Talk:Chain (unit)

Untitled

The page shows a side box with 11.821 mile/chain. It's easy to show consistency with the rest of the article: 80 chain/mile and 5280'/mile = 66'/chain x 80 chain/mile = 16.5'/rod x 4 rod/chain x 80 chain/mile, etc. Or, 1 mile/80 chain = 0.0125 mile/chain. --KCK 21:33, 15 August 2006 (UTC)

Merge Gunter's Measurement?

This article contains almost the complete contents of the Gunter's measurement article and perhaps these articles should be merged, and a redirect placed from Gunter's. 148.63.234.151 08:26, 22 August 2006 (UTC)

My opinion is that a person that has found this unit somewhere and just to know what it is and what it is equivalent to, should have a quick way to do that, without the need to read (and know) all of the history of the Gunter's measurement and without the need to know the whole system. So a page named chain (or chain (unit)) make sense to me.

Moreover if a redirect should be place, it would better if it redirect to a section named Chain rather than to the whole article Gunter's measurement. So it would be better that such a section exists first. -- AnyFile 07:43, 19 July 2007 (UTC)

I think both of the above comments are right, but on balance I think Gunter deserves the credit for inventing the surveying device, which led on to the unit of measurement.

I've enhanced this page with the units of measurement discussion, and I have created a Gunter's chain page and transferred all the surveying stuff to that.

I'm still worried that the North American and Australian stuff remaining on this page looks anecdotal and non-authoritative; if any editors can improve those sections it would be very helpful.

Afterbrunel 10:40, 18 August 2007 (UTC)

Side box error:

In the side box headed 1 chain =, under Imperial units, is the equivalence 1 chain = 12.5x10^-3 miles. That figure should be 12.5x10^-2 miles, or 125x10^-3 miles, which is 0.125 miles, which is one-eighth of a mile.64.193.92.84 00:54, 18 August 2007 (UTC)

Are you sure? A chain is 1/80 mile, so it is 0.0125 miles. Afterbrunel 10:44, 18 August 2007 (UTC)

Another side box error: it says that one chain is 22.0000 yards or 66.0001 ft. Where did this 0.0001 come from? Metric conversion? I'm changing this to 66.0000 ft, as a yard is exactly 3 feet. Lieutenant pepper (talk) 21:22, 6 August 2012 (UTC)

Never mind. It looks like that is because those not meter units are auto calculated(?). That's pretty cool. Lieutenant pepper (talk) 21:24, 6 August 2012 (UTC)

The conversion factor in the infobox was bogus. Fixed now, thanks. Hqb (talk) 07:18, 7 August 2012 (UTC)

Hqb you gave me a good laugh. Maybe there's a big conspiracy out there!  ;-) Surveyor792 (talk) 06:10, 29 September 2013 (UTC)

Fair use rationale for Image:Sectional appendix chains.gif

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BetacommandBot 04:55, 16 September 2007 (UTC)

Fair use rationale for Image:Sectional appendix chains.gif

Image:Sectional appendix chains.gif is being used on this article. I notice the image page specifies that the image is being used under fair use but there is no explanation or rationale as to why its use in this Wikipedia article constitutes fair use. In addition to the boilerplate fair use template, you must also write out on the image description page a specific explanation or rationale for why using this image in each article is consistent with fair use.

Please go to the image description page and edit it to include a fair use rationale. Using one of the templates at Wikipedia:Fair use rationale guideline is an easy way to insure that your image is in compliance with Wikipedia policy, but remember that you must complete the template. Do not simply insert a blank template on an image page.

If there is other fair use media, consider checking that you have specified the fair use rationale on the other images used on this page. Note that any fair use images uploaded after 4 May, 2006, and lacking such an explanation will be deleted one week after they have been uploaded, as described on criteria for speedy deletion. If you have any questions please ask them at the Media copyright questions page. Thank you.

BetacommandBot 20:31, 23 October 2007 (UTC)

Usage in India

I think it is very much in use in India. All land measurements/survey for commercial purposes are done using the Chain. India is hugely influenced by Britain in this and a lot of other things. And we stick to our traditions. 59.180.161.253 (talk) 17:17, 8 January 2008 (UTC)

Removed Non-Factual Claim

Removed/Edit: "It is important to remember that the miles and chains are used to identify locations, not as an actual measurement of distance." This claim has no citation and is, in any event not-factual. Certainly not as entered in any event. Chainage can be seen marked with spray paint on many structures such as platforms which confirms that there is no active intermingling of metric with Miles/Chainage. Example. Down platform, Mansfield, Nottingham. Recently spray painted chainage intervals in bright pink every 22 yds. Avoiding trespass one should be able to mark off 22 paces along these marks. Locations will continue to be marked in M/Ch but the fact that this is a measure of distance has passed over the head of the original editor. Relay locations (locs), AHB, AOCL, CCTV, Tunnels or other crossing, other equipment are referred to by M/Ch and there has been a rolling program of clearly identifying the same across the UK which anyone can check. Mileage/quarter marker posts are retained usually on the "up" side, which provide benchamark offsets to chainage. If reinstated it needs proof/citation. — Preceding unsigned comment added by 86.3.101.212 (talk) 21:42, 14 October 2008 (UTC)

