On this day in 1877 Thomas A. Edison conceived the first idea for his phonograph, the very first mechanical tool for recording and reproducing (replaying) sound. The phonograph also was the invention that first gained him public notice.
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.