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Communications The Internet

Email In the 18th Century 279

Posted by kdawson from the before-morse-code dept.
morphovar forwards a writeup in Low-tech Magazine recounting an almost-forgotten predecessor to email and packet-switched messaging: the optical telegraph. The article maps out some of the European networks but provides no details of those built in North America in the early 1800s. Man-in-the-middle attacks were dead easy. "More than 200 years ago it was already possible to send messages throughout Europe and America at the speed of an airplane — wireless and without need for electricity. The optical telegraph network consisted of a chain of towers ... placed 5 to 20 kilometers apart from each other. Every tower had a telegrapher, looking through a telescope at the previous tower in the chain. If the semaphore on that tower was put into a certain position, the telegrapher copied that symbol on his own tower. A message could be transmitted from Amsterdam to Venice in one hour's time. A few years before, a messenger on a horse would have needed at least a month's time to do the same."
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Email In the 18th Century More

Email In the 18th Century

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  • Spam? (Score:4, Funny)

    by AlphaDrake ( 1104357 ) * on Sunday December 23, 2007 @07:27PM (#21801196) Homepage
    Did spam make it across these networks as well?

    "Having trouble with the smell of thine donkey? Only have the one mistress? Try friar pete's ol' fashioned elixer de skunke, it's new lead based formula works wonders like that Jesus guy over there"

    • Re: (Score:3, Interesting)

      by K. S. Kyosuke ( 729550 )
      Ah, yes, Claude Chappe's optical telegraph. :-) Nice that people still remember these. You can also read about them here [wikipedia.org]. The part about the system cost compared to the electric telegraph is really interesting. It is not very suprising that this system was ultimately replaced soon after electrical telegraphs had become available. (One has to ask why Czech Post - providing virtually the same quality of service - has not yet seen the same fate? ;-))
      • According to a legend that I did not verify, one of the Rotschild's became immensely rich because he knew before anybody else in London about the defeat of Napoleon in Waterloo : according to that legend, he bought a lot of stocks & shares because they were quite low, and could sell them when the news reached the press.

        I am not sure it is true because the Chappe code was normally secret, so looking at the signs coould not really help. The operators themselves did not undertand what they were transmitt

        • Re:Chappe's telegraph and buiding of a fortune (Score:5, Informative)

          by AI0867 ( 868277 ) * on Sunday December 23, 2007 @10:30PM (#21802258)
          actually, the story was more interesting
          -Rothschilds get information early
          -other people know rothschilds get the information early
          -rothschilds dump all their stock
          -everyone else dumps their stock
          -stock crashes
          -rothschilds buy everything

          massive stock manipulation, but I guess that was legal back then.

          (or at least this is the version I heard)

          • Re:Chappe's telegraph and buiding of a fortune (Score:4, Interesting)

            by instarx ( 615765 ) on Monday December 24, 2007 @06:26AM (#21804338)
            actually, the story was more interesting
            -Rothschilds get information early
            -other people know rothschilds get the information early
            -rothschilds dump all their stock
            -everyone else dumps their stock
            -stock crashes
            -rothschilds buy everything

            massive stock manipulation, but I guess that was legal back then.

            Actually this would be perfectly legal today. Getting public information faster than everyone else is smart, not illegal; and there is noting illegal about selling stock to drive the price down and then snapping up deals. Market-makers do it every day to shake out margin traders.

      • Re:Spam? (Score:5, Informative)

        by AKAImBatman ( 238306 ) <akaimbatman AT gmail DOT com> on Monday December 24, 2007 @01:46AM (#21803228) Homepage Journal

        It is not very suprising that this system was ultimately replaced soon after electrical telegraphs had become available.

        Actually, it wasn't. The electrical telegraph had a very rocky start. Both France and Britain had optical telegraphs in place and were uninterested in investing in this new "electric" form of telegraph. Especially since those who worked on electric telegraphs were often untrained quacks.

        It took a relatively new nation that lacked a telegraph (i.e. the United States) to cause the electric version to catch on. Even there, it took a while before the possibilities were really explored. Once it caught on, though, it caught on like wildfire. Didn't take long for an international telegraph to get setup, and for ticker-tape machines to appear.

