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Chappe Telegraph HTML5


Brought To You in cooperation with the Musée des Arts et Métiers - Paris.

The aerial telegraph  created by Claude Chappe (1794) is a means of optical communication. The telegraphic network  was made up of a succession of semaphores perched atop towers that were 6 to 12 kilometers apart. The position of the semaphore wings indicated a coded message to be transmitted. Each such position corresponded to a number which directed the receiver to a specific page in a notebook where the message in letters  could  be found.

Click on the "operation" key to manipulate the telegraph.

To decode the message, use the controls at the base of the first telegraph to reproduce the signals sent by the second telegraph.

Learning goals

  • To illustrate a mode of communication.
  • To introduce the notion of encoding information.

Learn more

An employee, called an operator, was  stationed in the interior of the semaphore (also called station). Using a telescope, he observed the positions of the wings of the semaphore preceding his…

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