 In 1922, he received his doctorate under L. S. Ornstein.He was an assistant at the University from 1921 to 1928, except for his postdoctoral study and research at the Ludwig Maximilian University of Munich under Arnold Sommerfeld, 1925 to 1926 on a Rockefeller Foundation Fellowship.He also spent 1928 to 1929 on a Rockefeller Foundation Fellowship at the University of Wisconsin–Madison.