        For those interested in the topic, I highly recommend the book The Victorian Internet [amazon.com]. It is well written, well researched, and tells a fascinating tale of the telegraph development that parallels the development of the Internet. On top of that, it sheds light on how the telegraph affected computer design and the communications protocols we use today. (e.g. ASCII is derived from the telegraph codeset called "Baudot Codes". Named for the inventor, Émile Baudot. He also has a measure of transmission speed named after him called "Baud". As in, a "300 Baud Modem". )

        • Re: (Score:3, Insightful)

          by K. S. Kyosuke ( 729550 )

          Actually, it wasn't. The electrical telegraph had a very rocky start. Both France and Britain had optical telegraphs in place and were uninterested in investing in this new "electric" form of telegraph. Especially since those who worked on electric telegraphs were often untrained quacks.

          In the same way as the transistor had in the first years of its existence? The vacuum tubes' manufacturers certainly also didn't want to give up. Even though the technological progress was already accelerating in the begin

      • Re:Spam? (Score:4, Informative)

        by Alioth ( 221270 ) <no@spam> on Monday December 24, 2007 @05:09AM (#21804092) Journal
        Terry Pratchett did - his recent book "Going Postal", one of the main "characters" of the story is the clacks - the Discworld optical telegraph network. It's a fun book.

    • Re: (Score:3, Informative)

      by Tablizer ( 95088 )
      Did spam make it across these networks as well?

      In an 18th-century British accent: "Oh bloody hell, I shall not need my wanker any bloody bigger! May the Queen assign lasting damnation upon your deplorable message."
             

    • Re:Spam? (Score:5, Funny)

      by morgan_greywolf ( 835522 ) on Sunday December 23, 2007 @08:18PM (#21801528) Homepage Journal
      Indeed. A guy named Isaac Bayes would stand between two of the towers and every time he spotted a reference to making your penis larger, he would create a lot of thick black smoke so as to block the transmission between two towers.

      And to this day, most spam filters are still called 'Bayesian filters.'

    • Re: (Score:3, Informative)

      by petermgreen ( 876956 )
      Did spam make it across these networks as well?
      I doubt it for simple economical reasons. Theese networks were probablly more expensive to use than the postal service and unsolicited bulk messages aren't really very urgent.

  • Light the Fires (Score:5, Funny)

    by coaxial ( 28297 ) on Sunday December 23, 2007 @07:29PM (#21801210) Homepage
    Gondor needs help.
    • And Rohan will answer! Muster the Rohirrim! Assemble the Men at Dunharrow, as many Men as can be found. You have two days. On the third, we ride for Gondor... and war.
  • I was reading something recently that discussed the US Postal Service in the late 19th century. In some major cities, like New York and Boston, the mail used to come as much as five times a day. That meant you could write to someone (local, served from the same Post Office) in the early morning, have it picked up in the first round, delivered in the second, have their reply picked up in the third, and delivered on the fourth. (And you could even send a reply back in the final pickup for delivery the next morning.) That's pretty good -- some people I know don't even check their email that often!

    If you wanted service and delivery times that good these days, you'd need to go with a courier service.
    • Where I work they just cut the internal mail service from 10 to 4 times per week, due to lack of demand. Can't say I've noticed!

      • Re:Postal mail used to be pretty good, too. (Score:5, Interesting)

        by iocat ( 572367 ) on Sunday December 23, 2007 @08:22PM (#21801554) Homepage Journal
        I remember reading an article a few years ago, on various companies' ettiquette for the term "email." Some caled it 'email,' some called it 'electronic mail,' some called it by a quaint brand name ('QuickMail', anyone?). The article noted that at Micorosoft, it was simply refered to as "mail." So the author asked the inevitable question: "What do you call something that comes in a physical envelope?" The answer? "FedEx."

        Anyway, there is a good book called The Victorian Internet that, despite its suspect name, is extremely well written and goes into great and fascinating depth on the telegraph (optical and electronic), as well as the pro-tech savvy of the Victorian age. I'm too lazy to put in a link for you, but I assure you, the google or the amazon can give you all the details.

    • It just shows that "progress" is not linear. Service in particular has declined. In the past service was limited by technology. Now that technology has caught up, service is limited by cost cutting etc. Or put another way, no longer are these organisations motivated to provide the best service they can, but are rather motivated to be as crap as they can and still get away with it. This is not limited to postal services either.

      • Re: (Score:2)

        by QuantumG ( 50515 )
        Or, ya know, the demand for hand delivered mail has gone down.
      • Any company who wants to survive will only provide services they can make a profit on.

        If you want something delivered in a hurry you can still get that service but you will have to pay a lot for it because the demand is sufficiantly low that someone will have to make a special journey. The reason the demand is low is because the phone network provides similar services at higher speed and lower cost for messages and there aren't that many people sending packages that are that urgent.

