6 ms·

Hydraulic Telegraph

38 points by tikwidd 7y ago

yummypaint 7y ago
Reminds me of the paris pneumatic clock system that would be built 40 years after the british telegraph. https://news.ycombinator.com/item?id=19441300 https://news.ycombinator.com/item?id=19441300
- est31 7y ago
  pneumatics are still used in organs today! (Not new ones, but old still deployed ones still have them) https://upload.wikimedia.org/wikipedia/commons/5/51/Salemer_M%C3%BCnster_Orgel_innen_Pneumatische_Traktur.jpg https://upload.wikimedia.org/wikipedia/commons/5/51/Salemer_... https://en.wikipedia.org/wiki/Tubular-pneumatic_action https://en.wikipedia.org/wiki/Tubular-pneumatic_action
  - dwringer 7y ago
    This made me recall reading about Douglas Engelbart's project from SRI (whence the computer mouse originated) that used a 5-key chording keyset that had pneumatic actuators for using the keys to output a data stream to the user haptically (from my reading it was unclear if this functionality was ever intended to be put in the mouse as well, which was used in the opposing hand). I wonder if anyone is aware of any existing modern (DIY?) projects to bring such a thing back to life?
JoeAltmaier 7y ago
Could have used the aqueduct as a telegraph as early as 7th century BCE - put a written message in the equivalent of a rubber duck, drop it in. A spotter on the other end dips it out and delivers the message. How could no one have thought of that?
- athenot 7y ago
  Maybe they wanted to send messages from one hilltop to another, where there was no aqueduct. Also the system described may be low bandwidth but it's also low latency. Would be useful to relay messages of a security/defense nature.
  - 0898 7y ago
    Could not much the same effect have been achieved by pulling on a piece of string?
    - rtkwe 7y ago
      You'd have to make a very long piece of string and avoid it snagging, getting cut, or breaking under it's own weight. Also along that distance there's going to be a lot of slack in the system so you'd have to take that up too.
- tgarv 7y ago
  That would only give you one-directional communication, while the hilltop-to-hilltop systems described in the article would work both ways.
  - JoeAltmaier 7y ago
    Still one-directional communications is useful. Think ordering by mail from Sears.
- krilly 7y ago
  I was just about to ask HN to come up with some communication devices using only ancient technology. Although your rubber duck system would require less manpower than a system of signal fires, it would be MUCH slower, and probably even slower than the chains of horse riders that delivered messages Pony Express-style across the Roman Empire. In an emergency, a message could be transferred over 100 miles a day. https://en.wikipedia.org/wiki/Cursus_publicus https://en.wikipedia.org/wiki/Cursus_publicus
  - JoeAltmaier 7y ago
    I imagine it would be useful for some information. Crop reports etc for helping predict market fluctuations. All aqueducts lead to the city after all! Where the markets are. Anyway its nearly free, and the infrastructure was always in place. I'm just surprised it didn't get used.
  - JoeAltmaier 7y ago
    Oh! And for your ancient-networking subject, I submit: * grow trees in rows; cut them in ascii sequences (a stump is a 0). Visible for miles! * scratch dated messages in turtles' shells; sample shells continuously and collate * spread gossip where the subject is a code e.g. marital infidelity means one thing, sexual preference another. Collect gossip and reconstruct. Use political topics for ack and nack. * Grow crops each year to encode the message: corn is a 1, soybeans a 0. Study crop market reports. Caution: baud rate is low and noise level high, recommend using ECC * Become a fashion icon. Adjust skirt lengths microscopically and seasonally to encode multiple bits! A plus: observation and measurement has side benefits Let me know if any of these suit your purposes. I release them to the public domain.
    - rtkwe 7y ago
      Friendly reminder that the code block style is basically unreadable on mobile (and not so great on desktop either) because it doesn't wordwrap.
      - JoeAltmaier 7y ago
mannykannot 7y ago
In the Roman version, the hydraulic part is a clock for generating and measuring signals having a specific duration.
- rtkwe 7y ago
  Yes. In a time before we really knew how to accurately measure short periods of time flowing water was one of the few ways humans had to meter out time. In theory a pendulum with the same weight and length could have served the same purpose with some limitations on the number of messages it could potentially convey.
- mannykannot 7y ago
  /Roman/Greek/ doh!
nkrisc 7y ago
Maybe I'm missing something, but with the Greek system why did they need to use draining water as a time-keeping method? Why not, after some acknowledgement sequence, does the signaler not simply wave the touch a specific number of times which the receiver could use to correlate with a predetermined list of possible messages? For example, signaler holds touch aloft continuously. Receiver notices and does the same to acknowledge. Signaler now waves the touch seven times. Receiver checks chart for which message 7 waves correlates to. Is that not effectively the same as the described method in the article but with less room for error due to timing? You also wouldn't need to keep the devices themselves calibrated, as if one drained faster than the other, you'll have a problem. You only need a mutually agreed upon chart of messages which is already a requirement with the water method. Basically, semaphore. Why not just semaphore? What is the advantage to their method? Is the timing method maybe easier if you were dealing with, say, 50 messages on the vessel? As opposed to coming up with a way to encode 50 different messages?
- rtkwe 7y ago
  Light on or off is a clear signal over a much longer distance than a light moving only a few feet. A simple candle can be seen a very long distance on a dark night but just moving it back and forth gets lost. There were no means of visual magnification available which is what makes semaphore possible over usable distances.
  - ncmncm 7y ago
    So, instead of waving the torch in the open you wave it next to a wall so it appears to go on and off. Same question.
    - nkrisc 7y ago
      I thought the same as well. Clearly the ancient Greeks weren't morons so there's probably a reason they did it the way they did. Thinking about it more, their system is probably much easier for a novice to use, or some random soldier grabbed for signal duty. There's no need to count and keep track of torch waves. The synchronization protocol seems pretty simple and the process afterwards is equally simple. Hell, your soldier doesn't even need to know how to count, if that was even a problem for the Greeks.

