This is none other than Frank Scott Hogg, Ph.D. (Harvard), Professor of Astronomy, etc, etc, and also the husband of Helen Hogg. I am sure you can find an obituary in the Journal [JRASC 45,1]. Frank had a weak heart and died prematurely in 1949, I believe -- otherwise he would have been the third Director of DDO. It is a good picture of him, showing his piercing but firendly eyes.
Photo by R. Northcott, Nov. 1950. Note by D.A. MacRae, 1998.