Chain - Furlong - Acre

I remember from some research I did years ago (unfortnately I have lost the references) that the acre was the amount of field that a plough team could expect to do in a day. It was a furlong long and 1 chain wide. Does anyone know it this is supported by the size of medieval strip fields? Dave Catlin (talk) 08:50, 30 May 2009 (UTC)

Some railway details removed

The following details about British railways was removed, as it is not relevant to article on chains. It might fit under miles or an article on railroads.

there have been instances of using miles and yards (on the former London Midland Region of British Railways) and more recently kilometres and metres. Northern Ireland Railways uses a system of miles and metres.

Railways were required originally to set posts at quarter mile intervals indicating the route mileage, and the mile and quarter mile posts can still be seen.

The company shall cause the length of the railway to be measured, and milestones, posts, or other conspicuous objects to be set up and maintained along the whole line thereof, at the distance of one quarter of a mile from each other, with numbers or marks inscribed thereon denoting such distances.

75.150.168.6 (talk) 16:51, 18 June 2009 (UTC)

References

Need evidence of the "symbol" usage

I removed the claim that the "symbol" for chain is 'ch' from the first sentence of the lead: see Wikipedia:Wikipedia_Signpost/2017-06-09/Op-ed on excess parenthetical detail in the lead. But I know of no evidence that this would even be correct: it is true that SI units have "symbols", which are explicitly not "abbreviations", so that by way of simple example, in Italian chilometro would have to be abbreviated without a 'k', but Italian uses the SI symbol like everyone else. However, I do not think there is any body, in the UK or anywhere else, laying down specifications for "symbols" for historical units. Chains were commonly abbreviated 'ch', but I bet 'chn' and other possibilities also occurred from time to time. So I think the infobox should also be changed. But anyway, this is a classic example of something which merely clutters up the first sentence. Imaginatorium (talk) 16:03, 16 July 2017 (UTC)

This is a good reason to remove it from the infobox (which I have done). If anyone finds a source, of course it can be re-inserted. We should not be synthesizing information by inference from an assumption that the SI pattern holds for non-SI units. —Quondum 16:53, 16 July 2017 (UTC)

The photo on the right was added with an edit summary "image of usage": this is evidence that "chain" may be abbreviated "ch", but we knew that already. A "symbol" is something different: normally part of an ISO standard, and specifically not an abbreviation but a sequence of one or more letters; this is not evidence that ISO claims 'ch' to be the symbol. (This is a subtle but real distinction, like the distinction between "use" and "usage", not to mention "abusage"). Imaginatorium (talk) 18:03, 23 July 2018 (UTC)

history/origin

The chain was already the surveyor's unit of measurement in the 9th century AD - Winchester, Oxford and other Saxon towns were laid out using it.Vince Calegon 11:20, 11 December 2017 (UTC) — Preceding unsigned comment added by Vince Calegon (talk • contribs)

Why is there a decimal remainder chain/link

The article says that there are 100 link in a chain, yet the chain is defined as having 100.084 links - not 100 exactly. Why not? Surely this article should explain? --88.97.11.54 (talk) 12:32, 29 January 2018 (UTC)

This is an obvious spoof so I have deleted it. By definition there are exactly 100 links in a chain. --88.97.11.54 (talk) 15:12, 29 January 2018 (UTC)

Forestry tools and equipment

I think the "Forestry tools and equipment" shortcut box at the lower part of the article does not belong here. 2A02:8084:9842:4000:85D8:1FDF:DF4C:8B3A (talk) 07:48, 19 June 2018 (UTC)

According to the "Instrument" section of the article, it does. It seems that an actual chain is used in US forestry work, therefore it is a tool or piece of equipment. Akld guy (talk) 08:56, 19 June 2018 (UTC)

Attempt to clean up the lede and the article

A lot of discussion has taken place on Wikipedia talk:WikiProject UK Railways on chainage, and this article does need to be more robust.--ClemRutter (talk) 10:48, 21 July 2018 (UTC)

I made a good faith attempt to improve the article, but all my changes were reverted. My main point was that the chain is an ambiguous unit, and it is a blatant mis-representation to pretend otherwise. I propose my edits be re-instated. Dondervogel 2 (talk) 11:27, 21 July 2018 (UTC)

@Dondervogel 2: - suggest you take on board the reasons that you were reverted. WP:V is policy, and as such, the reversion is justifiable although your editing was in good faith. Mjroots (talk) 12:22, 21 July 2018 (UTC)

@Mjroots: OK. The reverting edit summary reads "Please discuss your changes, some of which are unsourced - the only new source that you have provided was published in India, and is likely to describe Indian practice"

• if just one of multiple edits was unsourced, the solution is either to request a citation or (at most) to revert the offending edit, but never to revert all edits
• being published in India is a stoopid reason to object to an English language source.