        That is progress, high fr

      • Re: (Score:3, Interesting)

        by c6gunner ( 950153 )
        With such a poor understanding of economics, it's surprising you were ever able to afford a computer!
    • New York also used to have a crazy pneumatic tube system that took mail from one part of the island to another. They shut it down after the invention of the Automobile. I suspect the advent of that, along with refinements in sorting, let them deliver more mail with fewer mailmen (with the side effect of it being less often). Considering that Labor these days is a lot more expensive than it used to be, that has to be a huge cost savings overall. That's probably better for most people's mail usage than five-t
      • The problem is that the mail men want to live a much more lavish life than they did 100 years ago. Even though nothing about their jobs has changed.

    • In some major cities, like New York and Boston, the mail used to come as much as five times a day.
      The Banks.
       
    • That's pretty good -- some people I know don't even check their email that often!
      Presumablly they did it because thier was sufficiant demand to make it worth doing it and there was sufficiant demand to make it worth doing it because other means of communication were too expensive to be common.

      If you wanted service and delivery times that good these days, you'd need to go with a courier service.
      Yes because it doesn't make sense to do mass rounds for a service only a few people require.

  • Ah, Clacks (Score:5, Informative)

    by The Grey Ghost ( 884000 ) on Sunday December 23, 2007 @07:31PM (#21801228) Homepage
    Apparently where Terry Pratchett got the clacks - http://en.wikipedia.org/wiki/Clacks [wikipedia.org]

  • but (Score:5, Funny)

    by Sobieski ( 1032500 ) on Sunday December 23, 2007 @07:32PM (#21801232)
    If it was "wireless and without need for electricity", then it was not electronic mail

  • Clacks! (Score:2, Interesting)

    by orkysoft ( 93727 )
    Those are the clacks! Did they have c-commerce back then, too? And clacksites?

  • "Minor" mistake but... (Score:4, Informative)

    by RobertM1968 ( 951074 ) on Sunday December 23, 2007 @07:32PM (#21801240) Homepage Journal

    "provides no details of those built in North America in the early 1800s. Man-in-the-middle attacks were dead easy"

    The "early 1800's" is the 19th Century - not 18th.

    • RTFA! (Score:2, Informative)

      by zebslash ( 1107957 )
      If you take the time to read the article, you will see the technology was invented and developed in France in 1791. But I forgot, this is Slashdot.
      • RTFA is an answer to people who don't read the articles, and get all their information from the summary.

        Not an excuse for poorly written summaries that obfuscate the true message of the article.

      • It's a slow news day... perhaps you are trying to say that whoever approved the summary on /. should have read the article so they would have gotten the summary correct?

        My problem isn't an inability to read the article... whoever wrote the title and summary seem to have had that problem.

  • I think China also had a simialer thing with the great wall. Dose anyone know more about this.

    • Re:did china do this as well on the great wall? (Score:4, Informative)

      by AlphaDrake ( 1104357 ) * on Sunday December 23, 2007 @07:39PM (#21801280) Homepage
      Link [wikipedia.org]
    • Don't know about china, but I do seem to remember this technique from a "Lord of the Rings" movie :) They were lighting fires atop towers rather than any complex signaling though.

      And I guess Native Americans' smoke signals would count also.

      • Re: (Score:2)

        by Teancum ( 67324 )
        One nice thing about the "lighting the fires atop the walls" would do is not only notify that an attack is happening, but also the direction it is coming from.

        The Internet Brain [wikipedia.org] talks a little about this a little bit, including some potential references to look at.
      • I also recall being taught about the Chinese fires in history class a long time ago so I think it's probably likely it's correct. No idea which dynasty or period it was in though. The Romans were playing this trick 2 millennia ago. An attack on Hadrians Wall could be notified by signal fire to Rome in less than 48 hours - half the length of Europe and crossing the Alps in the process. ISTR from school history (so it may be wrong....) that from the Wall to London via Eboracum it was only something like six

        • Re: (Score:3, Informative)

          by rapiddescent ( 572442 )

          The roman signal stations are still on the Ordnance Survey maps in Perthshire [streetmap.co.uk] with signal stations some 1km to 3 km apart on hill tops. This link shows a signal station proximity to a camp with a much bigger fort to the west. infact, this area of Scotland is littered with roman remains because they had to exit in a big hurry regularly as the Scots kicked italian ass on a regular basis.

          they also had signal stations on the Antonine Wall [wikipedia.org] which was some 100km north of the famous Hadrians Wall.

