French Semaphore Telegraph
the Revolutionary and Napoleonic Wars communication systems
were pretty basic, mainly relying upon mounted despatch
riders, although in 1793 a Frenchman came up with a suggestion
that would transform long-distance communications.
Chappe's semaphore telegraph took quite some time to be
accepted by revolutionary officials, but once the teething
problems had been ironed out it was rapidly adopted.
1794 communications towers within line-of-sight of each
other allowed the French to send a signal from Paris to
Lille - a distance of some 191 kilometres - in five minutes.
success of the system meant new tower lines were constructed
reaching out from Paris to Dunkirk, Brussels, Boulogne,
Antwerp, Metz, Lyon, Milan, Venice and Mantua.
message could be sent to Venice in six hours!
telegraph was a small tower upon which stood a black 9-metre
mast with a moving wooden cross-piece, measuring 30cm by
regulator, as it was known, had a 1.8 metre indicator at
each end and had four basic positions - horizontal, vertical
or at 45-degree angles.
not in operation the indicators were left as horizontal
extensions of the regulator and these would then be moved
in seven combinations of angles at 45-degree tilts.
up the Chappe semaphore tower had 196 combinations known
as signs and would be worked by a series of pulleys and
a good operator three signs could be sent in a minute -
providing the visibility was good - although turning the
signs into code would further speed a message's journey.
French spent some time trying to develop a wagon-mounted
version of the Chappe system, but funding for research was
Picture courtesy of l'Ecole
Centrale de Lyon