Dondervogel 2 (talk) 12:35, 21 July 2018 (UTC)

I think it only fair that Redrose64 is given the opportunity to comment. Mjroots (talk) 12:37, 21 July 2018 (UTC)

Meanwhile i have undone that reversion because otherwise .us, .ca, .au etc sources are to be ignored. There may well be good reasons to challenge Dondervogel 2's edit but this one is not reasonable. [For example, the surveying chain in India is just that - a surveying chain]. --John Maynard Friedman (talk) 14:43, 21 July 2018 (UTC)

I have revised the lead to distinguish between the practice of surveying using a fixed length chain and the statute measure [which is the primary topic of the article]. --John Maynard Friedman (talk) 14:59, 21 July 2018 (UTC)

Dongervogel's direction is clearly the right one, just needs some additional sources.  — SMcCandlish ☏ ¢ 😼  06:58, 23 July 2018 (UTC)

Definition

The definition section needs changing again, it has become confused between surveying chains and the "standard chain" as a unit of measure. IMO, it should only be about the latter. I suspect that where we have come unstuck is that surveying chain redirects to Guntner's Chain buwhereas it should stand on its own. --John Maynard Friedman (talk) 16:16, 21 July 2018 (UTC)

I don't understand the distinction you are making between a surveying chain and any other kind of chain. For example, Rowlett does not make this distinction, defining "chain" as "a unit of distance used or formerly used by surveyors". Can you explain? Dondervogel 2 (talk) 16:42, 21 July 2018 (UTC)

Also, the statement that a different (metric) definition of the chain is 20 m got lost from the opening paragraph. I can see it's there in the second but then giving the impression the metric unit is somehow less important than the English one, when I see no evidence of this. It's important to mention the two main definitions early on. I accept that other less widely used definitions (eg 30 m, 100 ft) can come later. Dondervogel 2 (talk) 17:48, 21 July 2018 (UTC)

@Dondervogel 2: Thanks for the hard work you are doing. The indian agri reference has to go though- it refers to the measuring instrument not a statutory distance. Unless we can find a reliable source there is no such length as a Metric chain. Have you another definition up you sleeve that proves me wrong- I think that we can increase Gunter's prominence, all folk that wanted tenure at a university took holy orders.ClemRutter (talk) 19:58, 21 July 2018 (UTC)

We still have Rowlett telling us that a chain is (or can be) 20 m. What do you propose to call that chain? Dondervogel 2 (talk) 20:02, 21 July 2018 (UTC)

I found this site telling us that Gunter's chain (or just "chain") is a unit of length equal to 22 yd. It also defines the terms engineer's chain and Rathbone's chain as measurement instruments of length 100 ft and 33 ft. Dondervogel 2 (talk) 20:07, 21 July 2018 (UTC)

And Google books tells us about 4 different chains

• Gunter chain: 66 ft
• revenue chain: 33 ft
• engineer chain: 100 ft
• metric chain: 20 m or 30 m

These chains are all measurement instruments, not units. Dondervogel 2 (talk) 20:14, 21 July 2018 (UTC)

This one is similar, with band chain thrown in for good measure. Dondervogel 2 (talk) 20:21, 21 July 2018 (UTC)

I'm stopping here. After a brief (~20 min) search I did not come up with any independent source to back up Rowlett's apparent statement that a chain can be a unit equal to 20 m. Perhaps he just got it wrong. A possible conclusion (if further searches also draw a blank) is that there really is only one unit called "chain" in modern use, and that unit is Gunter's chain of 22 yd? That would be an important conclusion. Dondervogel 2 (talk) 20:28, 21 July 2018 (UTC)

There are several reasons why I reverted Dondervogel 2's changes.

• They made wholesale undiscussed changes to an article that they knew full well to be at the centre of a disputed topic.
• They added just one new source, a page from a website for an Indian publication, which is probably fine for describing Indian practice; but it cannot be held to be a reliable source for British practice.
• The article is about the unit of measure, and not the instrument used to measure that unit. This is made clear by the disambiguator right there in the page title.

Consider my third bullet here. It is claimed that there is a "metric chain" of 20 metres. There may well be a physical device, constructed in the form of a number of interconnected pieces of metal, which when extended to its fullest extent is exactly 20 metres between its ends. But how many surveyors using this instrument to measure the side of a plot of land will say "the length of this side is two chains and three metres"? I suspect that none of them will: what they will actually write down will be 43 m. It could also be argued that a chain is ten yards, because in gridiron football they use a chain that is exactly 10 yards in length in order to determine how much distance needs to be achieved in the next series of downs.