          So this is

  • Semaphores and smoke signals are ancient (Score:5, Interesting)

    by davidwr ( 791652 ) on Sunday December 23, 2007 @07:34PM (#21801254) Homepage Journal
    Native American smoke signals date back to pre-Columbian times.

    Torches and and other forms of optical telegraphy date back to ancient times.

    Thanks to the seminal work of J. Hofmueller and his colleagues, modern flag semaphores can also be used to encapsulate IP datagrams [ietf.org]. Presumably, this is more efficient than delivering the same traffic by animal transport [ietf.org] but less efficient than by wire or radio.

  • Telegraph Hill in San Francisco (Score:5, Interesting)

    by ortcutt ( 711694 ) on Sunday December 23, 2007 @07:35PM (#21801266)
    Telegraph Hill in San Francisco was at one time the site of an optical telegraph. Hence the name.

    The hill owes its current name to a semaphore, a windmill-like structure erected in September 1849, for the purpose of signaling to the rest of the city the nature of the ships entering the Golden Gate. Atop the newly-built house, the marine telegraph consisted of a pole with two raisable arms that could form various configurations, each corresponding a specific meaning: steamer, sailing boat, etc. The information was used by observers operating for financiers, merchants, wholesalers and speculators. As some of these information consumers would know the nature of the cargo carried by the ship they could quickly predict the upcoming (generally lower) local prices for those goods and commodities carried. Those who did not have advance information on the cargo might pay a too-high price from a merchant unloading his stock of a commodity -- a price that was about to drop. On October 18, 1850, the ship Oregon signaled to the hill as it was entering the Golden Gate the news of California's recently acquired statehood.
    Telegraph Hill [wikipedia.org]
    • Flagstaff hill in Melbourne was used to watch for ships approaching the harbour. A flag would be raised to relay the observation of an incoming ship. Not quite as handy as a proper telegraph but one bit communication served the purpose.

  • patent trolls (Score:3, Funny)

    by yabba-dabba-do ( 948536 ) on Sunday December 23, 2007 @07:37PM (#21801270)
    In other news, NTP is now looking for someone to sue over this infringing technology.

  • The Victorian Internet (Score:5, Interesting)

    by blamanj ( 253811 ) on Sunday December 23, 2007 @07:38PM (#21801274)
    Tom Standage's book covered this quite well [amazon.com].
  • please watch this space for 3 hours in order to view it

    my comment is currently being transmitted from schenectady to poughkeepsie and the bad weather is interfereing with the candles staying lit

  • Common in Italy in the middle agaes (Score:3, Informative)

    by Anonymous Coward on Sunday December 23, 2007 @07:41PM (#21801300)
    The whole cost of Southern Italy is full of towers that were used a light based communication/alarm system, especially against the raids of the so called saracens (people from the Islamic nation from the south) in the middle ages. I believe that a similar system was also used in Roman and possibly Greek times. The distance between the towers is also similar, 5-20Km.

  • So... (Score:5, Funny)

    by Rip Dick ( 1207150 ) on Sunday December 23, 2007 @07:42PM (#21801306)
    Was the Optical Telegraph networked described by the clueless politicians of the time as a "series of flags"?

  • Wow! (Score:3, Funny)

    by sunspot42 ( 455706 ) on Sunday December 23, 2007 @07:45PM (#21801330)
    Looks like the Victorians could copy and transmit data faster than Windows Vista!

    • My semaphore tower sucks (Score:5, Funny)

      by Jesus_666 ( 702802 ) on Sunday December 23, 2007 @08:50PM (#21801714)
      I don't want to start a holy war here, but what is the deal with you semaphore fanatics? I've been sitting here at my freelance gig in front of a semaphore tower (a 1860/300 w/64 flags) for about 20 weeks now while it attempts to copy a 17 Meg file from one city on the east coast to another city. 20 weeks. At home, on my dovecote running Columba livia domestica, which by all standards should be a lot slower than this semaphore tower, the same operation would take about 2 weeks. If that.

      In addition, during this file transfer, the newspaper will not work. And everything else has ground to a halt. Even my inkwell is straining to keep up as I type this.

      I won't bore you with the laundry list of other problems that I've encountered while working on various semaphore towers, but suffice it to say there have been many, not the least of which is I've never seen a semaphore tower that has run faster than its dove counterpart, despite the semaphore towers' faster signalling architecture. My pigeonry with 8 Columba palumbus' runs faster than this 300 flag-position machine at times. From a productivity standpoint, I don't get how people can claim that the semaphore tower is a superior machine.

