Millikan was Vice Chairman of the National Research Council during World War I. During that time, he helped to develop anti-submarine and meteorological devices. During his wartime service, an investigation by Inspector General William T. Wood determined that Millikan had attempted to steal another inventor's design for a centrifugal gun in order to profit personally. Wood recommended termination of Millikan's army commission, but a subsequent investigation by Frank McIntyre, the executive assistant to the army chief of staff, exonerated Millikan. He received the Chinese Order of Jade. After the War, Millikan contributed to the works of the League of Nations ' Committee on Intellectual Cooperation (from 1922, in replacement to George E. Hale, to 1931), with other prominent researchers (Marie Curie, Albert Einstein, Hendrik Lorentz, etc.). Millikan was a member of the organizing committee of the 1932 Los Angeles Olympics, and in his private life was an enthusiastic tennis player. He was married and had three sons, the eldest of whom, Clark B. Millikan, became a prominent aerodynamic engineer. Another son, Glenn, also a physicist, married the daughter (Clare) of George Leigh Mallory of "Because it's there" Mount Everest fame. Glenn was killed in a climbing accident in Cumberland Mountains in 1947.