The 1824 Weights and Measures Act introduced imperial standards based on physical objects with certain characteristics, such as the Imperial Standard Yard, and a single set of volume measures based on the new Imperial Gallon for dry and liquid measures to replace several that were in existence. To mark 200 years since the passing of the 1824 Weights and Measures Act, I look at the main features of the Act and ask whether it was a help or a hindrance on the path to metrication in the UK.
The Imperial Standard Yard was introduced and defined as the “Straight Line or Distance between the Centres of the said Two Points in the said Gold Studs in the said Brass Rod, the Brass being at the Temperature of Sixty-two Degrees by Fahrenheit’s Thermometer”. This referred to the straight brass rod in the custody of the clerk of the House of Commons. This yard served as the base unit in the imperial system whereby the other units of imperial length were defined as parts or multiples of the Imperial Standard Yard. Units of area were defined with reference to the yard or derived units of length.
The Standard Brass Weight of One Pound Troy Weight in the custody of the clerk of the House of Commons served as the base unit of weight from which the other imperial units of weight were defined. This weight was called the Imperial Standard Troy Pound. The definition used for recreating it, in case it is lost, destroyed, defaced or damaged in some other way, was “a Cubic Inch of distilled Water, weighed in Air by Brass Weights, at the Temperature of Sixty-two Degrees of Fahrenheit’s Thermometer, the Barometer being at Thirty Inches, is equal to 252 Grains and 458 thousandth parts of a Grain, of which, as aforesaid, the Imperial Standard Troy Pound contains 5760″.
The Act introduced the Imperial Standard Gallon as the standard measure of capacity for liquids and dry goods not measured by heaped measure. The Imperial Standard Gallon was defined as “Ten Pounds Avoirdupois Weight of distilled Water weighed in Air, at the Temperature of Sixty-two Degrees of Fahrenheit’s Thermometer, the Barometer being at Thirty Inches”. The other imperial measures of capacity were defined as parts or multiples of the Imperial Standard Gallon.
Let me explain the difference between the troy and the avoirdupois systems for readers who are unfamiliar with these different weights. A troy ounce is one-twelfth of a troy pound, a pennyweight is one-twentieth of a troy ounce, and a grain is one-twenty-fourth of a pennyweight. Hence, one troy pound is equal to 5760 grains. One avoirdupois pound is equal to 7000 grains. An avoirdupois ounce is one-sixteenth of an avoirdupois pound, and a dram is one-sixteenth of an avoirdupois ounce.
The Act defined the standard for heaped measure for coals, culm (waste coal), lime, fish, potatoes, fruit and all other goods and things commonly sold by heaped measure. The heaped measure was the bushel, defined in the Act as eight imperial standard gallons. The heaped measure contained 80 pounds avoirdupois of water, made round with a plain and even bottom, and being 19½ inches “from Outside to Outside of such standard measure as aforesaid”. The Act stated that such a bushel shall be heaped in the form of a cone at least six inches tall. Anything not sold by heaped measure must be sold by the imperial standard of weight or measure.
These defined measures came into force on 1 May 1825. Section 23 of the Act repealed numerous archaic Statutes, Ordinances and Acts that relate to weights and measures.
To some extent this Act gives the lie to the fantasy that Britain’s imperial measures are ancient. They were standardised no more than 40 years before the first of decision to metricate, even though that was to come to nothing for another hundred years.
Despite the Act’s attempt to set standards for the primary units and repeal arcane laws, it did not radically change the multiplicity of customary weights and measures used throughout the country. Indeed, it expressly states that “it shall [be] lawful [to] buy and sell goods and merchandize (sic) by any weights or measures established either by local custom or founded on special Agreement” provided their exact relation to the standard units defined by the Act was generally known.
The 1824 Act standardised and clearly defined many existing weights and measures throughout the UK and replaced various capacity measures with one (i.e. one imperial pint, one imperial gallon, etc). They became the standard weights and measures that were used across the British Empire. Meanwhile, France adopted the metric system in the late eighteenth century after the French Revolution. Other European countries followed suit during the nineteenth century. As the imperial system was the standard measurement system across the Empire, the British hesitated to adopt the metric system. These factors seem to be major obstacles to the adoption of the metric system. The British have had difficulties with metrication ever since. Why have the British been unable to fully adopt to the metric system unlike the rest of Europe?
