While at Victoria, he made important contributions to the observation and interpretation of emission lines in the spectra of certain hot stars, to the understanding of the nature of the gas clouds in interstellar space and to the development of instrumentation for astronomy.
As Dominion Astronomer he guided the postwar development of astronomical and geophysical research in Canada. Combining his knowledge of Astronomy and his interest in geophysics, he initiated a highly successful program in the identification and study of meteorite craters in Canada. Recognized internationally as one of the leading astronomers of his day, he was the recipient of many honours, including the Order of Canada. In September 1987 minor planet 3314 was named after him.