{"id":2425,"date":"2025-03-21T18:34:28","date_gmt":"2025-03-21T18:34:28","guid":{"rendered":"https:\/\/szmz.hu\/teaching\/?page_id=2425"},"modified":"2025-04-30T13:34:57","modified_gmt":"2025-04-30T13:34:57","slug":"mediahistory-bridging-distance-in-space-and-time","status":"publish","type":"page","link":"https:\/\/szmz.hu\/teaching\/media-history\/mediahistory-bridging-distance-in-space-and-time\/","title":{"rendered":"MediaHistory: Bridging Distances in Space and Time"},"content":{"rendered":"\n

Recommended reading:
Wolfgang Schivelbusch: The Railway Journey<\/em>: The Industrialization of Time and Space in the Nineteenth Century<\/em>
Wolfgang Schivelbusch: A vas\u00fati utaz\u00e1s t\u00f6rt\u00e9nete-a t\u00e9r \u00e9s az id\u0151 iparosod\u00e1sa a 19. sz\u00e1zadban – A t\u00e9r \u00e9s az id\u0151 iparosod\u00e1sa a 19. sz\u00e1zadban<\/em>, Napvil\u00e1g Kiad\u00f3, 2008<\/p>\n\n\n\n

Schivelbush_railway.pptx<\/a><\/p>\n\n\n\n

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In 1792, Claude Chappe built a long chain of signaling towers in France. Semaphors imitating human arms were installed on the top of the towers, which could be observed using telescopes from the neighboring towers. By 1793, the 15 towers, each 13km apart, formed a chain of 190km long. 11 years later by 1804 the system was extended to a 370km long semaphor-chain between Paris and Dijon. The experienced staff transmitted messages extremely efficiently: several hundred messages were distributed daily, with a the average speed of 30 minutes of delivery time.<\/p>\n\n\n\n

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Rees’s Cyclop\u00e6dia (published between 1802-1820), Plates Vol. IV, “TELEGRAPH”, Fig. 4; from a digital scan at https:\/\/archive.org\/details\/cyclopaediaplates04rees<\/figcaption><\/figure>\n\n\n\n

Five years before Chappe the Hungarian Jozef Chudy (Pressburg (Bratislava\/Pozsony), June 14, 1753 \u2013 Pest, March 4, 1813) invented the firs optical and acoustic telegraph. Chudy is the composer of the first hungarian language opera: Pikk\u00f3 hertzeg \u00e9s Jutka Perzsi<\/a><\/em>. In 1787 Chudy publishes a 15 page long booklet describing his invention (Beschreibung eines Telegraphs, welcher im Jahr 1787 in Pre\u00dfburg in Ungarn ist entdeckt worden [Description of a Telegraph Discovered in 1787 in Pressburg, Hungary]).<\/p>\n\n\n\n

Chudy’s optical system was a device with five separate light elements arranged side by side, or with one light source behind a construction with five openable shutters. With the on and off states of these lights 32 combinations are possible. Each combination mean a letter of the alphabet: OOOOI stands for the letter A, OOOIO means B, OOIOO is C, etc. The start of the message can be signalled by opening all the five shutters simultaniously. By adding another two lights, arranged above and under the 5 main ones, punctuation and upper and lower cases can be signalled.<\/p>\n\n\n\n

For the acoustic telegraph Chudy proposed two versions. In the first system two easily distinguishable high and low notes substitute the lamps’ on and off states. The notes can be played on drums, bells or any musical instrument. In the second system Chudy proposed to use one note. Here, the two values are a single sound and two sounds substituting the lamps’ on- and off state. This system has the advantage that no musical instrument is required, but much louder gunshots could be used instead<\/p>\n\n\n\n

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Chudy wasn’t able to find sponsors to develop his system, thus both his invention and name are fairly known today. Some years later Chudy tried to draw attention to his invention by composing a one-act opera: Der Telegraph oder die Fernschreibmaschine (The Telegraph or, the Tele-typewriter)<\/em>. The premiere was on the 3rd of January, 1796. (Compositions by Chudy have not survived.)<\/p>\n\n\n\n

Similar visual signaling systems were replaced by wired, later wireless telegraph, the use of morse-code, than telefax.<\/p>\n\n\n\n

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For the production of long cables a flexible insulator is required – this was the gutta-percha latex.<\/p>\n\n\n\n

Gutta-percha latex is biologically inert, resilient, and is a good electrical insulator with a high dielectric strength. Scientifically classified in 1843, it was found to be a useful natural thermoplastic. In 1851, 30,000 long cwt (1,500,000 kg) of gutta-percha was imported into Britain. During the second half of the 19th century, gutta-percha was used for myriad domestic and industrial purposes, and it became a household word. In particular, it was needed as insulation for underwater telegraph cables, which, according to author John Tully, led to unsustainable harvesting and a collapse of the supply.
Western inventors discovered the properties of gutta-percha latex in 1842, although the people of its Malayan habitat had used it for many applications for centuries. Allowing this fluid to evaporate and coagulate in the sun produced a latex which could be made flexible again with hot water, but which did not become brittle, unlike rubber prior to the discovery of vulcanization.<\/p>\n\n\n\n

By 1845, telegraph wires insulated with gutta-percha were being manufactured in the UK. It served as the insulating material for early undersea telegraph cables, including the first transatlantic telegraph cable.<\/p>\n<\/div>\n\n\n\n

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In 1873, when installing the Trans-Atlantic Telegraph connection, the cable was tested at the same time as laying it. They used the high-resistance semiconductor, selenium. Accidentally they discovered its sensitivity to light, the photosensitivity.<\/p>\n\n\n\n

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