Look at it this way: there is a unit called a foot, defined as twelve inches; and some people do have a lower extremity that is exactly twelve inches from heel to toe. These people might consider themselves fortunate in being able to measure the length of something like a room in a reasonably exact manner. But not all people have feet of that size; some might have feet that are, say, 10¼ inches long (these people may still measure out a room in the same manner, but they apply a suitable calculation to obtain the actual length) yet we do not misdescribe the foot (unit) as 10¼ inches to suit such people. So, we must not confuse the unit of measure with the measuring instrument. --Redrose64 🌹 (talk) 20:47, 21 July 2018 (UTC)

Thank you for explaining. I accept your third bullet (which you did not mention in your edit summary), but not the other two. Unless someone can demonstrate otherwise my conclusion is the same as yours, that there's no such thing as a metric chain (unit) equal to 20 m. Dondervogel 2 (talk) 20:52, 21 July 2018 (UTC)

Further cleanup needed

It becomes obvious how the confusion arose [yes, me too] when so much of this article is clogged with material about surveying chains. So i propose the following drastic edits:

1. delete Other instrument [sic] entirely
2. contemporary usage, reword as modern usage
   1. delete Texas chain
   2. arguably delete au and nz, since the text describes historic use, not modern use
   3. change North America to USA, delete ref to historic use in ca from penultimate para, delete para about NY subway as about instrument not unit
3. change surveying chain from a redirect to be a primary article to contain some of the material deleted here and a lot of the material about other chains from Gunter's chain.

Comments? --John Maynard Friedman (talk) 22:40, 21 July 2018 (UTC)

It would help if we had an article entitled Chain (measuring instrument). We could then move much of the surplus material instead of having to deleteit. Dondervogel 2 (talk) 22:54, 21 July 2018 (UTC)

@Dondervogel 2: Thats what John Maynard Friedman is saying. I am happy with the surveying chain solution.

Note also that, as an integer- {{convert|66|ft|m}} = 66 feet (20 m) but to 3dp, {{convert|66|ft|m|3}} = 66 feet (20.117 m) which explains additional confusion. Subsidary Gunter articles need to be proof read to see that they are using {{convert|66|ft|m|3}} at critical spots. ClemRutter (talk) 08:19, 22 July 2018 (UTC)

Oh yes, I see that now. Bullet 3 says just that but in different words. Go for it. Dondervogel 2 (talk) 08:52, 22 July 2018 (UTC)

• Oppose. Do not delete Texas, NY, .au, .nz, etc., usage. If it's no longer modern usage, just move it out of that section. Some of these other ideas might be permissible, but they need to be discussed separately. We are not going to nuke historical information just so people PoV-pushing about the UK standardized chain in some train articles can get their way.  — SMcCandlish ☏ ¢ 😼  06:55, 23 July 2018 (UTC)

Disambiguating the chain

I suggest we create a number of redirects to this article in the form Chain (22 yards), Chain (20 metres), Chain (30 metres), etc (which could each redirect to a suitable subheading or anchor point, if there is one). Then an article quoting a distance in chains could use a piped link to the appropriate redirect (e.g. 32 [[Chain (22 yards)|chain]]s) instead of direct to the article. The link will then have a tooltip that clarifies what a chain is. -- Dr Greg  talk  14:27, 21 July 2018 (UTC)

Just use {{convert}}, that way you can use the level of accuracy appropriate to the context. Thryduulf (talk) 14:40, 21 July 2018 (UTC)

Though creating the redirects will be harmless.  — SMcCandlish ☏ ¢ 😼  06:36, 23 July 2018 (UTC)

Proposed split

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

---

Following discussion above, it is proposed that this article be split so that it contains only material about the statute chain (22 yards). Material about surveying/surveyor's chains are to be moved to a new article. Any comments by Wednesday 12:00 UTC please, as I believe that it to be a non-controversial change. --John Maynard Friedman (talk) 20:12, 22 July 2018 (UTC)

• Strongly oppose. I think this is a very bad idea: one of the problems of Wikipedia (and of articles on units in particular) is that it looks like a fragmented collection of factoid scrapings. Articles should be there to explain topics, including the often convoluted connections between variant versions of units (for example). The unit "chain" (as part of the standard system of Engl(and)ish length measures) needs to be related to its origin (if this is the case) in Gunter's chain as a surveying tool, and also related to derived units such as any metric approximate equivalents. Actually I think the Gunter's chain article could be merged into this article as the "Origin" section. Imaginatorium (talk) 04:20, 23 July 2018 (UTC)

Apart from trying to write an article on a tool and a unit of length in one article- we can raise that later, have you found a source that verifies that the four rod measure (chain) was invented by Gunter. It seems likely and is often assumed. ClemRutter (talk) 08:37, 23 July 2018 (UTC)

• I'd keep the device article separate, but summarize it in "Origin" here.  — SMcCandlish ☏ ¢ 😼  07:13, 23 July 2018 (UTC)

