What is Semaphore?

            Do you know what was used for signaling from high towers, and transmitting messages between distant points before the invention of telegraph? It was semaphore. Semaphore is a Greek word meaning signal carrier it is a method used for signaling or conveying information by changing the position of a flag, light, etc. the first such system was developed by Cloude Chappe of France in 1794 that employed a ser of arms that were pivoted on a post. The arms were mounted on towers built 8 to 16 kilometers apart. The messages were read with the help of telescope.

The Semaphore signaling system

            Modern semaphores include movable arms or rows of light, simulating arms, which are displayed form towers and are used to signal railroad trains. The continuance of the use of semaphore for signaling is still found in the Indian railways.

            The ships on sea still use the semaphore signaling system to communicate messages. This involves human arms holding a small flag in each hand. When humans send the messages, the sender usually moves the flags in his hands at different angles to indicate the letters of the alphabet.