Talk:Optical telegraph

Untitled 2007 comment

Notice:

the sections "Article split?" and "Domel" have been moved to Talk:Semaphore, since the article has been split.

the sections "Semaphore code space", "Total rewrite", "Externa link cleanup", "Copyrighted signals?", have been moved to Talk:Flag semaphore, since the article has been split.

--Once in a Blue Moon (talk) 21:13, 30 December 2007 (UTC)

Distance

Someone should really add in distances between semaphore station to give readers an idea of how far and quickluy messages travelled. 178.54.232.147 (talk) 20:44, 24 October 2015 (UTC)

References in fiction

Isn't it a bit weird that Alexandre Dumas and Ernest Hemingway are mentioned under 'Popular culture'? These would, by any account, be 'high culture'. Although I am not proposing a category 'References in High Culture' it might be a good idea to change the heading to something else like 'References in Art & Litterature' or something. Or just 'References in fiction', how's that??

Lord of the Rings

I think that semaphores where used in one of the Lord of the Rings novels/movies, although I need to verify this. Any LoTR buffs? GChriss 15:02, 16 March 2006 (UTC)

There was a series of beacons in The Return of the King, which are a much simpler type of 'optical telegraph'. JeffUK 10:52, 1 April 2006 (UTC)

They're actually more akin to those originally used on The Great Wall of China--190.74.122.75 12:13, 16 August 2007 (UTC)

Reason for rewrite

edit summary by user:diza

no order ,one need to finish this article in order to know what it is about. mechnical arms are mentioned only 2-3 paragraph after they are introduced via ancient name ..etc'.)

--Dodo bird 18:41, 29 March 2006 (UTC)

Relative Costs section

Where does the information in the section "Relative Costs' come from?
There's some missing context here - for instance, I presume these figures are adjusted in line with inflation, given the size of the wages in comparison with the "twenty five sous per day" described in the previous paragraph?
The timing "at most ten hours a day" is contradicted by the previous paragraph (where it says that the signalmen must work "at present from half past three till half past eight"). --David Edgar 11:39, 30 October 2006 (UTC)

Cleanup

The two pages Semaphore (comunication) and Semaphore (communication) are both based on the same article but have been copyedited into two different ways. They should be merged. -- JeLuF 10:17 Dec 31, 2002 (UTC)

I'm not sure we need disambiguation for this anyway -- see Talk:Semaphore -- Tarquin 10:28 Dec 31, 2002 (UTC)

I have also remove - A Manual of Signals: For The Use Of Signal Officers In The Field for being some thing about the army, not semaphore...209.247.21.165 14:25, 27 May 2007 (UTC)

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A "symbol" and "code" are different things. A "code" is a scheme to translate a string of "symbols" into natural language. I fixed the article. Also, the title is misspelled- "communication" has two "m"s. I don't have time to fix it. (gotta go).

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I have found a great website (personal page) about french optical telegraph history. The Chappe telegraph site contains very interesting materials. I am going to contact the author to propose him to help writing the optical telegraph article. -- Valery Beaud

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I think this page needs to be merged with optical communication. --Piotr Konieczny aka Prokonsul Piotrus 21:09, 9 Jun 2004 (UTC)

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196 symbols is equivalent to a (log(196) / log(2) =) 7.615-bit number. If 36 of these could be sent in 32 minutes, that is a signalling rate equivalent to 36*7.615 bits / 32 minutes = 0.143 bits per second. Not sure if this is relevant enough to put in. - Omegatron 03:04, July 24, 2005 (UTC)

Words and etymology

Something to note, perhaps in the lead-in or later in the historical section:

• Telegraph first used in 1794, literally "that which writes at a distance," from the French télégraphe, from télé- meaning "far" (from Greek. tele-) + -graphe. The signaling device had been invented in France in 1791 by the brothers Chappe, who had called it tachygraphe, literally "that which writes fast," but the better name was suggested to them by French diplomat Comte André-François Miot de Mélito (1762-1841). The word was first applied in 1797 to an experimental electric telegraph (designed by Dr. Don Francisco Salva at Barcelona); the practical version was developed 1830s by Samuel Morse. Source: [1]
• Semaphore first used in 1816, probably from the French word sémaphore, literally meaning "a bearer of signals," ultimately from the Greek sema meaning "sign, signal" + phoros meaning "bearer," from pherein meaning "to carry." Source: [2]

A few things that struck me as being included in the article:

1. Telegraph was used first; semaphore was 20 years later (according to this source).
2. The Chappe brothers originally named their invention tachygraphe.
3. The word Telegraph was picked up for the electric telegraph.
4. Apparently the french didn't use the word telegraph; instead going semaphore? I've been told that the French prefer their own terms for technical things instead of imported words (citing cultural pollution).

- Davandron | Talk 18:21, 23 April 2007 (UTC)

Relative cost

I notice the cost breakdown is in US dollars of an unknown era. Is there some way to discover the actual costs or, second best, to identify when the conversion was made or whether it was on the basis of wages or other kind of comparison? Jim.henderson (talk) 14:17, 24 August 2008 (UTC)

Map of French system

Is a map of the French system available anywhere? I think this is such a map, but no information is given as to its licensing and so on. I think it'd be great to have a map showing the extent of the system. TastyCakes (talk) 22:20, 2 March 2010 (UTC)

History and France

The article as a whole is written with acceptable organization although the description of the Chappe design is misleading and out of place. The format of the article being broken up by country of origin and use is helpful. The sources and credibility are lacking due to the small amount of references, none of which are used in backing the section on France which is the backbone of the article. The references used are credible and from scholarly locations, however vague they may be.