      Semaphore addicts, flame me if you'd like, but I'd rather hear some intelligent reasons why anyone would choose to use a semaphore tower over other faster, cheaper, more stable systems.

  • Sempahore towers (Score:3, Informative)

    by Uomograsso ( 968695 ) <alan+slashdot@clifford.ac> on Sunday December 23, 2007 @07:51PM (#21801362) Homepage
    There is a reconstructed tower at Chatley Heath near Guildford, England, which was part of the route from the admiralty in London down to Portsmouth.

    There are still some left in Barbados:

    http://photo.clifford.ac/2007/Barbados.October/tn/dscn2211.jpg.index.html [clifford.ac]

    and here is what you see when looking at Cotton Tower from Grendade Hall:
    http://photo.clifford.ac/2004/Barbados.April/tn/p4130674.jpg.index.html [clifford.ac]

    --
    Alan clifford
    • This one [surrey.ac.uk] is better, in my opinion, it displays the stone clac^H^H^H^Hsemaphore tower and the wooden part on top structure to relay the messages.
  • Anyone familiar with the Patrick O'Brian novels featuring Jack Aubrey or the C.S. Forester novels featuring Horatio Hornblower will recognize these...
  • American Indians did this long before that with smoke signals with people on top of hills.

    Theory goes that long before that the ancient pagans of Europe did a similar thing near stonehenge.

  • They're in an old movie too (Score:3, Informative)

    by belmolis ( 702863 ) <billposerNO@SPAMalum.mit.edu> on Sunday December 23, 2007 @08:11PM (#21801488) Homepage

    I remember first seeing these in an old movie, which I remember as being in black-and-white. It may have been an old version of The Count of Monte Cristo.

  • Sorry, but... (Score:5, Informative)

    by djupedal ( 584558 ) on Sunday December 23, 2007 @08:14PM (#21801500)
    The Great Wall in China put similar means to use hundreds of years earlier.

    Colored flags, whistling arrows, fires & hand signals all worked as part of a communication chain that spanned greater distances as well (6,400 km).

    And 'man-in-the-middle' attacks were usually over before they began :)
  • For more detail, read The Victorian Internet [tomstandage.com]. It is an awesome book.

  • Fax History (Score:2, Interesting)

    by Tablizer ( 95088 )
    Perhaps slightly off-topic, but its interesting how long the fax machine has been around. From wikipedia:

    Scottish inventor Alexander Bain is often credited with the first fax patent in 1843. He used his knowledge of electric clock pendulums to produce a back-and-forth line-by-line scanning mechanism.

    Frederick Bakewell made several improvements on Bain's design and demonstrated the device at the 1851 Great Exhibition in London.

    In 1861, the first fax machine, Pantelegraph, was sold by Giovanni Caselli, even b

  • And before that, since about 1500 AD, signal guns were commonly used. The bit rate was rather low, but by using bespoke messages, a signal could be sent across a country at the speed of sound.

  • taggers are fucking illiterate (Score:5, Informative)

    by toby ( 759 ) * on Sunday December 23, 2007 @08:20PM (#21801542) Homepage Journal
    BEACONS of Gondor, for Sauron's sake.

    BEACONS.

    If you can't afford a dictionary, rednecks, at least Google.

  • Semaphores weren't the first (Score:5, Funny)

    by Jesus_666 ( 702802 ) on Sunday December 23, 2007 @08:21PM (#21801548)
    Actually, the semaphore-based network wasn't the first on in Europe. Before it, there was a simpler network based around mutexes, but it wasn't very popular because it got quite bothersome once you had more than two people communicating. Still it was a major step forward from the previous concurrent networks where the non-locked shared message space meant that if two people broadcasted at the same time they'd overwrite each other's messages.

    Much later, North America would see an experimental monitor-based optical messaging network, but the cost of keeping hundreds of big CRTs powered on all the time quickly put an end to it.

  • "Virus" (Score:4, Funny)

    by Tablizer ( 95088 ) on Sunday December 23, 2007 @08:31PM (#21801608) Journal
    network consisted of a chain of towers... placed 5 to 20 kilometers apart from each other. Every tower had a telegrapher [worker], looking through a telescope at the previous tower in the chain...

    Back then when a "node was infected with a virus", it was literal.
       

  • The First Time Information Outpaced Man (Score:5, Insightful)

    by Hubec ( 28321 ) on Sunday December 23, 2007 @08:41PM (#21801650)
    Before the semaphore telegraph a man could travel faster than information. Am I the only one who thinks that's just really cool? The whole concept of being able to race across the globe faster than events is completely alien to our current existence.

