Cloud chambers were originally designed to study radioactivity. Scottish physicist Charles Thomson Rees Wilson (1869–1959) invented the chamber in 1912, winning the Nobel Prize in physics in 1927 for his invention. The procedure involved saturating an enclosed chamber in water vapor until it was supersaturated. Ionized particles would then be passed through the chamber, serving as nuclei around which droplets would form. This had the advantage of making the particles visible to physicists, and the behavior of the particles could be studied.