# Discworld question, re: clacks towers. **URL:** \ **Category:** Cafe Society\ **Created:** [October 13, 2004, 10:33pm UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109 "2004-10-13T22:33:42Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Lobsang](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lobsang/32/4067_2.png) [@Lobsang](https://boards.straightdope.com/u/Lobsang)\ **Post date:** [October 13, 2004, 10:33pm UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/1 "2004-10-13T22:33:42Z")
In “Going Postal” It is mentioned that the older clacks towers need line of sight to work. Bearing in mind that most of the ‘technology’ in discworld is based on real world technology at _least_ a hundred years old, how is this achieved? And which book (if any) is mostly _about_ the introduction of clacks towers? (I’ve noticed that often the books are about the establishment of a service. The truth was about the introdcution of a Newspaper to Ankh-Morpork. Going Postal is obviously about the re-introduction of the postal service) ---
**Author:** ![Miller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/miller/32/481_2.png) [@Miller](https://boards.straightdope.com/u/Miller)\ **Post date:** [October 13, 2004, 10:54pm UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/2 "2004-10-13T22:54:13Z")
> [@Lobsang](#): > > In “Going Postal” It is mentioned that the older clacks towers need line of sight to work. > > Bearing in mind that most of the ‘technology’ in discworld is based on real world technology at _least_ a hundred years old, how is this achieved? Not sure what you mean… they’ve just built a butt-load of towers across the continent, each one just within visual range of the next. Dunno if they use telescopes to cross the less settled areas or what. It would make sense, but I don’t recall any specific mention of their use in a clacks tower. Technologically, there’s nothing at all fancy here: it’s considerably less sophisticated than the telegraph, although conversely much more complicated. Training up enough cryptologists to man all those thousands and thousands of clacks towers must be a tremendous bottleneck, not to mention building and provisioning the towers themselves. Far more expensive than a wooden pole and some copper wire with an operator at each end. > [@](#): > > And which book (if any) is mostly _about_ the introduction of clacks towers? (I’ve noticed that often the books are about the establishment of a service. The truth was about the introdcution of a Newspaper to Ankh-Morpork. Going Postal is obviously about the re-introduction of the postal service) There isn’t a book that focuses on the invention/introduction of the clacks towers, unless you count _Going Postal_. It’s just sort of grown up in the background of a bunch of other novels. ---
**Author:** ![silenus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/silenus/32/166_2.png) [@silenus](https://boards.straightdope.com/u/silenus)\ **Post date:** [October 13, 2004, 10:54pm UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/3 "2004-10-13T22:54:29Z")
IIRC, the clacks just sort of developed in the background of several stories. **The Fifth Elephant** uses them as a plot device, and they were starting to get installed as far back as **Jingo**. ---
**Author:** ![mkl12](https://avatars.discourse-cdn.com/v4/letter/m/b4bc9f/32.png) [@mkl12](https://boards.straightdope.com/u/mkl12)\ **Post date:** [October 13, 2004, 10:55pm UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/4 "2004-10-13T22:55:04Z")
The clacks were introduced in _The Fifth Elephant_. That book wasn’t about the clacks though. I’ve been wondering about the technology, too. Maybe I should re-read _The Fifth Elephant_, I don’t remember if it was explained there. ---
**Author:** ![photopat](https://avatars.discourse-cdn.com/v4/letter/p/e95f7d/32.png) [@photopat](https://boards.straightdope.com/u/photopat)\ **Post date:** [October 13, 2004, 10:58pm UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/5 "2004-10-13T22:58:05Z")
In Jingo there was a scene aboard the Boat in which Leonard is mentioning the notion of color as language, such as in semaphore and Vetinari makes some notes about it. I’ve always suspected that Vetinari let the idea leak to somebody (not Dibble, of course) who saw the business opportunity in long range communication and thus the clacks tower was born. ---
**Author:** ![Lobsang](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lobsang/32/4067_2.png) [@Lobsang](https://boards.straightdope.com/u/Lobsang)\ **Post date:** [October 13, 2004, 10:59pm UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/6 "2004-10-13T22:59:42Z")
For _Miller_ and others. By line of sight, I mean there is a direct path between towers for light to travel. Maybe I mis-read the passage but it implied that new towers work even if there is something in the way between towers. ---
**Author:** ![Lobsang](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lobsang/32/4067_2.png) [@Lobsang](https://boards.straightdope.com/u/Lobsang)\ **Post date:** [October 13, 2004, 11:01pm UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/7 "2004-10-13T23:01:47Z")
Most mundane thread correction of the year: I meant to **bold** Miller’s name, not _italic_ it. ---
**Author:** ![silenus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/silenus/32/166_2.png) [@silenus](https://boards.straightdope.com/u/silenus)\ **Post date:** [October 13, 2004, 11:04pm UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/8 "2004-10-13T23:04:50Z")
**Lobsang** , could you find the passage in question? Remember the key plot point at the end of the book involves line-of-sight transmission. ---
**Author:** ![Lobsang](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lobsang/32/4067_2.png) [@Lobsang](https://boards.straightdope.com/u/Lobsang)\ **Post date:** [October 13, 2004, 11:08pm UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/9 "2004-10-13T23:08:16Z")
I should add that I am about halfway through the book. I have no idea which part of the half I’ve read the passage is in. I will look through it when I get the free time to do so. ---
