3 ms·

Does anyone know how the telegraph lines were architected? Did you have segments of shared stations, where a message sent from one station was echoed to all th

Does anyone know how the telegraph lines were architected? Did you have segments of shared stations, where a message sent from one station was echoed to all the connected stations, with one responsible for forwarding messages across segments? Just curious what the path of a message from, say, New York to Chicago was.

dbcurtis 3y ago
You raise an interesting question, but note that this article is about KPH, a radio telegraph station, not land-line telegraphy. I don't know much about your actual question though.... I know that there were "repeaters" in the lines, basically a relay with a local battery, on longer lines. I know railroads had their own network of telegraph circuits between stations, with poles along the track right-of-way. I know that the first trans-Atlantic telegraph wires was what led to research into basic transmission line theory, since the first cables only allowed pitifully slow signalling and the reason why was not well understood. If you look at old photographs of rail road right-of-way, you see 6 or 8 wires or more, so they obviously were running multiple telegraph circuits along the line. In passing, I will note the trivia that land-line Morse (the original) and international radio-telegraph Morse is different in a few characters, because some of the character "clacks" become difficult to distinguish as "beeps" under noisy conditions. You have successfully nerd-sniped me today, well played.
Animats 3y ago
For big operations such as Western Union, it was store and forward. Links were point to point links with messages hand-copied to paper at relay stations. Paper messages were sorted by hand, and re-sent by outgoing operators. Large buildings with large staffs were required.[1] KPH was such a relay station, where messages went from land lines to radio and back. Low-traffic lines and railroads tended to have many stations on one wire. Similarly, ships could talk to each other by radio. To get into the interconnected system, you had to go through a gateway to a commercial network, and there would be charges incurred at that point. [1] https://www.wondersofworldengineering.com/telegraph_office.html https://www.wondersofworldengineering.com/telegraph_office.h...
- cpeterso 3y ago
  Some messages were sent through relays, or the lines could be tapped, I wonder if any telegraph operators encrypted their messages using a shared key.
  - pjlegato 3y ago
    Telegraphic ciphers and codes were common, both to save money through compression, and as it was well known that many people would be reading and re-transmitting the message as it worked its way through the system. There were various standardized codebooks published for when the message was not secret and compression was the only consideration: https://en.wikipedia.org/wiki/Commercial_code_(communications) https://en.wikipedia.org/wiki/Commercial_code_(communication... Frequent telegraph users with an additional need for secrecy, such as investment bankers, developed similar proprietary in-house codebooks.
eszed 3y ago
If you're interested in this topic, here's a book to read: https://en.m.wikipedia.org/wiki/The_Victorian_Internet https://en.m.wikipedia.org/wiki/The_Victorian_Internet It's been twenty+ years since I last owned a copy, but it was one of my favorite books for a while. The bulk of the material is about pointing out amazing parallels between behaviors on the early internet and century-previous telegraph / wireless networks, but it also discusses physical and network protocols - not, perhaps, in huge depth (I don't remember exactly), but everything mentioned in sibling comments was familiar to me.

dbcurtis 3y ago

You raise an interesting question, but note that this article is about KPH, a radio telegraph station, not land-line telegraphy. I don't know much about your actual question though.... I know that there were "repeaters" in the lines, basically a relay with a local battery, on longer lines. I know railroads had their own network of telegraph circuits between stations, with poles along the track right-of-way. I know that the first trans-Atlantic telegraph wires was what led to research into basic transmission line theory, since the first cables only allowed pitifully slow signalling and the reason why was not well understood. If you look at old photographs of rail road right-of-way, you see 6 or 8 wires or more, so they obviously were running multiple telegraph circuits along the line. In passing, I will note the trivia that land-line Morse (the original) and international radio-telegraph Morse is different in a few characters, because some of the character "clacks" become difficult to distinguish as "beeps" under noisy conditions. You have successfully nerd-sniped me today, well played.

Animats 3y ago

For big operations such as Western Union, it was store and forward. Links were point to point links with messages hand-copied to paper at relay stations. Paper messages were sorted by hand, and re-sent by outgoing operators. Large buildings with large staffs were required.[1] KPH was such a relay station, where messages went from land lines to radio and back. Low-traffic lines and railroads tended to have many stations on one wire. Similarly, ships could talk to each other by radio. To get into the interconnected system, you had to go through a gateway to a commercial network, and there would be charges incurred at that point. [1] https://www.wondersofworldengineering.com/telegraph_office.html https://www.wondersofworldengineering.com/telegraph_office.h...

cpeterso 3y ago
Some messages were sent through relays, or the lines could be tapped, I wonder if any telegraph operators encrypted their messages using a shared key.
- pjlegato 3y ago
  Telegraphic ciphers and codes were common, both to save money through compression, and as it was well known that many people would be reading and re-transmitting the message as it worked its way through the system. There were various standardized codebooks published for when the message was not secret and compression was the only consideration: https://en.wikipedia.org/wiki/Commercial_code_(communications) https://en.wikipedia.org/wiki/Commercial_code_(communication... Frequent telegraph users with an additional need for secrecy, such as investment bankers, developed similar proprietary in-house codebooks.

eszed 3y ago

If you're interested in this topic, here's a book to read: https://en.m.wikipedia.org/wiki/The_Victorian_Internet https://en.m.wikipedia.org/wiki/The_Victorian_Internet It's been twenty+ years since I last owned a copy, but it was one of my favorite books for a while. The bulk of the material is about pointing out amazing parallels between behaviors on the early internet and century-previous telegraph / wireless networks, but it also discusses physical and network protocols - not, perhaps, in huge depth (I don't remember exactly), but everything mentioned in sibling comments was familiar to me.