The illustrations of Chappe and his semaphore tower are accurate although the picture of the tower near Saverne is misleading and doesn’t properly represent what an actual example looks like. The pictures is misleading due to the simple fact that the towers rarely stand alone and the picture fails to show the pivoting beams used for signaling because of the angle at which the photo was taken. The proper names for the arms are not used either, the main and vertical beams are called regulators and indicators respectively.

The section on History is a little vague and fails to mention or credit the Romans and the rest of the Mediterranean countries for their use of optical telegraphy while also leaving out the Native Americans and their deep history in signaling. The section on France is thorough, although the article says the first optical telegraph arrived in 1792 which is not totally accurate. The article as a whole has pretty solid information with the exception of History section. One positive aspect of the article is that it has not been marred by conflicting information and multiple contributors. HIST406-10110425205Brownley (talk) 20:29, 3 October 2010 (UTC)

But how does it work?

The article does not actually describe how it works. Is it like visual morse code? Reading this, I have no idea. — Preceding unsigned comment added by 206.130.174.61 (talk) 19:51, 28 June 2011 (UTC)

Yup, you've got the right idea with "visual Morse code". Any set of distinctions visible from a distance can potentially work (with or without telescopes; you can work without them if the stations (or ships) are close enough to each other). All you need is to know the code. For [simplistic] example, if two 2 black panels and 1 white panel means "A", you can begin spelling "apple". You'd use other panel combinations for the other letters. Some of this is suggested (if not deeply explained) in the section "Description".

Before radio communications were developed (radiotelegraphy, radiotelephony), ships (especially naval ships) often communicated this way. People with flags would stand there and wave them in certain combinations. The receiver would see them by either naked eye or telescope. Check out the pictures in the article flag semaphore to see how they made each letter or digit.

One neat thing about semaphores is that it only takes one visible distinction to successfully communicate, such as light/dark, on/off, white/black, etc, if you're willing to communicate in binary, like a computer network does. Morse's code in a sense uses only one distinction, dot/dash (ignoring on/off for the moment), although it only takes 4 bits to make a unique letter, which makes it easier for humans to use than 8-bit (or higher) computer-speak.

One other neat thing about communicating using only bits is how incredibly clever and complicated you can get by layering many levels of simple ideas. This is what makes fields like information theory, computer science, software development, and network engineering so damn hard for all of us non-geniuses to master, even though "it's all very simple in principle". — ¾-10 00:17, 29 June 2011 (UTC)

Timeball Tower

Surely this is a type of semaphore as well, according to the description? 92.20.125.234 (talk) 08:09, 30 October 2011 (UTC)

History of Chappe system

The section on the development of the Chappe system looks reasonable but is unreferenced. This BBC reference, How Napoleon's semaphore telegraph changed the world, tells this story well, and supports the Lille and Conde statements, but needs to be incorporated, if the original reference for the para is not known. Onanoff (talk) 13:09, 17 June 2013 (UTC)

Link from the Optical Telegraph

caution should be used when using information from the map on http://www.vauxhallandkennington.org.uk/telegraph.shtml as the locations are slightly wrong. Woodcock Hill is shown as being south of St Albans when in fact it just north! There was no Semaphore Station in St Albans, I think what has happened is that someone has displayed the location address from being Woodcock Hill near St Albans to Woodcock Hill, St albans and hereby thinks they are two separate locations see https://wiki.riteme.site/wiki/Sandridge. The Lilley Hoo station is also actually Telegraph Hill, being over a mile north of Lilley Hoo. Pandaplodder (talk) 13:18, 24 October 2013 (UTC)

Trivia sections are deprecated

"Incidental appearances of X in fiction" is not encyclopediac content for an article about X. WP:NOTRIVIA is a policy that says Wikipedia is not to collect indiscriminate information. A recitation of incidental uses of a concept is of no value to informing users about the concept without explanation or commentary on the significance of each appearance. We don't list every time the Coyote got conked on the head in the article on anvil, for example. Just because it's 19th century trivia doesn't make it non-trivial. --Wtshymanski (talk) 19:27, 1 November 2018 (UTC)

This is not trivia. When Rodolphe Töpffer depicts a semaphore line in one of the first comic strips in history in 1831, this is encyclopedic. Stendhal, Alexandre Dumas and Hector Malot are 19th century famous writers, and if they describe a semaphore line in one of their works, it is encyclopedic. All the other authors mentioned in the section are sufficiently famous to have their page in Wikipedia, and if they put in scene a historical or fictitious semaphore line, it is encyclopedic as well. Sapphorain (talk) 20:10, 1 November 2018 (UTC)

19th century pop culture has more EV than 21st century pop culture? I'm looking at MOS:POPCULT and I don't understand. --Wtshymanski (talk) 01:06, 5 November 2018 (UTC)

• You seem confused over the difference between "trivia" and "in popular culture".