• Oppose. I'm not on board with this either. First off, we don't split up articles to carry the day in an ongoing dispute (namely this one, which has spilled over to here). Secondly, this would be a "user-hateful" idea, and sorely inconsistent with our treatment of other units that have multiple measurements, e.g. ounce and pint). We sometimes have additional material in another article, and cross-reference it (e.g. the Troy ounce link at Ounce; it redirects to Troy weight, the article on the system). We have separate articles when the units are unrelated (measuring different things) and coincidentally have the same name (e.g., see the Carat disambiguation page), which is not the case here.  — SMcCandlish ☏ ¢ 😼  06:49, 23 July 2018 (UTC)

  (ec) The purpose of the split would be to clarify the distinction between Chain (unit) and Chain (measuring instrument). At present the two concepts are intermingled in a horribly confusing way and splitting them would bring clarity to the debate. It would be different if we had an article called Chain that said says "Amongst other things a chain can be something to keep you locked up, or something you hang around your neck, or a unit, or a surveyor's measurement instrument". In that situation we'd have one big disambiguation article, but would it help? I prefer the approach with multiple articles, one on each distinct subject - each pointing out relevant interconnections. Dondervogel 2 (talk) 08:45, 23 July 2018 (UTC)

• Strongly supportDifficult to follow as this occurs on so many pages. The origin seems to be some sloppy writing in 2007. To shoot down some ducks: there is one unit of measurement called the chain- not many. It may have been one of Edmund Gunters achievements to define it (measurement) as one eightieth of a mile, and to find an artisan to produce one Gunter's chain (article). That article was factual incorrect to suggest it predated the theodolite which was one of Digges achievements. (I still have to see a reliable source that attributes the measurement to the article.) We are talking of a time when an inch was defined as 3 barley grains,Weights and Measures Acts (UK)#Statutes of uncertain date where a rod was a unit of area and of length, and the acre was a fiscal unit (the area that could be ploughed by one team of oxen in a day. Onto surveyors chains(article): Gunter's was one- but the most significant was for cartography was Ramsden's, used for the measurement of the baselines of the Anglo-French Survey (1784–1790) and the Principal Triangulation of Great Britain. Now Ramsden's chain is a redirect in (again a article redirecting to a length) but Ramsden surveying instruments exists and has some Gunter stuff that needs checking. I haven´t checked the history so I suspect it was a redirect from Surveying chainredirect, the article we propose to float!

This level of confusion needs to sorted by separating out again the sheep from the ducks. Chain (unit)(measurement) that gives {{convert}} somethng to link, and actually focuses on the title. Surveying chain (article) to give a home to Ramsden and Gunter and a myriad of other regional variations.ClemRutter (talk) 08:37, 23 July 2018 (UTC)

Yes, this is also how I see it. After first reading the article, I was convinced there were multiple ambiguous units, all called "chain" (because that's what the article appears to say) and that has important implications for the ongoing debate at UK Railways. The title of the article is "Chain (unit)" so let's focus its content on the unit and not the different surveyors' measurement instruments. Of course it can (should) have a history/etymology section telling us how the name of the unit came about. Dondervogel 2 (talk)

Well, we agree that the different variants need to be sorted out. But I think this is best done by detailing the difference, not by shoving them off to different places. Where would you write the comparative information? Imaginatorium (talk) 10:57, 23 July 2018 (UTC)

I don't understand. What comparative information? Dondervogel 2 (talk) 12:13, 23 July 2018 (UTC)

Well, there should be the history of how the word "chain" came to be attached to a unit of land measurement, and the variant values it had until the standardisation (in England at least) to 22 yds. Then there can be a summary of notably distinct values. There really is not very much that needs to be said, but for example the Ramsden version might merit a paragraph and a picture. The problem with a split is that one article has to be titled something like "Units of length called a 'chain', but not equal to 22 yds". This does not strike me as a coherent topic. Imaginatorium (talk) 12:21, 23 July 2018 (UTC)

That's not consistent with my understanding of the proposal. What I support is one article on all units called "chain" and another on surveyors' measurement systems. The two concepts are mixed up in the present article. Dondervogel 2 (talk) 12:26, 23 July 2018 (UTC)

Sorry, I did not read the proposal very carefully. It wants to split this article into two: one being this article restricted to mention of the statute chain of 22yds, the second being about surveyors' measuring instruments in the form of chains (we already have one on Gunter's, and an article on Ramsden's various devices). The article is not long enough that separating it into separate bits will benefit the reader, who wants to know "What is a chain in this context? Where did the name come from? Are there varying values for it?" One article can explain all this; lots of separate microviews leave the reader as perplexed as before. Imaginatorium (talk) 13:21, 23 July 2018 (UTC)

I would not object to a solution along those lines, but in my opinion an article combining the unit with the measurement systems would need a new title. The present title implies a scope limited to the unit. Dondervogel 2 (talk) 14:16, 23 July 2018 (UTC)