38 points by tikwidd 7y ago

Reminds me of the paris pneumatic clock system that would be built 40 years after the british telegraph. https://news.ycombinator.com/item?id=19441300 https://news.ycombinator.com/item?id=19441300

est31 7y ago
pneumatics are still used in organs today! (Not new ones, but old still deployed ones still have them) https://upload.wikimedia.org/wikipedia/commons/5/51/Salemer_M%C3%BCnster_Orgel_innen_Pneumatische_Traktur.jpg https://upload.wikimedia.org/wikipedia/commons/5/51/Salemer_... https://en.wikipedia.org/wiki/Tubular-pneumatic_action https://en.wikipedia.org/wiki/Tubular-pneumatic_action
- dwringer 7y ago
  This made me recall reading about Douglas Engelbart's project from SRI (whence the computer mouse originated) that used a 5-key chording keyset that had pneumatic actuators for using the keys to output a data stream to the user haptically (from my reading it was unclear if this functionality was ever intended to be put in the mouse as well, which was used in the opposing hand). I wonder if anyone is aware of any existing modern (DIY?) projects to bring such a thing back to life?

JoeAltmaier 7y ago

Could have used the aqueduct as a telegraph as early as 7th century BCE - put a written message in the equivalent of a rubber duck, drop it in. A spotter on the other end dips it out and delivers the message. How could no one have thought of that?