Yes, trivia should go. Trivial content about trivia in popular culture should go too. However references in popular culture to the topic are permissible, provided that they're relevant and substantial. So popular culture where the topic becomes a plotline (as described here) is reasonable, where a passing mention usually isn't. Andy Dingley (talk) 10:13, 5 November 2018 (UTC)

• In my view, use of a thing in a work of fiction, even a substantial use in a notable work, is trivia and does not elevate that thing to being part of culture, popular or otherwise. It is out-of-universe discussion in RS of the use of that thing in the work that verifies the thing has entered the cultural consciousness. Having said that, in reply to Mr. Shymanski, 19th century pop culture does have more significance that 21at century pop culture in the context of this article. Use in works from around the time of the device's innovation show that it has become familiar to a wide audience, especially if it is used without the author feeling the need to explain what it is. SpinningSpark 17:26, 8 June 2019 (UTC)
  • Well,then, we should say something like "By the year 18-blah, the semaphore telegraph was so well known that it could be an essential plot element in an early comic strip without particular explanation." or something of that ilk (if we could find a reputable source that could support that observation). Explain *why* appearing in a comic strip is the significance, here. All kinds of stuff appears in comics and we don't have a link to Andy Capp under brick, for example. Dumas also described swords and horses, but those articles are bereft of links to Dumas. That somethign is well known enough to appear in a comic strip or novel doesn't really seem encyclopedia-worthy to me. --Wtshymanski (talk) 02:28, 9 June 2019 (UTC)
    • We already know that your only interests on WP are in merging unrelated articles, deleting IPC sections (see IBM 5100) and snarking at how awful other editors are. Cut it out, we're tired of you and your utter negativity. Andy Dingley (talk) 09:35, 9 June 2019 (UTC)

Time zones and message speed

@RobinClay: Do you have a source for the claim you inserted with this edit that the claimed London to Plymouth transit time of less than eight minutes was "suspect" because the route crossed time zones? Or is that your own surmise? The admiralty of that period had a huge investment in establishing the difference between local noon and Greenwich noon for navigation purposes, so it sounds unlikely that they would make such a schoolboy error. SpinningSpark 17:12, 8 June 2019 (UTC)

Also, presumably the way this was worked out was that London said "Hey P, txt me back rn" and 16 minutes later Plymouth messaged back with "'Sup? I'm looking at the sea". Standard time zones aren't needed for Round-trip_delay_time. I'd strike the relevent text... Joe (talk) 09:31, 8 July 2019 (UTC)

Since user:RobinClay has declined to justify that edit after we have waited a month, I think it safe to assume that it is WP:SYNTH so I have deleted it. SpinningSpark 13:14, 8 July 2019 (UTC)

Chappe code accuracy

Alleged Chappe code

I have some serious doubts over the correctness of the Chappe code shown in this article. The Commons page says it is sourced from this site which does not appear to meet our requirements for a reliable source. As far as I can make out, it is a personal website and gives no indication where the information came from. Shaffner's Telegraph Manual says that the codes for dispatches (rather than control codes) were always sent with the regulator (the central bar) in the same diagonal position (but written either horizontally or vertically depending on whether the regulator was returned to the horizontal or vertical position afterwards, thus doubling the number of code points). The regulator in our chart is in all four of its possible positions. This book gives the Foy-Breguet telegraph code, which was supposed to mimic the Chappe code. The regulator is shown in the same position for all code points (it was actually incapable of moving in the Foy-Breguet instruments) and is completely different from our chart. The same code is shown on this well-researched page by Professor James B. Calvert of the University of Denver. In short, I think it should be dumped or replaced as it is highly dubious and has probably already spread all over the internet. SpinningSpark 12:49, 18 September 2019 (UTC)

More evidence that this is wrong is found in Gerard G. Holzmann, The Early History of Data Networks ISBN 0818667826. The full code is not given, but on page 76 there is an illustration with Chappe's name being transmitted on a line of towers. The codes shown do not correspond to our table. In any case, showing the alphabetic code is misleading. Most messages were passed using numeric codes for entries in the code book for phrases, names, and locations. This 92-character code is shown in this book. I propose to replace the image with this code, but will hold off for a few days for comments before actually doing the work. Other possibilities to display are the pre-1795 much slower 10-character code and the all-horizontal code introduced in 1837 (Holzmann, p. 88). The latter is presumably the basis for the Foy-Breguet code. SpinningSpark 17:18, 19 September 2019 (UTC)

Finally found a book source giving the alphabetical code Wrixon, Codes, Ciphers, and Secret Languages, and again it doesn't agree with our article. These codes match the illustration in Holzmann's book except that they are mirror images, but this did occur as it depended on whether one was viewing the signal upstream or downstream. Wrixon doesn't date the code but it is probably very early since three letters are uncoded and we know that there was a 94-codepoint codepage for letters, numerals, and common syllables by the early 1800s. I still couldn't be 100% certain that the code in our article never existed, but I think there is more than enough evidence now to remove it as dubious. SpinningSpark 11:09, 20 September 2019 (UTC)

Here's what I have from book sources,

Chappe alpha code, undated but likely very early (Wrixon)

Chappe numeric code c. 1794 (Bouchet)

Chappe numeric code c. 1809 (Bouchet)

Foy-Breguet code c. 1845 (Guillemin)

Chappe alphabet c. 1794 (Edelcrantz)

The reasons for thinking the first one is very early:

1. Missing codes. While it was not unheard of for telegraph codes to substitute other letters they couldn't code for (C&W5 had six letters missing for instance, and note J is missing on the original chart too), we know Chappe eventually had a 94 code-point page for letters numbers and phonemes. Unlikely that not all letters were represented in that code.
2. There is good reason to believe that the code for "F" later became the code for "A", and the code for "C" became the code for "CH".
3. The code for "I" is not at a multiple of 45°, a firm rule of the established Chappe code. This cannot be simply badly drawn in the source since it would then be identical to the code for "K". SpinningSpark 17:23, 22 September 2019 (UTC)

Finally got a book source (Coe The Telegraph [3]) with the code in the article. However, it cites the Morse Telegraph Club newsletter as the source (which cannot be found online). There's a strong suspicion of WP:CIRC going on here. I'm still not seeing an historical source, or a source that clearly has access to historical sources. SpinningSpark 12:56, 25 September 2019 (UTC)

