1 son, James Martin. Assistant in theoretical astronomy, Leiden U., 1923-1927. Fellow International Education Board at Yale and University of California, 1927-1928. Instructor astronomy Yale 1928-1933, assistant professor, 1933-1939, associate professor, 1939-1941, professor astronomy, director Observatory, since 1941.
Editor Astronomical Journal, since 1941.
Member American Association for the Advancement of Science, American Astronomical Society, American Association Variable Star Observers (president 1941-1943), Astronomical Society of Pacific, International Astronomical Union, National Academy Sciences, American Academy Arts and Sciences, Royal Astronomical Society (foreign associate), Royal Netherlands Academy Sciences (correspondent), American Geophysical Union, Buenos Aires Academy Sciences (correspondent 1961), Sigma Xi.