Search results
Results from the WOW.Com Content Network
Replica of a Chappe telegraph on the Litermont near Nalbach, Germany. Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message.
A single needle telegraph (1903) A needle telegraph is an electrical telegraph that uses indicating needles moved electromagnetically as its means of displaying messages. It is one of the two main types of electromagnetic telegraph, the other being the armature system, [1] as exemplified by the telegraph of Samuel Morse in the United States.
Cooke and Wheatstone's five-needle telegraph from 1837 Morse telegraph Hughes telegraph, an early (1855) teleprinter built by Siemens and Halske. Electrical telegraphy is a point-to-point text messaging system, primarily used from the 1840s until the late 20th century.
Progress in electric devices in Europe lead inventors to create electrical telegraph systems, such as the Cooke and Wheatstone telegraph in England. They invented complex systems with a separate key for each letter of the alphabet.
The first use of the word semaphore in reference to English use was in 1816: "The improved Semaphore has been erected on the top of the Admiralty", [12] [13] referring to the installation of a simpler telegraph invented by Sir Home Popham. [citation needed] Semaphore telegraphs are also called, "Chappe telegraphs" or "Napoleonic semaphore". [14 ...
A needle instrument from a Schilling telegraph. The Schilling telegraph is a needle telegraph invented by Pavel Schilling in the nineteenth century. It consists of a bank of needle instruments (six as developed for use in Russia) which between them display a binary code representing a letter or numeral.
Diagram of a Chappe telegraph. The regulator is segment AB. The indicators are segments AC and BD. The mast is the vertical beam. At its base is the mechanical device (the manipulator), which the operator uses to form the signal and which reproduces it in miniature (segments ac and bd).
Wireless telegraphy or radiotelegraphy, commonly called CW (continuous wave), ICW (interrupted continuous wave) transmission, or on-off keying, and designated by the International Telecommunication Union as emission type A1A or A2A, is a radio communication method.