@Imaginatorium: Rest assured there is enough material for two full articles. It does take time to read all the articles - we have nothing on Ramsden- that is a redirect but material hooked onto the article on Ramsden surveying instruments, I wrote all that above see#here. I could be more definite if I had the source that said Gunter had invented the word chain- for a 4 rod measure, as it is, fifty years later it was being used to solve a problem that had not existed when he did so. There have been some lovely derivatives to the chain (unit) from AU and US; including a series of placenames Three Chain Road, and a song. When it comes to the accurate use of measuring chains, there is the corrections needed for sag, trees in the way, elevation and temperature as well as links to basic triangulation. There is material. We just need the pigeonholes to post the two pigeons.ClemRutter (talk) 17:49, 23 July 2018 (UTC)

• Support on the whole. Two provisos though, which are (I hope) a tightening up of the wording of the original proposal, rather tan a modification of its intent. Firstly the unit article should not just be about the statute chain; it should also deal with other units of measurement of length known as 'chains' (such as the pre-imperial Scottish and Irish chains). Secondly, for instruments the term 'surveyors' chain' is sometimes used to distinguish a 66-ft 100-link instrument from a 100-foot 100-link instrument (an 'engineers' chain'): I would trust that the proposal uses the term in a more inclusive sense and the instrument article would cover chain-type length measuring devices used by surveyors or by engineers. Rjccumbria (talk) 18:21, 23 July 2018 (UTC)

Thanks for that- the supporting references for the term 'surveyors' chain' v 'engineers' chain' is found in Slater and Saunders 2006 ClemRutter (talk) 19:43, 23 July 2018 (UTC)

I would prefer to see the "material" first, and decide on any necessary split later. But I repeat the basic point, which is that if there is a complicated or confused relation between two things, what is needed is an article that explains this relation. Putting them in separate boxes might be easy, but is also a way to avoid explaining the relationship at all. Just to contribute a new issue: did Gunter really "invent" the chain that became the unit? Someone contributed a Dutch map engraving showing a surveyor supposedly holding "Gunter's chain", but this was in 1607, which is 13 years before Gunter announced his idea. Imaginatorium (talk) 18:37, 23 July 2018 (UTC)

Have you got a link to the engraving. The original'chain' was used by the Egyptians, and the rope caps are in the archaelogical record. Slater and Saunders 2006 is well referenced and useful. Gunter did make an invention while holding a professorship of astronomy at at Greshams College. All the Enc Brit and Gresham history sites use wording such as

Gunter also invented 'Gunter's chain' which was 22 yards long with 100 links. It was used for surveying and the unit of area called an acre is ten square chains. Gunter also studied magnetic declination and was the first to observe the secular variation.

Was the invention that it was 4 rods long, or that it had 1 hundred precision links or that for the first time an astronmer had addressed the problem. 16 1/2 feet was an obvious fraction of a statute mile but was that the - linking up official measurements to the vernacular perch (rod)? A bit of expert help from the Maths History Community is needed.

The second part of your post is relatively easy to do. We release Surveying chain from its redirect and c&p referenced (instrument material) over from here and the Gunters and Ramsden surveying instruments. Then we can sandbox here or just edit out dup material from here and Gunters chain. lets see what Wednesday brings.ClemRutter (talk) 19:44, 23 July 2018 (UTC)

@ClemRutter:. The engraving is cited at talk:Gunter's chain#Usage in picture on Dutch map from 1607. I hope to use it as the lead illustration of the surveying article. --John Maynard Friedman (talk) 22:09, 23 July 2018 (UTC)

archive.org offers on a "log in and borrow for 14 days" basis English land measuring to 1800; instruments and practices by Richeson, A. W. (Allie Wilson), 1897-1966 (MIT, 1966 - I think) which presumably would be of some relevance to the proposed articles. Rjccumbria (talk) 21:41, 23 July 2018 (UTC)

Clarification

I really ought to have stated the full proposal rather than assume that all interested parties were already following, so let me do so now:

• we already have two articles, chain (unit) and Gunter's chain, that overlap so much as to be in effect wp:forks. Each discusses surveing chains in general, Guntner's chain in particular, other measuring chains, the statute chain as a legal measure, other chains that are de facto but not de jure measures. All in all, a mess that [IMO] needs disentagling.
• we have a third article surveying chain that at present is a redirect to Guntner's chain, even though there are 'competitor' surveying chains.
• so the proposal is that we have these three articles

1. chain (unit) be only about the statute chain [measure], with a main link to its basis, Guntner's chain.
2. surveying chain be about all types of surveyors' and engineers' chains, with main links to the unit and the detailed article [with a summary] on Gunter's chain, but describes all the other chains itself.
3. Gunter's chain is about that - and only mentions [via link back to the surveying article] that other chains exist[ed] (naming them). IMO, there is relatively little work to do on that article; it is mainly the unit article that has become bloated.

