The clacks in Terry Pratchett's Discworld novels is a network of semaphore towers stretching along the Sto Plains, into the Ramtops and across the Unnamed Continent to Genua. It was introduced in The Fifth Elephant, and has become the Discworld's first telecommunications network. While the system structure is that of a telegraph, elements of it are often described as similar to the Internet; for example, it threatens to make the Post Office obsolete in Going Postal and is sometimes described as 'c-mail' (a clear reference to e-mail). Terence David John Pratchett OBE is an English fantasy author (born April 28, 1948, in Beaconsfield, Buckinghamshire, England), best known for his Discworld series. ... The Discworld is a series of 35 humorous fantasy novels and a number of shorter works by Terry Pratchett set on the Discworld. ... A Chappe semaphore tower near Saverne, France The semaphore line, or optical telegraph was a signalling system invented by the Chappe brothers in France. ... In Terry Pratchetts Discworld, Sto Plains is a rich country, full of silt and cabbage fields. ... The Ramtops are a fictional mountain range appearing in Terry Pratchetts Discworld series. ... Genua is a fictional city from Terry Pratchetts Discworld novels. ... The Fifth Elephant is the 24th Discworld novel by Terry Pratchett. ... The Discworld is the setting for all of Terry Pratchetts Discworld series of novels. ... A telecommunications network is a network of telecommunications links arranged so that messages may be passed from one part of the network to another over multiple links. ... Telegraphy (from the Greek words tele = far away and grapho = write) is the long distance transmission of written messages without physical transport of letters, originally over wire. ... Wikipedia does not yet have an article with this exact name. ...

A possible influence for the clacks system is the very similar semaphore network in the Keith Roberts novel Pavane. Both are based on the real-world optical telegraphs used in the early 19th century before electrical telegraphy made them obsolete. The name itself may have been inspired by 'clackers', the term for operators of mechanical computers in William Gibson and Bruce Sterling's steampunk novel, The Difference Engine. A Chappe semaphore tower near Saverne, France The semaphore line, or optical telegraph was a signalling system invented by the Chappe brothers in France. ... For the former head of the Grenadian security forces, see Keith Roberts (Grenada). ... Pavane by Keith Roberts is an alternate history science fiction novel first published by Rupert Hart-Davis Ltd in 1968. ... The optical telegraph preceded the electrical telegraph. ... Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ... Telegraphy (from the Greek words tele = far away and grapho = write) is the long distance transmission of written messages without physical transport of letters, originally over wire. ... Some credit William Gibson with writing the most clear-cut examples of the Science Fiction genre known as cyberpunk, as well as coining the term cyberspace. ... Bruce Sterling at the Ars Electronica Festival Michael Bruce Sterling (born April 14, 1954) is an American science fiction author, best known for his novels and his seminal work on the Mirrorshades anthology, which defined the cyberpunk genre. ... A rocket lands on the moon in Le Voyage dans la Lune, the film adaptation of Jules Vernes From the Earth to the Moon. ... The Difference Engine is an alternate history novel by William Gibson and Bruce Sterling. ...

A typical clacks tower

A typical clacks tower is three storeys tall, made of wood, and probably looks like it was put together in a hurry, because it was. They tend to be eight miles apart.

The ground floor is a storeroom. The second contains an office, a kitchen and, in out-of-the-way towers, a bunkroom. The top floor contains the controls. Two chairs face identical control boards on either side, each connected to the panels on the opposite side. There is a keyboard, and levers and pedals. Sometimes entering a code will alter the configuration of the system, probably beneficially (but see Smoking GNU, below.)

History

The history of the clacks network was detailed in Going Postal. The invention was originally made by an artificer called Robert Dearheart, conducting experiments in an abandoned wizard's tower halfway between Ankh-Morpork and Sto Lat. The basic mechanism he came up with was a two-by-three array of wooden panels, with pulleys that could drop shutters over them, creating a code. A series of high towers, with one of these mechanisms on each side and someone ready to relay the codes, could send messages across at the speed of light. The panel also had a recess for a lamp, meaning messages could be sent at night. Going Postal (ISBN 0385603428, published by Doubleday) is Terry Pratchetts 33rd Discworld novel, released in the United Kingdom on September 25, 2004. ... Ankh-Morpork is a fictional city-state which features in Terry Pratchetts Discworld series of fantasy novels. ...

