Talk:Earth-return telegraph/GA2

GA Review

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Reviewer: Wasted Time R (talk · contribs) 21:35, 15 October 2020 (UTC)

I have begun reviewing this article. Wasted Time R (talk) 21:35, 15 October 2020 (UTC)

Thanks for reviewing Wasted Time R. SpinningSpark 13:56, 16 October 2020 (UTC)

GA review (see here for what the criteria are, and here for what they are not)

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A solid article, does not need many changes

1. It is reasonably well written.

   a (prose, spelling, and grammar): b (MoS for lead, layout, word choice, fiction, and lists):

   Some prose could be clearer in my view, see below

2. It is factually accurate and verifiable.

   a (reference section): b (citations to reliable sources): c (OR): d (copyvio and plagiarism):

   One minor issue in the references, see below

3. It is broad in its coverage.

   a (major aspects): b (focused):

   A couple of aspects could be discussed and relationship with other articles is unclear, see below

4. It follows the neutral point of view policy.

   Fair representation without bias:

5. It is stable.

   No edit wars, etc.:

6. It is illustrated by images and other media, where possible and appropriate.

   a (images are tagged and non-free content have fair use rationales): b (appropriate use with suitable captions):

   Couple of issues in the captions, see below

7. Overall:

   Pass/Fail:

Re breadth and relationship with other articles:

This article does not mention or link to the Single-wire earth return article, but that one has a top xref to this one. Maybe there could be a {{See also}} to that one from the "Description" section here?

I don't think a link there would be particularly helpful. That article is about (or mainly about) power distribution. Our article here gives all the explanation of earth-return that is necessary (or it should do). SpinningSpark 13:35, 18 October 2020 (UTC)

How about creating a "See also" section in the article and making it an entry there? It's definitely on a related topic. Wasted Time R (talk) 22:16, 19 October 2020 (UTC)

Done SpinningSpark 12:37, 20 October 2020 (UTC)

There is also some discussion of earth return in the High-voltage direct current. But there's really no place in any of these articles that discusses why earth return actually works. Because it will be counter-intuitive to many readers: Yes, earth has some metals in it, but it's mostly soil and rock, which in isolation are poor conductors. And how does the current find its way back to this particular source? Why can't the current go to any other plate buried in the ground? I realize it isn't necessarily this article's responsibility to explain this – so this isn't actionable for this GA review – but it's something to think about.

However, there is no discussion here about soil resistivity, and I have seen that mentioned as a consideration in reading about earth-return arrangements for telegraph lines. For example this college course page says that in drier climates there might have to be multiple ground stakes, or water might have to be poured onto stakes, to improve conductivity.

I've expanded on soil as a conductor a little. I struggled to find a good source on the practice of pouring water on the earth spike. I'm sure I've seen a source saying that was the practice in parts of the southwest US, but I can't find it again. Possibly India as well. The source I've used is actually discussing field telephones in WWI, not telegraph, but I think it's justifiable. Earth-return phone lines have never been very successful and in trench warfare conditions they were often unusable. They often resorted back to telegraphy (the phones actually had a feature specifically for this) and the source says they were used in this way.

I like the material you added on this and I think the source is fine to use. My only suggestion would be that you added a link to the general resistivity, but maybe a link to the more specific soil resistivity would be better? Wasted Time R (talk) 22:16, 19 October 2020 (UTC)

Done, I didn't know (or had forgotten) that article existed. SpinningSpark 12:37, 20 October 2020 (UTC)

On the question of how the current finds it way back, this is not a question for earth-return articles to answer. Any circuit that uses a common return conductor between different parts has the same question, and this will apply universally to almost all circuit boards in electronics – all parts of the circuit are unbalanced "single-ended" with the return connected to a 0V rail or plane. It is a misconception to think that the electrons entering the plane have to find their way to the other end of circuit. They do not know where they are going when they set off, and in reality go only a very short distance. What really happens is that when a source is pushing electrons into a wire, it sucks electrons from the common plane (in this case Earth). When the current reverses electrons are pushed back into the Earth. This is just Kirchhoff's current law at work. Another way of thinking of it is that the Earth is so huge that it can absorb or supply any amount of charge required. In this respect it can be thought of as a giant capacitor rather than a conductor. It's the electromagnetic wave travelling down the line that carries the information in any communications system, not the charges, which hardly move at all. This is all basic electrical science which it would be inappropriate to delve into deeply in this article. SpinningSpark 15:16, 18 October 2020 (UTC)