You can find a full copy of the 1824 Weights at Measures Act at https://www.legislation.gov.uk/ukpga/1824/74/pdfs/ukpga_18240074_en.pdf.
On the history of metrication, see https://en.wikipedia.org/wiki/Metrication and https://ukma.org.uk/what-is-metric/uk-progress/uk-metric-timeline/.
Metric Views 
From the point of view of sorting out the mess in English units of measure, this act was probably a reasonable act. It should however be viewed alongside the 1835 Act which outlawed heaped measures and added stones, hundredweights and tons to the list of legal units. The 1835 Act did not however define any subunits of the inch with the result that when I was at school, the rulers that we used had four systems of units on them – inches and tenths of an inch, inches and sixteenths of an inch, inches and tenths of an inch and metric units. The act also failed to define the chain.
One of the blunders that was made when passing this legislation was not testing the back-up techniques for re-creating the yard. When the prototype yard was lost in the fire at Westminster in 1834, the technique defined in the Act proved inadequate and the prototype yard had to be recreated by reference to the best copies that were available.
The definition of the gallon appears to be influenced by the definition of the litre in that it made reference to 10 lbs of water, just as the litre made reference to one kilogram of water. The choice of “10 lbs” suggests that they were thinking along decimal lines but lacked the wherewithal to fully implement a decimal system of units.
The real harm that this act did to metrication was that it put the imperial system on a sound basis such that it could be used in manufacturing and since the industrial revolution was well under way in England in 1824, but not elsewhere in Europe, allowed British industry to develop at the expense of her European neighbours. Germany, in particular, was not slow to recognise the value of a standardised system of weights and measures and in 1851 the various German states in the Zollverein (Customs Union) standardised on the metric system for inter-state trade and commerce. After German unification in 1871, the metric system became the legal standard in the German Empire.
Although the 1824 Act gave a number of short-term advantages, it created a system that was very difficult to dislodge and in the long term has probably caused considerable harm by not only forcing British industry to change in the 1960’s and 1970’s in order to make up lost ground in the export market, but also helped create a “Little England” mentality which means that although our children are taught metric units in school, they use imperial units in the playground and at home which, in turn, probably ripples through to our export market.
1835 Act: https://www.google.co.uk/books/edition/A_Compendious_Abstract_of_the_Public_Gen/woJRAAAAYAAJ?hl=en&gbpv=1 (pg 137)
LikeLike
It is ironic that most of the old British Empire, which as cited above propped up the Imperial system of weights and measures far too long while the rest of the world adopted the metric system, has abandoned Imperial in favor of metric (with Canada still in a bit of a muddle but doing its best nonetheless and I think a few of the former Carribean island colonies also not quite there yet with metric).
Ezra aka punditgi
LikeLike
What an embarassing way to design a weights and measures system – basing it on a unit of mass that was virtually obsolete, and which ended up being abolished not long afterwards, in 1879.
It must have been particularly embarassing, also, for those involved to announce such an unnecessarily complicated new system when the far more logical and easy-to-use metric system had recently been developed.
Whilst the Troy pound might theoretically have been the base unit in the new system, in practice it was the Troy grain, which was equal to 1/5760 of a Troy pound. The imperial pound being equal to 7000 grains, and the imperial ounce being equal to 437.5 grains.
The 1824 Act also failed to create a single system of measures for volume.
Not only did it create a significant divergence from the units used in the USA, with their “the pint is a pound the world around” mnemonic, but the newly-defined gallon-pint-fluid ounce system was also incompatible with the cubic inch, cubic foot, cubic yard system, which already had unhelpful conversion factors of its own:
1 cubic foot = 1728 cubic inches
1 cubic yard = 27 cubic feet
1 cubic mile = 5 451 776 000 cubic yards
As this US TV sketch in the link below might have put it;
Q: And how many pints are there in a cubic foot?
A: … Nobody knows
LikeLike
m said:
“Not only did it create a significant divergence from the units used in the USA, with their “the pint is a pound the world around” mnemonic,….”
This is not true, even in the US. A pint of 473 mL would have a mass of 473 g. A pound in the US is 454 g. For it to be true, a US pint should be 454 mL. The mnemonic is based on 16 ounces equaling both a pint and pound, but the ounces in each case are different.