Does that change anyone's view? --John Maynard Friedman (talk) 19:15, 23 July 2018 (UTC)

• Not mine. I still support the proposal. Dondervogel 2 (talk) 19:38, 23 July 2018 (UTC)

Insufficient consensus

I can't claim to have a consensus for the change as I originally proposed and so it fails. I accept and agree with the argument that the article Gunter's Chain is satisfactory and should be left alone. I still believe that this article is a mess and would support a proposal to split it [rather than just delete the extraneous material]. --John Maynard Friedman (talk) 13:24, 25 July 2018 (UTC)

@Imaginatorium:

@SMcCandlish:

I agree the consensus is not there for the proposed change and that the article is a confusing mix of unit and measuring device. It's as if we had one article covering both Meter and Metre. IMO that would not make sense, and I have the following question: How can the article be improved to address the confusion without splitting it in the way proposed? Dondervogel 2 (talk) 13:57, 25 July 2018 (UTC)

I contest that any of the unit material is extraneous. "Doesn't relate to the most common chain unit definition today" does not equate to extraneous, just inconvenient for some people (editors, not readers; the latter would be very inconvenienced by splitting, or by deletion). With regard to measuring devices, I set to work on that material. Detailed below.  — SMcCandlish ☏ ¢ 😼  19:02, 25 July 2018 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Starting some cleanup work

I began with the section on the measuring devices. It's relevant to have concise WP:SUMMARY info on them (and two don't have articles of their own). I merged out most of the Ramsden's material. The rest were already quite short. I then merged the redundant "See also" link in, and moved the entire section to near the bottom. Next, I patched up the geographical material (merged Texas to North America, arranged the material logically, copyedited a lot, and expanded the Texas (vara) section with links and stuff, but I don't have any more info on the unit. Didn't do anything with the .au/.nz section or the material above it.  — SMcCandlish ☏ ¢ 😼  18:59, 25 July 2018 (UTC)

PS: This is all I'm going to put in on it any time soon. There's a bigger thread above about a lot more cleanup work to do. Someone else's turn. :-)  — SMcCandlish ☏ ¢ 😼  19:07, 25 July 2018 (UTC)

PPS: Here's a multi-diff of all the changes [1].  — SMcCandlish ☏ ¢ 😼  19:13, 25 July 2018 (UTC)

I'll have a go in a couple of days (family commitments). Could someone check whether Chain (unit) is consistent with other measurements ? Should it be Chain (length)? ClemRutter (talk) 21:14, 25 July 2018 (UTC)

I'm not yet convinced this is the best solution but let's give it a whirl. There are many measurement instruments called "chain", some of which are only loosely connected with the unit chain. I don't believe this article is where these belong but in the absence of an alternative I've added some stubs, which need expanding. Dondervogel 2 (talk) 20:40, 25 July 2018 (UTC)

I have just picked up Chambers Dictionary of Science and Technology ISBN 0550 141103 it has definitions of chain (surv), p196, engineer's chain, p406 and Gunter's chain p532, which make a useful lede for the article on surveyors chain. I am not sure that Ramsden was anything more than a precision instrument manufacturer- and the only reference Chambers has is Ramsden eyepiece (phy,surv)- a precision eyepiece with a cross hair? ClemRutter (talk) 21:14, 25 July 2018 (UTC)

I think that precisely what this article does not need is the addition of any number of fragmentary and not-very-well-documented factoids listing just any measuring instrument that has "chain" somewhere in its name. For example, "Revenue chain" is based on a self-published Indian site; yet the stub description does not even mention India (or wherever it is used), and the "cadastral survey" is two wl's away from an explanation that it means "survey for legal purposes". It looks from the SOED as though this term is extremely marginal. WP articles should be explaining things to ordinary readers who want to understand stuff, not just listing as many obscure factoids as someone can find. Sorry, I'll try to write a suggested article outline soon. Imaginatorium (talk) 05:59, 26 July 2018 (UTC)

@Imaginatorium:

• It remains my opinion that an article entitled Chain (unit) should focus on the unit. It can contain limited information about measurement instruments where relevant to the development of the unit. This is why I favour a separate article entitled Chain (measurement instrument) or similar.
• In the absence of such a (separate) article the only place to put the information is here.
• The revenue chain is widely cited

Dondervogel 2 (talk) 06:51, 26 July 2018 (UTC)

@Imaginatorium: That is exactly why, after a lot of research, that the proposal was made to limit the article to the unit of length and to take the 'factoids' into a separate article. Are you now saying you now support the proposal you killed? All the way through the debate you have been repeating points that already existed in the discussion logs a week or so previously. The Indian site is not reliable- but we knew that, it can only be used to inform us of interesting terms that need to be fully investigated. It was jumped on in the 'old days' because it contained all the right words for a reference- that the WPeditor needed, and before he had read it or tested the text. I have family commitments for the next 30 hours, so I am holding back but then will come in and edit fully. Your vision of what WP is fine, but sadly limited. Many ordinary readers have Maths degrees and expect to find a high degree of precision- ordinary does not mean average. On this topic you need to do a lot of background reading- I have pointed you to many pdfs. Maths topics generally are more difficult to source. Please listen to Dondervogel 2 who has put a lot of time into this.ClemRutter (talk) 07:40, 26 July 2018 (UTC)