See also the alphabetic chart I put into Telegraph code § Chappe code. This is extracted from a book by Edelcrantz, a telegraph developer in Sweden contemporary to Chappe. It is very similar to the code above from Wrixon and most of the problems with Wrixon can be explained as typos by comparing them. However, Edelcrantz, who got the chart from a report published in Leipzig, is not sure about its authenticity. SpinningSpark 13:33, 2 November 2019 (UTC)

It appears that the code I am questioning originally appeared in an illustration in the Gentleman's Magazine, November 1794, p. 992. However, it also says "...the alphabet may be changed at pleasure, it is only the corresponding person who knows the meaning of the signs."[4] That indicates to me that they made it up for the sake of demonstration. SpinningSpark 13:37, 3 November 2019 (UTC)

I've moved the Edelcrantz chart out of the telegraph code article to here because I think this one is highly dubious too. This was originally published in Leipzig in 1794. All the secondary sources giving alpha codings, like Wrixon, can be traced back to either this one or the Gentleman's Magazine. Both of them clearly don't know the actual code used, the Leipzig one is suspiciously German-language orientated, and neither of them conform to the known protocol of the Chappe system (like moving to an H or V position after setting the code on a diagonal). I don't think these belong in a Wikipedia article, unless it is a demonstration of how people are inclined to fill in the blanks when faced with a lack of information.

On the other hand, the 92-symbol code is reliably traceable to a codebook in the French Postal Museum. SpinningSpark 16:01, 4 November 2019 (UTC)

Vibration system

I removed this from the article;

There is system of conveying information that for data transmission uses vibration generator instead of optical sources, and for detecting signals uses real-time high-speed computer vision system.

How is a vibration generator connected with the optical telegraph? SpinningSpark 20:02, 21 September 2019 (UTC)

References

Propose renaming

I propose to rename this article Optical telegraph. The article was originally at that title, but got merged to this page after a fork article got created firstly at Semaphore then Semaphore line and finally Semaphore telegraph. Pinging user:Jim.henderson who questioned the name change here]. My rationale for the name change is that shutter telegraphs are not called semaphore. Only telegraphs with moveable arms like Chappe's are called this (and frequently without the telegraph suffix). Many sources clearly make this distinction;

• "The Shutter Telegraph...Edelcrantz had decided to abandon the Chappe-like design of a semaphore telegraph with articulated arms..."—Holzmann & Pehrson
• "...the superiority of what is called the Semaphore over the Shutter Telegraph...is now generally acknowledged."—Charles Pasley [5]
• "Two optical telegraphs, built by and for government, were of particular importance: the semaphore of the First Republic, France, 1794; and the shutter telegraph of the Admiralty, England, 1795." The New Encyclopaedia Britannica, 1994.
• "The Swedish mechanical telegraph differed from the French one in that it did not use the semaphore system"—Greene [6]

It is clear that either the article is at the wrong title, or that the optical telegraph page should never have been merged into it. SpinningSpark 23:46, 31 October 2019 (UTC)

Sentence structure

"Semaphore lines were a precursor of the electrical telegraph, which replaced them half a century later, and was also cheaper, faster, and more private." Where did you people learn to write, or read for that matter? I assume the meaning here is that semaphore lines are older than the electrical telegraph, and that the electrical telegraph was cheaper, faster, and more private than the semaphore lines had been, but that is not what is so inelegantly stated. Gimelgort (talk) 16:39, 2 March 2020 (UTC)

Popular culture authors

@Sapphorain and Wtshymanski:. I'm willing to accept that Pratchett's Discworld is part of popular culture, but I'd take some convincing that any particular thing he has written about, such as his "click-clacks" has risen to that level. Have independent sources said so? Are click-clacks written about without reference to Pratchett in the way, say, that Superman is talked about without reference to the DC comics universe? If not, the material doesn't really belong in this article. But there are other places to discuss it, there are many Pratchett related articles on Wikipedia, including an article on this particular book. SpinningSpark 11:15, 4 March 2020 (UTC)

• Clacks has certainly gone beyond the general level of Discworld. There's a boardgame based on it, there's the usual spin-offs of miniatures, Clacks postage stamps, a Haynes manual (facsimile at least).

When is Superman ever "written about outside the DC universe"? Would their IP lawyers take that as a defence for my new "Superman and the Clacks Towers" graphic novel?! As soon as you mention "Superman", you're into that DC universe - even if Superman (unlike the Avengers) is a somewhat stand-alone part of that, and we're not implicitly into "Superman meets Spiderman" all the time.

Incidentally, we might not discuss Holmes' choice of outerwear at hat (nor do we mention Pratchett at telegraph), but we do at deerstalker, Ulster coat, Inverness cape and calabash pipe. Andy Dingley (talk) 11:42, 4 March 2020 (UTC)

Well George Bernard Shaw wrote Man and Superman with no regard to DC comics at all. Martin of Sheffield (talk) 12:03, 4 March 2020 (UTC)

BTW, I'd restore Pratchett, no opinion on the other as I've never heard of it.Andy Dingley (talk) 13:53, 4 March 2020 (UTC)

• Oh lovely, now we have an anonymous IP from Guildford joining in. Will someone please remind me which of the I B Wright / Bhtpbank socks that one will be? Andy Dingley (talk) 13:53, 4 March 2020 (UTC)

Spinningspark, There's this article in the Telegraph -

∰Bellezzasolo✡ Discuss 13:54, 4 March 2020 (UTC)

References

Inflation

@BCthroughNL: That a template is used on "numerous articles" still does not excuse one from providing a reference. It is certainly not acceptable to change the data of a referenced fact and not update the reference. More importantly, I question whether the inflation template is providing the most suitable inflation index. My understanding is that it is based on consumer price inflation, which is not always appropriate for business and industry. Inflation here can be wildly different from consumer prices depending on the sector and business model. The index I am referencing is based on labour costs which is much more appropriate for a labour intensive industry like this one than consumer prices. SpinningSpark 20:01, 5 March 2020 (UTC)

