When was the system of levers added to the flute?

The system of levers was added to the Flute in the early 19th century, particularly around the 1830s. This innovation was part of a broader evolution of the instrument aimed at improving playability and expanding the range of notes. The most significant advancements were made by flute makers like Theobald Boehm, who developed the Boehm system, which incorporated a key mechanism that allowed for more precise control and easier fingerings. This design has largely influenced modern flute construction.