Metric pound

In several countries, upon the introduction of a metric system, the pound (or its translation) became a historical and obsolete term, although some have retained it as an informal term with no specific value. In German, the term is Pfund, in French livre, in Dutch pond, in Spanish and Portuguese libra, in Italian libbra, and in Danish and Swedish pund.

Though not from the same linguistic origin, Chinese jīn (斤, also known as "catty") in mainland China has a modern definition of exactly 500 grams, divided in 10 liǎng (两). Traditionally around 605 grams, the jin has been in use for over two thousand years, serving the same purpose as the "pound" for commonly used weight measurement.

Hundreds of old pounds were replaced in this way. Example of the old pounds are one of around 459 to 460 grams in Spain, Portugal and Latin America; one of 498.1 grams in Norway, and several different ones in what is now Germany.

Since the introduction of the kilogram scale and measuring instruments only in grams and kilograms. A pound of product must be determined by weighing the product in grams, since the use of the pound is not sanctioned for trade between the European Union.

• La Pound Castellana was widely used in Spain and its American territories. This pound was equivalent to 16 Castilian ounces (460,093 grams). According R.D. 9/12/1852, equals 460,093 grams. 100 Pounds are equivalent to 1 quintal, which is still widely used in the markets of Bolivia and other countries of the region.
• La Castilian pharmaceutical pound was used in Spanish pharmacology, differing from the Anglo-Saxon pound. This pound was equivalent to 12 medicinal ounces (345,069 75 grams).
• La Catalan pound (lliura) It was 400 grams. This pound was also divided into 12 ounces.
• Other Spanish pounds had different values, such as 350 grams of Zaragoza, or 492 grams (or 17 ounces) of Guipúzcoa.
• La Neapolitan pound, used in the kingdom of Naples, was equivalent to 320,759 grams.

In Spain the pound is still used for the weight of sheep or lambs in many areas of Extremadura and some in Andalusia.
In the weight and price of pigs still in the market of Extremadura and Andalusia, they continue to be quoted in arrobas and pounds.

A rice is 11.5 kg.

An arroba (@) is 25 pounds

A fifth 4 @ or 100 pounds.

So 1 kg is 2,1739 £

Or a pound is 0.46 kg.

Use in weapons

Smooth-bore guns and carronades are designated by the weight in imperial pounds of round diameter solid iron shot that fits into the barrel. A cannon that fires a 6-pound bullet, for example, is called a six-pounder. Standard measurements are 6, 12, 18, 24, 32, and 43 pounds; 68-pounder, and other non-standard use weapons of the same scheme also exist. See carronade.

A similar definition, using lead bullets, exists to determine the caliber of a shotgun.

The pound as a monetary standard

The first coin issue in Rome, made in the 4th century B.C. C., was the As Libral, whose weight was based on that of the Greek pound, and was 327.4 grams of silver. The rest of the coins issued throughout its history, such as denarii and sesterces, were based on subdivisions of this monetary pattern.

In the year 800 Charlemagne adopted the pound of 489.6 grams divisible into 2 marks. It was used as a standard for the size of the coins, establishing that each pound was equivalent to 20 salaries or 240 pieces of money.

Money only existed as real currency. Salaries, marks, and pounds were units of account.

1 pound = 20 salaries = 240 moneys (whose name comes from Denial).