LikeLiked by 1 person
@Daniel
Mnemonics are just memory aids. They aren’t intended to be precise legal definitions. There was a similar mnemonic that became familiar during the early days of metrication in the UK in the early 1970s:
“a litre of water’s a pint and three-quarters”
LikeLiked by 1 person
Thinking practically about today: could Elon Musk finally contribute to finally, after “inching” (see DeGrasse Tyson) for decades, make the US metric…? Thus accelerating also the still partial metrication of Canada and the UK: independently of judging his person and achievements (for example, the Hyperloop is essentially a Swissmetro 2.0: nothing really original): only, sadly, from a merely practical point of view. Of course, all this should have been done in other ways, in the past: but maybe this one could be a last resort – who knows…
LikeLike
punditgi/Ezra brings up a very interesting point. Due to the extensive metrication programs carried out in the former British empire the imperial version of ancient units is pretty much on the verge of extinction. It may take a few more generations for it to be accomplished, but it is pretty much a reality that imperial won’t last far into the future.
However, as long as the US exists it is almost guaranteed that the pre-imperial version of ancient units will continue to exist as the US has no intention of ever completing metrication. As long as the US retains its superpower status and has control of much of the world, FFU (Fake Freedom Units or Fred Flintstone Units) will persist far into the future and as a thorn in the side of metric users.
The Americans seem to go to no expense to propagate FFU as much as they can in front of the whole world, mostly through their standards, the media, especially through the internet. Anyone who learns the American version of English almost is required to have an understanding and is forced to communicate in FFU. Immigrants to the US often still communicate with each other in their native languages but measure only in FFU and often pretend to have forgotten metric and feel a need to reject it. I’m sure in some strange way, these immigrants are encouraged to communicate with their families in the old country in their new found FFU.
Maybe there is hope. As more and more countries join BRICS and reject American unipolarism for a multi-polar world a strong rejection of both the dollar and FFU can be accomplished in the near future. We can only hope.
LikeLike
Sven,
I’m sure with the friendship connection between Elon Musk and Donald Trump, if Elon was serious about metrication for the entire country and not just a for a number of companies to use in secret, something would have been said by now. With that closeness to Donald and with the republicans having a majority in both the house and senate as a result of the election, now would be anew window opening to push metrication, but don’t get your hopes up.
Elon also is not a friend of SI. He prefers the “old metric” cgs version of units, where the tonne (megagram) and kilogram are units of force/weight instead of mass.
But, for some reason not understood, all the captains of industry whose companies use metric or SI internally seem to want to keep it a big secret and not let the population know they use metric/SI internally and go out of their way not to promote metric/SI to the general population.
LikeLike
Musk was brought up in South Africa so he had minimal exposure to customary or imperial units until he left South Africa at the age of 18 – South Africa having adopted the metric system at about the time he was undergoing potty training.
LikeLike
Practically all units of measurement, including metric ones, have been redefined to greater accuracy over the years, as technology has advanced. As stated, the 1824 act standardized and accurately defined many existing measures. As Martin pointed out, the Act failed to define the chain. The Gunter’s chain, devised in the early 1600s, based on 22 yards, was a serious method of working in decimal terms. Thus the acre became 10 square chains, making calculation of land areas much easier.
The success of the metric system lies, I believe, on the fact that it was an entirely new system, with no attempt to latch into existing units. The basis of the Paris meridian, from pole to equator, ties in with the principle of the right angle being divided into 100 grades, a system which I think the French use to this day. The rest of the metric system is based on this, though units have been redefined in more-accurate terms.
So, yes, the 1824 act was a hindrance; it simply reinforced old values with stricter definitions, discouraging the uptake of metric.
LikeLike
Commenters have narrowed in on the fact that political will is lacking – with respect to completing the process, let alone metricating road signs – so the question is, how is that political will to be generated?
As without it, then the changes will be minsucule at best on the 40th anniversary of this report being published.
LikeLike
The troy ounce isn’t the only old unit of mass taking a long time to die out. There are also ‘tael’ and ‘tola’.
See: https://www.gov.uk/guidance/gold-acquisitions-imports-investments-and-vat-notice-70121
LikeLiked by 1 person
Just came across a package of gluten free rolled oats that lists the weight of the product as 2.27 kg. Strangely, this is an odd size in metric plus there is no Imperial or US Customary indication (which is legal in Canada but illegal in the USA). The product is easily available on Amazon, etc.
Ezra aka punditgi
LikeLike
Re: Ezra aka punditgi’s comment about illegal (in the USA) metric-only labels.
The US NIST did a study of the issue and reported :
LikeLike