    Hmmm... Let me put it this way; Before the semaphore telegraph, the world was split into a very large number of simultaneous but completely separate realities. As soon as that telegraph came into existence those realities began merging into one.

    • Re: (Score:3, Insightful)

      by complete loony ( 663508 )
      Certainly the latency was lower, but the bandwidth sucked. Don't underestimate the bandwidth of a state coach full of parchment.

  • Horses versus humans (Score:5, Interesting)

    by Tablizer ( 95088 ) on Sunday December 23, 2007 @08:45PM (#21801678) Journal
    Article: Humans or horses can maintain a speed of 5 or 6 kilometres an hour for long distances.

    It may defy common sense, but a runner in top shape can almost match the pace of a horse over long distances. There used to be a yearly contest in England, and a human sometimes won. Our ancestors used to chase down pray by outlasting them in the heat (some isolated tribes still do). Our sweating system keeps us cooler than hairy animals. However, it may be more economical to wear out a horse than a human. Plus, a horse can carry more.
       
    • 'used to be'?

      It's still run every year. http://llanwrtyd-wells.powys.org.uk/eventmanvhorsevbike.htm [powys.org.uk]

      These days they have bikes too.

    • Re: (Score:3, Insightful)

      by demonlapin ( 527802 )
      That's a nice story, but experience [thislife.org] disagrees with you. Quadrupeds move much more efficiently than we do. We're smarter than they are, so we take advantage of their behaviors to kill and eat them. Driving herds off cliffs, e.g. However, the experience of the Plains Indians with horses pretty clearly shows that people will take any advantage they get and use it to master their surroundings. If people on horses were inferior to people on foot, they wouldn't have bothered to become expert horsemen.

    • Re: (Score:3, Interesting)

      by ucblockhead ( 63650 )
      Plus, a single person can switch horses. That's how the Pony Express worked, and it's how people could make 200 miles a day even in classical times.
  • purple monkey dishwasher

  • Man-in-the-middle attacks? (Score:4, Insightful)

    by Dan East ( 318230 ) on Sunday December 23, 2007 @09:44PM (#21802024) Journal
    Man-in-the-middle attacks were dead easy.

    No they weren't, and the article doesn't say that they were. Man-in-the-middle attack means that transmitted data can be modified, or entirely new data can be introduced. Think about it. You have a telescope permanently aimed at the next station in line, viewed by a person who has spent thousands of hours staring at that station. Now don't you think if someone, somehow, got in that exact line of sight with their own semaphore in attempt to transmit their own data, that it would be extremely obvious to the operator that something was very wrong?

    What the article does say is that the system is vulnerable to eavesdropping. However, a number of solutions would be available. Shutters could be used to restrict visibility of the semaphores to the line of sight of the next tower. Since they were elevated, it would be difficult to get into that line of sight in most terrain. Obviously, the messages themselves could be encrypted as well. The semaphore operators did not have to understand their message. They simply moved the position of their signaling arms to match the position of the sending tower. The sending tower would visually verify that the receiving tower had properly copied the data. The operators did not need to know what the data meant to relay the information - only the initiator and consumer of the information needed the ability to encrypt / decrypt, which is still where we stand today.

    Telegraph was very much open to eavesdropping - in fact, I believe it was much easier. Simply pigtail off of any of the thousands of miles of wire, and run a line to a comfortable listening post out of sight of the railway or road. With radio it became even easier!

    Dan East

    • Re: (Score:3, Insightful)

      by kobotronic ( 240246 )
      Your telescope is trained at the next semaphore tower, yes. But can you tell whether the operator sitting hidden beneath and pulling the levers is the person it is supposed to be, or perhaps some impostor who by use of force or bribery took over the controls? Isn't this a plausible injection vector for a man in the middle attack?
      • No, because one of the towers on either side of that tower (depending on which direction the message was being transmitted) would see that data is being sent that was not being relayed from their tower. They could then invalidate the message by using some other method of messaging - physically bypassing the compromised tower by courier probably being the easiest and fastest.

        Dan East
        • Fair enough. So in order for this to work an attacker would have needed to subvert not just one tower but two towers in a row, and the towers must be situated such that the last un-subverted tower in line of the signal would not pick up on the failure of the first subverted tower to react to the obviously wrongly relayed message from the second corrupted tower.
  • The clacks, I think he called it?

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