MILLIKAN, ROBERT ANDREWS ) , Ameri can physicist, was born at Morrison, Ill., March 22, 1868, and re ceived his education at Oberlin College (A.B., 1891; A.M., 1893) where he was instructor in physics 1891-93. He then proceeded to Columbia University (Ph.D., 1895), and the universities of Berlin and Gottingen (1895-96). In 1896 he was appointed assist ant in physics at the University of Chicago, with which institu tion he continued to be associated for the next 25 years in the department of physics, being professor from 1910 to 1921. In 1921 he became director of the Norman Bridge laboratory of physics and chairman of the executive council of the California Institute of Technology at Pasadena, California. He was vice chairman of the National Research Council, Washington, D.C., in 1917, and chief of the science and research division of the Signal Corps, U.S.A., with the rank of lieutenant-colonel. In 1922 he was the first exchange lecturer to Belgium on the C.R.B. Founda tion.
The best known of his researches were the "oil drop" experi ments, undertaken with the view of making measurements of fundamental electrical quantity. They proved conclusively that all electrons are alike, and yielded the most accurate determination of the electron thus far made. He also undertook researches into
photoelectric effect. Later research of his has tended definitely to bridge the gap between light and X-ray phenomena and to yield new information on the radiating properties of light atoms. He has recently brought new precision to the study of cosmic rays. He was awarded the Nobel Prize in physics in 1923 for his work in isolating and measuring the electron, and in making the first exact photoelectric determination of the light-quant. He received the Edison Medal for especially meritorious work in the field of elec tricity, and the Hughes Medal of the Royal Society in recognition of his determination of the electronic charge and other physical constants. He is also the recipient of the Faraday medal and the Matteuci medal. (See also PHYSICS and ELECTRICITY, ATMOS PHERIC : Cosmos Radiation.) Millikan was the author of the following, among other works:— Mechanics, Molecular Physics and Heat (t9oi); Electricity, Sound and Light (1908) ; The Electron (1917) ; Practical Physics (1920) ; Science and Life (1923) ; Science and the New Civilization (193o), in addition to numerous contributions to technical periodicals.