I understand that it's a wave traveling back and that the actual charged particles only move a little. I guess what's puzzling me is that even before the advent of trams, why wouldn't telegraph lines using earth return interfere with each other? If there are earth-return lines A and B both in operation reasonably near each other, aren't the return currents from A going to end up at the B source just as much as they end up at the A source? So I remain in the belief that a brief, concise explanation of why this works would be a benefit to readers here. Wasted Time R (talk) 22:16, 19 October 2020 (UTC)

The simple answer is that there is not a complete circuit between A and B. It is a fundamental tenet of electrical network analysis that there must be a complete circuit for current to flow. The article already says "complete circuit" and I've now repeated it for emphasis. As I said above, common return paths are a basic electronic design technique. It is not the place of this article to teach basic analysis. In fact, it is not the place of Wikipedia, by policy, to teach anything. Different parts of your mobile phone circuit all use a common return path. Those parts are much closer together than any telegraph offices ever were, they are even closer than two lines going to the same office. Yet your mobile phone works just fine with that. It is, of course, possible to get interference between two telegraph lines, but this was never a major problem in the telegraph era due to the very slow signalling speeds (slow by modern standards). SpinningSpark 12:37, 20 October 2020 (UTC)

Re the prose:

... not wanting to patent the idea for the public good – I know what this is trying to say, but it could be read as that he did not want to patent an idea that would improve the public good. Should be rephrased.

Done SpinningSpark 15:46, 18 October 2020 (UTC)

... Earth return became so ubiquitous – This needs to be "However, Earth return soon became so ubiquitous" or something like that. Because the previous sentence says earth return was so little known that Morse wasn't aware of it, and yet now this sentence is saying it's ubiquitous. So the language needs to emphasize that there was a big transition.

There is no "however" to avoid overuse of the word (which is a common complaint in Wikipedia reviews). The article does not say that Steinheil's work was "little known". I think it actually spread quite rapidly in Europe and it was certainly being used in Britain and the Empire by the mid-1840s. Morse was a little out of the loop in the US, but he rapidly adopted the idea there too. I've added the word "immediately" to try to clarify that. SpinningSpark 15:46, 18 October 2020 (UTC)

Your change makes this clear. Regarding 'however', you must be having reviewers who have bought too heavily into the WP:WTA list ... Wasted Time R (talk) 22:16, 19 October 2020 (UTC)

... and got as far as provisional protection - For clarity, maybe should add "before the claim was denied" or "before the application was withdrawn" (depending upon what happened).

I have no information on the patent being denied. I'm not even sure that there exists a public record of refused patents. As I understand it, a failed patent is simply not issued, so we can see the application - and then nothing happens. The patentee might get a private letter saying it is not going to be issued, but nothing is in the patent database. This page says "This patent application was never sealed" which seems to confirm that point. If you do know of such an archive that is publicly accessible, I'll try and get the information. SpinningSpark 15:46, 18 October 2020 (UTC)

The introduction of electric power, especially electric tram lines, ... – This should be given a date. From the article linked to, this happened during the 1880s?

We can put a date on the introduction of electric trams (I've added something on that), but putting a date on when they became an issue for telegraphy is more problematic. It was a slowly increasing difficulty as trams became more common. Similarly, we can't put a definite date on when motor traffic started to cause city congestion, it just got steadily worse over the years. SpinningSpark 16:14, 18 October 2020 (UTC)

... especially electric tram lines, seriously disturbed earth-return telegraph lines. – Trams are usually associated with cities. Did the tram lines disrupt only telegraph lines running into the same cities, or more broadly?

I don't have a source discussing this, but its going to be trams near the receiving station (and to a lesser extent the sending station as well). How near is near? Well the Cape Town example where they had to extend the balanced line six miles out to sea before the problem was cleared gives the reader some idea of that. SpinningSpark 16:14, 18 October 2020 (UTC)

high-speed automatic working – This term could use a little explanation or a link.

