Robert A. Millikan

Robert A. Millikan (1868-1953) received the 1923 Nobel Prize for his work in determining the charge of the electron and for work confirming Einstein's photoelectric equation. In 1909 he performed the famous "Millikan oil drop experiment" in which was able to suspend tiny droplets of oil in an electric field and therefore measure their charge accurately. The charges were found to be multiples of a number he determined to be 1.64 x 10^-19 Coulombs, a number which compares favorably with the currently accepted value of 1.602 x 10^-19 C for the charge of an electron.