The creation of the French State Telegraph was at the instigation of one man - Claude Chappe - who became the system's Chief Engineer.

He had been experimenting with different types of telegraph since 1790.

Using a system of telescopes, pendulum clocks and a large board, painted white on one side, black on the other, he had managed to transmit several sentences over a distance of 16km (10mi).

By 1793, Chappe had abandoned his synchronised clocks and adopted a semaphore system, which was technically simpler and easier to read at a distance.

The semaphore telegraph consisted of a large horizontal beam with two smaller wings, known as indicators, at each end. The angle of the wings could be adjusted, in increments of 45°, and thus they were capable of sending signals using a prearranged code.

Chappe persuaded the French government to allow him to build the first telegraphic connection - between Paris and Lille, a distance of approx. 190km (120mi). It involved 15 stations and began operating on 16th July 1794.

France was at war on several fronts and the system was soon to prove its value.
On 15th August 1794, the telegraph brought fast and fresh news to Paris that the French had recaptured the city of Le Quesnoy, from Austrian and Prussian forces. As a result of this success, the network was extended.

Napoleon was a great enthusiast for the semaphore telegraph. In 1804, the year he declared himself emperor, he ordered the construction of a data link, strictly for government use, from Lyon, across the Alps, to Turin and Milan.

It took five years to build but, when completed, meant that a message could travel from Paris to Milan in 30 minutes under optimum conditions. If the weather was bad and visibility poor, messages could take two or three days. Each station was manned by two operators, who passed on the coded messages without understanding their meaning.

From 1759 to 1855, it grew from 15 to 556 stations; at its height, it connected 30 French cities to Paris and employed more than 3,000 people.

Many other countries followed France's example. Similar networks appeared in Sweden, Denmark, Finland, England, Germany, Spain, Russia, Australia and the US.

Source:
Gerard J. Holzmann - Station to Station [Communicating Business. Spring 1995]. Based on his book (with Björn Peterson), The Early History of Data Networks [IEEE Computer Society Press. 1995]
Also available as a hypertext document:
www.it.kh.se/docs/early_net/
Information on the history of the optical telegraph in Sweden and Russia: <A HREF="http://www.telemuseum.se/historia/optel