Stone (unit) - Great Britain and Ireland

Great Britain and Ireland

During the Middle Ages, a conveniently-sized rock was often chosen as a local standard for weighing agricultural commodities, but the weight of such rocks varied with the commodity and region. By the late Middle Ages, international trade such as England's exports of raw wool to Florence required a fixed standard, and in 1389 a royal statute of Edward III fixed the stone of wool at 14 pounds.

In England potatoes were traditionally sold in stone and half-stone (14 pounds and 7 pounds, respectively) increments, but the Oxford English Dictionary contains examples including the following:

The 1772 edition of the Encyclopædia Britannica defined the stone as follows.

STONE also denotes a certain quantity or weight of some commodities. A stone of beef, in London, is the quantity of eight pounds; in Hertfordshire, twelve pounds; in Scotland sixteen pounds.

In 1661 the Royal Commission of Scotland recommended that the Troy stone be used as a standard of weight and that it be kept in the custody of the burgh of Lanark. The Scots stone was equal to 16 Scots pounds (17 lb 8 oz avoidupois or 7.936 kg). The tron (or local) stone of Edinburgh, also standardised in 1661, was 16 tron pounds (24 lb 1 oz avoidupois or 9.996 kg) In 1789 an encyclopedic enumeration of measurements was printed for the use of "his Majesty's Sheriffs and Stewards Depute, and Justices of Peace, ... and to the Magistrates of the Royal Boroughs of Scotland" and provided a county-by-county and commodity-by-commodity breakdown of values and conversions for the stone and other measures. The Scots stone ceased to be used for trade when the Act of 1824 established a uniform system of measure across the whole of the United Kingdom, which at that time included all of Ireland.

Ireland used the pound avoidupois: before the early nineteenth century, as in England, the stone varied both with locality and with commodity (e.g., the Belfast stone for measuring flax equaled 16.75 pounds)with the most usual value being 14 pounds. Among the oddities related to the use of the stone was the practice in Clare of a stone of potatoes being 16 lb in the summer and 18 lb in the winter.

Traditionally live animals were weighed in stones of 14 lb, but once slaughtered, their carcases were weighed in stones of 8 lb. Thus, if the animal's carcase accounted for 8⁄₁₄ of the animal's weight, the butcher could return the dressed carcases to the animal's owner stone for stone, keeping the offal, blood and hide as his due for slaughtering and dressing the animal. The 8 lb stone continued to be used for meat at Smithfield until shortly before the second world war.

The Weights and Measures Act of 1824 (which applied to all of the United Kingdom) consolidated the weights and measures legislation of several centuries into a single document. It revoked the provision that bales of wool should be made up of 20 stones, each of 14 pounds, but made no provision for the continued use of the stone. Ten years later, a stone still varied from 5 pounds (glass) to 8 pounds (meat and fish) to 14 pounds (wool and "horseman's weight"). However, the Act of 1835 permitted a stone of 14 pounds to be used for trade but other values continued to be used - Britten, in 1880 for example, catalogued a number of different values of the stone in various British towns and cities ranging from 4 lb to 26 lb The value of the stone and associated units of measure that were legalised for purposes of trade were clarified by the Weights and Measures Act 1835 as follows:

In 1965, the then Federation of British Industry informed the British Government that its members favoured the adoption of the metric system. The Board of Trade, on behalf of the Government, agreed to support to a ten-year metrication program. There would be minimal legislation, as the program was to be voluntary and costs were to be borne where they fell. Under the guidance of the Metrication Board, the agricultural product markets achieved a voluntary switchover by 1976. The stone was not included in the Directive 80/181/EEC as a unit of measure that could be used within the EEC for "economic, public health, public safety or administrative purposes", though its use as a "supplementary unit" was permitted. The scope of the directive was extended to include all aspects of the EU internal market as from 1 January 2010.

With the adoption of metric units by the agricultural sector, the stone was in practice no longer used for trade, and in the Weights and Measures Act 1985, passed in compliance with EU directive 80/181/EEC, the stone was removed from the list of units permitted for trade in the United Kingdom. In 1983, in response to the same directive, similar legislation was passed in Ireland. The Act repealed earlier acts that defined the stone as a unit of measure for trade. (British law had previously been silent regarding other uses of the stone.) However the stone remains widely used in Britain and Ireland for human body weight: in those countries people may commonly be said to weigh, e.g., "11 stone 4" (11 stones and 4 pounds), rather than "72 kilograms" as in many other countries, or "158 pounds" (the conventional way of expressing the same weight in the United States and Canada). The correct plural form of stone in this context is stone (as in, "11 stone" or "12 stone 6 pounds"); in other contexts, the correct plural is stones (as in, "Please enter your weight in stones and pounds").

In many sports in both the UK and in Ireland such as professional boxing, wrestling and horse racing the stone is used to express weight; in most other countries kilograms are used exclusively. However in July 2012 it was announced that at three of London's main race courses metric units would be trialled alongside imperial units. In the Olympic Games kilograms are used to define the weight divisions in Greco-Roman wrestling, freestyle wrestling, boxing and judo.