Ronnie Cohen looks at the measurement muddle in the British Isles during the eighteenth and nineteenth centuries. As our nearest neighbours on the Continent might say, ‘Plus ca change, toujours la meme chose’.
Imperial units such as the acre, stone, pound, ounce, fluid ounce and gallon are still encountered in the UK, even though no longer in official use. They are often heard in conversations and are used, though not consistently, in the media. We take it for granted that these units should have just one meaning but what is not well known is that there were often several.
There have, for example, been many acres, now defined as 4840 square yards, as shown in the following table:
|Version of Acre||Number of Square Yards|
|Preston acre||4840, 7840, 9000 and 10240|
|Barnsley acre||4840, 6084, 7840 and 10240|
Body weight is often quoted in stones and pounds in the UK. The stone of 14 avoirdupois pounds is now the only stone that survives. However, many different varieties of stone were used for weighing commodities in the nineteenth century. This is shown in the following table:
|Version of Stone||Number of Avoirdupois Pounds|
|Stone of glass||5 lb|
|Stone of butcher’s meat||8 lb|
|Stone of iron wire up to 20 gauge||10½ lb|
|Stone of iron wire above 20 gauge||10 lb|
|Stone of iron||14 lb|
|Stone of wool sold by growers||14 lb|
|Stone of wool sold by woolstaplers to each other||15 lb|
|Stone of wool, at Belfast and Dublin||16 lb|
|Stone of flax, at Newry||16 lb|
|Stone of cheese||16 lb|
|Stone of flax, at Belfast||16¾ lb and also 24½ lb|
|Stone of wool, at Darlington||18 lb|
|Stone of wool, at Downpatrick||24 lb|
|Stone of hemp||32 lb|
There were once three different hundredweights: 100 lb, 112 lb and 120 lb. For each of these, there was a ton of 20 hundredweight. Hence there were also three types of ton: 2000 lb, 2240 lb and 2400 lb. Neither the Imperial ton nor the hundredweight remain as primary measures, the former having been supplanted by the tonne of 1000 kg.
There were also four miles used within the UK: the English mile of 1760 yards, the Scotch mile of 1977 yards, the Irish mile of 2240 yards and the nautical or geographical mile of 6080 feet. The nautical mile has since been replaced by the international nautical mile of 1852 metres for marine and aviation transport. The English mile survives officially throughout the UK for ‘road traffic signs, distance and speed’ – an example of English imperialism?
There were once three different systems of pounds and ounces in use. As well as the avoirdupois and troy systems, there was also the Dutch system. As the 1862 Report (see below) stated, “If you buy an ounce or pound of anything, you must inquire if it belongs to Dutch, troy, or avoirdupois weight.” Confusingly, there are 12 troy ounces in a troy pound. Today, only the troy ounce survives as a primary unit, and then only for dealing in precious metals.
The standard Imperial gallon was introduced in the 1824 Weights and Measures Act in an attempt to emulate the metric system, being defined as the volume of ten pounds of distilled water. It is approximately 277.42 cubic inches. This replaced the corn or Winchester gallon of 268.8 cubic inches, the wine gallon of 231 cubic inches and the ale gallon of 282 cubic inches. These gallons were all in common use in the eighteenth century. For these older gallons, there are corresponding pints that are one eighth of the gallon. Today, the Imperial pint is the sole survivor as a primary unit, but only for draught beer and cider and for doorstep milk.
By the time of the 1824 Act, the United States had enjoyed over forty years of independence from Britain. They were using the corn gallon as their standard dry gallon and the wine gallon as their standard liquid gallon and were not inclined to replace them with the new standard UK gallon. These differences account for the different volume measures between Imperial and those used in the US to this day.
The Report of the Parliamentary Select Committee on Weights and Measures of 1862 described the variety of units that were once used in the UK. With the exception of information about pints and gallons, details of these customary units can be found in the DTI transcript of the report, available here:
An original copy of the report may be found here: