Talk:History of the metric system/Archive 1

Leading up to The French Revolution
The sequence of events and the relevance of the politics mentioned (e.g. the convocation of the Estates-general) are very hard to follow in this section. It would be good if someone with the reference books to hand were to clean it up to make it more coherent. Otherwise, I am inclined to reduce most of the politics to something along the lines of "Following the Revolution of 1789, the Revolutionary government...". Any reaction? Awien (talk) 20:01, 10 December 2011 (UTC)

Reference to the work of Pat Naughtin
If Pat Naughtin ("Mr Metrication"), his opinions, views or work are to be referenced in this article, readers need to be made aware that he was (unashamedly) a metrication promoter and campaigner. He was following a single-minded and uncompromising pro-metrication and anti-customary units agenda up until his death last year (July 2011). Not to mention that, or to pretend otherwise, risks misleading readers to assume that his opinions were incontrovertible or unbiased. His website and accolades on the websites of various metrication pressure groups, and of others (, [] ,) make that abundantly clear. MeasureIT (talk) 12:07, 31 December 2012 (UTC)


 * It appears that Naughtin's interpretation of the work of John Wilkins is also being used (albeit indirectly via information from the website of the UK Metric Association or others using that as a source) to support claims about Wilkins's role (without necessarily stating it to be based on Naughtin's work) in the history of the metric system in at least the following articles: History of the metric system (this article), Metric system, International System of Units, Metre and Lists of British inventions! MeasureIT (talk) 17:03, 31 December 2012 (UTC)

What weasel word, and why all the rest too?
Can User:Martinvl please explain in more detail this edit of his, and particularly tell us which word he removed as a weasel word. Then perhaps he will put back the rest that he also removed, or at least explain why he felt the need to remove all that too. MeasureIT (talk) 20:25, 1 January 2013 (UTC)


 * The whole tone of the sentence " the late Pat Naughtin, a tireless metrication promoter from Australia ... " is unencyclopeadic. I am not going to enlarge on the matter.  It just is. Martinvl (talk) 21:01, 1 January 2013 (UTC)


 * So your edit summary was inaccurate - your were not just "removing weasal word (See WP:WEASAL) by MeasureIT". You were actually reverting everything I added - it was a full revert, and now, even after I have asked for an explanation, you are refusing to explain in detail why.


 * How can we make constructive and consensual progress on the article if you revert everything I add, use false edit summaries, and refuse to discuss why you have reverted or attempt to reach a compromise? MeasureIT (talk) 21:29, 1 January 2013 (UTC)


 * Given the lack of response, I put back some of the content that was reverted, but modified it slightly in an attempt to address what I perceive to be the concerns of User:Martinvl. I'm trying to reflect the truth of the situation rather than misrepresenting it. MeasureIT (talk) 22:40, 2 January 2013 (UTC)


 * Unfortunately, your edit seems to have injected actual WP:WEASEL words instead of avoiding them. And while I agree with your perception that was less than helpful and collegial in his initial response here, 24 hours is far too short enough time to allow for a response. VanIsaacWS Vexcontribs 23:10, 2 January 2013 (UTC)


 * I have again removed the WP:WEASEL words. I did not repond with 24 hours becaue I have a life. In response to my being "less than helpful and collegial", please read this. Martinvl (talk) 09:40, 3 January 2013 (UTC)


 * No, you have once again removed my entire contribution and restored your favoured wording, using a misleading summary again, and without answering the outstanding question of what are the specific weasel words you claim to have removed. Perhaps you could at the same time justify the weasel words that you have now put back in there too. MeasureIT (talk) 07:27, 4 January 2013 (UTC)

The number of "modern writers" who support Naughtin's theory about Wilkins
Do we need to say how many? Should we say "many" without a reference specifically supporting that assertion by explicitly saying it? I've just removed the unsupported weasel word (WP:WEASEL, and replaced it with "four" (it is followed by four references), but I am uncomfortable with the whole idea. And one of those references has had doubt about its reliability raised by User:Ergative rlt in this discussion: "Talk:Lists of British inventions". Any ideas? MeasureIT (talk) 18:52, 4 January 2013 (UTC)


 * I've again flagged the Craig cite as possibly unreliable. The doubt was, as pointed out above, raised in the discussion at: "Talk:Lists of British inventions". MeasureIT (talk) 23:28, 4 January 2013 (UTC)


 * I have removed the "unreliable" flag - that is your view, let the readers decide.
 * I have removed the "Weasal" flag - you have clearly not read WP:WEASAL. The word "Many" in this context is 100% correct!!!!
 * I have removed your POV regarding Naughtin.
 * Martinvl (talk) 07:23, 5 January 2013 (UTC)


 * Not my view, that view is reflected in respected publications as referenced above, and how can the readers know if they aren't alerted to it? I've restored the flag as the evidence is compelling.
 * I read WP:WEASEL, have you? You need a cite containing the word "many" in that context to support that - or it is merely weasel.
 * My expansion on Naughtin is factual and pertinent to the context, not POV. He was a metrication promoter. He did postulate about the meaning of a chapter in that essay. It did receive national press coverage. It was following that coverage that other writers took notice. If you disagree with any of those facts then state which, specifically, here so we can discuss it.
 * MeasureIT (talk) 09:54, 5 January 2013 (UTC)

"Many" is not a weasal word
The word "Many" is not a "Weasal" word. It is a known fact that at least one 20th century editor (who I have cited) has credited Mouton with initating the metric system - I have seen many (yes MANY) similar citations. We cannot say that all 20th century editors concur with this. How else do you word this, or is MeasureIT just being bloody-minded. Martinvl (talk) 10:08, 5 January 2013 (UTC)


 * It is an unsupported attribution. The claim of "many" needs supporting by a reliable source, it isn't there, so is definitely "weasel". And no, "one" does not equal "many".


 * How would I word it? If I had a reliable source that explicitly supported it, I might say "many", otherwise if I was writing about the opinion given in just one source (as currently in the article) I would attribute it to that source; something like: "McGreevy, in his book on the subject, credits Mouton with initiating the metric system...". But I wouldn't expect to get away with extrapolating or inferring anything more than that. That is how encyclopaedias such as this should be written, rooted in reliable sources and not based on the personal opinion or zealotry of the particular contributing editor. Is that where you have been going wrong - have you misunderstood your role here? MeasureIT (talk) 18:49, 5 January 2013 (UTC)

Misrepresented or unreliable sources
Of the sources being used to support an expanded role for WIlkins - the claims based around being "one of the principal originators of the metric system" - all either fail to back the claim or otherwise suffer from problems (including one with a major reliability problem). Going down the list:
 * Fandree's "Chapter 6: By Tens and Tenths – Metric Measurement" is a set of course notes or brief study guide, not something that would normally be considered a reliable source, and in no way backs the claim. Its sole mention of Wilkins is "1668 John Wilkins, first secretary of the Royal Society of London, suggests a base 10 system of measurement." - nothing about his system being a percursor to the modern metric system (which the source identifies as being the work of the French Academy of Sciences), nothing about Wilkins as a "principal originator" or originator of any form, and nothing about Naughtin. This source has also been discussed at the Fringe theories noticeboard, where another editor agrees that it doesn't back the claim.
 * Calloway's "God's Scientists" says "He devised an early metric system, an undertaking that has likewise been acknowledged and praised by posterity", but does not say that Wilkins developed or helped to develop the current metric system. It does mention a BBC video that claims the metric system to be British, but says nothing about the truth of that claim (and still refers to Wilkins' system as "a metric system" - my emphasis) and the video is already cited in the article. There is nothing directly about Naughtin.
 * Cook's "Miles to meters" is about highway signage, and mentions Wilkins only in passing: "Then, in 1668, John Wilkins developed a decimalized system of standard weights and measures." The remainder of the section talks about Mouton and other French scholars, crediting them with the metric system. The source says nothing about Wilkins as a possible influence, and nothing about Naughtin. Discussed at fringe theories as well.
 * Craig's "No Child Left Behind." This is an incredibly shoddy source, a mass of almost random quotation and advocacy. While it claims that "the underlying ideas also came from England ... The key principles ... were proposed by Dr. John Wilkins", this material is quoted from the UK Metric Association, and like the rest of the quotes that make up the bulk of the paper, is presented without any sort of analysis. This and other feature of the paper led me to check up on the publishing journal International Journal of Applied Science and Technology and its parent Centre for Promoting Ideas, and what I found isn't good. CPI and its publications are accused of being fraudulent publishers, "predatory" journals who don't perform true peer review, lie about their editors (including adding the names of actual academics to their editorial board without their knowledge or permission), who have had their journals yanked from scholarly catalogs and databases, and who are placed on "publishers to avoid" lists. See the Times Higher Education, The Australian, or Beall's lists of suspect publishers here or his lists of predatory publishers for 2012 and for 2013. Given the lack of a "reputation for fact-checking and accuracy", this doesn't look like a reliable source.
 * Dew, "The Hive and the Pendulum". Note what's on the first page: "DRAFT: PLEASE DO NOT CITE WITHOUT PERMISSION OF THE AUTHOR". Beyond this, the paper doesn't support the claims in the article: Wilkins is briefly mentioned as a metrology reformer, but is not treated as a developer of the metric system, and the latter is described as "the French Revolutionary metric system". There is no mention of Naughtin.
 * "Celebrating metrology: 51 years of SI units" says "One of the first ideas for a universal metric system can be accredited to John Wilkins, ex secretary of the Royal Society, who outlined a new decimal system of measurement in 1668 in his book, ‘An Essay towards a Real Character and Philosophical Language’.", but does not link Wilkins to the development of the later metric system, and in fact traces the histry of the metric system to Lavoisier and others commissioned by Louis XVI ("the story of the now standard international measurement system starts here."). No mention of Naughtin.
 * Stone's "Metrication policies and technical communication". Probably comes closest of all the given sources of backing the claims made, but even there has problems. First, it's a newsletter, not a professional or scholarly publication. He also solely cites Naughtin for this section: why not just offer a cite to Naughtin's article instead? It does show that at least one other person besides Naughtin himself thinks the latter's ideas have merit though.

In short, that Wilkins was a metrology reformer who had a number of ideas similar to ones that later appeared in the metic system is backed by the sources, but the claim that he was "one of the principal originators of the metric system" - or even any sort of originator - is not, and some of the given sources actually contradict the claim. There is also nothing to suggest that "many" people are following Naughtin's ideas: the only source expressing agreement is Stone, and even the BBC video mentioned by Calloway just gives a very short clip of Naughtin making his claim, and neither advocates for him or presents anyone else agreeing with him. A couple of sources from the above list could be used to replace the primary and BBC source in the "Wilkins" section of the article and the ABC news source in the "Universal Measure" section (the latter especially looks to fall foul of WP:NEWSORG for this subject); Dew and Calloway are probably best for this. Stone could be possibly be used to argue notability for Naughlin, but shouldn't be used for claims about Wilkins. Otherwise, the use of these sources, and some of the surrounding material involving Wilkins, has problems with WP:RS, WP:SYNTH, WP:BURDEN, and WP:OVERCITE. Ergative rlt (talk) 20:49, 5 January 2013 (UTC)


 * Ergative failed to look at one reference - Wilkins' original work. If can be found either as a 20 MB PDF file or a much shorter transcription by Naughtin. Anybody who is studing science or engineering at undergraduate level soudl be able to understand this document and shodul also have sufficient background to be able to comment on Naughtin's commentary.  If you actualluy read Naughtin's commentary what you will see are:
 * Wilkins proposed a system that encompassed many of the concepts (as opposed to the detail) of the French metric system of 1799. This observation can be verified by any physics or engineering undergraduate and since it does not make any novel proposditions, it is not original research.
 * Jefferson's proposed system encompassed many aspects of Wilkins's proposal, anbd refiuned other aspects such as using a solid pendulum rather than a bob pendulum. Again this can be verified by our undergraduate friends.
 * Naughtin investigated the possibility that Jefferson was aware of WIlkins' writings, but on his own admission, could not prove things one way or the other.
 * In short, Naughtin did not add anything other than publicity, and his curiosity was triggered by somebody else's blog.
 * Newton is credited with developing the corpuscular theory of light, but no-one credits him with having anything to do with the the theory of quantum physics. During the nineteenth century corpusciular theories were nver taught - everybody who had anything to do with optics preferred the wave theory of light. In 1905 Einstein explained the Photoelectric effect in terms of light being composed of what we now call photons, the theory that earned him the Nobel Prize.  Some university and college courses give credit to Newton (it was actually Pierre Gassendi) for having the foresight to predict that light is corpuscular in nature, it has a finite speed and that it has a kinetic energy - which exactly describes what we know about photons, but nobody stats that Newton actually foresaw quantum theory or the concpet of Wave–particle duality.
 * In exactly the same way, Wilkins produced a theory which was implemented a century later. Wilkin's model for systems of measurement are very similar to what was actually produced by the French a century later.  Just as the corpuscular theory of light has a place in physics text books, Wilkin's theories have a place in the development developemtn of the metric system.
 * Now if MeasureIT would just get off my back, I can rewrite certain sections to reflect that there is uncertainty in how much influence Wilikins had and at the same time ensure that credit is not given where it is not due. Martinvl (talk) 22:12, 5 January 2013 (UTC)

Wilkins and Burattini - origin of modern term meter
The article states that Burattini "backed" Wilkins' idea of a universal measure and translated it into Italian, and implies that this translation was the basis for the modern term meter. The statement is unsourced, and I can't find anything saying that Burattini's metrico catallico was a translation of Wilkins' term (as opposed to an independent coining), or that either term was used by the French in settling upon meter. The only source saying something similar is Naughtin, and even he hedges his bets with "probably", is an SPS who doesn't appear to be an authority on etymology, the history of science, etc., and whose claim otherwise appears to be undue, as there don't appear to be any prominent adherents of the claim. Ergative rlt (talk) 20:49, 5 January 2013 (UTC)

Recent edit by Martinvl
"Such as" implies or suggests there may be others. This isn't supported by the cited references, so I have flagged it as weasel words as per WP:WEASEL. Please either provide a reference explicitly confirming that there are others, or reword the sentence to reflect what is supported.

The "vc" (unreliable source?) flag was removed from the Craig cite, but no explanation was given, Please provide an answer to the questions raised about the reliability of the Craig cite at "Talk:Lists of British inventions", and as raised in the section above: "Talk:History of the metric system/Archive 1", or remove the cite, but please don't just remove the flag without justification.

MeasureIT (talk) 10:50, 7 January 2013 (UTC)


 * Flagging "Such as" as a weasel word is pedantry. One need only google "mouton 1670 metric" to get many more.  So how many do you want?
 * I am currently looking for modern texts on the history of measurement. Surprisngly many authors like ot be paid for their work, so they don't leave it lying around without payment.
 * Martinvl (talk)


 * No, it's not "pedantry". It's called verifiability. The readers should be able to reliably verify everything they read in an article. They shouldn't be expected to do there own leg-work in Google in an attempt to see if what they are reading in Wikipedia could possibly be justified. If it is true and it is worthy of inclusion, reliable sources must surely be plentiful. If sources are not easy to find (as you seem to be implying here) then, presumably the claims are dodgy ones. MeasureIT (talk) 20:48, 7 January 2013 (UTC)


 * While I don't expect readers top do any legwork, I do expect other editors who are making a challenge to do a little legwork. You might notice that the two citations were chosen with care - one was French, dated 1901, the other British dated 1995 - opposite ends of the century, different countries. Martinvl (talk) 22:28, 7 January 2013 (UTC)


 * You agree then, that by giving vague attribution (one at each end of the century implying that it happened in between too), and dressing the statement with authority, but with no substantial basis, you present the appearance of support for the statement but deny the reader the opportunity to assess the source of that viewpoint (who said there are ones in between those end dates too). MeasureIT (talk) 07:40, 8 January 2013 (UTC)


 * NO I DO NOT AGREE. As I do not intend trapsing around libraries to satisfy your on-going demands, I do not intend continuing this discussion. Martinvl (talk) 10:23, 8 January 2013 (UTC)

Note, as we seem to be going around in circles here, I have now asked at Third opinion for another opinion on this. MeasureIT (talk) 22:17, 8 January 2013 (UTC)

Third Opinion
Wow. Wow. Wow. First of all, I'm going to suggest a cool down, for the both of you. It is extremely unfortunate to see two editors squabbling over each other due to each other's differing opinion on the Metric system. But you two don't stop there. You two go on and you begin chase after each other's flaws trying to find something to justify your opinion that the other is wrong. You went so far that the one of you ended up getting yourself blocked over this argument, and the other receiving a warning. Now this is not the point of a third opinion and you have most likely deduced that by now, I just quite simply needed to tell the two of you that. The truth of the matter is that two of you have shown good sides of the argument in your squabbling, I just wish you could have stopped being so disagreeable with one another so that you could reach a general consensus. What I have to say about the article is this: While the metric system is known for being "exclusively used" by the Europeans, this is not completely true. In fact, the majority of the resources I found were saying these things. While one of you "teased" the other about how it wasn't simple to just Google for more sources to support their argument, I did just that. What I found was pages upon pages of scholarly articles and textbooks stating what one of you was trying to explain to the other. The problem was the fact the two of you were so eager to engage in an edit war. This war in a large way destroyed some of the credibility of this article. One of you, if not the both of you is/are mathematicians. I would like to think that two mathematicians or at least two parties interested in math could discuss such a topic on a scholarly or professional level. I suggest removing the weasel word tag. There is enough evidence to support the claim "many" were saying said thing.02:51, 9 January 2013 (UTC)

Note on removed vc template
MeasureIT asked me on my talk page why I removed the tag that was added. In my judgment the edit was made to score rhetorical points rather than to improve the article, so I reverted it. I also went to the library. Danloux-Dumesnils has an excellent history of the metric system in his The Metric System: A Critical Study of its Principles and Practice (1969) that does not mention Wilkins. However, the more recent From Artefacts to Atoms does (Quinn, 2011, OxfordUP). I'll be adding these over the coming days. Based on the Quinn book I find the cite in question to be credible and appropriate. I think Quinn is a better cite and, if there's consensus, Quinn might replace it. So the tag has served its purpose. Garamond Lethe 07:04, 9 January 2013 (UTC)


 * Hi Garamond,
 * Thank you for your suggested citation. I have implemented it. Martinvl (talk) 08:18, 9 January 2013 (UTC)

Seems you guys have been arguing about Wilkins for 208 years
(Repeated from WP:FTN) In 1805, just 10 years after the French adopted the metric system, a letter appeared in the Philosophical Magazine of London (Vol. 21, No. 81, Feb 1805, pp. 163–173) arguing that all the essentials were invented by Wilkins and decrying the fact that it was implemented by the French without acknowledging the British priority. After quoting at length from Wilkins' book, it says (p.170):
 * "The above extracts contain, as far as I know, the earliest sketches of the ingenious methods therein proposed; and our neglect of such suggestions of our own countrymen, has been very properly rewarded by our obliging neighbours, who, as in other instances, have done our nation the honour to adopt and combine them, without distressing our modesty by an acknowledgment. I have no room or time, at present, to expatiate on this becoming and characteristic exercise of politeness."

Is that great or what? They did insults better then too! Zerotalk 15:47, 9 January 2013 (UTC)

Incidentally on page 173 there is an intriguing comment "the decimal division of weights and measures has long been established in China", which seems to be true (more on that later). Zerotalk 15:47, 9 January 2013 (UTC)


 * That is really cool. Would either you or Martinvl like to add that?  I think it would work great as a note.  Garamond Lethe  16:13, 9 January 2013 (UTC)


 * That article is gold-dust. The really interesting  bit is the note about Liebnitz' disagreements with Wilkins (I don't know why: Liebnitz and Newton hated each other, Newton and Hooke hated each other, Wilkins worked wot Hooke. Since Liebnitz had read Wilkins and he worked with Mouton, could there have been plagurism?  Of course we cannot state that in the article, but we can record what was written and as long as we don't draw any conclusions, we are not guilty of WP:OR. Martinvl (talk) 16:40, 9 January 2013 (UTC)


 * I have rewritten the section. I have done my best to present the facts, but not to add any WP:POV or WP:OR. Comments please? Martinvl (talk) 22:12, 13 January 2013 (UTC)


 * Thanks for following up on this. It looks good except for the last sentence:  Dominus noted that the names used for various masses were a factor of ten greater than expected.  That reads as though the names were greater than expected.  Garamond Lethe  23:13, 13 January 2013 (UTC)

Comment about re-written section
(A bit long, sorry!)

I arrived here after intersecting links from a noticeboard discussion and from a MOS edit. Here, for what they're worth, are my comments on the rewording of the "Universal measure" section.


 * 1) I think the first paragraph (the one about Charlemagne) should be moved to the "Leading up to the French Revolution" section, and merged into the bit about France having a "multitude of units of measure". It would add necessary context to that, but is confusing - and leading nowhere - where it currently is.
 * 2) Looking at the section as a whole, there is no explanation as to what a "universal measure" is and there does not seem to be any "master" source references (or even single reference) which brings together these individual historical discoveries and proposals as parts of the history of the metric system. The whole section comes across as though the editor here has pieced it together himself, from first principles. Is it indeed the mainstream view of that history?
 * 3) If we look at each separate element of the "history", the individual paragraphs, the introductory one, including the details about Simon Stevin seems light on references and light on cohesion. What's the relevance of the mention of his "the tenth" pamphlet? In the absence of a reference, is it fact or opinion that he "first introduced decimal numbers in daily life in Europe"? Has his own opinion that "this innovation was so significant..." been made notable in any reliable sources? Why is "universal measure" in quotes (and what is it?) - is it a direct quote from the source? What supports this sentence: "It was only in the late eighteenth century that proposals were made for the use of a universal measure in the spheres of commerce and technology."? What is the definition of a "modern writer" and was this the reason for the attempted MOS edit? Is the statement "Quinn (2012) makes no mention of Mouton ", and its interpretation here a notable opinion, or the opinion of the editor here?
 * 4) In the subsection about Wilkins, I'm not sure I understand the meaning of the notion that he wanted units "derived from natural phenomena" - the word "phenomena" is usually used to describe things that cannot be explained. What is the "quicksilver experiment"? The term "universal measure" is used again with no explanation of what is means. Did Wilkins know it was Torricelli's idea that he was discarding? Why is "measure" and "measures" in quotes - are they direct quotes? Is Naughtin's self-published analysis considered to be a reliable source? What is the last paragraph, mentioning what Dew noted, actually adding?
 * 5) On to the Mouton subsection. Do we know how long Mouton was working on his book - we have a lot of detail trying to suggest that Wilkins worked for many years on his, and whether he was aware of the writings of Wilkins? How did he know how long a virgule was (185.2 mm) if the length of the circumference of the earth couldn't be measured?
 * 6) In the 17th century developments subsection, why is it notable that both Jean Picard and Christiaan Huygens were interested in, or even supported, Moutons work? And how do we know that Gottfried Leibniz had the same ideas? How was the second, as used to time pendulums in the 17th century, measured or defined? How do we know that "The quest for the "universal measure" went into abeyance for nigh on a hundred years." - is there an RS stating it?
 * 7) In the subsection Leading up to the French Revolution, the bit about Charlemagne would set the context here. Is there a source for "perilous state", or is it editorializing? Who said "the need for standardisation of weights and measures had become apparent"? Who were the "mob" who stormed the Bastille? Who confirms that the nobility "surrendered their privileges, including the right to control local weights and measures" - especially the emphasis on W&Ms? Did Louis XVI charge "a group of experts" after he had surrendered his privileges"? The Tallyrand paragraph is short on sources and short on clarity - it assumes too much knowledge of 18th history and personalities and uses abbreviated terms - "Jefferson presented to Congress" should say "Jefferson presented to the U.S. Congress", what is the "Constituent Assembly", who was Tallyrand. In short: it comes across as a random collection of factoids put next to each other, but with unsupported associations.
 * 8) In the final section about Wilkins and Mouton, we see Naughtin cited again - who was he, and has any of his work been peer reviewed? Whose view is it that his work contradicts the "twentieth century assumption", and where is that collective, century-long, assumption described in such terms? Where has whether the "Wilkins' Essay influenced the design to the French metric system of the 1790's" been debated? Whose view is it that the work of Wilkins has received little attention? Whose opinion is it that "there is little evidence to show whether or not Jefferson or the French Revolutionary leaders derived the concept of defining unit mass in terms of a unit volume of water independently of Wilkins"? The very last paragraph sounds like a bit of a personal ramble, attempting to excuse the editor's failure in the article to prove that the work of Wilkins had an influence on the history of the metric system.

If any of my points are unclear, please ask for fuller explanations!

Stevengriffiths (talk) 17:40, 14 January 2013 (UTC)


 * Hi Stevengriffiths,
 * Thank you for your comments. If there is a lot to say then obviously it must take a good deal of space.  I will be working through these points. Martinvl (talk) 19:17, 14 January 2013 (UTC)


 * Resonse to Q7
 * I think that I have answered most of the points brought up, either by further explanation or by the addition of citation. A few points of clarity - the nobility, not the king, surrendered their rights to set local weights and measures. Yes, the term "perilous statge" was editorialising on my part - how else do I condense five pages into one line?  Martinvl (talk) 22:25, 14 January 2013 (UTC)


 * Response to Q7, Q1
 * I have moved the section about Charlemagne as suggested. However the first few paragraphs need some tidyng up as there is a certain amount of duplicate material. Martinvl (talk) 17:46, 15 January 2013 (UTC)


 * Response to Q2, Q3
 * I have done a little restucturing to show the interconnections between teh various sections. Martinvl (talk) 17:46, 15 January 2013 (UTC)


 * Response to Q4, Q5 and Q6
 * I have tidied up the section on Wilkins,. I think that it is clearerd now - I trust that it is now obvious to the reader that Wilkins was not discarding Torricelli's concept, but rather stating that it was unsuitable as a standard becasue it was too variable.
 * I put "measures" in quotes because it was taken straight from Wilkins' text. In modern language we would use the phrase "unitsd of measure".
 * I have clarified how Mouton "knew" the value of the earth's circumference - he didn't, he used a value calculated elsewhere. I have also clarifed where the sources for the values of the virgula.
 * I have removed Leibnitz' from the discussion and have expanded on the work of Picard and Huygens, putting them into perspective. Martinvl (talk) 19:45, 16 January 2013 (UTC)


 * I've tidied it up a bit further. Stevengriffiths (talk) 23:23, 16 January 2013 (UTC)


 * Thanks for the changes so far. I agree with most of them (apart from the Magna Carta - see later). Martinvl (talk) 21:18, 17 January 2013 (UTC)


 * Response to Q8
 * I am in the process of rewriting that subsection - my working text is at User:Martinvl/Sandbox4; please ignore other sections, they are just there to ensure that citations do not get disturbed.


 * Magna Carta
 * I moved the bit about the Magna Carta back to its original position. The point being made was that whereas France had thousands of units of measure - the pied varied from town to town (depending on how the lord could fleece the peasants), England had the principal (not alweays followed) of one unit of measure.  The actual units of measure changed from time to time, for example, the length of the foot was reduced by a factor of 1/11 a hundred years after the Magna Carta (the rod, pole and perch retained their lengths which is why we had the awkward factor of 16.5 feet (5.5 yards) in a pole, rood or perch. This change is another reason for moving it away from the text that discussed ussia - Peter the Great aligned the Russian foot with the English foot of 1744 (I think), not 1215. Martinvl (talk) 21:18, 17 January 2013 (UTC)


 * Sorry, I had to revert your "rewrite" as you had based it on an old copy and had accidentally lost many recent copy edits and corrections which had taken place since your copy was taken. Please use the latest version as the basis of any rewrite to try to prevent this from happening. Stevengriffiths (talk) 16:49, 18 January 2013 (UTC)


 * Hi Stevengriffiths
 * I have tweaked my rewrite, but not yet copied it back into the article - you can see it at User:Martinvl/Sandbox4. On reading the letter in the Philosophical Magazine (1805), I felt that this contained a summary of why Mouton was given credit that should have gone elsewhere.  I deliberately trimmed the section down so as to make space for that discussion.  The letter is probably more reliably sourced than Naughtin and was better researched. Naughtin was a metrication commentator and motivational speaker who died in 2011.  His work was self-published, which is why I have steered away from his analysis, but if we see him drawing attention to Wilkins' Essay in the same light as we see the child who asked why the Emperor was not wearing any clothes, then it is perfectly valid to include that observation.
 * Will you have a look at the rewrite and comment on it.?


 * Hi Stevengriffiths,
 * I have undone your last section because of a few technicalities. Wikipeida does not normally add dates of birth and death in the text as you did when you wrote "Gabriel Mouton (1618-1694))".  The date which I quoted (1670) was the date when he published his work - this is a standard way of making such quotes. It also lets teh reader know which work was published first - in this case it is far more important to know that Wilkins published in 1668 and Mouton in 1670 than to know their dates of birth and death.
 * You replaced the text "as the originator of the metric system" with the text "as the originator [of?] some of the underlying principles used in the design of the metric system". McGreevy actually stated (p 140) "The originator of the metric system might be said to be Gabriel Mouton, ...". Numerous other twentieth century publications use similar language. Martinvl (talk) 17:53, 18 January 2013 (UTC)
 * I've put back my changes, but also taken account of your comments about the dates and McGreevy. We need to be careful not to generalise too much based on one sample. Stevengriffiths (talk) 19:07, 18 January 2013 (UTC)
 * Hi Martinvl, I took a look at your sandbox copy of an update to the "Roles of Wilkins and Mouton" section. I'm not keen on the generalisations based on just one or two sample sources (such as you derive from Bigourdi's and McGreevy's books) or the speculation you make about whose work influenced who. With all due respect; what we really need is notable and reliably supported outside comparison of Wilkins and Mouton (and whoever else might have contributed anything), and not our personal conjecture based on personal analysis of random documents found using Google. The impression that I get from reading it is that you are scouring Google to find references that promote the work of Wilkins, but are not going to the same lengths to find references that support the work of Mouton, or of anyone else. In other words, rather than trying to balance notable views and opinions about the likely influence of the various players bringing ideas to the table, your piece comes across as an attempt to construct a case in support of Wilkins. Stevengriffiths (talk) 19:54, 18 January 2013 (UTC)

Regarding Stevegriffiths's edits
You summarized Bigourdan as Mouton having provided the "underlying principles used in the design" of the metric system. I'm not seeing how that portion of the text describes underlying principles. What I do see is: "On voit que le projet de Mouton est, sans aucune différence de principe, celui qui a ét réalisé par notre Système métrique" or, per google, "We see that the project Mouton is no difference in principle, one that fl [sic] produced by our metric system." Could you explain where you got "underlying principles"?

As to the rest of the edits, I believe Martinvl is closer to the style used in wikipedia.

Garamond Lethe 22:02, 19 January 2013 (UTC)


 * I'd already re-phrased it to be closer to the text you quoted. My main point was that we should not be extrapolating two writers, with two different takes, into an over generalization of the view of "twentieth century writers", not without a reliable source that makes that same point. Our role is to report notable views, supported by reliable sources and not to give our own views supported by sources which have been searched for to support our view.


 * Don't you the get impression that I get from reading the current article content, that rather than trying to balance notable views and opinions about the likely influence of the various players here, it comes across as an attempt to construct a case in support of Wilkins? Stevengriffiths (talk) 22:25, 19 January 2013 (UTC)


 * I think the article accurately reflects that a case for Wilkins has already been constructed and that this is the current consensus in the literature. This seems to be relatively recent:  Danloux-Dumesnils (1969) doesn't mention Wilkins at all, but Terry (2012) treats Wilkins's contribution as settled fact.  So in between the two I expect there's some scholarly paper that rediscovered Wilkins and that's now the current thinking.  If you have citations to the contrary they'd be most welcome.


 * As to the level of generalization: I think the previous text was supported by the citations given.  If you think this is an overgeneralization then provide a citation to the contrary.  But absent a that kind of citation, rewriting this sentence misses the point:  we've moved from one consensus to another.  I don't see a need to provide a per-citation detail of the previous consensus in this context.  Garamond Lethe  22:50, 19 January 2013 (UTC)


 * Shapiro (1969) discusses the role of Wilkins, stating that he was asked England's Royal Society to devise a "universal standard of measure". The concept was obviously the subject of discussion by then, at least. That only one or two notable commentators since then has given him any credit is hardly evidence of a current consensus. We need sources to support the view that the focus has changed from Mouton to Wilkins, and not merely express our own views, supported by by nothing more than one or two exceptions to the norm over the last century, or more. Stevengriffiths (talk) 23:11, 19 January 2013 (UTC)


 * A single citation can be enough to establish consensus, and I have no idea why you think we need a cite explicitly detailing the change of consensus. If you have citations that indicate there isn't a consensus then bring them out and we'll take a look.  Garamond Lethe  01:29, 20 January 2013 (UTC)


 * I have made a number of changes (based on what I have written in at User:Martinvl/Sandbox4). The changes that I have actually imlemented is a tighter wording of the first sentence which, amongst other things, has meant replacing "Bigourdan in 1903 and that of MGreevy in 1995" by "Bigourdan (1903) and MGreevy (1995)" which is the normal academic style. In the earlier vesions I wrote that Wilkins' Essay attracted little interest, I have now refined that to show that there was considerable interest, but in the field of onomasiology rather than in the field of systems of measurement.
 * I am happy to remove the sentence about the final four years of WIlkins' life - its only impact is to show why Wilikins did not follow up his Essay.
 * I would also like to replace the final paragraph in which I move the emphasis from Naughtin's blog to the letter in the Philosophical Magazine (1805). A draft text is in User:Martinvl/Sandbox4.
 * Finally, what scholarly work caused writers to emphasise Wilkins rather than Mouton? That work was, I believe, Naughtin.  During his lifetime (he died in 2011), he produced a regular blog "Metrication Matters", sections of which have been reproduced on other websites (including university course notes) which gives them at least some credibility. As regards the reliability of his 2007 publication - how "reliable" was the small boy who shouted "Why isn't there emperor wearing any clothes?". Naughtin was, after all, merely (and I believe unknowingly) repeating what was written in the Philosophers Magazine in 1805 - that British involvement in the development of the metric system had been "airbrushed" out  by the editors of the Encyclopédie.Martinvl (talk) 08:37, 20 January 2013 (UTC)


 * You (Martinvl) illustrate beautifully the point I am making. If there was a reliably sourced opinion that said "Wilkins' Essay attracted little interest" and then a source appeared later that gave the opinion that "there was considerable interest in Wilkins' work", then you could have legitimately compared and contrasted the difference between the two.


 * As it is though, what you are, in effect, saying is "I had originally thought that Wilkins' Essay attracted little interest, but now I've uncovered a letter in an early journal in which he is mentioned, it appears now that there was considerable interest in him after all" - but you can't legitimately put that in the article because Wikipedia is supposed to be based on fact and notable and reliably sourced views, and not on your current personal point of view. You need to read the WP:OR policy and you will see what I am saying described and explained in detail, with examples, similar to what you are doing here, used to illustrate what is not acceptable. Stevengriffiths (talk) 12:55, 20 January 2013 (UTC)


 * One source says that there was little interest, but does not qualify the statement, the other says that there was considerable interest and does qualify the statement, but the interest appears to be in a field other than systems of measurement. I am trying to keep the article below 100 kB and we have just gone over that value (see WP:LENGTH).
 * (The above was written by Martinvl).


 * Which source says "Wilkins' Essay attracted little interest"?
 * Which source says "there was considerable interest in Wilkins' work"? Stevengriffiths (talk) 14:21, 20 January 2013 (UTC)


 * It was Barabara Shapiro (1969) who said that Wilikns' work had been widely distributed and Wright-Henderson (1910) who said that the book received little attention. Martinvl (talk) 14:31, 20 January 2013 (UTC)


 * So why have you removed the statement that "Wilkins' Essay attracted little interest" or as you put it above: "now refined that to show that there was considerable interest", if that view of "little interest" was supported by the source you mention? Stevengriffiths (talk) 14:46, 20 January 2013 (UTC)

The article contains many examples of contraventions of WP:OR
Here are the particular policy clauses (from the WP:SYN section of WP:OR) that supports me on this:
 * "Do not combine material from multiple sources to reach or imply a conclusion not explicitly stated by any of the sources."
 * "If one reliable source says A, and another reliable source says B, do not join A and B together to imply a conclusion C that is not mentioned by either of the sources. This would be a synthesis of published material to advance a new position, which is original research.[8]"
 * "A and B, therefore C" is acceptable only if a reliable source has published the same argument in relation to the topic of the article."
 * "If a single source says "A" in one context, and "B" in another, without connecting them, and does not provide an argument of "therefore C", then "therefore C" cannot be used in any article."

The article, and particularly the section "Development of underlying principles", contain several examples of all of these as I describe above. What can we do to clean it? Stevengriffiths (talk) 15:46, 20 January 2013 (UTC) Stevengriffiths (talk) 15:46, 20 January 2013 (UTC)
 * Revert back to June? VanIsaacWS Vexcontribs 16:50, 20 January 2013 (UTC)


 * I believe that I have cleaned up most if not all the WP:OR and WP:SYN that might have been present. In particular, I have replaced Naughtin's analysis (as opposed to his statement of verifiable fact) with the analysis of the correspondent of the Philosophical Magazine (whose letter was reviewed by the editor of the magazine). Martinvl (talk) 22:15, 20 January 2013 (UTC)

16th century origins?
The opening sentence of the article makes the bold claim that "The origins of the metric system can be traced back to the 16th century,...". Hoping to find evidence to support this, I read on, but never actually found it. It seems that a Flem, Simon Stevin, may have introduced decimal arithmetic into Europe in the 1580s, but there is nothing anywhere else to suggest that this was the catalyst, or even played any role at all, in the development of the system by the French in the 18th century. As the link with the Flem is, at best, tenuous (there is nothing to suggest that those who introduced the metric system were aware of Stevin or that the metric system could not have been developed even if decimal arithmetic had never been invented), I don't think the article should lead with this particular opinion. Cobulator (talk) 22:08, 6 July 2013 (UTC)
 * Alder, writer of The Measure of All Things (cited in the article) uses Stevin as his starting point. Martinvl (talk) 06:18, 7 July 2013 (UTC)
 * Alder only seems to mention Stevin on one page, page 91. What are the first 90 pages about (or even the last 389 pages)? I suspect Stevin has been given undue weight here, in the context of the origins of the metric system. Cobulator (talk) 11:51, 8 July 2013 (UTC)
 * Of course I am going to defend Alder's position - if you want to question the statement, why don't you read Alder for yourself. You can probably buy a copy reasonably cheaply, or if you live in a country or are a member of a university that has a reputable library service, borrow a copy. Once you have done that, you will be able to see why Alder did not mention Stevin in the preceding 90 pages. Martinvl (talk) 11:58, 8 July 2013 (UTC)
 * Have you read it? If you have, is it your opinion that Alder holds Stevin up as the originator of the metric system, despite only mentioning him in one sentence of his 480 page book about the metric system? Cobulator (talk) 12:09, 8 July 2013 (UTC)
 * We could equally say that the origins of the metric system can be traced back to 300BC and Euclid as Euclidean geometry was used to triangulate the length of the meridian initially used to define the length of the metre. But that would also be a personal opinion, and giving undue weight. Cobulator (talk) 14:17, 9 July 2013 (UTC)
 * Alder's version does not suggest that the metric system has its origins in the introduction of decimal notation. According to Alder, the root of the metric system was the French revolutionary desire to use natures constants, rather than the dimensions of royal personalities, as the basis for their measurement system. Everything else, coherency, the decimal nature and the prefix concept were all afterthoughts. 212.183.140.1 (talk) 10:04, 18 July 2013 (UTC)
 * Page number please for this suggestion, or better still, chapter number and note number and source associated with the note (to enable different editions of the book to be reconciled with each other if necessary). For more information about Stevin, why not do a Google search using the search string "Simon Stevin metric system" and see how many hits you get?
 * Please also read WP:BRD - the essence of which is that while a discussion is taking place, the article is restored to its last stable state. In line with this, I have reverted your changes. Martinvl (talk) 21:10, 18 July 2013 (UTC)
 * May I say Martinvl, it looks like you are grinding an axe here. You have struck out valid comments here by Cobulator without addressing them. You reverted my changes three times today: the first time you commented they added nothing, the second time you called them disruptive and the third time you are pleading WP:BRD.
 * Rather than edit warring, policy shopping, failing to assume good faith and generally looking for excuses to reinstate your favoured interpretation of Alder's book, please support your version, specifically that the introduction of the principle of a decimal numbering system is actually the origin of the metric system: with quotes from the book that support that, and please answer the other points made above about the sequence of introduction of the key features of the metric system.
 * Alder's section, The Measure of Revolution (or similar), supports my points, specifically the order: 1. natural units, 2. interrelated units, 3. decimal numbering system and 4. common prefixes. That same section also contains the one sentence mentioning the introduction of the decimal system, but also explains how, after Tallyrand's proposal of the principle of interrelated units was voted into law and added as the second feature of the French metric system, that the discussion about whether a duodecimal or decimal numbering system should be used started. The decimal system was finally chosen as the third feature of the system. So I maintain that it is incorrect to describe the decimal numbering system as the origin or the metric system. 212.183.128.246 (talk) 22:00, 18 July 2013 (UTC) (apologies for the annoying ip address changes, although my system is permanently connected, this seems to be a feature of operating in weak signal areas) 212.183.128.246 (talk) 22:07, 18 July 2013 (UTC)
 * It might be noticed that the second word of the article "origins" is written in the plural, not singular, so the statement "So I maintain that it is incorrect to describe the decimal numbering system as the origin or the metric system" in that it refers "the origin" (Singular) makes a statement about something that does not exist. Martinvl (talk) 06:35, 19 July 2013 (UTC)
 * So now you wish to try arguing semantics, rather than substance. In this context both words mean the same thing, as the OED puts it: "[origin] (also origins) the point or place where something begins, arises, or is derived...". The point or place (note the singular nature of their definition).
 * Are you arguing that Alder asserts that the 16th century proposal for a decimal numbering system was the point or place that the French metric system began, arose or was derived? If you are, please provide the appropriate quotes from his book. And if it makes it easier for you to comment upon: I also maintain that it is incorrect to describe the decimal numbering system as the origins or the metric system. I look forward to your comments, and please answer the substantive points, rather than more unreasonable reasons to avoid answering them. 212.183.140.44 (talk) 07:54, 19 July 2013 (UTC)

The previous editor wrote "Are you arguing that Alder asserts that the 16th century proposal for a decimal numbering system was the point or place that the French metric system began, arose or was derived?. I am not - to do so would be WP:SYN.  I am repeating what I read in Alder.  I could of course have used any one of these (or other) sources. Martinvl (talk) 10:22, 19 July 2013 (UTC)
 * Naughtin (2009)
 * USMA (2002-2012)
 * Wandmacher & Johnson (1995) p 293
 * Bahr, Degarcia & Bahr (2010) p 427
 * Klempiner (1974)
 * Ostdiek & Bord (2008) p 10
 * Smeaton Platinum Metals Review (2000)
 * Schaschke (1998) p1
 * You are taking us around in circles now - that is where this discussion started. Can you give the quotes from Alder that you believe supports the statement, the statement that you insist on keeping in the article, the one that claims the decimal numbering system to be the origins of the metric system. 212.183.128.208 (talk) 10:57, 19 July 2013 (UTC)
 * Well of course if you design the search to return only what you want to see (as in the example above), you will only see that. However, if you frame the search more neutrally, then the results will be entirely different. My search also brought up a reliably sourced analysis of Ken Alder's book which gives a different conclusion to yours, and a conclusion consistent with the other mainstream sources thrown up by that neutral search, that the origins lie in the ideology leading to the French revolution. 212.183.128.143 (talk) 17:23, 20 July 2013 (UTC)


 * Perhaps one should also look up "metric system" in the "mainstream" Penguin Dictionary of Mathematics (9780141920870). Quote: "First suggested in 1585 by Simon Stevin, it later found a champion in Lagrange, and was formally adopted in 1795 . . . ".
 * Oppose removal of reference to Stevin. Please restore the original text. --Boson (talk) 22:58, 20 July 2013 (UTC)

It is quite hard to know exactly what is being argued about here. There are three separate issues involved, which are being confused. Zerotalk 02:57, 21 July 2013 (UTC)
 * 1) The use of decimal notation for numbers.  This is relevant to the history, but the fact that we use decimal notation to write distances in feet and inches shows that it is not the same as the metric system. The main relevance is that calculation with measures based on ten is easier if the number notation is also based on ten.  If Simon Stevin did nothing except popularize decimal notation, his appearance in the article would be dubious.
 * 2) The use of weights and measures based on powers of ten.  This is obviously far more to the point.  Simon Stevin proposed a system of weights, measures, and coinage in which there were named units differing from each other by powers of ten.  He gives quite explicit examples, for example naming a unit of length, its tenth, and its hundredth.  This is different from merely writing numbers in decimal and obviously must be included.
 * 3) The nitpicking over the word "origins".  It is perfectly commonplace for an idea to appear and disappear a number of times before it sticks.  Stevin and others had the idea of weights and measures based on ten long before the French revolutionaries had it, but was it their ideas that stuck?  Did the French know about the earlier ideas?  In this we should follow what good sources say and not attempt to make our own storyline. It is actually pretty easy by careful choice of words.  Instead of saying that the metric system originated with Stevin, we just have to say that it was first proposed by Stevin. Similarly with other people like Wilkins. Then, in discussing the French we should report what specialist scholars write concerning where they got their ideas from (and since there are such specialist scholars and their work is readily accessible we should devalue popular works, encyclopedias, etc.).


 * I agree with Zero, the problem isn't about whether Stevin introduced decimal numbering, he apparently did: but it's about what the mainstream, reliably sourced, consensus believes the origin of the metric system to be. Martinvl asserts above that his view is from Alder's book - that synthesis by Martinvl is contradicted by a reliably sourced review of that book that is cited above. Martinlvl then produced above the results of a search tailored to produce his desired results, that is not acceptable. A search for "origins of the metric system" amongst mainstream sources does not support that fringe view, so to put that view as sentence number one in the lead is simply disruptive. This relentless edit-warring to push that view is indefensible.


 * If the IP editor actually took the trouble to read the article, he would see that THREE citations have been given, yet he persists in trying to twist one of them while ignoring the other two. Martinvl (talk) 08:38, 21 July 2013 (UTC)


 * Though it is probably nitpicking and I don't personally think "origins" necessarily implies that the French were consciously aware of Stevin's proposals, particularly at the level of precision appropriate for the lede, I have no problem with a rewording of the sentence that omits the use of the word "origins" and instead says something more like the entry in the Penguin Dictionary of Mathematics, preferably also making it clear that Stevin's proposal was not just a form of decimal notation. However, we should be careful not to imply that what Stevin proposed was exactly what was later implemented. That is how I understood the motivation for using the word "origins". Perhaps something on the lines of "the ideas behind the metric system go back to . . .", though that may be a bit too vague. --Boson (talk) 15:40, 21 July 2013 (UTC)


 * How about "The concepts behind the metric system are known to have been developed in the 16th and 17th centuries ...". I have avoided using the word "first", we don't know that this was the first, but we do know that it was one of the earliest developments. Martinvl (talk) 21:04, 21 July 2013 (UTC)
 * Perhaps just "were developed"? --Boson (talk) 15:06, 23 July 2013 (UTC)

I see we have now moved away from the assertion that Alder's book supports the notion that the metric system had its origins in the 16th century. Now, perhaps, we can make it clearer in the lead that the true catalyst and origin of the metric system was French revolutionary dogma - that everything be rationalised and given order, and certainly removed from the control of the aristocratic classes. The choice of the natural length standard (be it size of the earth or the length of a second pendulum) and the number base (decimal or duodecimal) were of lesser/no importance to the original implementers of the system. 212.183.128.159 (talk) 09:29, 29 July 2013 (UTC) Striking out text added by a confirmed sockpuppet. Martinvl (talk) 10:06, 29 July 2013 (UTC)

Implementation in Revolutionary France (1792–1812)
It seems to me that it would be good to make the sentence structure match in the numbered list of tasks: all gerunds (measuring, etc.), all infinitives (to measure, etc.), or all simple verbs (measure, etc.). Maybe all gerunds, as in the first three? What do you think? Awien (talk) 12:05, 2 August 2013 (UTC)
 * I have implemented the gerunds option to all five items in the list. Martinvl (talk) 14:24, 2 August 2013 (UTC)

Rose-tinted view?
This article is rather skewed in its presentation of the metric system. Little mention is made of criticism of the system or of the cases where it has been rejected. I think a more neutral POV is required. Credibility gap (talk) 20:42, 28 October 2013 (UTC)


 * Sorry, I don't agree with your theory. The article is about the wider metric system. It starts of with the metrification in France of the units of length, area and volume, and then it goes on to the development of a coherent metric system, including Volts, Amps, etc, and then International System of Units (SI). Your edit moved the France: Mesures usuelles (1812–39) from the Worldwide adoption of the metric system into a new section on "Rejection of the metric system", which I don't think is true. France, and if you read the article, British scientists and engineers continued to develop these metric units of length, area and volume into International System of Units. It is clear that the French wanted to keep the old names, and the article states that the old names were refined in metric units. (For example: Thus the toise was defined as being two metres with six pied making up one toise, twelve pouce making up one pied and twelve lignes making up one pouce. Likewise the livre was defined as being 500 g, each livre comprising sixteen once and each once eight gros and the aune as 120 centimetres.[72]). The French rejected decimal time and so did the rest of the world. The article makes that clear when it refers to the CGS and MKS systems - "s" is for seconds (60 in one minute, 60 minutes in an hour, 24 hours in a day, seven days in a week).


 * I'm make the assumption were are both British, but we may not be and it does not really matter. If we are British, then we would buy most things in metric units: electricity is measured and sold in units of kilowatt.hours (and measured by Volts and Amps - also metric units), B&Q would sell us metric-sized electricity cables, plumbing fittings, timber and tins of paint, wallpaper is metric, bags of sand, gravel and cement are metric. I have milk delivered to the door step it comes in pint bottles, but from the shop its more likely to in plastic bottles or tetrapacks in metric units (0.454 or 1 litre). We can of course buy beer and lager by the glass at the pub and it comes in pint glasses, but in cans its more likely to be metric. Wine and spirits are sold in metric units. Petrol or diesel is sold in litres, but roads are measured in miles and speed limits are in miles per hour. Eggs I think come in half dozens or dozens. Temperature is mostly Celsius, but we prefer to go on holiday when its in the high 70s and low 80s (Fahrenheit). Local English trading standards officers prosecute market traders who sell fruit and veg by the pound and confiscate their imperial scales ("metric martyrs"). Mostly likely I'll buy metric nuts and bolts, but if I'm repairing something old, I might need to use Whitworth threads (BSW), BSF or even BA threads. Those can't be bought at B&Q, but taps and dies can still be bought (I buy them, for a start). My theory is that the UK is a metric country, but the people think that we are not because beer and milk is sold in pints and we use miles and miles per hour on the roads. A metric ton (or tonne) is almost a ton, road vehicles have been metricated. Most scientific measures of energy are in Joules (a metric unit), but there are also Calories (also a metric unit).
 * So what have the British rejected; metric bottles of milk delivered to the door step, but far, far, far more people buy metric containers of milk at the supermarket or the corner shop; metric beer and lager glasses in pubs (but not metric wine glasses and spirits glasses); metric speed limits on roads and metric "mile measures". Everything else in the article, we have in Britain: volts, amps, joules, ohms, farads. We might refer to acres of land, but it is more likely to be hectares of land; and when did you last use Chain (unit)s or rod (unit)s and perches for linear measurement


 * In respect of the UK, the article states: "In 1824 the Weights and Measures Act imposed one standard 'imperial' system of weights and measures on the British Empire.[82] The effect of this act was to standardise existing British units of measure rather than to align them with the metric system. During the next eighty years a number of Parliamentary select committees recommended the adoption of the metric system each with a greater degree of urgency, but Parliament prevaricated. A Select Committee report of 1862 recommended compulsory metrication, but with an "Intermediate permissive phase", Parliament responded in 1864 by legalising metric units only for 'contracts and dealings'.[83] Initially the United Kingdom declined to sign the Treaty of the Metre, but did so in 1883. Meanwhile British scientists and technologists were at the forefront of the metrication movement – it was the British Association for the Advancement of Science that promoted the cgs system of units as a coherent system[1]: 109 and it was the British firm Johnson Matthey that was accepted by the CGPM in 1889 to cast the international prototype metre and kilogram.[84] In 1895 another Parliamentary select committee recommended the compulsory adoption of the metric system after a two-year permissive period, the 1897 Weights and Measures Act legalised the metric units for trade, but did not make them mandatory.[83] A bill to make the metric system compulsory in order to enable British industrial base to fight off the challenge of the nascent German base passed through the House of Lords in 1904, but did not pass in the House of Commons before the next general election was called. Following opposition by the Lancashire cotton industry, a similar bill was defeated in 1907 in the House of Commons by 150 votes to 118.[83] In 1965 Britain commenced an official program of metrication that, as of 2012, had not been completed. The British metrication program signalled the start of metrication programs elsewhere in the Commonwealth, though India had started its program before in 1959, six years before the United Kingdom. South Africa (then not a member of the Commonwealth) set up a Metrication Advisory Board in 1967, New Zealand set up its Metric Advisory Board in 1969, Australia passed the Metric Conversion Act in 1970 and Canada appointed a Metrication Commission in 1971. Metrication in Australia, New Zealand and South Africa was essentially complete within a decade while metrication in India and Canada is not complete. In addition the lakh and crore are still in widespread use in India. Most other Commonwealth countries adopted the metric system during the 1970s.[85]" For the USA, it states: "The United States government acquired copies of the French metre and kilogram for reference purposes in 1805 and 1820 respectively. In 1866 the United States Congress passed a bill making it lawful to use the metric system in the United States. The bill, which was permissive rather than mandatory in nature, defined the metric system in terms of customary units rather than with reference to the international prototype metre and kilogram.[86][87]:10–13 By 1893, the reference standards for customary units had become unreliable. Moreover, the United States, being a signatory of the Metre Convention was in possession of national prototype metres and kilograms that were calibrated against those in use elsewhere in the world. This led to the Mendenhall Order which redefined the customary units by referring to the national metric prototypes, but used the conversion factors of the 1866 act.[87]:16–20 In 1896 a bill that would make the metric system mandatory in the United States was presented to Congress. Of the 29 people who gave evidence before the congressional committee who were considering the bill, 23 were in favour of the bill, but six were against. Four of the six dissenters represented manufacturing interests and the other two the United States Revenue service. The grounds cited were the cost and inconvenience of the change-over. Subsequent bills suffered a similar fate.[79]". Pyrotec (talk) 22:22, 28 October 2013 (UTC)


 * Thanks, but none of that treatise on how metrified(?) the UK is answers my concern that the article is skewed, in fact it has reinforced it. I think we need to cover criticism in adequate detail. Credibility gap (talk) 22:43, 28 October 2013 (UTC)

Mesures usuelles, adoption or rejection?
Mesures usuelles has been given as an example of worldwide adoption of the metric system. It was in fact the opposite. France had adopted the metric system in the 1790s, but as it was so unpopular, Napoleon abolished it again, and introduced instead, a system based on the pre-metrication measures - known as mesures usuelles. I created a new section named "Rejection of the metric system" and moved Mesures usuelles to it, but another editor has reverted my change, with no substantial justification, so far, so I think the content of this section needs to be reviewed for NPOV and accuaracy. Credibility gap (talk) 21:12, 28 October 2013 (UTC)


 * The above user wrote on my talkpage and asked me to respond, but did not wait for me to do so, thereby causing an edit clash with my response. The above editor has clear not read the article and is deliberately introducing distortions and inaccuracy in his claims. The article clearly states: "Napoleon himself ridiculed the metric system, but as an able administrator, recognised the value of a sound basis for a system of measurement", "all government, legal and similar works still had to use the metric system and the metric system continued to be taught at all levels of education", "a new system of measure – the mesure uselles or "customary measures" was introduced for use in small retail businesses" and "The names of many units used during the ancien regime were reintroduced, but were redefined in terms of metric units. Thus the toise was defined as being two metres with six pied making up one toise, twelve pouce making up one pied and twelve lignes making up one pouce. Likewise the livre was defined as being 500 g, each livre comprising sixteen once and each once eight gros and the aune as 120 centimetres.[72]". Small retail businesses were clearing using a metric systems, but merely kept the old names, which had to be adjusted to fit the new units. Pyrotec (talk) 22:35, 28 October 2013 (UTC)


 * I added both sections to this talk page before I posted anything to your talk page. The first section I added (above) is timed 20:42 UTC, the second (this one) is timed 21:12 UTC and my post to your talk page is timed 21:19 UTC. There should not have been a clash.
 * The French introduced the metric system in 1795, not in 1812. It was unpopular, even ignored, from day one. In 1812 the French rejected the deeply unpopular metric system, replacing it with Mesures usuelles. Indeed Ken Alder, in his book "The Measure of all Things" (oft cited in the article) states (p. 275) that "The French were not only the first nation to invent the metric system: they were also the first to reject it". There is a distinction to be made between adoption and rejection, and the two need to be given balanced coverage. Credibility gap (talk) 23:04, 28 October 2013 (UTC)


 * Sorry, I don't agree with your theory. The article is about the wider metric system. It starts of with the metrification in France of the units of length, area and volume, and then it goes on to the development of a coherent metric system, including Volts, Amps, etc, and then International System of Units (SI). Your edit moved the France: Mesures usuelles (1812–39) from the Worldwide adoption of the metric system into a new section on "Rejection of the metric system", which I don't think is true. France, and if you read the article, British scientists and engineers continued to develop these metric units of length, area and volume into International System of Units. It is clear that the French wanted to keep the old names, and the article states that the old names were refined in metric units. (For example: Thus the toise was defined as being two metres with six pied making up one toise, twelve pouce making up one pied and twelve lignes making up one pouce. Likewise the livre was defined as being 500 g, each livre comprising sixteen once and each once eight gros and the aune as 120 centimetres.[72]). The French rejected decimal time and so did the rest of the world. The article makes that clear when it refers to the CGS and MKS systems - "s" is for seconds (60 in one minute, 60 minutes in an hour, 24 hours in a day, seven days in a week).


 * I'm make the assumption were are both British, but we may not be and it does not really matter. If we are British, then we would buy most things in metric units: electricity is measured and sold in units of kilowatt.hours (and measured by Volts and Amps - also metric units), B&Q would sell us metric-sized electricity cables, plumbing fittings, timber and tins of paint, wallpaper is metric, bags of sand, gravel and cement are metric. I have milk delivered to the door step it comes in pint bottles, but from the shop its more likely to in plastic bottles or tetrapacks in metric units (0.454 or 1 litre). We can of course buy beer and lager by the glass at the pub and it comes in pint glasses, but in cans its more likely to be metric. Wine and spirits are sold in metric units. Petrol or diesel is sold in litres, but roads are measured in miles and speed limits are in miles per hour. Eggs I think come in half dozens or dozens. Temperature is mostly Celsius, but we prefer to go on holiday when its in the high 70s and low 80s (Fahrenheit). Local English trading standards officers prosecute market traders who sell fruit and veg by the pound and confiscate their imperial scales ("metric martyrs"). Mostly likely I'll buy metric nuts and bolts, but if I'm repairing something old, I might need to use Whitworth threads (BSW), BSF or even BA threads. Those can't be bought at B&Q, but taps and dies can still be bought (I buy them, for a start). My theory is that the UK is a metric country, but the people think that we are not because beer and milk is sold in pints and we use miles and miles per hour on the roads. A metric ton (or tonne) is almost a ton, road vehicles have been metricated. Most scientific measures of energy are in Joules (a metric unit), but there are also Calories (also a metric unit).
 * So what have the British rejected; metric bottles of milk delivered to the door step, but far, far, far more people buy metric containers of milk at the supermarket or the corner shop; metric beer and lager glasses in pubs (but not metric wine glasses and spirits glasses); metric speed limits on roads and metric "mile measures". Everything else in the article, we have in Britain: volts, amps, joules, ohms, farads. We might refer to acres of land, but it is more likely to be hectares of land; and when did you last use Chain (unit)s or rod (unit)s and perches for linear measurement


 * In respect of the UK, the article states: "In 1824 the Weights and Measures Act imposed one standard 'imperial' system of weights and measures on the British Empire.[82] The effect of this act was to standardise existing British units of measure rather than to align them with the metric system. During the next eighty years a number of Parliamentary select committees recommended the adoption of the metric system each with a greater degree of urgency, but Parliament prevaricated. A Select Committee report of 1862 recommended compulsory metrication, but with an "Intermediate permissive phase", Parliament responded in 1864 by legalising metric units only for 'contracts and dealings'.[83] Initially the United Kingdom declined to sign the Treaty of the Metre, but did so in 1883. Meanwhile British scientists and technologists were at the forefront of the metrication movement – it was the British Association for the Advancement of Science that promoted the cgs system of units as a coherent system[1]: 109 and it was the British firm Johnson Matthey that was accepted by the CGPM in 1889 to cast the international prototype metre and kilogram.[84] In 1895 another Parliamentary select committee recommended the compulsory adoption of the metric system after a two-year permissive period, the 1897 Weights and Measures Act legalised the metric units for trade, but did not make them mandatory.[83] A bill to make the metric system compulsory in order to enable British industrial base to fight off the challenge of the nascent German base passed through the House of Lords in 1904, but did not pass in the House of Commons before the next general election was called. Following opposition by the Lancashire cotton industry, a similar bill was defeated in 1907 in the House of Commons by 150 votes to 118.[83] In 1965 Britain commenced an official program of metrication that, as of 2012, had not been completed. The British metrication program signalled the start of metrication programs elsewhere in the Commonwealth, though India had started its program before in 1959, six years before the United Kingdom. South Africa (then not a member of the Commonwealth) set up a Metrication Advisory Board in 1967, New Zealand set up its Metric Advisory Board in 1969, Australia passed the Metric Conversion Act in 1970 and Canada appointed a Metrication Commission in 1971. Metrication in Australia, New Zealand and South Africa was essentially complete within a decade while metrication in India and Canada is not complete. In addition the lakh and crore are still in widespread use in India. Most other Commonwealth countries adopted the metric system during the 1970s.[85]" For the USA, it states: "The United States government acquired copies of the French metre and kilogram for reference purposes in 1805 and 1820 respectively. In 1866 the United States Congress passed a bill making it lawful to use the metric system in the United States. The bill, which was permissive rather than mandatory in nature, defined the metric system in terms of customary units rather than with reference to the international prototype metre and kilogram.[86][87]:10–13 By 1893, the reference standards for customary units had become unreliable. Moreover, the United States, being a signatory of the Metre Convention was in possession of national prototype metres and kilograms that were calibrated against those in use elsewhere in the world. This led to the Mendenhall Order which redefined the customary units by referring to the national metric prototypes, but used the conversion factors of the 1866 act.[87]:16–20 In 1896 a bill that would make the metric system mandatory in the United States was presented to Congress. Of the 29 people who gave evidence before the congressional committee who were considering the bill, 23 were in favour of the bill, but six were against. Four of the six dissenters represented manufacturing interests and the other two the United States Revenue service. The grounds cited were the cost and inconvenience of the change-over. Subsequent bills suffered a similar fate.[79]". Pyrotec (talk) 22:21, 28 October 2013 (UTC)


 * Did you mean to paste all that here too, as none of it addresses the concern that I raised in this section, or was it a mistake? Credibility gap (talk) 23:09, 28 October 2013 (UTC)
 * You appear to have raised only two concerns: one that I undid your edit without explanation - I have now replied to that. Your second concern relates to NPOV and accuracy and possibly the article is skewed in its presentation, but no detail is given. I have replied to that, giving examples of where the article provides information on countries that have not fully adopted metrication. I've also tried to say here that the article is about more than just metrification of length, area and volume. I would suggest the UK and the USA (two obvious examples) have adopted all or most of the scientific parts of SI units, but there is ambiguity on the full or partial implication of metric units for length, area, volume and weights. It would help if you could state precisely what the problems are. I did not write the article, I assessed it for GA and I asked for certain improvements. I believe that in its current form it has a NPOV and is accurate. You appear to disagree, so I would like clarification of what you disagree with and I'd like supporting evidence (or more precisely statements verifiable back to WP:RS). Pyrotec (talk) 23:35, 28 October 2013 (UTC)


 * I initially raised two unrelated concerns. The first, raised in the section above, is my concern about the balance of the POV in the article. I believe it portrays the system in a rosy light, without due weight being given to criticism of the system. My second concern, raised in this section, is that Mesures usuelles have, mistakenly, been portrayed as an adoption of the metric system, when in fact they are a rejection of it, implemented by Napoleon to replace it after the French population comprehensively spurned it.


 * You initially pasted identical, unnecessarily long, wall-of-text replies to both concerns. Supporting your unreasoned rebuttals with vast copy & pasted tracts from the one-sided text that I was commenting on. Those replies, which failed to address either of my concerns, then went on, again at great length, and supported by streams of text from the article itself, with a commentary about how proactive the UK had been in metricication and how significantly metric it was, and doubting that the UK had rejected metrification, neither of which I had questioned or even mentioned. You then went on with pastings about the other English-speaking countries, again from the one-sided view contained in the article.


 * So neither of my concerns have been adequately addressed yet. As a reminder they basically were:


 * 1. That the article is rather skewed in its presentation of the metric system, with little mention being made of criticism of the system or of the cases where it has been rejected. I think a more neutral POV is required. Examples of criticism and rejection include the French themselves, of whom Alder, in his book cited in the article, says: "The French were not only the first nation to invent the metric system: they were also the first to reject it". According to Warwick Cairns, in his book "About The Size Of It", the Japanese has been trying to metricate since 1924. Cairns also tells of the failed 1961 attempt by South Korea to metrify - noting that they started the process again in 2007. Cairns also mentions that Guyana has made switches every few years since 1981.


 * 2. Why has Mesures usuelles, which was a French rejection, rather than an adoption, of the metric system, been included in the "worldwide adoption of the metric system" section?


 * Please keep your answers succinct, and answer each point separately. Credibility gap (talk) 20:37, 31 October 2013 (UTC)

I don't see anything here that needs to be addressed. You think there are NPOV problems. I happen to disagree. I don't find your argument or your sources persuasive. Ditto for Mesures usuelles. In a different forum, I might be persuaded to point out why you're making a poor argument, but that's not why we're here. If you can convince others, more power to you. Until that happens, I don't think any more needs to be said. Garamond Lethe t c  22:29, 31 October 2013 (UTC)


 * I am afraid that whether you agree or not, the information I provided shows that there are points of view that have not been addressed in the article, so its NPOV is brought into question. This therefore does need addressing. If it is shown that the sources are mistaken or otherwise unreliable, then we may well dismiss them, but not otherwise. Credibility gap (talk) 22:42, 31 October 2013 (UTC)
 * From your comments above you, Credibility gap, you appear not to have read the article in full. There is a distinction between the wider metric system and metric measures of length / volume and weight. Your argument seems to be only about these latter two. So, I'll confine my comments to these points.
 * Firstly, the article states in respect of France, "poorly managed", "Napoleon himself ridiculed the metric system", "...the metric system unpopular". These are don't seems to be rose-coloured statements, so I'd reject any claim of bias. The article states that government, legal and similar works still had to use the metric system. It also states that French public continued to use the old names for units "usual measures" (English translation) but they were redefined and directly related back to metric measures. You've so far produced no evidence that the government stopped using metric units. All you have is that the French people did not like it.
 * Is it the section title Worldwide adoption of the metric system, that you object to? Would a change to, say, Hesitant adoption of metric weights and measures be more to your liking?
 * What article are you reading, it clearly states that the UK did not adopt metric weights and lengths in 1924 and spent the next 84 years prevaricating and "In 1965 Britain commenced an official program of metrication that, as of 2012, had not been completed."? In respect of the the USA its been rejected "The grounds cited were the cost and inconvenience of the change-over. Subsequent bills suffered a similar fate".
 * Secondly, I'd agree that the article does not mention Japan, and the other two countries. Why don't you add them to the current section? Japan is clearly a major world supplier of machine tools and measuring equipment, and in the UK it mostly supplies metric machine tools and measuring equipment, I used to use Mitutoyo (its clearly readily available) equipment so I do find that comment of yours counter-intuitive. I'm content to accept that this section does not discuss Asia, but that point was only brought up indirectly on 31 October. Pyrotec (talk) 12:45, 3 November 2013 (UTC)


 * User:DeFacto won't answer you as User:Credibility gap; that sock's been blocked and the case closed. NebY (talk) 13:22, 3 November 2013 (UTC)
 * Thanks NebY for the update. Pyrotec (talk) 13:51, 3 November 2013 (UTC)
 * In the light of all the comments above, I modified the section title to Adoption of the metric weights and measures, which is perhaps slightly more NPOV; and I removed from the subsection title on France the words Mesures usuelles (1812–39) and added another paragraph to it to cover post-Mesures usuelles. I think that this covers most of the points, with the exception of subtopic "metrication in Asia" which does not not appear to be covered at present in en.wiki. Pyrotec (talk) 14:15, 3 November 2013 (UTC)

Looks reasonable. Thanks for making a cleanup pass. <tt>Garamond Lethe t c </tt> 14:22, 3 November 2013 (UTC)

70, 80, 90
Was there any discussion, in 1793, among the fans of decimalisation about replacing the vigesimal French counting numbers 70, 80 and 90 by septante, octante and nonante? Or would that have been too revolutionary? Ceinturion (talk) 10:15, 9 February 2016 (UTC)

Origion of Metric
The direct origion of the metric was based on Cassini's geographic system, applied to a new angle measure.

Cassini proposed a system using the nautical mile rated at 6000 feet, divided into 1000 toise, etc. The model of the sphere of the earth he used was Bessel's version. The new metric system reformed the angle system, to 400 degrees of 100 minutes of 100 seconds, and the minute of arc becomes the kilometre (which serves the role of the land and sea mile). The principle of creating an angle system, and deriving the length system therefrom is seen also in Essig's "Douze, notre dix future" (Straussburg, 1952), where the angle system is duodecimal, of 144 degrees of 144 minutes of 144 seconds, the kilometre dozenalle being a minute of arc.

The other 'novel' feature was to connect capacity (that is, volume by bulk comparison) with geometric volume. There is however some hundred years history of making this connection. The wine gallon of 1707 was set equal to a cylinder seven inches' diameter and six inches high. This with pi=22/7, gives 231 cu inches, which became a later value retained in the USA.

The metre of 1792 was set to 443.44 Paris lines on the toise of Peru, this is the value from Bessel's ellipsoid used for the survey. The accumulation of errors in the survey resulted in a shorter metre of 443.296 Paris lines on the toise of Peru. The legal standard to 1866, was the Paris quadrant itself, the metre d'Archives is a replica of the legal length. The bar of 1866 in the X-form became the legal international metre from 1867.Wendy.krieger (talk) 11:55, 10 December 2016 (UTC)


 * Friedrich Wilhelm Bessel (1784-1846) had not yet been born at the time of Cassini's survey; his reknown Bessel ellipsoid wasn't published until 1841. Cassini's survey assumed a spherical model for the earth, even though Newton in 1687 had decried that the earth was an oblate spheroid and stated its more approximately correct dimensions. So it was known or suspected in 1792 that Cassini's figure was too big. Méchain and Delambre degraded our knowledge of the earth, because their figure was much farther from the modern one of 443.40 Paris lines than Cassini's earlier one. It didn't take but a few years before their short metre was apparent. Sbalfour (talk) 20:54, 27 December 2017 (UTC)

Stevins "La Disma"
Stevins wrote well after the decimal digits, and well before the decimal point. His main contribution to the debate was to add decimal divisions of the unit. His work was not to introduce the method of digital calculations, or of the decimal point (which appeared in the 17th C).

Fibonacci used a system of added fractions, or continued numerators.

The columns to the right of the unit, were called primes, seconds, thirds, fourths &c, the column-names were indicated by a circled number, either above or following the number. The number we write as 0.00305, was given as 3(3) 5(5), and said as three thirds, five fifths. This system was still understood well into the nineteenth century, when Maxwell proposed the CGS prefixes (BA report, 1873), be the unit prefixed with an ordinal for a part, or suffixed with the cardinal for the multiple. So the quadrant of the earth, at 10^7 metres, is a 'metre-seven', while the unit that Angstrom used for his solar spectrum, was intended to be a 'tenth-metre'.

Sir Isaac Newton in the second volume of the Principa, gives measures to fourths and fifths of sexagesimal, the simple numbering of equal columns to the right by ordinals seems to be well understood, it survives today as the divisions of the degree or hour to minutes and seconds. Wendy.krieger (talk) 12:03, 10 December 2016 (UTC)

Grave
The fabricated explanation that the grave was renamed to kilogram in 1795, because "it resembled the aristocratic German title of the Graf, an alternative name for the title of Count that, like other nobility titles, was inconsistent with the new French Republic notion of equality (égalité)" should be removed from the article, because it is a fabrication, not supported by a reference. In addition, the explanation is unlikely because 'grave' is a common word in French, meaning 'serious', not associated with the rarely used German word 'Graf'. Ceinturion (talk) 19:06, 23 May 2017 (UTC)
 * I agree - it's gone. Not found in source cited. Extraordinary claims need extraordinary sources. This one needs (2) unimpeachable scholarly corroborating sources. Sbalfour (talk) 22:48, 25 December 2017 (UTC)

Article review
I don't think this article was written by metrologists or historians. I think it was scrapped together from historical alphabet soup. It's not bad, actually - it's reasonably coherent, consistently footnoted, and only has two factual errors (that I've found so far). It's just quirky. Sbalfour (talk) 23:26, 25 December 2017 (UTC)
 * Lead: we need to stay tightly focused, and pay careful attention to technical diction and fact checking
 * A whole paragraph is devoted to a relatively inconsequential organization, the CGPM, and short-shrift is given both the CGS and MKS systems, which at base ARE the metric system or systems today and historically.
 * During this period, the metre was redefined in terms of the wavelength of the waves from a particular light source mumble... there's just something nebulous about this statement - 'wavelength of waves'? what other thing could have a wavelength?  'particular light source' is wonderfully uninformative. 'During this period' the last date referred to was 1971, but the meter was redefined in 1960. It's not true any more anyway - it's now defined in terms of the speed of light in a vacuum.
 * In 1960, the CGPM launched the International System of Units (in French the Système international d'unités or SI) [with] ... 22 further units derived from the base units. No, there wasn't. The katal wasn't defined until 1999.  As I recall, there were 6 units defined after the 1960 publication.
 * By the end of the 19th century, four principal variants of the metric system were in use for the measurement of electromagnetic phenomena: ... and one [based] on the metre-kilogram-second system of units (MKS system). Not quite - the MKS system proper was defined by Giorgi in 1901.  The referred to system called the 'International System' used units defined by the Metre convention.
 * Focus and Structure: I have just a bit of trouble divining what really matters from the structure.
 * The article really begins in 1791 and ends in 1960; before that we have History of measurement and after that, we have International system of units. That's the way the encyclopedia works now, when there is a cluster of articles.  Each article needs to maintain a tight focus to avoid duplication and complement other related articles.  Content should be merged into and split out (merged to other articles) accordingly.
 * There are only 4 metric systems leading to the SI: the French system of 1799; the cgs system of Maxwell and Kelvin formalized by the BAAS in 1874; the Metre convention/MKS system of Giorgi in 1901; and the rollout of the SI 1948-1960. These, along with possibly a pre-metric era summary, structure the article, and are its level 2 sections.
 * In section Development of underlying principles, the three Work of  subsections are not at the same "level" as the following subsections by century. Given their small size, they can/should be subordinated as untitled paragraphs under a unifying subsection of the same level as the century ones, such as The early work or Late Renaissance.  Maybe The natural philosophers as they tended to call scientists in the middle ages.
 * There are three level 3 subsections on electrical units, Electrical units, A coherent system, and Naming the units These certainly ought to be brought together.  The latter section probably ought to be relegated to a footnote.
 * Most of the pre-1791 stuff is only tangentially relevant. Section Work of Simon Stevin is just diversionary; it's about another thing. It's highly relevant that Maxwell incorporated decimal divisions and multiples of his units rather than sexigesimal. Considering the length of the article, maybe it should start in 1791 and carefully hew to the four threads enumerated above.  The pre-1791 stuff might be better placed in a generic article on the History of measurement. That'd include everything through the last paragraph of section 18th-century international cooperation.  That title is a misnomer, a diversion of focus: the great themes of history give us the picture of the 18th century - in the penumbra of the moral imperative of the renaissance, it was the Age of Reason and the Time of Revolution.  'Cooperation' falls by the way side.  We need that picture, because it tells us what is expected to happen there.  Lavoisier, the great champion of the metric system, was beheaded (along with King Louis XVI, the only French king ever to suffer such a fate).  France repudiated the metric system. These are acts big and small, of revolution.
 * Adoption of the metric weights and measures: this is essentially Metrication and we have a constellation of articles specifically devoted to that. It is the longest (8 level 3 subsections) and least vital portion of the article. We're dealing with pure vs applied science. This article is about the evolution of the [pure] science; the applied science is about adoption of the metrics.  They are two separate topics, and two separate articles.  This section should be split out forthwith and merged into the Metrication set of articles.
 * The Twentieth Century section title epitomizes the lack of focus: it is two topics. The first half of the 20th century is about the halting displacement of the cgs by the MKS, alongside customary systems like the U.S and British Imperial systems.  The second half after 1948-1960, is about adoption  and evolution of the science.  Hence Chaos and Conformity.  The section should be split forthwith to reflect the topics with which it deals, and the resulting sections given titles that bring those topics into focus.
 * Section Development of a coherent metric system: a rather expansive title; The title implies that this is where we discuss the derivation of coherent units, but there's no mention of them. There's no discussion of the origin and magnitude of the sexagesimal second, only that Gauss used the unit.  This section is basically about the elaboration of units of the old csg system many of which were non-coherent.  This section is not about its subject; the true subject matter, if stated succinctly, which would be the title of the section, would be: 'Chaos of the 1800's except for the Metre Convention, and Giorgi's unifying proposal of the early 20th century'.  That tells us exactly what the section is about.  Nobody was working to develop anything coherent in the 1800's; the beginning of a coherent system didn't start until 1901.  Thissection is an incongruous conjunction of chronologies, and should be dissolved.  Most of it should be merged into the section Development of the underlying principles, since we're still working on defining a unit of time and a unit of illuminence and fighting over electrical units. All text relating to a coherent system should be merged into the section Twentieth century, because that's when it started and continued.
 * The section names James P. Joule but doesn't define joule, the SI derived unit of work or energy??
 * Exposition and style - the article is long-ish and a bit x-rayish, with interspersed tidbits of interest only to history buffs. It's hard to pick them out just to copy them here, rather than edit them out or integrate them on the spot. This'll take a sharp pencil and eagle eyes.
 * Section Development of a coherent metric system, lead says, At the start of the nineteenth century, ... This concept, which enabled thermal, mechanical, electrical and relativistic systems to be interlinked was first formally proposed in 1861: special relativity didn't arrive until 1921. This statement is incongruous.  Let's keep relativity out of the article - focus in the small this time.  Also subsection Time, Work, and Energy, the context is the 19th century, but there's Einstein's $$e=mc^2$$ in the middle, which didn't arrive until the twentieth century, 1922.
 * section Development of underlying principles introduction, Twentieth-century writers such as Bigourdan (France, 1901) and McGreevy (United Kingdom, 1995) credit the French cleric Gabriel Mouton (1670) as the originator of the metric system. Let's stay away from expansive, opionated and possibly controversial statements like this, and credit Moulton with what he did do, which is factual: he defined the standard of length in terms of the earth's meridian circumference.
 * Subsection Electrical units is dense and opaque I'm not even sure I can divine from it the definition of an ampere (for French physicist André-Marie Ampère) which was 1/10th of the cgs unit of electric current, the abampere or biot in the EMU system of electrical units, and was based on the electromotive force of the Daniell cell.
 * section Proposed revision of unit definitions - too many organizations and acronyms
 * section Spain: the last paragraph is the bio of a man, not about metrication of the country. The last two sentences belong under section Convention of the Metre not in this obscure subsection.  Other than that the text of the paragraph is immaterial and can be deleted.
 * section Meridianal definition, the first paragraph about Borda and his views is immaterial and can be deleted
 * The sections Electrical units, A coherent system, and Naming the units are a single topic, a long and heady one - 10 hefty paragraphs. Maybe it could be mostly parceled out to International System of Electrical and Magnetic Units, and given lip service here. It's a matter of balance. Five modest paragraphs (~25 lines) should be more than enough here.
 * The Electrical units section has an associated table with 13 definitions of technical quantities, and 6 quantities used in this section (P, V, I, Q, E, T) are omitted from the table - that makes 19. Then there is the twice-used quantity $$4\pi$$; of course we know its numerical value ~12.6, but conceptually it represents something rather vital, which is nowhere to be found. These should tell us straight up that we've copied out part of a textbook into the article.  The article is not about understanding the electrical units, but describing their history.  The sections needs revision to a more expository style.
 * In the section Twentieth century (and a few from elsewhere), a raster of acronyms [USNO, CIPM, BIPM, CGPM, IEC, A.E.C., BAAS, CIE, IUPAC, IUPAP, CIS, CCU ...] appears. It's daunting and distracting. All these organizations and their acronyms need to be removed to footnotes.  We want to emphasize what was done, not who did it.  The style here should be a flowing narrative, not back-to-back factoids composed gramatically as sentences.
 * In the latter half of section 18th-century international cooperation, there's a lot of tangential people names and associated trivia, like "...Riggs-Miller lost his British Parliamentary seat in the election of 1790". Huh?  Not all these names are equally important, and most can be removed or moved to footnotes.
 * Coverage
 * the unit of time - the sections Decimal time (1793) and Angular measure (c. 1793) are prattle. We don't measure time or arcs in 100ths of anything. They should be deleted from the article.  The unit of time we have today and have always had, is the sexagesimal second, which had its origin in the astronomical observations of the ancient Sumerians and a peculiar modulo 12 counting system where the thumb pointed to each of 4 finger bones in cycles totaling 12, and each cycle was counted on the 5 fingers of the other hand.  The daytime was divided into a cycle of 12 periods marked by division of sunlight and shadow on a dial, and the day and night were two cycles; each period was divided into 60 n'ths, and each n'th into 60 i'ths, seconds.  That's why clockfaces have 60 tickmarks today, a second is a tick, and is 1/86400th of the day.
 * where's the history of the 22 derived units of the SI?
 * there's no coverage of the SI base units candela or second (except Gauss' use of the second); exposition of the mole, a unit with a long history is relegated rather incongruously to a subsection under 20th century.
 * the ampere is covered (section Electrical units) but the penultimate consideration, what conceptually is an ampere, is just not there
 * the cgs system is covered piecemeal; where are the extensive set of common derived units - erg, dyne, gauss, calorie, barye, biot, maxwell, oersted - and that's only about half of them; some of these like the gauss (instead of tesla), are in more widespread use today than their SI counterparts
 * Copyediting
 * Four sections have explicit dates as part of the section heading. Since these sections start out with sentences delimiting the dates of the events, these dates are superfluous and should be deleted
 * science did not understand the concepts of base units and derived units. Bah - science doesn't understand things, humans do. Say something else.
 * lignes, an arcane French unit of length is used several times in the text, footnoted by "All values in lignes are referred to the toise de Pérou, not to the later value in mesures usuelles. 1 toise = 6 pieds; 1 pied = 12 pouces; 1 pouce = 12 lignes; so 864 lignes = 1 toise." which is more arcane French units. That's obfuscating, because nobody knows what those are.  A lignes is ~2.25mm or .09in. That's much more informative, and all the context of the article demands.
 * the metric system... [was] implemented by French Revolutionaries: 'revolutionaries' tend to be men with guns, and they certainly were during the French revolution. The metric system was implemented by men of science, and they probably weren't revolutionaries in the colloquial sense.
 * section Meridianal definition: spelling, people. According to Webster's Third New International Dictionary and the Oxford English Dictionary (British English), the spelling is meridional; neither dictionary lists an alternate spelling of meridianal.  Meridian as in meridian moon is also an adjective and may be the better choice here.
 * when the new revolutionary government captured the idea of the metric system - colorful, just a little too colorful. I think 'captured the idea' means 'warmed up to' in this context; the right word may be: 'adopted', 'enforced', 'imposed', or maybe just 'considered' (or 'reconsidered').
 * Scholarship
 * the degree centigrade - The centigrade, as an angular measure, was adopted for general use in a number of countries, so in 1948 the General Conference on Weights and Measures (CGPM) recommended that the degree centigrade, as used for the measurement of temperature, be renamed the degree Celsius. That's nonsense.  The degree centigrade, it's unit, magnitude and name, were derived from the temperature scales of Swedish astronomer Anders Celsius 1742 and French physicist Jean-Pierre Christin 1743.  From Centi- hundredth, and grade a gradient or gradation (from Latin gradus “a step, pace, position"): a hundreth of the span from the freezing point to the boiling point of water is a degree centigrade, and the scale is the Celsius scale.  It's confounding that this definition of the degree centigrade is in a section about clocks.
 * section Meridianal definition (SIC) says the middle of the quadrant, where the effects of the Earth's oblateness were expected to be the largest. Who says the earth is oblate? (Newton, 1687) Cassini's earlier survey had used a spherical model of the earth; Mechain and Delambre used an ellipsoidal one. I think that's worth elaborating on (see Bessel ellipsoid, though the geodesic model wasn't available until 1841).  The section might acquire an interesting and vital perspective from Ken Alder's "The Measure of All Things: The Seven-year Odyssey and Hidden Error that Transformed the World" Simon & Shuster, 2002 ISBN 9780743216753.  Delambre and Mechain knew their reported meridian data was short; Delambre himself suggested the best value for the metre was 443.35 Paris lines.  It didn't take long before their short meter became apparent. The best recent source may just be "Why does the meter beat the second?" P. Agnoli and G. D'Agostini at https://arxiv.org/pdf/physics/0412078.

Article revision
The Review section above is extensive. What do you do? There are two approaches: top-down and bottom-up.

In the bottom-up approach, we do the small things first: copy-editing, etc, working up from the existing text, until we get to re-organizing whole subsections, sections, etc. The advantage here is that one can stop at any time, and have a stable article. Big changes can be deferred until debated and individual consensus is obtained. This is more of a cooperative or design-by-committee approach.

In the top-down approach, we survey the article, and make a list of topics, taking into account additions and changes as per the Review section, especially the Focus and Structure notes. Large textual changes that are to be split out and become new articles, merged into existing articles, or deleted, are made. The list of topics is ordered chronologically, tiered into major and sub-topics, and the level two sections named and laid out. Then section headings and [missing info] template tags are added for sections which do not have text in the existing article. Then cut/paste text of sections from the existing article to fill the sections of the new article. Then correlate the Review notes with sections, and redraft accordingly. Editors will need to be delegated to write the missing sections. The lead may have to be redrafted, because the scope of the article may (and probably will) have changed. The vision and structure of this approach will probably be that of a single person, a kind of editor-in-chief for the purpose. Once the article is laid out, there's more room for individual contributors.

Focus:
 * Split out most of section Development of underlying principles and merge to History of measurement; condense and retain paragraphs on Wilkins and Moulton; Work of Simon Stevin portion may merge to Decimal system instead
 * Split out section Adoption of the metric system and merge to Metrication
 * Split out most of Twentieth Century (it's post-1960 20th century, mostly) and International System of Units (SI) and merge to International System of Units
 * Split out most of section Electrical units and merge to International System of Electrical and Magnetic Units; leave a condensed narrative-style paagraph or two of this here - some of the text may be acquired from the merge of International system of units#History#The cgs and MKS systems
 * delete or merge sections Angular measure and Decimal time to Astronomy and Clock or elsewhere
 * merge most of International system of units to here

Balancing this, a major new subsection The Derived units of the SI with 22 topics each of at least a few paragraphs divided into several level 3 subsections, will be created. No text currently exists for these, though some can probably be borrowed from individual articles on for example Watt, etc. We also need new level 3 (or possibly level 2) sections for the history of candlepower, sexagesimal second, and degree centigrade.

We also need to consider International system of units, Metric system, Introduction to the metric system and Metrication: what should be where. Sbalfour (talk) 23:18, 27 December 2017 (UTC)

Article coverage
Here's another perspective on what the article should cover, and how much for this or that:

The history here (for now at least) spans 226 years from 1791 (and fragments from earlier) to 2017.


 * Pre-metric system history is ~8 years from 1791-1799, 0.4% of the 226-year span
 * The French metric system existed 75 years from 1799 to the Metre convention 1874, 33% of the span
 * The cgs system existed for 74 years from 1874 through the end of the war, 33% of the span
 * (Georgi's 1901 MKS proposals lay mostly fallow for 47 years until the working paper of the CGPM in 1948)
 * The working paper proposals lasted from 1948-1960, 12 years or 5% of the span
 * The MKS/SI has existed for 57 years from 1960 on, 25% of the span

This article is about the pure science of measurement; the adoption of it, metrication, is about the applied science and is a parallel history mostly post-1960 that's properly the topic of another article.

That could/should give us a perspective on plausible ratios for textual content; true, not all portions of history are equally important or rich in relevant content, but I don't see we need to stray too far from this perspective - there's plenty to say about any 50 year or longer period. We have almost no coverage of the 74 years of the cgs and the familiar cgs units of calorie, dyn, erg, gauss, and about 15 more. If the cgs isn't the metric system, I don't know what it is, and it's all or mostly history now.

Sbalfour (talk) 18:34, 28 December 2017 (UTC)

New lead and a new beginning
Normally, we write the article, then condense increments of each section into a lead. However, when we compose the article (like a college essay) we write an outline, like an abstract, and expand it into the article. That abstract could as well serve as the lead. BUT, when we start from the top down, we're more likely to focus on what matters. When you write, speak with your pen. Here's how:

[proposed lead] or A brief history of the metric system
In the Age of Enlightenment following the Renaissance, natural philosophers defined units of measure in terms of physical phenomena: the length of a pendulum with a "swing" of one second was the proposed unit of length. The second as a fraction of a fraction of the day, they borrowed from astronomical observations of the ancient Sumerians of Mesopotamia, and their sexagesimal (base 60) counting system. One tenth of a unit length - a ratio that would ever after characterize the decimal metric system - cubed, defined a volume, the litre. The weight of that volume of water was the kilogram. A degree of temperature was a centi-grade, a hundredth of the gradient of the temperature range of liquid water, and the Celsius scale in units of it was named for the 18th century Swedish astronomer who devised it. Later, in pre-industrial England to facilitate uniform gaslamp lighting, a law defined the brightness of a then-common whale wax candle as a standard of illumination, a candlepower.

In the French revolution which initiated the Napoleonic Republic, men of science brought order to the chaos which was the French mesures usuelles by defining the metre as a fraction of Earth's circumference, and casting the metre and kilogram in immutable precious metal to provide a durable and accessible standard for the sciences and trades. With these, the first metric system became the law of France at the turn of the century. Thence, Spain, in order to facilitate trade, adopted the French system, and soon thereafter, most of the European community.

But the metre/kilogram units were inconveniently large for the sciences, so grew up another system in the latter half of the nineteenth century, which used a hundredth of the metre - a centimetre - and a thousandth of the kilogram - a gram - along with the sexagesimal second as the units, which was called the centimetre/gram/second or cgs system of units. Many derived units were defined for use in the sciences, such as those for power and energy. That was a time of great advancement in electromagnetism due to the theories of Faraday, Maxwell and others, and necessary units were defined in different ways, so that chaos again rained upon the system of measures.

At the dawn of the industrial era, an ersatz unit of electric current, the ampere, related to the potential of a Daniell voltaic cell and unit resistance of a length of telegraph cable, was defined so that ratios between the various electromagnetic as well as other units were unity. A coherent system of units based on the French artefacts which had since been refashioned in the Treaty of the Metre, along with the second and ampere, came into being, and was the Metre/Kilogram/Second or MKS system of measures. The system lay fallow for half a century, while systems in use were a mixture of customary, like the British Imperial system and U.S common measures, cgs systems in the sciences, and a few MKS systems in international trade.

In mid-century, the international organization responsible for maintaining standards of measurement drafted a new proposal based on the 1901 MKS units, plus degree Kelvin - a degree centigrade of a scale starting at absolute zero - and the nineteenth century candlepower - now renamed the candela - as well as a comprehensive set of 16 derived units of electromagnetism, irradiance, power, energy and others. The system was finalized in 1960, called the International System of Units or SI, and was the birth of the modern metric system. The system was subsequently adopted by most of the industrialized world except the United States.

In the more than half century since the birth of the SI, a seventh base unit, the mole - shorthand for a quantity "molecular weight in grams" long used by chemists to titrate reactions - and six additional derived units have been added to the roster. The base units, except the kilogram, have been defined and redefined in terms of physical constants of nature like the speed of light, which are invariant to a high degree and can be measured with great accuracy. Several relevant constants of nature in addition to the speed of light, have been determined very accurately for this purpose, and may be assigned exact values in the near future. The result will be that the standards of measure so defined provide precision tools for the sciences on both large and small scales, and for industry, trade, and general use.


 * Did the title get your attention? I did say 'speak with your pen'. I wanted your attention. I wrote to get it. Now that you've read it, what do you know about the history of the metric system?  Where did we get our second, candela, kelvin, metre, kilogram, ampere, mole?  Can you answer those questions by reading the original?  It is perfectly clear from the original, that there were exactly 4 metric systems in history?  Organizations don't do science, men do.  Men have names, but it matters less what their names were, and more what they did.  This describes what they did.  Now we know exactly what we're going to write about. Sbalfour (talk) 06:23, 29 December 2017 (UTC)


 * Hmm. It only got my attention by being an incongruous choice.  While it makes your point about writing style, I would not consider Hawking to be a reliable reference.  For example, his description of the origin of the metre seems to be suspect.  —Quondum 12:54, 29 December 2017 (UTC)
 * The link to Hawking was just an attention getter because everyone has seen that title; I don't intend to use him as a reference. Sbalfour (talk) 15:53, 29 December 2017 (UTC)
 * Well, then, are you looking for a critique of the passage as a lead or section in the article? I alluded to an accuracy issue: the pendulum as described seems to have been proposed as a unit of length but rejected as inherently inaccurate, and its closeness to the final metre appears to be nothing more than complete coincidence. It is too long as a lead but with detail that does not belong, even though it its readable tone is fine for a lead.  Despite being very readable with good information for a school kid, it's tone is not encyclopaedic, which makes it awkward (inappropriate?) style for a reference section.  Are you proposing a summary section, of which detail is to be elaborated in subsequent (sub)sections?  —Quondum 18:05, 29 December 2017 (UTC)
 * I think I'm proposing a new lead. My essay is ~150 words (about 7-8 lines, a paragraph) longer then the existing lead which is modest for a rather long article. So I don't think length is a compelling factor here. It could be shortened.  There's logically 6 parts: pre-metric system; French metric system; cgs system; MKS system; SI system; and post-SI.  My essay is 6 paragraphs, and that's exactly how it got to be 6.  Its narrative tone was chosen for the lead; so you are correct, it cannot be a reference section.
 * I'm not so sure we know that the length of a pendulum with half-period of a second defining almost the same meter as 1/10,000,000 of a quadrature of earth's meridian is coincidence. It was, however, how the liter and kilogram got their original magnitudes.  One may speculate why they didn't define the metre to be 1/1,000,000 of the distance between Dunkirk and Barcelona, since that is what they measured. It's actually ~1072 kilometers, so a millionth would have been just a little too much longer than the pendulum length.  They didn't know where the North pole was - they certainly didn't go to look for it. But they did know from Cassini's survey, that a 1/10,000,000 of the quadrature was very close to that pendulum length. The pendulum experiments had been going on in diverse locations for more than a century since Wilkin's proposal - that's why they knew they needed something a little more deterministic.  Yeh, we probably ought to say the meter as a standard of measure has always been a fraction of earth's circumference.
 * What detail do you think we could/should omit from the passage? If shorter is better, then kill two birds, and I'll try editing it in place.  I do espouse, as WP itself suggests, that the lead should be a self-contained mini-article; if one reads nothing but, it should be informative, factual and in some sense 'complete' - the existing lead only tells us where we got the metre and kilogram, not any of the others (it doesn't even name Giorgi's unit as the ampere; someone who doesn't know may assume it was a volt, ohm, gauss, or something else).Sbalfour (talk) 19:27, 29 December 2017 (UTC)
 * To assist our dialog, here's a list of topics most or all of which are mentioned at least peripherally in the proposed lead:


 * 7 base units, origin
 * predecessor units:
 * pendulum unit length
 * litre as cubic decimeter, basis of kilogram
 * candlepower
 * degree centigrade & Celsius scale
 * kilogram and meter artefacts
 * French metric system
 * adoption of French metric system
 * Treaty of the Metre
 * cgs system
 * cgs development/adoption
 * conflict of cgs electrical units
 * decimal ratios, coherency and base/derived unit structure of the metric system
 * MKS system
 * failure of adoption of MKS system
 * CGPM (by role or possibly name)
 * SI predecessor working paper
 * SI system
 * SI adoption except United states
 * post-SI units
 * definition of units by physical constants
 * speed of light is exact, defines metre & kilogram remains a physical artefact


 * There are 28 topics, and only 23 sentences in my whole essay - that's pretty compact. So let's prioritize and chop as necessary.
 * I am confused. Why a lead title? In wikipedia, leads have no title. What was meant by the first sentence "the length of a pendulum with an arc of one second was the metre"? Perhaps "the length of a pendulum with a period of two seconds was the metre", but that would still be problematic. Ceinturion (talk) 14:25, 29 December 2017 (UTC)
 * The title is an artifice because an essay should have a title. It's also a bit of hyperbole, since the essay is about a limited portion of time, that of the metric system, not all of time.  If it becomes the lead of the article, it will not have or need a title. I originally wrote that it was a pendulum with a period of one second, but knew it to be wrong.  Maybe it's a 'swing' of one second, but that's mixing colloquial and technical diction a little too loosely. If it's a period of two seconds, we wonder why a period of one second wasn't chosen. The picture is both trite and vivid: the swinging pendulum of a Svengali, counting one, two, ... and the length of that pendulum is a metre. So what's both proper and elegant diction? Sbalfour (talk)
 * OK, objection well taken - one second of arc is not the same as the arc traversed by a pendulum with a half-period of duration one second. So I've changed it to "swing", and think maybe the sense is better as well. Sbalfour (talk) 17:37, 29 December 2017 (UTC)


 * As a lead, I have some comment. Firstly, it is an essay as you say.  A lead should not be a summary, but rather an overview.  And it should not be an essay.
 * "There's logically 6 parts": No. At least not associated with phases of development of metric systems, as you seem to suggest.  The first paragraph serves a function with respect to the entire topic, not as the first part of a sequence.  The first sentence particularly should have a particular structure.  The second paragraph  of the, minus its first sentence, is very informative: it contains IMO the nub of the development of the modern SI (including the central concepts of base/derived units and coherence and that it covers mechanics and electromagnetics), and we should not lose that.
 * "My essay is ... longer then the existing lead which is modest for a rather long article." I think this way of looking at it is not helpful.  The lead should be as concise as possible consistent with its objects, such as establishing the context, defining the topic, an giving a good sense of what material is covered by the article, but not the detail of that material.  The existing lead is already not concise enough.
 * Your proposed lead seems very much based around the seven base units and their individual histories. This should be about the development as a system of measurement.  Much of the thinking that went into it was around how the system acts together, so this is core.  IMO, there were also some very serious missteps more recently (candela, sievert), for which historical background might be useful.
 * I would start by laying out the structure and its functions, followed by text to fill those functions. I do like the top-down approach, since this should produce a coherent whole.  And I feel guilty that I am only critiquing, rather than copyediting.  But in truth, at the rock face I am best at tweaking detail, and hopelessly inefficient at wordsmithing to meet my own critiques and suggestions.  —Quondum 14:24, 30 December 2017 (UTC)
 * Hmmmm... Your viewpoint is compelling. I have much to reconsider.  The units are a system, with meaningful abstract properties as you emphasize (and I didn't).  In a more granular way, the individual units are meaningful because they relate to familiar physical phenomena in a convenient way.  The metre is a conveniently short/long measure because 1/100 of it is smaller than most objects in trade, and 100 of it is larger than most man-made objects.  A kilogram is a hand-sized heavy object (most such objects are not as dense as platinum, so they're notably somewhat larger).  A 100kg boulder (standard) wouldn't be a very useful object to compare anything against.  So the conceptual and sensory nature of our standards is very compelling in itself.  Why a candle or a mole?  Because they were very useful before they were part of any system.  Why a volt?  It was ~ the output of a voltaic cell (today, 1.56V might be a better base unit).  I think we may want both the system and its constituent units' histories.  If we are mostly interested in the properties of the system, we can read the International system of units article.  Here the essay sits, because I'm trying it out.  It may sit forever.  Sbalfour (talk) 06:41, 31 December 2017 (UTC)
 * I can see that we look at different aspects of the system. In my perception, the questions you consider, such as what magnitudes to assign to individual units, are only worth asking at all once a series of much deeper questions have been answered and principles developed, such as: How to distill metrology to base dimensions?  (There are at most four.)  How to simplify calculation?  (Powers of 10.)  Once these are settled, the choice of unit values is highly constrained, and finding "practical" values is almost an afterthought.  The real history will recount what drove the development if the metric system, which is mostly not about the units themselves.  Broader historical patterns can be observed: the practically driven era up to the 18th and 19th centuries, the insight-driven development of Maxwell's era, and the modern conservativism of the CGPM.  The modern SI is like a young woman coming of age: a rude, undisciplined kid who became a promising but awkward teenager, developing into beautiful young adult – but then you notice that she can't let go of her Linus blanket.  A history that does not build a comprehensive picture, to me, is not history.  Just because the units are the face of the system does not mean that they are the whole story.
 * Why the kilogram and not the gram (and similarly for any other unit)? Coherence may have played a significant role.  Both of these are practical enough, as units of mass, to be considered as a unit.  But what about pressure?  Atmospheric pressure is $1.013 g⋅m−1⋅s−2$ – a numeric value up there with the speed of light.  All the coherent derived units must be considered.
 * With the broader history as a backdrop, one can consider the present, as any historian might. The modern era has brought us unprecedented understanding of how to (nearly) perfect a truly fundamental and universal metrological system, all with measuring sticks that are becoming so precise and reliable that we can distinguish a second in the age of the universe, with an understanding of physics that successfully predicts entire classes of particles and phenomena long before we develop the tools to verify them.  This gives a framework in which one can ponder the gross inconsistencies: why are the four electromechanical dimensions so metrologically well-developed and indeed the basis for the whole SI, while the anthropocentric units candela and sievert are retained but only crudely defined?  And why are their definitions so jarringly different, despite their similarity?  Why are they included, whereas other human-specific sensitivity disciplines are excluded?  A history would be incomplete without some explanation of how this came to be.   —Quondum 13:38, 31 December 2017 (UTC)
 * I actually agree more with you, than with my precis. Giorgi's arguments about the unity of electro-mechanical dimensions goes deep, too deep for dissection in an overview.  Does it matter how many dimensions there were? If there'd been 5, the argument would still be the same.  Candela... monochromatic yellowish-green light doesn't occur in nature, and certainly isn't very useful, no matter where it occurs.  Seeing isn't about watts/area, but about discrimination; the spectrum matters more than the power.  Sievert we should just do away with - what were they thinking?  When we get to considering the vagaries of human flesh, we enter the biological sciences, and leave the physical ones.   I don't think we can cover the electromechanical versus humanist units argument in a overview, either. Becquerel...can we really quantify an effect of the weak nuclear force in sec-1 units?  We're out of history now, and into speculation.
 * You bring up an interesting point about gram/kilogram choice: I previously stated that the cgs system as well as MKS system, was homologous, meaning that the units were on the same "level". An object weighing a kilogram or a few of them would probably have length of most or all of a meter.  It would be less convenient to measure it in centimeters. But things weighing grams, would likely have length dimension in centimeters.  A homologous system isn't necessarily coherent - it has a weaker property, but one worth having.
 * For any article in WP, I like to see the opening sentence say "A foo is a bar, baz, quux." Now we know what we're talking about.  The opening sentence, and all of the opening paragraph of the existing article, is sort of just jumping in.  It says things (facts), rather than talking about concepts.  Now: "The History of the metric system is the history of systems of measurement since the 18th century."  That's trite - it says nothing, but it expresses the right sense.  As you note, the second paragraph is wordy, but not bad.  We don't need to know there were 4 systems and what they were based on; rather more important is why 3 base units weren't enough, and chaos was inevitable until they figured out that one, and exactly one, more was needed.  We might be able to make a summary point for that in an overview.  I'm going to give it a try.  The last two paragraphs of the existing lead are spillage, because one has to ramble on to the end.  And it blunders in stating that the SI in 1960 had 22 derived units. How did all those editors and reviewers let that pass?  I'm not going to fix it, maybe you can.  But I'm thinking bigger now.  If I can get you to buy in, I'm going to replace the lead.  I can do the writing, but we're not there yet. Stay tuned, while I incorporate your presentation into verbiage. Regards, Sbalfour (talk) 18:21, 1 January 2018 (UTC)

Ok, this is overview-like, rather than essay-like, though it's still rather speakeasy in tone. If the "level" is right, the tone is easier to fix. If shorter is better, then this one is better: 28% shorter in words than the existing lead. I've tried to avoid naming things, like people, places, countries, organizations, and even the names of the units except those directly involved in the conceptual evolution of the system. Readers who want the who, what, where, may infer from the overview that those are things reasonably expected to be found in the article. Dates matter greatly in a history article, so there should be no ambiguity concerning timeline - 18th century to present and beyond - or when defining events occurred at least generally, like "late 19th century". (as the lead, it won't need a title). Cheers, Sbalfour (talk) 20:40, 1 January 2018 (UTC)


 * I've tried to restructure it a bit. An organizing principle of the lead is having a clear function for each paragraph, with the first saying what the topic is, so I have separated this from start of the historical account.  The subsequent ones I felt could be what it started with, the emergence of organizing principles, and the latest developments.  It is still not organized fully this way, and I'm not even sure this is the best core idea for each.  —Quondum 03:58, 2 January 2018 (UTC)

Overview of history of the metric system
The history of the metric system is the history of efforts since the Renaissance to quantify useful dimensions of our physical world and to define unit measures of them, to bring the units together as practical systems, and get the systems into general use to facilitate science, industry and trade.

The early units, into the 18th century, were taken from natural phenomena, like the properties of water, the rotation of day and night, and distances upon the earth. For convenience, man-made objects were fashioned to act as references for some of them: metre bars, weights, and clocks.

Advances of science and the demands of commerce during the 19th century and into the early 20th century brought a deeper understanding of the relationships between diverse types of quantity and the need for a more integral and extensible system of units. This led to a small set of units and rules to combine them, with units of length, mass and time describing all "mechanical" quantities, including the derivation of units like acceleration, power and momentum. The development of electromagnetism resulted in new units being defined, but which did not share in the simple relationships of the system of mechanical dimensions. In the late 19th and early 20th centuries, the need for an electromagnetic unit was recognised. Decimalisation and a concept called coherence allowed the derivation of units of any quantity known, all with regularity and with 1 as the only conversion factor.

Adoption of the new system was slowed by the human resistance to change despite its evident advantages, and took over a half century. A body, the Conférence générale des poids et mesures (CGPM), was created and tasked with standardising the system of units, which became known as the International System of Units (SI) in 1960. It has become the dominant system of weights and measures in use today.

In the half century since adoption, defining precise measures without the vagaries of natural phenomena and man-made artefacts has become possible using only invariant relations between dimensions of the physical world, like the speed of light which relates distance and time, to produce units defined with unprecedented precision and reproducibility, which are realised as everyday units such as seconds and kilograms for science, trade, and general use.

Split/merge of the article
The history of the metric system now exists in duplicate, this article and International system of units. That really ought not to happen, and how it happened, was that the article 'History of the metric system' was originally created then merged into the International system of units article as History section(s). Then, the original article was later recreated in place. Bzzzzzttt. So now we need to do it all over again, only in the other direction: merge the original history sections from the SI article here (and delete them there), and split out the SI evolution sections here and merge them into the corresponding sections in the SI article. The evolution of the SI in the modern era isn't quite history yet, and fits better in the article about the SI itself.

The SI really began after the war with the draft proposal of 1948. So any text that mentions a date after the war, which includes everything in the Twentieth century section except the first two subsections, and all later level 2 sections, gets split out. To prepare for that, I've had to snip and paste various bits and pieces around to get that clear dividing line. History, in the big as well as small, needs to be in chronological order and the really big section Twentieth century just wasn't, so it's hard to split as well as to understand the major themes there. It needs structured by events and their causes, the warp and weft of history, not unit names. Until I've made the split, the article will be in significant flux and I may not be able to finish it all in unit time(!) Sbalfour (talk) 20:23, 30 December 2017 (UTC)

Ok, ready to pull the plug. Some of the text is a bit scrappy, and some refs may have gotten misplaced; nits for later. Sbalfour (talk) 00:17, 31 December 2017 (UTC)

Thermodynamics
I'm a bit puzzled by (with edit comment Thermodynamics: Irrelevant to temperature measurement in 19th century, and still irrelevant today). Surely the thermodynamic theory of gases is central to thermometry, and is even built into the proposed redefinition of the kelvin that has been recommended by the CIPM to take effect in 2019? —Quondum 17:20, 31 December 2017 (UTC)
 * The text stuck out in the middle of nowhere underneath the electrical stuff, and I couldn't relate it to other text in the article, even though I knew it would be used to take definition of the Kelvin out of experimental measurement and give it a thermodynamic basis. I'll take another look, and move the text into the redefinition section, or somehow associate it with the Kelvin. How much do we want to speculate about 2019? Sbalfour (talk) 19:13, 1 January 2018 (UTC)
 * OK, restored from whence it came while I think about it. Sbalfour (talk) 19:20, 1 January 2018 (UTC)

Time, work and energy
This section is a hodge-podge. The really important thing here is the BAAS definition of the cgs system 1861-1873. That really ought to be raised to a level 2 section, since lots and lots of subsequent derived units are gated on this. The rest of the section should be split out - the various unrelated quips don't need a section. Sbalfour (talk) 22:15, 1 January 2018 (UTC)

These two subsections don't belong in this level 2 section at all, which starts out with the 1873 establishment of the cgs by the BAAS. These events occurred well before any metric system existed and really belong in the section Development of underlying principles in a new subsection Early 19th century work, though that extends that level 2 section past the 1812 cutoff date of the next level 2 section. The first half of the 19th century had more significant advances in the sciences than almost any other 50 year era, and these two tiny quips are all that's here?? They need to be moved somewhere, or the focus and title of the enclosing section changed, because it's about the cgs and nothing but. Sbalfour (talk) 23:12, 1 January 2018 (UTC)

Electrical units section: electric and magnetic constants
The sidebox "defines" symbols used in some rather arcane equations (though quite commonplace if you're an electronic professional). The electric and magnetic constants ("permittivity of free space" and "permeability of free space"), do I know what those mean? (Of course I do; I'm an electronic technician). However, I have to look them up again, to make sure I understand them in context. Man-in-the-street doesn't have a clue, nor would he have a clue to tell him for example that permittivity of free space is a physical electric constant in farads-per-meter that represents the ability of free space to support electric lines of force. "Electric force" to man-in-the-street is volts, amps or whatever; he doesn't know anything about electric fields, or even have a sufficient idea what 'farad' represents other than he's seen it on that hulking cylinder in his car audio system. The presence of those two terms in a article about history of a mostly non-technical subject is an indictment. The electric constant in everyday life is sorta-kinda related to the dielectric strength of air, 21.1kv/cm: air doesn't conduct electricity very well, and neither does a vacuum - that's why the electric constant is small. The permittivity of iron on the other hand is rather large, as well as its permeability. One still needs to know in a conceptual sense what a farad and henry represent to understand those definitions. Seriously, we could spend a whole article worth of text to convey an adequate enough understanding of what those equations represent to justify keeping them in the article. Are we going to do that? It'd be a really long footnote. Sbalfour (talk) 16:59, 2 January 2018 (UTC)
 * Since this article is about the history, it follows that constants, units, the impact of electromagnetic discoveries, and the various systems (CGS etc.) can be mentioned, as appropriate, but listing them does not need to be comprehensive. However, technical detail and equations do not belong.  Removal seems sensible, as long as both the detail and history of the systems are to be found in appropriate articles.  For example, the distinction (at a technical level) between ESU and EMU must be clear in the associated a technical article.  —Quondum 17:54, 2 January 2018 (UTC)

"Practical" system of units"?
In this section, it says, The unit of length adopted for the practical system was 107 m (approximately the length of the Earth's quadrant), the unit of time was the second and the unit of mass an unnamed unit equal to 10−11 g. What kind of scale can measure 10-11 grams? (remember, this was in the ~1860's. Horse poop on the sidewalks was the biggest "practical" problem.) What kind of measuring stick is 107 m long? Can anything on the order of that long weight only on the order of that much? Some editor wrote that. What was he thinking? Sbalfour (talk) 05:19, 4 January 2018 (UTC)
 * That is actually about the old QES system, which should not be called practical as a whole. Some of its units were practical (its electrical units and energy units), but its units of length and mass were not. The multipliers 107 and 10-11 were due to the search for a coherent system of units that included the practical units, before Giorgi changed $$\mu_0$$. In SI, the force per length between two wires is $$ \frac{F}{x} = \frac {\mu_0}{ 2 \pi} \frac {I_1 I_2 } {r}$$, the energy dissipated in a wire is $$E = I ^2 R t$$, and energy equals work $$E = F L$$. Hence the units of L and M can be derived from the electrical units: $$[L] = [\mu_0]^{-1}[R][t] $$ and $$[M] = [\mu_0]^2[I]^2[R]^{-1}[t]$$. In the old QES $$[\mu_0]$$ was 107 times smaller than in SI, so [L] was 107 m and [M] was 10-14 kg. Ceinturion (talk) 13:37, 4 January 2018 (UTC)
 * (!) Unbelieveable. I would've scratched it out as a misprint.  In order to put that pithy phrase in the encyclopedia, which a rational person like me would dismiss as a misprint or vandalism, one has to provide some kind of justification.  Your equations do just that, though I dread adding that level of math to an historical article.  Math scares readers.  I can read the equation just fine. The issue as I see after a little digging, was that the cgs ohm as defined by existing weighs and measures, was something like 10-10 of an ohm today, and they were measuring tens to hundreds or more of miles of telegraph cable in units of "resistance".  So they wrote a lot of zeros :-(  The QES system (didn't notice that acronym anywhere in the article, or "Quad-Eleventhgram-Second" either), didn't care about length and weight, it was about making a"practical" ohm in terms of mechanical measures.  In units of velocity, how fast is an ohm? Runs fast, go catch it! Thanks, Sbalfour (talk) 16:51, 4 January 2018 (UTC)
 * A related question that might be interesting for the article is why Giorgi's idea resulted in MKS instead of MGS (which would have been elegant, all base units without a prefix). The article currently claims that Giorgi made the practical electrical units such as ampere and ohm coherent with "the three base units in the 1861 BAAS report" (supposedly meaning CGS?) by choosing a new value for $$\mu_0$$. But that is incorrect, it is impossible to make ampere and ohm coherent with CGS. It is only possible for systems with $$[L]^2/[M] = 1~m^2/kg$$ as is easily derived from the two above equations for [L] and [M]. In that case $$[\mu_0] = [L]^{-1}[R][t]$$. For example it is perfectly possible for QES and MKS, as $$[L]^2/[M] = 1$$ for both. It is also possible for [L] = 10 cm and [M] = 10 g. But it is impossible to make ampere and ohm coherent with MGS, as $$[L]^2/[M] = 10^3$$. Ceinturion (talk) 12:28, 7 January 2018 (UTC)

I've renamed the subsection to aid search and bring the system's conventional name into the article. There's more to do here. Four trivial dates are entered in this quaint subsection: 1881, 1889, 1893, 1908; four meetings/congresses are enumerated (first, second and two others), a city name (Chicago), and an organization name, IEC. The IEC is mentioned (7) times in the article, four of them right here, all of them marginal and probably superfluous. The IEC is worth a footnote in the entire history. These would be included in a professional research paper on International system of units, but this is a topical article on a sweeping facet of history spanning four centuries since the Renaissance. The only reason this whole subsection needs mentioned is that the International units' magnitudes were jump-shifted into the SI electrical units in 1948. How about a focus statement like this: "Late in the 19th century, another system of electrical units derived from the EMU and scaled for practical use, particularly telegraphy, was defined; it was later renamed the International system and became the basis of the SI electrical units." Anyone needing detail can follow the link to the relevant article. Here's the criteria for level of detail: anything contributing to the development of the topic in the article, like a particular detail used later, needs elaborated in the subsection. Anything else can be abrogated. Sbalfour (talk) 19:16, 4 January 2018 (UTC)
 * An explanation for the chosen practical units would be nice. The QES subsection might be something like:
 * The CGS units for voltage and resistance, equivalent to 10-8 V and 10-9 Ω in SI units, were too small for practical electricians. Their work was in the range of 1 V to 1 MV, and 1 Ω to 1 GΩ (high resistance values were used to specify the leakage resistance of the gutta percha insulation of 1 mile of undersea telegraph cable).Latimer Clark 1861 The committee of the BAAS therefore defined "practical units" that were decimal multiples or submultiples of the coherent units, and assigned the names volt, ohm, ampere, coulomb and farad to them. These units became more popular than their coherent counterparts. As a curiosity, Maxwell noticed that they would be coherent in combination with a length unit of 107 m, a mass unit of 10-14 kg, and the time unit of 1 s. Nobody used that length unit and mass unit, but the coherent extension of the practical units was sometimes referred to as the QES system. Ceinturion (talk) 00:39, 5 January 2018 (UTC)

lead & CGPM
The third paragraph of the lead is verbose verbiage, oral flatulence. Why don't we just say, "The 1875 Treaty of the Metre resulted in the creation of an international body, the Conférence générale des poids et mesures or CGPM responsible for maintaining weights and measures." Or capture the thrust of history rather than cite facts: "The seminal 1875 Treaty of the Metre resulted in the fashioning and distribution of metre and kilogram artefacts, the standards of the future coherent system that became the SI, and the creation of an international body Conférence générale des poids et mesures or CGPM to oversee systems of weights and measures based on them." Speak with your pen. Sbalfour (talk) 21:50, 4 January 2018 (UTC)
 * I like the first option, because it is slightly easier to read. (A wikilink to CGPM could be added). Ceinturion (talk) 21:23, 5 January 2018 (UTC)
 * Hmmm, I just implemented the second one, because two things really happened as a result of the Treaty of the Metre: the CGPM was born, and we got standards for a new system, which became the MKS and went on to become the SI. Both are fairly important.  Sbalfour (talk) 21:41, 5 January 2018 (UTC)
 * Fine. The second paragraph of the lead needs some improvement too. It seems to say the coherent system was proposed by Maxwell. That should be Gauss. Ceinturion (talk) 12:09, 6 January 2018 (UTC)
 * Hmmmm. Gauss advocated the first integrated system of mechanical units with dimensions mass, length and time; but Maxwell was the first to propose the system have a base unit/derived unit structure, right?  Both are elements of what we call coherency: you can't effectively derive anything until you have a reasonable set of bases.  I need to go back and read my sources carefully, you may be right. Sbalfour (talk) 16:11, 6 January 2018 (UTC)
 * Gauss and Weber invented the concept that all magnetic and electrical units can be derived from the mechanical units (millimetre, gram, and second). Maxwell understood the importance, added the terms coherent, base units and derived units, and made the world accept it.
 * I think the old paragraph "Development of a coherent metric system" was incorrectly renamed to its opposite, "Development of non-coherent metric systems". The important step is that Fourier introduced dimensional analysis in 1822. That is the essence of coherence. Gauss and Weber didn't write any dimensions to their various numerical results arising from their experiments, but from their texts these dimensions can be extracted. The theory of dimensions, as first stated by Fourier, was applied to electromagnetism by Maxwell.Ceinturion (talk) 20:29, 16 January 2018 (UTC)

lead & France
Do we really need to know that France blanched for ~30 years at adopting the metric system? We could just say that by mid-century most of Europe (implicitly including France) had adopted it. Why do we need to know that King Louis XVI had a fall from power, or even that there was a King? The king didn't measure anything. The first paragraph of the lead is not a place for detail. And I don't think the King, government or anyone else actually worked on reforming the old system - they just started over. The sense is wrong too: the first sentence says the metric system arrived, but then the next sentence says they went to work reforming the old one. Does that mean they worked on the old one after they got the new one? Actually, it reads plausibly if we just delete the second sentence about the king getting his head chopped off. Sbalfour (talk) 21:44, 5 January 2018 (UTC)
 * Removing the second sentence is fine. In addition, the word "temporarily" might be removed from the first sentence. The sentence "By 1812 .. France had reverted to units similar to those of their old system .." might be changed into "In 1812 .. France temporarily reverted to a compromise between the metric system and traditional units" Ceinturion (talk) 12:09, 6 January 2018 (UTC)

One more nit: the first sentence (the most important sentence to say what we mean) says: the existing system of measures... had fallen into disrepute. Disrepute has the denotation, 'low esteem', but a connotation of 'morally corrupt'. Think of 'house of ill-repute' (~ 'disrepute'). The old system, through connivance and ignorance, meant some were getting cheated, but the larger issue was that it was impractical for even honest merchants to conduct business with those units. I can think of terms like impractical, infeasible, untenable, unworkable, chaotic, fragmented, unreliable - some or all of which have better denotational semantics. Consider, in contrast, the phrase "the old rutted serpentine road had fallen into disrepute". See, the sense is all wrong: an old rutted road cannot be morally corrupt, and neither can a system of measures. Disrepute is colorful - it jabs us in the hypothalamus - but it's not good NPOV diction. Sbalfour (talk) 18:41, 6 January 2018 (UTC)

first sentence and paragraph of lead
I'm not sure we actually have either of these.

The first sentence should say, "The history of the metric system is about when ."

The rest of the first paragraph should say things like:
 * "It also includes and ."
 * "These things are associated with (or result from) <broader social, cultural, political, etc phenomena>"
 * "<the more important things> are centered on, , <certain characteristic events>".
 * "At the beginning of the period, the situation looked like ...".
 * "At the end of the period, the situation looked like ..."

The rest of the paragraphs can be structured either vertically in chronological order, each covering some period of the history or horizontally in order of importance, each covering some 'thread' or topic spanning the history. Don't mix and match here, that's confusing.

This is supposed to be a GA quality article. I'm having just a bit of a conniption.

Sbalfour (talk) 00:49, 6 January 2018 (UTC)

Here's an example of how to translate about what into writing:

The history of the metric system is the nearly four-hundred year saga since the Renaissance to devise and deploy integrated and extensible systems of measurement for useful natural quantities. The story includes theories of electromagnetism, mechanics, and thermodynamics, actions of standards organizations and governments, and fortuitous events. Science, commerce and useful measures evolved together; revolution and war, and cultural zeitgeist as well as lethargy shaped them. The meaningful events centered around integration of disparate units into rational systems and the realization of standards for them. Over the history, the first intuitive dimensions of mass and length became of convenience and necessity, the current system of electromechanical and human-perceptual dimensions realized as a set of coherent base and derived units.

How much more useful is it to know this, than that the King of France got his head chopped off? It practically wrote itself, according to the structure I elaborated:

The history of the metric system is the nearly four-hundred year saga since the Renaissance to devise and deploy integrated and extensible systems of measurement for useful natural quantities.
 * The story includes theories of electromagnetism, mechanics and thermodynamics, actions of standards organizations and governments, and fortuitous events.
 * Science, commerce and useful measures evolved together; revolution and war, and cultural zeitgeist as well as lethargy shaped them.
 * The meaningful events centered around integration of disparate units into rational systems and the realization of standards for them.
 * Over the history, the first intuitive dimensions of mass and length became of convenience and necessity, the current system of electromechanical and human-perceptual dimensions realized as a set of coherent base and derived units

It says more in 5 sentences than the entire existing lead. There is also a nascent potential replacement for the entire lead in a section Overview of history of the metric system above on the talk page. It needs a more structured opening paragraph; maybe this is it.

Sbalfour (talk) 21:27, 6 January 2018 (UTC)

A summary timeline
Because I'm relatively familiar with the history here, I freehand created a timeline of major events. Covered are the units, systems, organizations (CGPM), and major confluences like Newton's model of the earth used by Mechain and Delambre. It's a judgment model, of course. A second picture of what we might do in the article. It suggests that anything in the timeline not covered in the article, certainly should be. And any level 3 or 4 section in the article that has no corresponding entries in the timeline, we should seriously question whether we need that text. Sbalfour (talk) 06:46, 6 January 2018 (UTC)

Humanism
The first paragraph of the lead says: In the era of humanism, the basic units were taken from the natural world.... Hmmmm... Humanism as a concept originated in the early 19th century, and generally refs to a period in the late Renaissance, which may be taken to end around 1650 with the invention of the clock (though that itself didn't end the renaissance). It usually refers to the period 1400 (or a little earlier) to ~1650. Alchemy and witchcraft still held sway. The early units were defined beginning in 1656 (clocks as measuring instruments, though the second was defined by astronomical observations of the ancients), 1668 (pendulum-meter and liter-kilogram) and 1670 (arcs of the earth). They sort of just miss the age of Humanism and fall into the Age of Enlightenment, which broadly might extend from 1675-1825, and yielded to the age of science. If 'units' obliquely refer to the weight of a liter of water and 1/10,000,000 of the meridian used as the basis of the French artefacts, then the time period falls squarely in the Age of Revolution (18th century). Humanism as a period isn't usually used in the context of the physical sciences, but more generally belongs to the realm of philosophy and sociology.

I'm going to say something different there, maybe: "In the Age of Enlightenment following the Renaissance,...". The Age of Enlightenment is more directly the cradle of scientific thought, and the connotation is better. Sbalfour (talk) 16:06, 7 January 2018 (UTC)

For all people for all time?
The lead says: The metric system was to be, in the words of philosopher and mathematician Condorcet, "for all people for all time". Aaaiieeeeee! Finding a scholarly 18th or early 19th century source for that catchy quote was unusually difficult, because the original was in French. That's not what Condorcet was referring to when he said that; he was referring to the earth as being perfectly spherical and eternal (even though Newton had told us more than 100 years before that the earth was NOT spherical, and exactly what shape it was), so that measuring it would provide a measurement for all people for all time. Condorcet committed suicide in 1794 rather than be captured and executed. Apparently no original document recording those words exists - it's a kind of written oral history - nobody know exactly when it was said or where, or to whom. As a matter of sholarship, I think the statement should be removed until an impeccable source can be found for it. Sbalfour (talk) 02:22, 8 January 2018 (UTC)

18th-century international cooperation
Focus: this article begins in 1792. Everything before that deserves one short subsection, maybe 3-5 paragraphs. This level 3 subsection contains 8 mostly fat paragraphs. The 2nd- and 3rd-to-last very fat (whale blubber) paragraphs uniformly contain statements with verbs like: proposed, examined, argued, considered, etc. This article is about scientific experiments - what men did. These men didn't do any experiments. I think these two paragraphs should be shrunk down to a pithy sentence each, and the 8 fat paragraphs here cut down by 2/3s, to 3-5 modest paragraphs, and the focus should be very tight: the scientific experiments that were conducted, and how their results contributed to the metric system. (Hint, hint): there aren't many experiments here that contributed anything at all. Plenty of things were tried and failed, a hundred more than are listed. We only need the ones that succeeded, and became part of the final product. Sbalfour (talk)

I've substantially reduced and restructured the section. There isn't much that needs to be said here, and I think the section's continued existence as a section is tenuous. Maybe roll it into the 17th century section and call that section something else since it'll span most of two centuries prior to the revolution, not one. Sbalfour (talk) 22:34, 8 January 2018 (UTC)

The opening statement
The article lacked a theme statement, and proper opening paragraph as we recognize. The required semantic structure of that statement is, for an article about foo: "A foo is a bar, baz, quux..." My statement does not conform, strictly. It is three rather speakeasy sentences. I could in fact, combine those three sentences using grammatical devices like semicolon and hyphen, or conjunctives like 'but' and 'and'. It wouldn't be pretty. If we use words like coherent in the lead paragraph, we must define them (more words), because it is expected to be in English that everyone understands. I would use those words in a scholarly paper. The encyclopedia is not a scholarly paper, it is everyman's bible of the world, and everymen speak and read simple sentences. Nor is it so very readable to say, "The history of the metric system is the history of systems of measure...". It conforms to the required semantic structure, but we just said the same thing twice and took a whole lot of column space to do it, and we haven't said what it is yet. Some editor will come along and "fix" the statement, and we may be the poorer for it. The phraseology is a reasoned approach, but it is part of a larger whole, and that whole may be yet more compelling than maintenance of that simple statement. Sbalfour (talk) 17:45, 8 January 2018 (UTC)

The organization of the article
Achtung!

I've been moving bits and pieces around in the timeline; now I'm considering what the timeline itself should be. My gut feeling is, that the timeline of the article should either be by events or eras. The original organization, before I muddied the waters a little, was mix-and-match: one was titled '17th century developments' and another 'Convention of the metre', and still another which was neither an event nor an era, 'Development of the principles'.

The existing organization is 9 major level 2 sections, rather a lot, and its timeline is muddy: the section 'Adoption of metric weights and measures' spans the periods of following sections. My take is that this section belongs in another article. It's sense is broken too, though it makes the timeline more recognizable: the level two section 'Development of non-coherent systems' is sequentially adjacent to the level three section 'A coherent system', but the major section 'Convention of the Metre' is in the middle.

The existing structure reminds me of a cartoon I once saw, about curbside recycling. It might have been a Dan Pizarro (Bizarro) strip. It was captioned something like 'Dumbo's recycling system', and showed three bins labeled Blue stuff, Animal stuff and Round stuff. The problem with major divisions like 'Development of the principles' is that it doesn't give us a clear boundary, either chronologically or ideationally: when is something a 'principle', and when is it something else, like a unit or an experiment, an invention or an event? It certainly seems a principle of the system that we define dimensional units in terms of constants of nature, but when we go to put that into the section 'Development of principles' where it certainly belongs semantically and conceptually, we discover that that section isn't about principles, but something else. A clock isn't a 'principle' but invention of the clock goes into that section; why is that? In an article with a conceptual and chronological span like this one, we need immediately recognizable division into units, and the major section titles to precisely define the boundaries of those units. To be explicitly clear, 'Development of the principles' is about failed or ignored experiments and impractical units and systems, things which did not go on to become part of the metric system. Nothing which became part of the metric system existed before ~1792.

By epistomological age, here's what the article looks like:


 * The post-Roman era (<1350}
 * The Renaissance (1350-1650)
 * The age of enlightenment (1650-1800)
 * The age of science (1800-1900)
 * The industrial age (1900-1950)
 * The modern age (1950-present )

The may be some division of conceptual content between eras, but there's a very clear chronological boundary between events: anything before this date goes there, and anything after it goes here.

Or how about by 'events' marked by definition of a system:


 * Weight and length (French system, Wilkins, etc)
 * Mechanical systems (Gauss)
 * Electrical unit systems (EMU & ESU, International system, etc)
 * The cgs system
 * The MKS system
 * The Practical system and the SI

There's some chronological slip-n-slide between event sections, but it's very clear what the content boundaries of the sections are.

Sbalfour (talk) 00:15, 9 January 2018 (UTC)

Implementation in Revolutionary France
There are 7 voluble paragraphs below the section title which are not in a subsection that tells us what they're about. They read like a section out of a junior high history book. I cannot tell what they are about. What matters here? There's a lot of anecdotal info about culture and history. In a professional paper, the whole section would be in an appendix about French culture and the French revolution to clearly demarcate that it is not part of the general topic of the article.

