Signals sent by means of torches indicated when to start and stop draining to keep the synchronisation. Tacticus's system had water filled pots at the two signal stations which were drained in synchronisation. The two most extensive systems were Chappe's in France, with branches into neighbouring countries, and the system of Abraham Niclas Edelcrantz in Sweden. Joseph Chudy's 1796 opera, Der Telegraph oder die Fernschreibmaschine, was written to publicise Chudy's telegraph (a binary code with five lamps) when it became clear that Chappe's design was being taken up. This was a telegraph code developed for use on the French telegraph using a five-key keyboard (Baudot, 1874). Teleprinters generated the same code from a full alphanumeric keyboard. That was a system using the Polybius square to encode an alphabet. The number of said torches held up signalled the grid square that contained the letter. Polybius (2nd century BC) suggested using two successive groups of torches to identify the coordinates of the letter of the alphabet being transmitted. The first experimental system over a substantial distance was by Ronalds in 1816 using an electrostatic generator.

On 2 March 1791, at 11 am, they sent the message "si vous réussissez, vous serez bientôt couverts de gloire" (If you succeed, you will soon bask in glory) between Brulon and Parce, a distance of 16 kilometres (10 mi). The work will be inspected by a designated authority at several stages before permission is obtained to energize the wiring from the local electric utility; the inspector may be an employee of the state or city, or an employee of an electrical supply utility. An electric arc occurs with each bounce and a pan and wire will soon both become worn through under such conditions. Cost The acquisition, deployment and rearrangement costs of UTP are very low, at least in inside wire applications. For overhead cables the fiber is integrated into the core of a phase wire. It was powered by two Siemens & Halske alternators rated 30 hp (22 kW), 2 kV at 120 Hz and used 19 km of cables and 200 parallel-connected 2 kV to 20 V step-down transformers provided with a closed magnetic circuit, one for each lamp.

26-29 Possibly the first alphabetic telegraph code in the modern era is due to Franz Kessler who published his work in 1616. Kessler used a lamp placed inside a barrel with a moveable shutter operated by the signaller. Likewise, the United States continued to use American Morse code internally, requiring translation operators skilled in both codes for international messages. However, this led to a breakthrough for the electric telegraph, as up to this point the Great Western had insisted on exclusive use and refused Cooke permission to open public telegraph offices. In July 1839, a five-needle, five-wire system was installed to provide signalling over a record distance of 21 km on a section of the Great Western Railway between London Paddington station and West Drayton. The Chinese signalling system extended well beyond the Great Wall. Signal towers away from the wall were used to give early warning of an attack. An optical telegraph is a telegraph consisting of a line of stations in towers or natural high points which signal to each other by means of shutters or paddles. Nothing else that could be described as a true telegraph existed until the 17th century. None of the signalling systems discussed above are true telegraphs in the sense of a system that can transmit arbitrary messages over arbitrary distances.

It was not until the Civil War that the government saw the true potential of the telegraph system. In 1790, the Chappe brothers set about devising a system of communication that would allow the central government to receive intelligence and to transmit orders in the shortest possible time. The Ming dynasty (1368-1644) added artillery to the possible signals. Few details have been recorded of European/Mediterranean signalling systems and the possible messages. The same applies to the kind of push-pull trains which have a locomotive at each end. Fault-sensing protective relays at each end of the line must communicate to monitor the flow of power so that faulted conductors or equipment can be quickly de-energized and the balance of the system restored. Third-rail systems can suffer disruption in cold weather due to ice forming on the conductor rail. In operating terms, the third rail is awkward because of the greater risk of it being touched at ground level. Annotation on a floating scale indicated which message was being sent or received. While the signalling was complex (for instance, different-coloured flags could be used to indicate enemy strength), only predetermined messages could be sent. By the Tang dynasty (618-907) a message could be sent 1,100 kilometres (700 mi) in 24 hours.

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