Done SpinningSpark 16:46, 18 October 2020 (UTC)

On land, repeaters would be used to overcome this problem, – How do repeaters strengthen an earth-return signal? Are they planted into the ground?

No, the repeaters are in the line, not the earth. I've tried to clarify this point. In telegraphy, repeaters are placed at intermediate stations and consist of a relay outputting a repeat of the signal but connected to the voltage of a local battery which brings the signal back to its original level. This is covered (admittedly briefly) in the repeater article. Relays are not unique to earth-return circuits, in principle, they can be used with any form of telegraph line so I'm not sure they should be explained in detail here. In the nineteenth century, there was no practical way of sealing a relay into an underwater cable and no means of powering it if they could. Repeaters did not come in to submarine cables until the technology had moved beyond telegraphy and relays, i.e., too late. SpinningSpark 16:46, 18 October 2020 (UTC)

The problem was so severe that not only ... – Repeat of 'problem ... so severe' from earlier in the paragraph, could be reworded.

Done SpinningSpark 16:46, 18 October 2020 (UTC)

Re the references:

There is a comma at end of fn 16 - not sure if it's a stray or there was supposed to be something after it.

Done SpinningSpark 16:55, 18 October 2020 (UTC)

Re the images:

The caption language bearing the single wire of an earth-return line is kind of confusing. It's not the poles in the image that are bearing the earth-return, it's the ground underneath the poles. That college course page mentioned above explains old images more clearly, in my view: The poles carrying the single wire show that the line is using an earth return.

Changed "line" to "circuit" to try to clarify this. SpinningSpark 16:55, 18 October 2020 (UTC)

Similarly, A disused pole of the Australian Overland Telegraph Line which used to carry four earth-return lines has the same potential confusion, even worse, if a reader thinks that the earth return lines are actually on the poles or that there are four earth-return currents coming back.

I've reworded the caption, but it really isn't possible to explain entirely in the caption. The reader really has to read the text for that. SpinningSpark 16:55, 18 October 2020 (UTC)

The Watson and Steinheil captions should be consistent about whether they use first and last name or last name only.

Done SpinningSpark 17:09, 18 October 2020 (UTC)

Finally, I did look at the GA1 review from a while ago, which seems to have gone off the rails. For what it's worth I type two spaces after a period also. It's how everyone was taught back in the day and it makes absolutely no difference in how a WP article appears to readers. Wasted Time R (talk) 14:21, 17 October 2020 (UTC)

The disagreement over sentence spacing was just silly and irrelevant. The substantive issues were a disagreement over whether water return paths should be discussed (which I argue is supported by sources including them as part of earth-return telegraph history) and the title of the "Description" section. On the latter, I still fail to understand the objection and the claim that "An encyclopedia doesn't describe" is just baffling to me. SpinningSpark 17:09, 18 October 2020 (UTC)

Thanks for your very helpful comments. I may not be able to start responding to them for a few days as there is a non-Wikipedia task that I simply have to get done this weekend. SpinningSpark 15:26, 17 October 2020 (UTC)

@Spinningspark: Take your time, no rush on these, especially given the circumstances we are all living through. Wasted Time R (talk) 22:53, 17 October 2020 (UTC)

I think I've replied to everything now. Some items haven't led to a change in the article; I hope I have explained those adequately, but if not, please come back on them. SpinningSpark 17:09, 18 October 2020 (UTC)

I just have a few follow-on comments, indicated above; everything else I am okay with. Wasted Time R (talk) 22:16, 19 October 2020 (UTC)

Regarding common return paths, the Ground (electricity) article does discuss the topic some. I get that there has to be a completed circuit for the current to flow, but organized return conductors within something like a mobile phone seemed inherently different to me than endless possible paths through the earth. But obviously not. Clearly my three college physics courses, including a semester of electricity and magnetism, were way too long ago! I am passing the article for GA. It's interesting and informative, good work on it. Wasted Time R (talk) 23:09, 20 October 2020 (UTC)