@Spinningspark: The reference is from 2015, and the value it gives is almost immediately outdated, not to mention out of context for a price referenced from over a hundred years ago. If you can find a source that allows us to keep the value up-to-date (and with a reasonable number of significant figures) I think that would be an appropriate compromise. BCthroughNL (talk) 21:10, 5 March 2020 (UTC)

@BCthroughNL: It is not for me to find another source, I was perfectly happy with the original source. You have made an edit that is clearly erroneous so it needs either reverting or improving. The issues with it are [1] that it has left the original citation in place, which does not agree with the data in the template you inserted, and [2] it has left the original descriptive text in place which is not a correct description of what the template is doing.

I do not think that the difference between 2015 and 2019 is a significant problem for a comparison to costs occuring well over two centuries ago. And by the way, the inflation template does not automatically update. Those updates occur when new datasets are available and editors spend time adding them in manually.

I don't know why you think significant figures is an issue. The source calculates to far more significant figures than the is provided in the input number. SpinningSpark 15:05, 6 March 2020 (UTC)

@Spinningspark: Watch your aggression my friend, we're both trying to improve an article hear. I'm being respectful and cooperative, it would be nice to see that reciprocated.

1. The citation is for 2015, and the template updates to the most recently available data. This does not disagree with the original citation.
2. The description correctly states the year the value is inflation-adjusted for.
3. I mention significant figures because you complained they were "excessive" in an edit revert. When I say "reasonable significant figures" I'm trying to give you some concession here.

I think it is unhelpful to leave an inflation-adjusted figure from a past decade. When I see an article with $XXX in 2008 (for example), I (and likely other readers) have a poor intuitive grasp of what that means in present dollars. I think it would be useful and easy to have the value adjusted using the inflation template, and see very little downside to it, especially when compared to the status quo. BCthroughNL (talk)

I'm sorry you feel I have been rude, but I am frustrated that you still seem not to be grasping the problem. I'm not being rude here, I am just trying to explain your error. The article says this dollar-converted, inflation-adjusted figure is indexed to labour costs. The index you are using in this template is not indexed to labour costs, it is indexed to consumer prices. This makes the statement untrue so cannot stand as it is. I have also just realised that the input amount you have put in the Wikipedia template is the 2015 dollar figure from Edvinsson's converter. That makes it far worse since one index is being used up to 2015 and an entirely different index from there to 2019. Any conversion has to start from the original figure in francs and convert it by one consistent method.

The point about precision is that the source quotes to three significant figures. You have used the template in a way that it displays to nine significant figures. This misleads readers into thinking the number is more precise than it actually is. You can fix this with template parameters but there is no point doing this since this is not an appropriate template in the first place.

Yes, it would be nice if we had a more recent figure, But right now we don't and putting in an incorrect number to overcome that is not the right thing to do. SpinningSpark 19:45, 6 March 2020 (UTC)

@BCthroughNL: Are you going to reply to this? Please watchlist the page, you shouldn't rely on people pinging you in conversations you are active in. SpinningSpark 09:30, 11 March 2020 (UTC)

Optical telegraph

Hello, I reverted your deletion of "is a semaphore system using". The optical telegraph is certainly a semaphore system. Would you please provide your reasons why you reverted this indisputable factoid? Thank you in advance. Blockhouse321 (talk) 10:00, 8 August 2021 (UTC)

First of all, I didn't delete it, I reverted it to a previous version and per WP:BRD, you should start a discussion when reverted, not just revert it back. I thought I explained adequately in my edit summary why I did this, but in case you didn't read it, here it is again: "Since the article distinguishes between semaphore and shutter telegraphs, that doesn't work as a definition". Having the article contradict itself in the opening paragraph of the lead is not good. SpinningSpark 10:13, 8 August 2021 (UTC)

Shutter telegraphs are a type of semaphore. Perhaps, you should have requested a discussion on the talk page before deleting the information. Please put the correct factoid back in the opening sentence. Thank you. Blockhouse321 (talk) 14:14, 8 August 2021 (UTC)

Beauchamp in History of Telegraphy clearly distinguishes shutters from semaphores: "The two systems which were in use, the shutter system and the semaphore system..." Holzmann & Pehrson in The Early History of Data Networks, a source heavily used in the article, seem to share that definition: "Why Chappe rejected the shutter principle and replaced it with semaphore arms, and Edelcrantz rejected the semaphore arms and replaced it with shutters is a mystery." Again, Craddock in What Ship, Where Bound?: A History of Visual Communication at Sea seems to take the same view: "Was it hubris at French advantage with Chappe's semaphore that the shutter system was adopted in England?" and elsewhere complains about the misuse of terms "many of the devices were known as 'telegraphs', often misnamed as 'semaphores' and vice versa". SpinningSpark 15:29, 8 August 2021 (UTC)

Semaphore is the use of an apparatus with telegraphy to create a visual signal transmitted over long distances. This would include Shutters. Blockhouse321 (talk) 18:57, 10 August 2021 (UTC)

Just reiterating your claim does not make it so. Nor does it nullify what my sources are saying. SpinningSpark 08:07, 11 August 2021 (UTC)

Request for comment on meaning of semaphore

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.

