He served as president of the Royal Astronomical Society from 1937 to 1939 , and at other times as the society 's secretary , treasurer and foreign secretary .
He was president of the International Astronomical Union from 1945 to 1948 .
president served as president of the Royal Astronomical Society from 1937 to 1939 , and at other times as the society 's secretary , treasurer and foreign secretary .
He was president of the International Astronomical Union from 1945 to 1948 .