In 1792, Chappe developed a new method of communications through a practical system of semaphore relay stations. The relay line consisted of towers fitted with a telescope, each placed between 12 and 25 kilometers apart. This system of so-called Chappe towers allowed for the swift transmission of crucial information, despite some of it being lost on the way.
On 1 September 1794, in less than an hour, Parisians were informed of the capture of Condé-sur-l'Escaut from the Austrians, 220 kilometers away, through the towers. Around this time, the Duke of Brunswick, the Prussian commander, was signalled with Chappe towers to invade Paris. However, Captain Thomas-Alexandre Dumas of the French Revolutionary Army had the Assassin Arno Dorian sabotage the towers before the signal could reach the Duke.