---

Should optical telegraph be described as always semaphore? This discussion also affects the semaphore article. 07:51, 14 August 2021 (UTC)

I have provided three sources above which clearly indicate that not all optical telegraphs are semaphores. Sources only call them semaphores if they employ arms (either human or mechanical). SpinningSpark 07:53, 14 August 2021 (UTC)

• Support the assertion that not all optical telegraphs are semaphores. Your sources show that at least some reliable sources associate semaphore with Chappe's system of arm signaling. Also the National Museum of the Royal Navy distinguishes Murray Shutters from the later semaphore towers. Both Britannica and Oxford Reference associate the semaphore system with Chappe's system and derivates like Popham's system, not Murray's system. --{{u|Mark viking}} {Talk} 10:51, 14 August 2021 (UTC)
• support leaving "semaphore" out (invited by the bot) This is not slam dunk, even if only some rarer meanings of semaphore included optical telegraph one could argue that the sentence is OK with "semaphore" in it. But based on going by the widely accepted meanings of the terms and also going by provided sources, IMO "semaphore" should be left out of that sentence. North8000 (talk) 13:26, 14 August 2021 (UTC)
• No, an optical telegraph is not exclusively a semaphore system. The article itself bears out this truth in its own prose which is further supported by the sources given.--John Cline (talk) 14:09, 14 August 2021 (UTC)
• Partial Support. Perhaps something along the lines of "semaphore-like"? I can understand reasons to not simply define it as "semaphore", as some uses of that term are precise enough to not fully apply to this subject. But the general idea of semaphore is probably the best way to give non-expert readers a good, quick idea of the subject -- just what we like for an article's opening sentence. --A D Monroe III^(talk) 18:20, 14 August 2021 (UTC)
• Optical telegraph systems make use of a network of apparatuses called semaphores. Any device that can convey a message by holding up a changing visual sign is a semaphore. A traffic light at a crossroads is a semaphore. Railway line traffic is traditionally managed with flags to indicate priority, called also semaphores. Semaphore, from greek sema (sign) + phoros (bearer) means "bearer of a sign". See the article on semaphores.--Megustalastrufas (talk) 11:03, 15 August 2021 (UTC) Optical telegraphs are all semaphore systems in the sense that they all make use of a network of semaphores (the apparatuses). Later telegraphs were cable/wire systems in the sense that they used cables/wires.Megustalastrufas (talk) 11:07, 15 August 2021 (UTC)
  • Another assertion without sources. The etymology of a word is not a reliable guide to its current meaning and use. SpinningSpark 11:14, 15 August 2021 (UTC)
  • The evidence is in the article semaphore, but here you are: --Megustalastrufas (talk) 11:38, 15 August 2021 (UTC)

References

• I'm afraid your evidence shows exactly the opposite of what you claim it does. The railway semaphore ref covers only railway signals using moveable arms, and the traffic signal semaphore ref explicitly says semaphore is different to traffic lights: "The earliest traffic signals did not consist of the tri-colored light system we use today. Rather, the semaphore signal was operated..." and later "The semaphore signal was used until the four-way, tri-colored light signal became the standard in 1935." SpinningSpark 11:44, 15 August 2021 (UTC)

• I see your point, but let's see, Britannica says: https://www.britannica.com/technology/semaphore. Semaphore, method of visual signaling, usually by means of flags or lights. Further in the text it says: Modern semaphores included movable arms or rows of lights simulating arms, displayed from towers and used to signal railroad trains. Semaphore signaling between ships, now largely abandoned, was accomplished by persons who held a small flag in each hand (...) For me it is clear that there is a general meaning for semaphore, and that the arms are one of the possibilities. Reviewing the other examples, it is true that popular use in modern English tends to identify semaphores with the arms, and that's what this discussion is about. I'm taking sides with Britannica.--Megustalastrufas (talk) 12:29, 15 August 2021 (UTC)

• Firt of all, a general encyclopaedia is not the most authoritative source to use here since they only cover topics very briefly, even one the size of Britannica. In any case, all their examples are of the moveable arm type and the phrase "movable arms or rows of lights simulating arms" is very suggestive that arms have to be involved somewhere. I also note that they mention flag semaphore in relation to maritime flag signalling which they say is largely abanoned but fail to include as semaphore the flaghoist signals of the international maritime signal flags which is still very much current. Also, I maintain that this division is not just a modern thing, it is just as clear in centuries old sources. SpinningSpark 13:00, 15 August 2021 (UTC)

• If the question is the meaning of semaphore:

>>>the Merriam Webster's answer is: https://www.merriam-webster.com/dictionary/semaphore an apparatus for visual signaling (as by the position of one or more movable arms). Which implies that the arms are just an example, or a common option.

>>>the Britannica (as above): https://www.britannica.com/technology/semaphore method of visual signaling, usually by means of flags or lights

>>>Dictionary.com https://www.dictionary.com/browse/semaphore 1. an apparatus for conveying information by means of visual signals, as a light whose position may be changed. 2. any of various devices for signaling by changing the position of a light, flag, etc. 3. a system of signaling, especially a system by which a special flag is held in each hand and various positions of the arms indicate specific letters, numbers, etc.