athenot 7y ago
Maybe they wanted to send messages from one hilltop to another, where there was no aqueduct. Also the system described may be low bandwidth but it's also low latency. Would be useful to relay messages of a security/defense nature.
- 0898 7y ago
  Could not much the same effect have been achieved by pulling on a piece of string?
  - rtkwe 7y ago
    You'd have to make a very long piece of string and avoid it snagging, getting cut, or breaking under it's own weight. Also along that distance there's going to be a lot of slack in the system so you'd have to take that up too.
tgarv 7y ago
That would only give you one-directional communication, while the hilltop-to-hilltop systems described in the article would work both ways.
- JoeAltmaier 7y ago
  Still one-directional communications is useful. Think ordering by mail from Sears.
krilly 7y ago
I was just about to ask HN to come up with some communication devices using only ancient technology. Although your rubber duck system would require less manpower than a system of signal fires, it would be MUCH slower, and probably even slower than the chains of horse riders that delivered messages Pony Express-style across the Roman Empire. In an emergency, a message could be transferred over 100 miles a day. https://en.wikipedia.org/wiki/Cursus_publicus https://en.wikipedia.org/wiki/Cursus_publicus
- JoeAltmaier 7y ago
  I imagine it would be useful for some information. Crop reports etc for helping predict market fluctuations. All aqueducts lead to the city after all! Where the markets are. Anyway its nearly free, and the infrastructure was always in place. I'm just surprised it didn't get used.
- JoeAltmaier 7y ago
  Oh! And for your ancient-networking subject, I submit: * grow trees in rows; cut them in ascii sequences (a stump is a 0). Visible for miles! * scratch dated messages in turtles' shells; sample shells continuously and collate * spread gossip where the subject is a code e.g. marital infidelity means one thing, sexual preference another. Collect gossip and reconstruct. Use political topics for ack and nack. * Grow crops each year to encode the message: corn is a 1, soybeans a 0. Study crop market reports. Caution: baud rate is low and noise level high, recommend using ECC * Become a fashion icon. Adjust skirt lengths microscopically and seasonally to encode multiple bits! A plus: observation and measurement has side benefits Let me know if any of these suit your purposes. I release them to the public domain.
  - rtkwe 7y ago
    Friendly reminder that the code block style is basically unreadable on mobile (and not so great on desktop either) because it doesn't wordwrap.
    - JoeAltmaier 7y ago

mannykannot 7y ago

In the Roman version, the hydraulic part is a clock for generating and measuring signals having a specific duration.

rtkwe 7y ago
Yes. In a time before we really knew how to accurately measure short periods of time flowing water was one of the few ways humans had to meter out time. In theory a pendulum with the same weight and length could have served the same purpose with some limitations on the number of messages it could potentially convey.
mannykannot 7y ago
/Roman/Greek/ doh!

nkrisc 7y ago

Maybe I'm missing something, but with the Greek system why did they need to use draining water as a time-keeping method? Why not, after some acknowledgement sequence, does the signaler not simply wave the touch a specific number of times which the receiver could use to correlate with a predetermined list of possible messages? For example, signaler holds touch aloft continuously. Receiver notices and does the same to acknowledge. Signaler now waves the touch seven times. Receiver checks chart for which message 7 waves correlates to. Is that not effectively the same as the described method in the article but with less room for error due to timing? You also wouldn't need to keep the devices themselves calibrated, as if one drained faster than the other, you'll have a problem. You only need a mutually agreed upon chart of messages which is already a requirement with the water method. Basically, semaphore. Why not just semaphore? What is the advantage to their method? Is the timing method maybe easier if you were dealing with, say, 50 messages on the vessel? As opposed to coming up with a way to encode 50 different messages?

rtkwe 7y ago
Light on or off is a clear signal over a much longer distance than a light moving only a few feet. A simple candle can be seen a very long distance on a dark night but just moving it back and forth gets lost. There were no means of visual magnification available which is what makes semaphore possible over usable distances.
- ncmncm 7y ago
  So, instead of waving the torch in the open you wave it next to a wall so it appears to go on and off. Same question.
  - nkrisc 7y ago
    I thought the same as well. Clearly the ancient Greeks weren't morons so there's probably a reason they did it the way they did. Thinking about it more, their system is probably much easier for a novice to use, or some random soldier grabbed for signal duty. There's no need to count and keep track of torch waves. The synchronization protocol seems pretty simple and the process afterwards is equally simple. Hell, your soldier doesn't even need to know how to count, if that was even a problem for the Greeks.