Today 199 years ago, the first (modern) optical telegraph line following the mechanical telegraphy system of the French inventor Claude Chappe was established between Metz and Mainz was established. No, this wasn't the first of its kind, but it was the first to connect the former already in France established telegraphy system with a (now) German city.
Today 219 years ago, the 'martyr of the revolution', Jean Paul Marat was assassinated by Charlotte Corday, a 24 year old girl. The physician, natural scientists, and political activist was a member of 'the Mountain', a group active during the French Revolution, and author of the radical newspaper 'L'Ami du peuple'.