I think the answer is clear.--Megustalastrufas (talk) 16:10, 15 August 2021 (UTC)

Yes, it is clear. The common denominator of every meaning given is that there is a change of position. Lights, arms and flags are included, but a static flashing light like the heliograph or Aldis lamp is strangely missing. Putting Dictionary.com on the same level as the Holzmann & Pehrson book shows a complete inability to assess the worth of sources (WP:RSCONTEXT). SpinningSpark 14:02, 17 August 2021 (UTC)

I don't mean to ruin a perfectly good argument, but is it possible that the meaning of "semaphore" is simply ill-defined? --Syzygy (talk) 07:14, 17 August 2021 (UTC)

@Syzygy: Possibly, but that doesn't mean the scope of our articles has to be ill-defined. Since we have masny sources that make a clear distinction, we can too (and no reliable in-depth sources are a slam-dunk contradiction of that). My problem here is that if one defines all things visual signalling as semaphore then a separate semaphore page (which is a new creation) seems unjustified. SpinningSpark 13:55, 17 August 2021 (UTC)

Much the opposite, a separate semaphore page makes sense precisely for that reason. It covers different kinds of semaphores, for railway, for traffic, and also for optical telegraphy - the latter being a network of visually connected semaphores.--Megustalastrufas (talk) 07:35, 18 August 2021 (UTC)

If the term "semaphore" isn't well-defined, there seems to be little point in discussing whether optical telegraphs are semaphores. From a cursory look at the topic, to me it looks as though older sources limit the term semaphores to "things with arms" (did it originate as a proper name for Chappe's invention?), while more modern authors take a more general view of "signaling devices". After all, nowadays the term has a related meaning even in computer programming. Would this help in resolving the conflict? --Syzygy (talk) 14:51, 17 August 2021 (UTC)

@Syzygy: I don't agree that modern sources take a different view. The three book sources I gave at the beginning of this discussion are all recent (Craddock was published this year) and all make a clear distinction. The sources offered in contradiction are not as authoritive and are either ambiguous or actually make my case for me. Quoting a dictionary entry saying "a visual signalling device..." just doesn't cut it. Dictionaries are careful in their choice of words. If they meant that to be the defining feature they would have said something like "any visual signalling device..." Enough authors have defined it well enough as using arms for that to be the basis of our article. The fact that semaphore has another meaning in computing is not relevant, Wikipedia is not a dictionary and articles should be about a single topic. SpinningSpark 09:10, 18 August 2021 (UTC)

The dictionary does say any so that part of your argument doesn't stand: any of various devices for signaling by changing the position of a light, flag, etc.

Your quote from Craddock doesn't make your point. Suppose it's vehicles we are discussing: Was it hubris at French advantage with Chappe's vehicle that the motorcycle was adopted in England? Would we conclude that a motorcycle is not a vehicle?

About the misnaming complaint, calling the optical telegraph the semaphore is indeed misnaming it, just as calling later telegraphs the cable, its is a typical synecdoche. Megustalastrufas (talk) 11:41, 18 August 2021 (UTC)

Megustalastrufas, respectfully, your initial relevant assertion was "Any device that can convey a message by holding up a changing visual sign is a semaphore. A traffic light at a crossroads is a semaphore." and is a bit self-conflicting because it includes "holding up" which supports SpinningSpark's argument and conflicts with your main one. If I take out the "holding up" and condense it, and add my clarifying words, it is : "Any device (= ALL devices) that can convey a message (such as a traffic light at a crossroads) is a semaphore." And at the core of that is that something (like a traffic light) with no mechanical motion is still a semaphore. And such an assertion/argument must be won in order for the change away from the long standing version to be valid. IMHO in all of your subsequent discussion you did not present anything to support that argument and even your own words seemed to no longer address/assert that initial argument. Sincerely, North8000 (talk) 12:31, 18 August 2021 (UTC)

@North8000 a traffic light is a set of coloured lights that is held up above a crossroad by means of a post, an arch, a bridge, a set of cables, or any other means to make it visible to drivers. That's why I said holding up, no movement implied; but I'll rephrase it for your benefit: A semaphore is any device that can convey a message by holding a changing visual sign so that it can be interpreted from a distance. The keywords are changing (whether it is by moving arms or switching lights), visual, message and distance. This is in line with the three dictionary definitions I provided above. Here's two more, that's five in total: https://www.thefreedictionary.com/semaphore The Free Dictionary 1. A visual signaling apparatus with flags, lights, or mechanically moving arms, as one used on a railroad. https://www.collinsdictionary.com/dictionary/english/semaphore 1. an apparatus for conveying information by means of visual signals, as with movable arms or railway signals, flags, etc. Moving arms are just one kind of semaphore - I can see that for some people, moving arms may well be the semaphore, as a popular antonomasia, but the others are semaphores as well. Megustalastrufas (talk) 14:48, 18 August 2021 (UTC)

IMHO even the references / links that you gave mostly support SpinningSpark's view & the longstanding text. Sincerely, North8000 (talk) 18:57, 18 August 2021 (UTC)

SpinningSpark's view is that semaphores are ONLY moving arms, while the references I gave state that semaphores are ANY visual signalling device, INCLUDING moving arms, but ALSO flags or lights (switched or shuttered).Megustalastrufas (talk) 08:20, 19 August 2021 (UTC)

I'm only trying to help here and I stand by my previous statement, short, vague and unsupported as it was. So I skipped an an analysis of what those sources said. But briefly/vaguely IMHO they provide a lot of support for saying that the pervasive meanings for semaphore all include some mechanical motion. And they gave no explicit support and only a small amount of implicit support for the notion of calling signaling that does not involve mechanical motion semaphore. Sincerely, North8000 (talk) 12:39, 19 August 2021 (UTC)

• Is this about the meaning of "semaphore"? Or of "optical telegraph"? What does "support" mean, when the first such vote disagrees with the proposition?

Anyhow, not all optical telegraphs are semaphores. Semaphores use physical movement perpendicular to the axis to the viewer. They move so as to look different - usually they rotate.

