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Change the flow of electricity at one point in a circuit, and detect the change at another point. What could be simpler? To make a telegraph, all you needed was:
Several people quickly came up with similar proposals. In 1837, Charles Wheatstone in England and Samuel Morse in the United States each perfected an electric telegraph for use over land.
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Telegraphy is simpler on land. When technical complications seemed to doom the idea of a transatlantic cable, an overland route from Europe was proposed, by way of Russia, Siberia, and Alaska. This wire came from a Canadian section of the project. |
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Iron telegraph wire: land line, 1865 National Museum of American History, from Western Union | |
| Pressing the key at one end of the circuit allows current to flow, which causes a magnet to pull down a lever at the other end. |
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Morse key and receiver, 1850s National Museum of American History, from C.M. Lewis and R.B. Freeman | |
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The first telegraph manual was written by Alfred Vail, a colleague of Samuel Morse. Vail's descriptions were very basic, but his book filled the bill as a guide for early telegraphers. |
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Alfred Vail, The American Electro Magnetic Telegraph (Philadelphia, 1845) Smithsonian Institution Libraries | |
