Messages Across the Semaphore Towers

Written by Studio AM.

Before electric wires carried news, France built chains of signal towers. In 1792, Claude Chappe presented an optical telegraph system. A tall mechanism on each tower had moving arms that operators could place in many positions. The coded positions represented numbers used to look up words and phrases in a shared codebook.

An operator watched the previous tower through a telescope. When its arms changed, the operator copied the position for the next tower to see. In this way, a message moved across the landscape without one messenger traveling the whole route. The network later linked Paris with distant cities and served the government.

The system was fast for its era, but visibility set a firm limit. Fog, heavy rain, darkness, or a blocked view could stop the relay. Towers also needed trained operators and an agreed code. Chappe’s network joined mechanics, language, and a line of attentive people. Its moving arms carried information only because every station performed the same small act in order.

Questions

Choose an answer. The explanation appears after you answer.

  1. Question 1 of 4

    What is the main idea of the passage?

  2. Question 2 of 4

    Why did an operator use a telescope?

  3. Question 3 of 4

    In this passage, what does “relay” mean?

  4. Question 4 of 4

    In what year did Claude Chappe present the optical telegraph system?

Score: none answered yet.

More passages

Practise reading