Jules Antoine Lissajous was a high-school teacher, then held prestigious administrative posts in the education system of various parts of France. He had trained in physics, and defended his dissertation on vibratory phenomena in 1850.
Chladni was a physicist whose work focused on experimental acoustics. He invented the “Chladni figure” and various instruments. Until his death, he continued to travel and present his inventions and findings to a wide audience.