(1865-1956) Professor of Astronomy at University of Toronto, President of the Society (1904-07), editor of the Journal and Handbook for 50 years, and an important figure in the creation of the David Dunlap Observatory.
(1865-1941) J.S. Plaskett played a pivotal role in the establishment of astrophysical research in Canada and helped to confirm the rotation rate of the Milky Way. He was an active member of the Ottawa Centre between 1907 and 1918, acted as an Associate Editor of the Journal for 28 years, and Society President (1914-15).
(1857-1940) F.R.S.C., F.R.A.S.C. Director of the Toronto Observatory and Superintendent of the Dominion Meteorological Service (1894-1929), and President of the Society (1902-03). He was knighted in 1916.
(1842-1905) B.A., M.A., M.B. A school inspector by trade. He built the 12½" reflector (the largest in Canada at the time) that he used to observe the heavens from his observatory on Talbot Street in Simcoe, Ontario.