Talk:Pound (mass)

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Lead Section[edit]

The "citation needed" on the # being used to mean pound as mass is by a link to another page with the citation[1]. Does anyone have access to a copy of this book to see it it has this info in it? -- (talk) 04:24, 11 October 2019 (UTC)Reply[reply]


  1. ^ Houston, Keith (20 October 2014). The Secret Life of Punctuation, Symbols, and Other Typographical Marks. W W Norton & Company.

London pound[edit]

A recent IP edit changed the following bold 16 to 15, from:

A London pound was equal to 7,200 troy grains (16 troy ounces) or, equivalently, 10,240 tower grains (16 tower ounces).


A London pound was equal to 7,200 troy grains (15 troy ounces) or, equivalently, 10,240 tower grains (16 tower ounces).

The edit was reverted by Jc3s5h. I think the IP's edit might be correct. According to sizes: pound avoirdupois:

1 London pound = 15 ounces of 450 grains = 6750 grains (437.4 grams)
1 troy pound = 12 ounces each of 480 grains = 5760 grains (about 373.2 grams)
16 tower ounces = 15 troy ounces exactly

I gather that the grain above is the same unit in each case. This is just a jumble of numbers to me but if there are 480 troy grains in a troy ounce, 7,200 troy grains = 15 troy ounces (not 16). Thoughts? Johnuniq (talk) 03:05, 2 January 2021 (UTC)Reply[reply]

I'm not vouching for it, but says the London pound (aka commercial pound or liber mercatoria) is "15 ounces of 450 grains each". Dondervogel 2 (talk) 08:48, 2 January 2021 (UTC) I just realised that's the same link as posted by Johnuniq. I just focused on a different part. Dondervogel 2 (talk) 13:39, 2 January 2021 (UTC)Reply[reply]
This seems relevant. Dondervogel 2 (talk) 12:10, 2 January 2021 (UTC)Reply[reply]
Doing a search with those arguments, the first hit was on the London Quarterly Review which said "The commercial pound , by which wine and most other articles were weighed , was then of fifteen ounces . ... And the ounce shall weigh twenty pence ; and twelve ounces make the London pound ; and eight pounds of wheat make a gallon ..." so 15 for the Commercial Pound and 12 for the London Pound. Sigh. --John Maynard Friedman (talk) 12:47, 2 January 2021 (UTC)Reply[reply]

I took another look, and also referred to NIST Handbook 44 (2020, pp. C-6, C-7). Handbook 44 has been adopted by all the US states in their measurement laws; a merchant who violates it risks seizure of improperly labeled goods, seizure of inaccurate measurement devices, fines, and if the merchant is really stubborn, jail.

That handbook states the avoirdupois grain, the troy grain, and the apothecaries grain are all equal; an avdp. pound is 7000 grains (numbers are exact unless otherwise stated). A troy or apothecaries pound is 5760 grains. An avdp ounce is exactly 437.5 grains. A troy or apothecaries ounce is 480 grains.

The article contains the following line:

1 London ounce (20 dwt) = 1 tower (or troy) ounce = 640 tower grains = 450 troy grains

A person who, in US commerce, treats 1 troy ounce as equivalent to 450 troy grains commits a criminal offense. The article is clearly wrong. I will put an appropriate template in the article. Jc3s5h (talk) 17:52, 2 January 2021 (UTC)Reply[reply]

That is the "London ounce", does it define a London Pound?
The 20 dwt (20 penny-weights, d being the historic abbreviation for penny, Latin: Denarius) measure is consistent with the old British definition, meaning that 12 London ounces = 240 sterling silver pennies = the original pound sterling, which in turn defined the original pound mass - literally the weight of a £'s worth of silver. Which is very little indeed nowadays! But that would mean 12 ounces to the pound, not 15 or 16? --John Maynard Friedman (talk) 19:24, 2 January 2021 (UTC)Reply[reply]

Bible as evidence of translation of[edit]

I deleted the following statement because the citation not only doesn't support it, it says something completely different:

The Greek μνᾶ (mna) was about one pound (see Mina (unit)), and the word is translated as "pound" in some translations of the Bible.<ref>For example the [[King James Version]], Luke, chapter 19</ref>

Luke 19:15 clearly states that the reference is to money, not mass – pound (currency), not pound (mass). Furthermore, the citation gives no information about the corresponding Greek text. If it is to be reinstated, a far better case is needed here first. --John Maynard Friedman (talk) 00:14, 21 March 2021 (UTC)Reply[reply]

Pounds as measurement of force, not mass[edit]

In the article, multiple times the “pound” is referred to as a way to measure mass. This is incorrect as the pound is a measurement of force which will change based on gravitational force. Mass will not change due to gravitational force. (talk) 01:30, 29 April 2022 (UTC)Reply[reply]

This article is about a unit of mass. For the unit of force see Pound (force). Dondervogel 2 (talk) 04:50, 29 April 2022 (UTC)Reply[reply]

Redefinition in terms of the kilogram[edit]

I'm interested in knowing how the exact number was chosen for the redefinition of the avoirdupois pound in terms of the kilogram. Was it based on weighing the physical prototype of the pound? Just one, or were there several prototypes weighed? If so, who did it, and when, and how? And so on. — The Anome (talk) 09:37, 3 June 2022 (UTC)Reply[reply]

Update: it was all in the article, just not easy to find. I've refactored things so that it's clearer, including linking the International Yard and Pound article. — The Anome (talk) 10:27, 3 June 2022 (UTC)Reply[reply]

Blockquote of British law[edit]

In Pound (mass)#Current use, the text of a British law is included. It is lengthy and unnecessary as part of main article. As a reference, a citation to the source is all that is required. Perhaps move it elsewhere down at end of article? Senator2029 【talk】 23:46, 4 September 2022 (UTC)Reply[reply]