Jean-Daniel Colladon Swiss physicist. Date of Birth: 15.12.1802 Country: Switzerland

1. Biography of Jean-Daniel Colladon
2. Experiment on Measuring the Speed of Sound
3. Contributions to Gas Lighting
4. Personal Life

Biography of Jean-Daniel Colladon

Jean-Daniel Colladon was a Swiss physicist who made significant contributions to the field of science. He initially studied law but later worked in the laboratories of Ampere and Fourier. In 1826, he received the annual prize from the French Academy of Sciences for his experiment on measuring the speed of sound in water. Colladon's expertise led him to become a professor of mechanics at ?cole Centrale Paris in 1829. However, he returned to Switzerland in 1839.

Experiment on Measuring the Speed of Sound

In 1826, Jean-Daniel Colladon and his friend, Swiss physicist Charles-François Sturm, conducted an experiment on the speed of sound in water on Lake Geneva. Using gunpowder and an underwater bell, they measured the time interval between the light flash and the arrival of sound at a known distance point (10 miles). The experiment revealed that at a water temperature of 8°C, sound traveled at a speed of 1412.1 m/s. Nowadays, the speed of sound in water is generally considered as 1500 m/s at a temperature of +15°C and salinity of 34‰.

Contributions to Gas Lighting

Aside from his work in physics, Colladon was also involved in the organization of street gas lighting in Geneva (1843-1844) and Naples (1862). His efforts in implementing gas illumination systems greatly contributed to the improvement of urban lighting and safety in these cities.

Personal Life

In 1837, Jean-Daniel Colladon married Stéphanie-Andrienne Ador. The couple had children named Andriana-Matilda, Jean-Marie, Pierre Louis Henri, and Marie Amelie. Colladon's sister, Antoinette Dunant-Colladon, is known as the mother of Henri Dunant, the founder of the Red Cross Society.