The (virtual) section is not about much, but it is about a little, what little matters. So I will tell you about the little: it is about the determination of the first two dimensional units of a scientific system of measures, weight and length. If what we write here is not about what the section is about, then we shall not write. Maybe it's all we need to say that these were taken from a volume of water and a fractional arc of the earth. The details, if one wished to draft any, would be in a footnote, because most of the details listed did not go on to become any part of the metric system defined. And we're done. 7 fat paragraphs have become a single sentence. If we wished to give ourselves writer's cramp, we could write three sentences, one on each of the measures and one on the adoption of a decimal radix. The moving finger writes, and having writ, moves on. (Edward Fitzgerald's translation of The Rubáiyát of Omar Khayyam, 1859). Sbalfour (talk) 20:01, 9 January 2018 (UTC)

I've split the section into two, and reduced the content by almost a half, and it needs reduced by at least half again. No experiments leading to the metric system were performed before ~1792, and nothing before that date is worth more than a tip of the hat. Sbalfour (talk) 04:21, 10 January 2018 (UTC)

Submultiple vs fraction?
@Sbalfour: I noticed you are replacing "(decimal) multiples and submultiples" by "(decimal) multiples and fractions". I agree "fractions" may be easier and better for many users of wikipedia. I was wondering, however, why "submultiples" has always (from 1795 on) been preferred by writers and expert organisations like BIPM and NIST. Wikipedia says: ''in some texts, "a is a submultiple of b" has the meaning of "b being an integer multiple of a". This terminology is also used with units.'' Perhaps because 1/3 is a submultiple, whereas 2/3 is not; and 1/10 is a decimal submultiple, whereas 3/10 is not? More likely, because in mathematics fractions may be larger than 1, such as 100/10; and because "decimal fraction" is the notation 0.37 for 37/100. Ceinturion (talk) 20:05, 9 January 2018 (UTC)
 * The encyclopedia is a more colloquial medium than the NISP and BIPM publications, which are for scientific use. 'Submultiples' is a kind of contrieved word which would not ordinarily occur in speech or informal scientific publications like Discover, Scientific American, etc.  It does indeed have a narrower meaning than 'fractions of'.  My wording is not so much deliberative as habitual, a style of writing. If you prefer, I (or you) can adopt the more technical term 'submultiples' for this article.  Sbalfour (talk) 22:49, 9 January 2018 (UTC)
 * I was mainly trying to understand the difference. I think I prefer "submultiple", it is not of great importance. Ceinturion (talk) 00:31, 10 January 2018 (UTC)

Work of Simon Stevin
I was dubious from the moment I saw this section in my first view of the article, because I am familiar with the history here, and do not know his name. Searching among my sources does not reveal his name, either. In addition, there are scholarly sources that document the presence of Arabic numerals and decimal counting systems in Spain as early as 962. By the 1430s, decimal systems in Europe are in wide spread use. The sources cited for this section are topical, and they themselves do not cite sources I can follow up on for their statements about Stevin. I'm going to strike it from the article for scholarship, unless someone can provide a citation to a professional peer-reviewed journal of history or mathematics with a reputation for accuracy to support the section. Sbalfour (talk) 05:47, 10 January 2018 (UTC)
 * You are misrepresenting his contribution, that is including fractions into the decimal notation. So instead of 941 304/1000, he wrote 941(0)3(1)0(2)4(3). For example on this page from his book. That is a significant step in the decimal notation. Ceinturion (talk) 08:16, 10 January 2018 (UTC)
 * It may have been a step in the development of the decimal system, but its relevance to the metric system is tenuous. Much of the point of the decimal and coherent nature of the metric system is to avoid all fractions, including decimal ones, so that for example we don't write .001 metre, but a millimetre. Calculating for example 1/12(=inch) x 5 = 5/12 foot is avoided. A whole facet of the metric notation, that of rationalization based on the Gaussian system of electrical units, fails of mention in the article. Its sole purpose was to eliminate multiplying/dividing by 4pi which appears ubiquitously in Maxwell's equations.  We use multiples as necessary, not fractions in the notation.  When we needed for example portions smaller than 10-12, the notation and prefixes were extended to 10-24 to avoid writing 1/1000 (or .001) picoseconds.
 * My searches through sources for science and history of measurement fail to turn up his name, generally confirming my gut feeling that the association wasn't considered significant. We're on tenuous ground going back to Arabic numerals and rational/irrational numbers, etc as part of the history here.  There's a whole lot of things necessary, science and mathematics in the age of enlightenment and before that were necessary precursors but aren't part of the continuous history of the metric system - if we had a book to write, we'd bring them in also, but we're not that book.  Is there a scholarly peer-reviewed publication that makes the association to Stevin?  This would be a professional periodical, and a credentialed researcher.  It won't have a name like 'Smoot's Ear', and the citation won't be a temporary URL to a Google book preview. Sbalfour (talk) 16:04, 10 January 2018 (UTC)
 * I agree Stevin does not need to be mentioned in this article about the metric system. I just did not agree with your statement that seemed to be generally dismissive of his contribution to the decimal system. Ceinturion (talk) 17:48, 10 January 2018 (UTC)
 * Arrrrgh... I perceived that I did not have consensus to unilaterally remove the subsection on Stevin's work, so I restored it! I rarely do anything to which another editor objects. I'll concede I misread Stevin's role in the decimal system.  I can of course, undo myself, but maybe I'll just leave it for now. A future reorg may see it be incorporated another way. Sbalfour (talk) 22:02, 10 January 2018 (UTC)

Adoption of metric weights and measures
This section is a substantive part of the article Metrication. In fact, it is so complementary to that article, that it drops right in, as if it had been clipped out of that article and brought here. I hope that's not the case. I do think that we ought to keep some part of the early metrication of France as part of this article, because what happened there is so indicative of cultural antipathy to adoption of the system generally that it's necessary to appreciate that as part of understanding the history generally. So I'm going to pick up that whole level 2 section and move it to the Metrication article, then summarize the Metrication of France as part of the Implementation in Revolutionary France section. This article ought to also have a main article hatnote somewhere directing readers to the Metrication article for info on adoption of the metric system. Given the existing structure of the encyclopedia, this division represents objectively, where that information is expected to be found. Sbalfour (talk) 17:48, 12 January 2018 (UTC)
 * Done. Sbalfour (talk) 22:22, 12 January 2018 (UTC)

Pre-1791 history
A parallel history of the metric systems exists in article International system of units. Its summary of everything prior to 1791 is in two sentences (though it has a paragraph on the Centigrade scale that is not covered here): The metric system was developed from 1791 onwards by a committee of the French Academy of Sciences, commissioned to create a unified and rational system of measures. The group, which included preeminent French men of science used the same principles for relating length, volume, and mass that had been proposed by the English clergyman John Wilkins in 1668[36][37] and the concept of using the Earth's meridian as the basis of the definition of length, originally proposed in 1670 by the French abbot Mouton. Pretty pithy summary. That section has a good focus on what the history is - it begins in 1791, and ends in 1960. It's a pretty significant history, though not so detailed as this one, and the largest part of that article. Here there's a 2000 word essay before one gets to the history itself, and that's a chore. There's a lot of detail here, like the locations of 6 pendulum measurements, when no pendulum length ever became part of the metric system. The details more properly belong in an article/section History of science or History of measurement if or when those articles/sections exist (and they certainly will). The whole section Age of enlightenment is more directly about the history of timekeeping: all those pendulums weren't scientific instruments, they were clocks. The pendulums of the clocks had to be adjusted so the clocks would keep time when transported, such as aboard ship.

I think all that's needed here is an overview of the scientific ideas and cultural forces that caused the metric system to come into being at the time and place it did and influenced the initial form it took. We never mention perhaps the most important event of all: Christian Huygen's invention of the pendulum clock in 1656 that could keep accurate time to the second, and whose characteristic pendulum length could be used as an easily replicable unit of length because everyone had a clock! Moulton himself said it was too hard to measure the earth, so we needed instead, a realizable representation of it, and that was a pendulum with fixed period. When the scientists of the French Academy came to their senses, they too realized that though their measurements of the meridian were in error, what mattered was that they had a realizable unit for the metre, not how big the earth was.

The writing of this section would be summary style; footnotes could supply details like the name of Newton's treatise in 1687, and links to articles like the one on Wilkin's book. The length would be somewhere between 2 sentences and 2000 words, maybe a few paragraphs worth. Sbalfour (talk) 22:19, 12 January 2018 (UTC)


 * I think that the "pithy summary" gives undue weight to the unrelated work of Wilkins, It reads as though the French knew about it or took it as a basis for the development of the metric system - I haven't seen evidence that they did. If we are to keep mention of his work in the article it certainly needs peer-reviewed academically reliable sources to support the notion that it was in any way influential or even relevant. -- DeFacto (talk). 23:02, 12 January 2018 (UTC)
 * Hmmmm... I agree there's an uncomfortable juxtaposition of Wilkin's, Mouton's and the French Academy's work there, and need a source that makes a connection Obviously, the pithy summary isn't all we would like to say, but it's all that was said.  Wilkin's work lay unused and possibly unknown for 120 years, and was buried obscurely in a philosophical essay on language.  The French Academy worked with pendulums extensively, because pendulum clocks were everywhere at that time.  Would you care to review a proposal for me?  Here's the link.  Of course, I do not say Wilkins or Moutons ideas were the basis of the French system. Sbalfour (talk) 00:22, 13 January 2018 (UTC)
 * I have read through the proposal you asked me to look at above, and have a few comments about it. But firstly I must say that I think it is beautifully written and very easy to read.
 * As I understand it, the measuring of the arc from Dunkirk to Barcelona wasn't really an experiment but more a practical application of an established surveying technique known as triangulation. And although the measuring project commenced in 1792, it wasn't finished until seven years later. I'm not sure that there were any specific advances in science or mathematics that were a prerequisite for the development of the metric system, but more that by giving themselves a clean sheet, they were able to design an idealistic system from scratch. It was a triumph of logical thinking, and could have worked similarly regardless of whether it was decimal based and regardless of the base length chosen to root it all in.
 * -- DeFacto (talk). 17:41, 14 January 2018 (UTC)
 * Thank you very much for your time and comment. A survey used triangulation, I know.  But I would call it an experiment because they did not accept Cassini's survey of the meridian in 1718 or Picard's survey of 1669 as 'good enough', just as I may not accept that a lightbulb labeled 60W is a 'good enough' measure.  So I go to the laboratory with it, and conduct a careful experiment to measure it.  The methodology for doing so is well established.  So they likewise conducted an experiment with established methodology, whose results they could not know ahead of time.  Well, as we now know, they were in error: Cassini's result was better.  Distinguish theoretical science: theory tells us what the result should be, or we calculate it. If we do not know how the result should come out because theory does not tell us, then we must conduct an experiment to find it.  If the men of the French academy had available to them the Bessel-ellipsoid model of the earth, with Cassini's measurements, they could have calculated a quite accurate estimate of the quadrature, i.e. theoretical science, and not need to conduct an experimental measurement. I elsewhere emphasize that measurement is an experimental science, and the history should follow what men did, rather than what they thought, examined, proposed, etc except as those things led to experiments that resulted in units or systems that became the metric system.


 * I do think that advances in cartography in the late 17th and through the 18 centuries were instrumental in the final definition of the metric system, and that pendulums were a diversion from it. No unit of measure was ever based on a pendulum. The article has the wrong emphasis - it needn't mention pendulums at all, except in passing. Sbalfour (talk) 21:38, 14 January 2018 (UTC)

Wilkins and the causal timeline of the metric system
Wilkin's work is not in the causal timeline of the metric system. What I mean by that is that if Wilkin's work had never been done (or never used or discovered, which appears to be the case), the metric system would be no different today. His work was unknown by his contemporaries in England, and there is no good evidence that it was known to the scientists of the French Academy in 1790.

Mouton's work possibly was, because he was a Frenchman, but it was 120 years before. It would be as we were to reach back to something done in 1897 to use it as part of a scientific experiment today. In the 18th century, cartography was a prominent undertaking for governance, navigation, and commerce. There were great surveys of the earth and France in 1669/70 by Picard and Cassini, and in 1718, 1744 and 1786 by a line of fathers and sons who were Cassini's. Cassini IV was on the committee that designed the metric system. He was an astronomer and surveyor - of course they were going to survey the earth. Before they did, they had the meridional survey of 1718 to use as the provisional basis of the metre. For a professional astronomer (i.e. astronomical surveyor), surveying the earth was a godsend; using it to fix the metre was secondary. There was a lot of water under the bridge since the ideas of Mouton.

When we write a history of scientific thought or philosophy, regardless of when it was discovered, we place that thought in the historical timeline of occurrence because it is a reflection of the times. But when we write of historical events, we place only those events in the timeline that were causally related to it, i.e. those that contributed to the final result. It's not always the case for historical writing generally, but science is about causality, so we write its history that way. By giving the work of Wilkins and Mouton each a level 3 topic section, we have written revisionist history, a kind of original research: we mark these events as essential stepping stones on the way to the metric system. Scholarly sources do not make a causal connection, only an incidental one. Mouton's proposals are worth a sidebar, a kind of 'Did you know ...?'. Wilkin's work is a footnote at best.

The metric system began spiritually in the Renaissance, and intellectually late in the Age of Revolution. It began functionally some time after 850A.D. with the disintegration of the Carolingian system. France lived with that system for nearly 1000 years; what caused it to change suddenly? That is one continuous snowballing continuum, and nothing is mentioned of it, or almost nothing except this paragraph. The warp and weft of history prior to 1790 is contained in three paragraphs: that one, the first paragraph of Late 18th-century: conflict and lassitude and the first paragraph of Preamble. Specific events like Newton's gravitational model of the earth play incidental roles (ultimately that is what invalidated the pendulum approach to measurement of length). The most important part is missing: the cultural, intellectual and spiritual environment of pre-revolutionary France. That's what changed. We have some of the backdrop, but none of the thrust. It's s lot easier to write a few factoids about Mouton than to write an interpretive narrative of France at that seminal time. That narrative would be justified, and it could be the largest level 2 or 3 section of the article. It is the place in history that matters most, and it roughly spans the reign of Louis XVI, maybe a little before. It's not about events, but about forces. So we don't mention that the king got his head chopped off. It's more important that Lavoisier got his head chopped off, but that's just morbid vicariousness.

One more note: the pendulum experiments in the time of Newton weren't about determining a standard of length; they were about the accuracy of clocks, which did not keep time when transported, particularly at sea. They culminated in the invention of the first accurate maritime chronometer by John Harrison in the 1730's. The standard of length had been since 1668 a graduated iron bar, the Toise du Châtelet (about 1.949m) in Paris, mortised into the wall at the foot of the great staircase therein and it was used as the metre (unit of length) of the meridional survey in 1792. They had known for more than a century that pendulum clocks were local to latitude. They chose the 45th parallel north which was midway between the pole and the equator, therefore an ascertainable place anywhere on the globe, as the defining latitude for pendulum length. It conveniently passed through southern France. But there was still the problem of determining how accurately the clock kept time before measuring its pendulum, and the available methods, solar (sundial) and sidereal (by astronomical triangulation) time were laborious and not so accurate as to interpolate in seconds. So the surveyed metre became the standard.

Sbalfour (talk) 18:53, 13 January 2018 (UTC)


 * There is evidence that Mouton was known to the scientists who made the metric system, because the prefixes deci, centi and milli were borrowed from Mouton. Ceinturion (talk) 01:29, 14 January 2018 (UTC)
 * Another point about the prefixes: the article currently says 'Decimal multiples of these units were defined by Greek prefixes: "myria-" .. and submultiples were defined by the Latin prefixes "deci-" ..', but the prefixes were neologisms, so 'Greek prefixes' should be replaced by 'prefixes derived from Greek', and 'Latin' prefixes by 'prefixes derived from Latin'. Prieur, who was an important force behind the adoption of the metric system, wrote in 1795 for example: 'kilo derives from kilioi, or rather chilioi, which represents thousand or a thousand times. The etymological root might have been better preserved by kilio or killi instead of kilo, but it would have resulted in less consonant syllables, or could be subject to silly wordplay; therefore kilo was preferred, which has no misunderstanding.' Ceinturion (talk) 11:30, 14 January 2018 (UTC)

Meridional survey
It's a rather pithy section, and perhaps captures the the gist of it, but I don't know anything about surveying. I don't know why it makes sense to measure only 1000 kilometers of the meridian when it is 10 million meters or 10,000 kilometers long. They must've at sometime had to go to Barcelona and Dunkirk, but what did they do there? There's the phrase "After the two surveyors met,..." Was this before they started or after they finished? Since the 2-toise long rods were prominently mentioned, we don't suppose that these were faithfully placed end-to-end across all of France and Spain to obtain the result? I know that it's an article about history, but the meaning of what they did there is lost without some kind of elaboration of the art of surveying. The most enduring and recognizable unit on all of earth, a meter or meter stick, was created there, and we don't know how it was done. Either in the text itself or in a sidebar, should be some science. Sbalfour (talk) 15:48, 14 January 2018 (UTC) I propose the following (surveyers among the editors can correct this): <div style="float:right; padding:1em; margin:0 0 0 1em; width:500px; border:1px solid; background:#faf3ee;">  The surveyer's science 

A survey of earth's meridian, that is, a great circle on the surface of the earth that passes through the poles, such as was done in the 18th century, was conducted in five parts. The dimension of interest was a quadrature of the meridian from the north pole to the equator passing through Paris, a distance which was known to be about 10 million meters in today's units.

First was demarcation of a precise point which defines the meridian to be measured, since only one great circle passes through any point. It was known at that time that the earth did not have perfect axial symmetry, so that selection of a meridian would affect the final result.

Second was establishment and measurement of baselines (there were two, for the northern and southern portions of the survey) in units of some standard, which was taken to be the existing toise of Paris. The baselines were two substantial subarcs of the meridian. They became the effective base units of length for the whole meridian.

Third was triangulation, the demarcation on the surface of the earth of vertices of great triangles with shared edges of known measure in ratios relative to the baseline. The first such known edge was the baseline itself. By means of angles subtended by edges of known measure, adjacent edges which were subarcs laying on the meridian became of known measure by the relations of trigonometry. A contiguous set of such subarcs constituted the distance to be measured..

Fourth was ascertainment of the latitudes of the endpoints of the measured distance by astronomical triangulation such as that done aboard ship for navigation.

Fifth was a calculation in several parts:
 * summation of the subarcs of the meridian in known ratios to the baseline, so that the entire measured distance becomes known as a ratio to the baseline
 * based on the latitudes of its endpoints as known positions of arc, obtain the measured distance as a fractional part of the quadrature of the meridian. From this obtain the quadrature in terms of a ratio to the baseline length. For this, since the shape of the earth was known to be an oblate spheroid, but the mathematical properties of that shape based on gravitation were not yet known, an approximation based on the declination of the earth's surface also measured in the survey was used.
 * using standard units in which the baseline was measured, obtain the quadrature of the meridian in terms of the standard units
 * divide the quadrature in standard units by 10,000,000 to obtain the dimension of the metre in terms of the standard; the result was an odd fraction of a toise, hence was converted to subunits of Paris lines (864 to the toise), and reported as 443.296 Paris lines to the metre.