Definition of acre

@Redrose64: There has been some misunderstanding caused by a long ago edit. The acre is defined as 10 square chains. Ten chains is one furlong. A long ago editor made the connection that one chain by one furlong is equivalent to an acre, which is true, but this then became a definition of the acre in this article, and was unreferenced. Even worse, the same notion was carried through to the acre article, where the acre is defined as one chain by one furlong. This is not true, and further down in the acre article it is even stated that the acre has no particular shape. It is very wrong to define it in terms of the furlong. Akld guy (talk) 23:41, 22 July 2018 (UTC)

Well, the SOED says, of "acre", that it was originally the amount of land that could be ploughed by a yoke of oxen in a day, and was "later limited by statute to a piece 40 poles long by 4 broad (=4840 sq. yds.), or its equivalent." So I think your statement is simply wrong: it is perfectly correct to define an acre in this way. Moreover, SOED gives the expressions "acre length", meaning a furlong, and "acre breadth", meaning a chain. (The definition of "furlong" also says something like a furlong being the "normal"?? length of a furrow. Seems odd, since it implies all fields were the same long dimension, but then, this was a long time ago.) Imaginatorium (talk) 04:49, 23 July 2018 (UTC)

I'd been thinking of raising this issue myself. There really is a historical reason for it being defined this way, but this is very unclear in the article text. It looks instead like some joker doing odd conversions for trivial purposes, when it really is not.  — SMcCandlish ☏ ¢ 😼  06:49, 23 July 2018 (UTC)

Exactly. Akld guy (talk) 07:07, 23 July 2018 (UTC)

Quite simple really. The acre was a economic measure, set to define the tax that the field should raise not a topological measure. In stoney gound the acre was bigger to compensate. Once you had a acre you drew a convenient furlong (about a oxens ploughing distance) and allocated perch widths of that furlong to you peasants and taxed them for that. Later (1500 ish) bureaucrats became interested and tried to triangulate these acres onto the new maps. The approximate size of a acre was 160 sq perches, so that was convenient as there were also exactly 640 in a square mile. Śee:Andrew Jones, Land Measurement in England, Agricultural Review — Preceding unsigned comment added by ClemRutter (talk • contribs) 09:04, 23 July 2018 (UTC)

In the days before mechanised ploughing, it was necessary to use animals to pull a plough, and animals (of whatever species) cannot work continuously; they need to be rested every so often. Centuries of experience showed what kind of distance could be expected of particular animals in particular quantities (given the same task, two horses together could work continuously for longer than one horse alone). When the animals are being rested, it is convenient for the ploughboy to also turn them and the plough around in order to plough the next furrow parallel to the previous one. In this way they would work across the land.

One common combination was the team (or yoke) of oxen, and the length of furrow that such a team could plough without rest became known as the furlong (furrow long). --Redrose64 🌹 (talk) 10:11, 23 July 2018 (UTC)

Removal of supposed "system"

I removed the claim that this is a unit in (just) two systems. I do not think this claim helps, because actually the chain is a historical unit, described in the English language by its "pre-system" origin in the tool used to measure it. The claim is also not really accurate, because (as described in the article) its usage is in fact much wider than these two systems. Imaginatorium (talk) 07:31, 28 January 2023 (UTC)

There are two issues at play here. First, Guntner created his chain to be 66 feet. At that stage it was indeed no more part of the Imperial system than would a piece of rebar I cut exactly 18 inches long to use as a quick measure because I need to cut many lengths of wood. But the difference is that his chain became adopted in US and UK statutes, thus making it part of those systems because that is how they are defined. So the key factor is that it ceased to be just a convenient surveyor's tool and became a statutory measure. So it is formally a unit in these systems.

But unless anyone else considers it important, I won't pursue the point. What about the infobox? --𝕁𝕄𝔽 (talk) 09:04, 28 January 2023 (UTC)

Consistency is important. Both US customary units and Imperial units describe the chain as part of these two "systems" of units. If that claim is incorrect (is it?) then the claim should be removed from those articles. Dondervogel 2 (talk) 10:57, 28 January 2023 (UTC)

@Quondum: Dondervogel 2 (talk) 20:54, 28 January 2023 (UTC)

I've re-inserted the claim in a way that hopefully does not invite interpretation as meant to mean exclusively to those systems. As far as I can tell, the unit as defined in these unit systems (including their statutory inclusion), which almost any modern use of the term is likely to mean. The concern that seems to have prompted the original removal, as given by the OP, is that there may have been an implication that it was defined only in these systems (but which rarely holds for any unit: for example, by the same criterion, we would not be able to say that the second or the metre are SI units). I don't agree with this concern, as my parenthesis here would suggest, but I have nevertheless tried to allay it. —Quondum 21:48, 28 January 2023 (UTC)