**Author:** ![Miller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/miller/32/481_2.png) [@Miller](https://boards.straightdope.com/u/Miller)\ **Post date:** [October 13, 2004, 11:18pm UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/10 "2004-10-13T23:18:50Z")
**Lobsang** , I recall that there was a subplot about John Dearheart having invented a new clacks system that was more efficient than the old one, but I don’t recall anything about it not needing line-of-sight. If there was something about that, it wasn’t explained in any more detail than you’ve already read, nor does it materially impact the plot of the novel. All the clacks towers featured in the novel use line-of-sight to communicate between cities. If I had to guess, I’d assume he’d invented a proper telegraph. It doesn’t really require any technology that the Disc doesn’t already have, or couldn’t reasonably invent from what they already know. ---
**Author:** ![cher3](https://avatars.discourse-cdn.com/v4/letter/c/da6949/32.png) [@cher3](https://boards.straightdope.com/u/cher3)\ **Post date:** [October 13, 2004, 11:24pm UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/11 "2004-10-13T23:24:32Z")
I’m not all the way through the book, yet, but I think somewhere there is a mention of Unmanned towers that can bounce a signal, maybe using a mirror of some sort. The implication seemed to be that you could bend the signal around an obstacle that way, without setting up a complete clacks tower. ---
**Author:** ![Lobsang](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lobsang/32/4067_2.png) [@Lobsang](https://boards.straightdope.com/u/Lobsang)\ **Post date:** [October 13, 2004, 11:35pm UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/12 "2004-10-13T23:35:12Z")
Ah, _Mirrors_! How could I have been so stupid?! ---
**Author:** ![rjung](https://avatars.discourse-cdn.com/v4/letter/r/45deac/32.png) [@rjung](https://boards.straightdope.com/u/rjung)\ **Post date:** [October 13, 2004, 11:52pm UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/13 "2004-10-13T23:52:37Z")
Haven’t read **Going Postal** yet, but how would a system with imps work? ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [October 13, 2004, 11:55pm UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/14 "2004-10-13T23:55:50Z")
Also the original clacks couldn’t work at night - the newer ones have lights. ---
**Author:** ![Charlie\_Tan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/charlie_tan/32/12582_2.png) [@Charlie\_Tan](https://boards.straightdope.com/u/Charlie_Tan)\ **Post date:** [October 14, 2004, 12:50am UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/15 "2004-10-14T00:50:57Z")
Actually, in Monstrous Regiment there are some references as to how it all works, including mechanical logarithms, or some such, shich my knowledge of math doesn’t cover. ---
**Author:** ![Odinoneeye](https://avatars.discourse-cdn.com/v4/letter/o/97f17d/32.png) [@Odinoneeye](https://boards.straightdope.com/u/Odinoneeye)\ **Post date:** [October 14, 2004, 12:57am UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/16 "2004-10-14T00:57:28Z")
Being that I’m too cheap to buy hardcover, I’m always a little behind in Discworld novels. In fact, I’m on just finishing up Monstrous Regiment. One of the characters, Lt. Blouse, starts talking about theories he has as to improve the efficiency of the clacks. Of course, since his religion finds them an abomination, he never had practicle experience. Maybe after that book, he was allowed to put some of his ideas to the test. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [October 14, 2004, 1:03am UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/17 "2004-10-14T01:03:10Z")
BTW: there was a sophisticated pre-telegraph system of sephamores in place in France as far back as the Revolutionary period. ---
**Author:** ![DrFidelius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drfidelius/32/3447_2.png) [@DrFidelius](https://boards.straightdope.com/u/DrFidelius)\ **Post date:** [October 14, 2004, 1:07am UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/18 "2004-10-14T01:07:40Z")
I haven’t read Monstrous Regiment, so Pterry may have said something that contradicts this, but… I had always thought that the clacks were based on the semaphore telegraph towers that had stretched from the Admiralty in London to the dockyards in Portsmouth. ---
**Author:** ![DrFidelius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drfidelius/32/3447_2.png) [@DrFidelius](https://boards.straightdope.com/u/DrFidelius)\ **Post date:** [October 14, 2004, 1:08am UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/19 "2004-10-14T01:08:49Z")
[http://www.wordiq.com/definition/Semaphore\_(communication)](http://www.wordiq.com/definition/Semaphore_(communication)) has some history of the semaphore towers. ---
**Author:** ![silenus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/silenus/32/166_2.png) [@silenus](https://boards.straightdope.com/u/silenus)\ **Post date:** [October 14, 2004, 1:14am UTC](https://boards.straightdope.com/t/discworld-question-re-clacks-towers/269109/20 "2004-10-14T01:14:02Z")
They started as semaphore towers, but they have evolved. Now, they use a grid of lights to send coded signals from one tower to the next.