There have been recent reports in the press a butcher in Devon has started to sell meat in pounds and ounces after the UK had voted to leave the EU in a national referendum on 23 June 2016. This butcher is now giving customers the choice to buy meat in pounds and ounces or in grams and kilograms.
According to newspaper reports, this measure has proven to be popular with customers and has gained a lot of support from the general public. This story has appeared in the Daily Express and The Sun, as you would expect. Apparently, some people think that it is a good idea to give shops and market traders the freedom to choose metric or imperial units to sell their products.
The problem with the use of mixed measures can be shown by comparing the following lists:
|Mixed Measures||Single Measure|
Which list is easier to compare? I give you no prizes for guessing the answer.
If traders were given the freedom to use whatever units they like, we could also end up with petrol priced in litres and gallons, fridges advertised with capacity in litres and cubic feet, electrical products described with a mixture of watts and horsepower, table sizes given in feet and metres, land areas advertised in acres and hectares, temperatures expressed in Celsius and Fahrenheit, etc. This makes comparisons needlessly awkward. We all need a single system of weights and measures that we can all understand and use. We do not need two systems.
These days, the major British supermarkets are almost exclusively metric. Most show unit pricing per kilogram, per 100 grams, per litre and per 100 millilitre. When we go to the supermarket, we take it for granted that we can quickly and easily compare prices between different products because they use a single, simple and consistent measurement system. This system is the metric system. Imagine how awkward that would be if supermarkets used incompatible measurement systems with awkward conversion factors.
The problem of using multiple measurement systems was considered by a parliamentary Select Committee on Weights and Measures in 1862. They found this situation unacceptable. Here is a quote for their report:
“The silent influence of usage has baffled the decrees of legislation; and we are still far distant from the uniformity at which we have so often, yet so vainly, aimed. Omitting many specific anomalies, we have no less than ten different systems of Weights and Measures, most of them established by law. Our neighbours, the French, and many other nations, have only one, founded on the mètre, which is a near approximation to the English yard.”
The report lists ten different measurement systems that were in use in the UK at the time:
- Grains, computed decimally, used for scientific purposes.
- Troy weight.
- Troy ounce, with decimal multiples and divisions, called bullion weights.
- Bankers’ weights, to weigh 10, 20, 30, 50, 100 and 200 sovereigns.
- Apothecaries weight.
- Diamond weights and pearl weights, including carats.
- Avoirdupois weight.
- Weights for hay and straw.
- Wool weight, using as factors, 2, 3, 7, 13, and their multiples.
- Decimal coal weights.
The report goes on to describe more measurement systems that were also in use in 1862. Alas, the problems with the use of multiple measurement systems has long been forgotten. Weights and measures are regulated by law to prevent the chaos that arises from the use of multiple systems of weights and measures and to ensure uniformity and common standards of weights and measures. This is the case, not only in the UK, but in most other countries.
This was no doubt in the mind of England’s King Edgar the Peaceful when he enacted in AD 965 a law “that only one weight and one measure should pass throughout the king’s dominions”, a principle that some, including that Devon butcher, have preferred to overlook in the 21st century.