Based on this he founded the Grand Trunk Company, which began creating a network of towers that would stretch across the continent. "High traffic" towers have more than six panels. The largest is the one on the huge hill in Ankh-Morpork called The Tump, which is the main junction between the city's clacks network (various city institutions, including the Guilds, and the Watch had installed small clacks towers on their buildings) and the Grand Trunk, the chain of towers that leads past Sto Lat, into Überwald, and from there to Genua. In the less civilised areas in the heart of the continent, they ran into problems, and most clacks towers in the Überwald area had fortified stone bases and, often, armed guards. The problem was particularly acute in Borogravia, where the towers were seen as an Abomination unto Nuggan, on the grounds that if messages were being sent through the air, prayers would get tangled up in them. In Terry Pratchetts Discworld series of fantasy novels, there are almost 300 Guilds in the city of Ankh-Morpork. ... Coat of arms of the Ankh-Morpork City Watch. ... In Terry Pratchetts fictional Discworld universe, Ãœberwald is a region on the other side of the Ramtops from Lancre and Ankh-Morpork. ... Borogravia is a fictional country in Terry Pratchetts Discworld series of novels. ... The Discworld gods are the fictional deities from Terry Pratchetts Discworld series. ...

Because so much of the material being sent was confidential, the senders would put it in their own code before being given to the clacks operators. The operators were, therefore, often surprised if they received a message they understood, outside the Overhead (the messages from and about the network itself).

The Grand Trunk employed a lot of gargoyles, as they were exceptionally good at sitting and watching without getting bored. Trolls in Terry Pratchetts Discworld novels, unlike the monstrous trolls of folklore and J.R.R. Tolkien, have been subverted into a moderately civilised race. ...

The success of the clacks network resulted in a fad for semaphore of all types, and fashionable Morporkians began carrying signal flags with them, to send messages to friends on the other side of the room. This appears to have died out, although the City Watch has its own semaphore network, with a relay station on the roof of the Old Lemonade Factory (the Watch training school).

Dearheart, and his employees, continued to improve the network. As the network grew larger, activating the shutters directly became too complicated, so methods of automating the process were introduced. Punch cards, nicknamed jacquards, were designed that would send certain messages automatically. Sent messages were also automatically recorded on punch cards, kept in a metal drum. They even worked out a way of coding pictures. The punch card (or Hollerith card) is a recording medium for holding information for use by automated data processing machines. ... Jacquard loom on display at Museum of Science and Industry in Manchester, England The Jacquard loom is a mechanical loom, invented by Joseph Marie Jacquard in 1801, which used the holes punched in pasteboard punch cards to control the weaving of patterns in fabric. ...

Unfortunately, Dearheart and those like him were brilliant at engineering, but not finances. A consortium of financiers had been embezzling from the company since it was set up. When it reached the point of collapse, they bought Dearheart and the others out with their own money.

Under the new management, the clacks network became more profitable, but less reliable. As the new owners didn't really understand the clacks the way the previous management had, they worked it until it broke. They maintained their monopoly by killing anyone attempting to set up another network, including Dearheart's son, John. In economics, a monopoly (from the Greek monos, one + polein, to sell) is defined as a persistent market situation where there is only one provider of a kind of product or service. ...

Clacks operators, therefore, could either keep working for a company that didn't really care about the clacks, or give up. Since the clacks tended to atract obsessive personalities, this was more than they could stand. One group, who had been working with John Dearheart before his death, set up an illegal clacks tower and used their knowledge of the system to send unauthorised messages in the Overhead. They worked out a way to send messages that would put unnecessary strain on the towers, putting them out of commission (in other words, the equivalent of a computer virus). They called themselves the Smoking GNU, from the clacks-jargon term for a really fast unlogged message. (The clacks system has also been cracked by Hex, after Ponder Stibbons connected it to the Unseen University's tower. Whether or not this is actually illegal is a question the faculty is carefully not asking.) In computer security technology, a virus is a self-replicating program that spreads by inserting copies of itself into other executable code or documents. ... Hex is an elaborate, Heath Robinson/Rube Goldberg-esque, magic-powered computer housed at the Unseen University in the Discworld series by author Terry Pratchett. ... In the fictional universe of Terry Pratchetts Discworld series of books, Ponder Stibbons is a wizard in Unseen University. ... The Coat of Arms of Unseen University. ...

In Going Postal, the consortium was exposed, and Havelock Vetinari proposed that the Ankh-Morpork Post Office take over the running of the system, most likely a refence to when the GPO (General Post Office) formerly ran the telephone network in the UK. However, the Postmaster, Moist von Lipwig has expressed his intention to return the Grand Trunk Company to the Dearheart family. Lord Havelock Vetinari is the Patrician of Ankh-Morpork, the head of the fictional city state of Ankh-Morpork in Terry Pratchetts Discworld series. ... The Ankh-Morpork Post Office is featured in the book Going Postal, the most recent addition to British fantasy author Terry Pratchetts Discworld series of books. ... GPO can refer to: General Post Office General Post Office (Dublin) United States Government Printing Office Group Policy Object, a mechanism in Microsofts Active Directory used to apply policies to directory objects. ... This article details minor Discworld characters; characters from the Discworld novels by Terry Pratchett who only appear in the background, or who have only had a brief starring role. ...

See also

• Victorian Internet