Optical telegraphs might use this too, because it works. But many did not. Some are shutters: visible or not, or black versus white. Some are simple movement, such as balls and cones hoisted up a pole. Some use the shapes of things up a pole. The simplest are flags. So no. Not all optical telegraphs are semaphores. Diaph0nous (talk) 15:12, 30 August 2021 (UTC)

Yes, it is confusing what "support" means. One would have to look at what people wrote.North8000 (talk) 15:59, 30 August 2021 (UTC)

Clarifying The wording at issue is a change made November 2020 which added "semaphore" resulting in "An optical telegraph is a semaphore system" which is essence a claim that all optical telegraphs are semaphores. For the first 18 years of the article it made no such claim. During some of it's years, it listed several types of optical telegraphs, one of them being semaphores. In essence a statement that the other types are not semaphores. In early August SpinningSpark reverted that change and was reverted and then they started this RFC.North8000 (talk) 16:25, 30 August 2021 (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.

Found paragraph that might need splitting

Specifically, this paragraph, from the section [i]n popular culture:

By the mid-19th century, the optical telegraph was well known enough to be referenced in popular works without special explanation. The Chappe telegraph appeared in contemporary fiction and comic strips. In "Mister Pencil" (1831), a comic strip by Rodolphe Töpffer, a dog fallen on a Chappe telegraph's arm—and its master attempting to help get it down—provoke an international crisis by inadvertently transmitting disturbing messages. In "Lucien Leuwen" (1834), Stendhal pictures a power struggle between Lucien Leuwen and the prefect M. de Séranville with the telegraph's director M. Lamorte. In Chapter 60 ("The Telegraph") of Alexandre Dumas' The Count of Monte Cristo (1844), the title character describes with fascination the semaphore line's moving arms: "I had at times seen rise at the end of a road, on a hillock and in the bright light of the sun, these black folding arms looking like the legs of an immense beetle." He later bribes a semaphore operator to relay a false message in order to manipulate the French financial market. Dumas also describes in detail the functioning of a Chappe telegraph line. In Hector Malot's novel Romain Kalbris (1869), one of the characters, a girl named Dielette, describes her home in Paris as "...next to a church near which there was a clock tower. On top of the tower there were two large black arms, moving all day this way and that. [I was told later] that this was Saint-Eustache church and that these large black arms were a telegraph."

I think the sentence starting with "[i]n Chapter 60" would be a good place to split it. Could anyone please tell me if this is a good idea? Thylacine24 (talk) 02:48, 7 May 2023 (UTC)

This paragraph mentions 4 very different works by 4 authors. To split it in just 2 paragraphs would be completely arbitrary and would not help the reading in any way. In my opinion it should either stay as it is, or be split in 5 (introductory sentence, and then one small paragraph for each work, Toepffer, Stendhal, Dumas, Malot).--Sapphorain (talk) 07:41, 7 May 2023 (UTC)

Murray shutter chain speed.

In Optical_telegraph#United_Kingdom, it says "Messages passed from London to Deal in about sixty seconds". In the external https://www.commsmuseum.co.uk/shutter.htm, it says the similar length chain from London to Portsmouth took about 15 minutes. The former is unbelievably quick. 11 gaps, so around 5½ seconds delay per relay station ~ I don't believe it. The latter at just over a minute per relay station seems much more plausible. Is there a source for the sixty seconds - or a source for any latency from London to Deal? -- SGBailey (talk) 20:43, 9 October 2024 (UTC)

60 seconds does seem like it is too short for any but the shortest message. For just sending a message forward one station by heliograph (which required far less mechanical motion than a shutter or semaphore), 12 words per minute were considered good practice. ~~ Macchess (talk) 05:21, 12 October 2024 (UTC)

A 5.5 second delay per station per symbol seems spot on to me (explanation below), but for a message of any significant length, the driving factor is the symbol to symbol time (20-30 seconds per symbol for the Chappe system, more below), and the system "wakeup time".

For the Chappe system, the Wikipedia article cites references as saying:

"A symbol sent from Paris took 2 minutes to reach Lille through 22 stations and 9 minutes to reach Lyon through 50 stations. A rate of 2–3 symbols per minute was typical, with the higher figure being prone to errors."

That is a latency of 5.5 seconds per station for relay station for Paris to Lille, but a 20-30 second symbol to symbol time.

=== what I think is going on ... ===

An intermediate station didn't wait for the entire message before starting their transmission, but passed on each symbol as it was recognized. The process at a given intermediate station "i" for each symbol would be:

(1) station i notes Nth incoming symbol from station i-1

(2) station repeats Nth incoming symbol

(3) station i+1 notes Nth incoming symbol from station i

(4) station i+1 repeats Nth incoming symbol

(5) station i notes that station i+1 has successfully repeated the Nth incoming symbol

[ Note that "control symbols" for:

"your incoming symbol is unclear" and

"your repeated symbol is incorrect" would come in handy)

Once the system was "primed", I would expect about 1 second for each of the steps, which gives a station latency of 5 seconds, on par with the advertised Paris-Lille latency of 5.5 seconds per station.

I would think that the largest time expenditure would be to "wake up" the system. Having operators standing by to react on 1 seconds notice for 12 hours a day seems unreasonable, even with shifts. I note the mention that a German system used synchronized clocks, with a message passed once an hour, on the hour, using a null message if no other traffic were planned. A similar system was used in the 20th century for monitoring for emergency marintime radio traffic - a 3 minute "monitor period" every 15 minutes. However, I have no idea how the Chappe system handled that sort of thing. ~~

P.S. A very early (1797) description by the Englishman Gamble says that the Chappe arms were allocated 4 seconds to move between positions, and then held that position for 16 seconds. If there were no attempt to verify that the symbol had been repeated correctly, and the operators were concentrating on the upstream system, that would also allow a 5 second symbol latency per station ~~ Macchess (talk) 21:50, 12 October 2024 (UTC)