Napoleonic semaphore was the world's first telegraph network, carrying messages across 19h-Century France faster than ever before. Now a group of enthusiastic amateurs are reviving the ingenious system.
Before the web, before the computer, before the phone, even before Morse code, there was le systeme Chappe.
Not for the first time or for the last, at the end of the 18th Century France made an important technological advance - only to see it overtaken by newer science.
In this case, it was the world's first ever system of telegraphy.
According to most accounts, the very word "telegraph" - distance writing, in Greek - was coined to describe Claude Chappe's nationwide network of semaphore.
At its most extensive, it comprised 534 stations covering more than 5,000km (3,106 miles).
Messages sent from Paris could reach the outer fringes of the country in a matter of three or four hours. Before, it had taken despatch riders on horseback a similar number of days.
But then it ended almost as quickly as it began. In the 1840s and 50s, electronic telegraphy - with stations set up along the new railway lines - began to take over.
The Chappe stations disappeared into obscurity, plundered for materials and buried in vegetation.
Only in recent years has a resurgence of amateur interest permitted a handful of sites to be rescued from oblivion.
One such is the station of Mollard-Fleury, half-way up a mountainside near Modane in the Alps.
Enthusiasts worked out the probable location by consulting maps in the archives in Paris. In 2002 they found the remains of the post in woods above the village of Sardieres.
Now they have just rebuilt an exact replica, using original designs drawn up by an inspector on the line.
Visitors who make it up the brisk climb find a two-room cabin of wood and stone. The second room contains a system of wheels and pulleys, controlling the signal system which is set on a mast above the roof.
A panaromic view looks south-east across the valley to more snow-capped mountains. Beyond is Italy.
"This station was part of the Lyon to Milan line that Napoleon built in 1805 as he prepared to resume war in Italy," explains Bernard Pinaud, who over the summer will give demonstrations of the semaphore.
"Ultimately it extended as far as Venice, allowing the emperor to get messages to his armies in northern Italy in a matter of a few hours."
One such message has been discovered in the records of a nearby village.
It reads: "The Legion of the South may recruit men in Turin from among the Piedmontese prisoners-of-war or Austrian deserters . However it must not recruit men who are not from Piedmont."
This message would have been transcribed into semaphore signs by a superintendent in Paris.
It would then have been passed down the chain of stations, each about 10km (six miles) and visible from the next.
In each hut, a single operator had the task of surveying his neighbours by telescope. As soon as there was activity, he copied down the signals and passed them on.
Of the meaning of the message, the operator had not a clue. He merely worked the machine.
Born into a family of scientists in western France, Claude Chappe (1763 - 1805) made the important observation that the human eye is excellent at discerning angles.
So he designed a system built round three parts - a long central beam, with two shorter arms attached at either end.
Each manoeuvre was reckoned to take about 30 seconds, and the messages were transmitted in full - words like "de" and "a" included. Telegram-ese had not yet been invented.
For the operators it was tiring and laborious, especially as they had pay docked for delays.
Still, by all accounts they acquitted themselves well. The record was 60 minutes for a message travelling from Paris to Strasbourg. It bore news of the birth of Napoleon's son.
We have a description of one of the Chappe stations in Alexandre Dumas's The Count of Monte Cristo, which was written in 1844 and set 30 years earlier.
The count sees the contraption "like the claws of an immense beetle" and feels wonder that "these various signs should be made to cleave the air with such precision as to convey to the distance of three hundred leagues the ideas and wishes of a man sitting at a table".
He then bribes the operator to send false information down the network, causing a financial panic in Paris.
From the outset, the prime purpose of the system was military.
Four years into the Revolution - with fears growing of foreign invasion to restore the monarchy - the Republican government commissioned Citizen Chappe to build the first line, from Paris to Lille.
A year later, in September 1794, the government heard news - on the day it happened - that the northern border town of Conde had been captured. They telegraphed back their congratulations, which were received in Conde the very same evening.
New lines opened to Strasbourg, then to Lyon and Brest. Napoleon built the line to Italy, and also - as he contemplated invading England - an extension to Boulogne on the English channel.
Under the restored monarchy after 1815, there were new lines to Marseille and to Bayonne in the south-west. The last stations were built in 1849, but by then it was clear that the days of line-of-sight telegraphy were done.
The military needs had disappeared, and latterly the operators' main task was transmitting national lottery numbers.
The shortcomings of visual communication were obvious. It only functioned in daytime and in good weather.
And of course the invention of electronic telegraphy changed everything. In 1844 Samuel Morse showed that it worked down a wire from Washington to Baltimore in the United States. Soon the Chappe towers were to look as antiquated as perfumed wigs.
Smoke, fire, light, flags - since time immemorial man had sought to speak over space.
What France did in the first half of the 19th Century was create the first ever system of distance communication.
On the long trek to the internet, it is an overlooked - but significant - early step.