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Record 1 2009-09-16


Subject field(s)
  • National Bodies and Committees (Canadian)
  • Mathematical Geography

The Dominion Observatory was founded for very pragmatic reasons. The objective was to have a longitude reference (with associated time signal) for surveying in Canada: "To open up the West". Surveyors in the field would compare the time signal of the Dominion Observatory with their local time determined by astronomical observations - the difference corresponding to longitude difference between Canada's prime meridian (Dominion Observatory) and their location. Construction of the building began in July 1902 was completed in 1905.


The Dominion Observatory was an astronomical observatory in Ottawa, Canada that operated from 1905 to 1970. The Observatory was also an institution within the Canadian Federal Government. The observatory grew out of the Department of the Interior's need for the precise coordinates and timekeeping that at that time could only come from an observatory. For several years they had used a small observatory on the Ottawa River for this purpose. In 1902 it was decided that Canada needed a larger national observatory similar to the Royal Greenwich Observatory in Britain. The new building was thus erected near Dow's Lake on the Agriculture Department's Central Experimental Farm land. This building was completed in 1905. Its main instrument was a 15 inch refracting telescope, the largest refracting telescope ever installed in Canada. While the building and institution were primarily dedicated to astronomical timekeeping in support of surveying, a number of other activities took place here. The Dominion Observatory was Canada's leading institution in Geophysics for many decades, which included the operation of Canada's national seismometer network. The facility did important work but with this bridgehead into the world of astronomy and the growth of the field of astrophysics Canadian astronomers quickly demanded a facility designed for the new scientific age.


  • Organismes et comités nationaux canadiens
  • Géographie mathématique

L'Observatoire fédéral fut fondé pour des raisons très pragmatiques. L'objectif était d'obtenir une référence de longitude (comprenant le signal horaire associé) pour l'arpentage au Canada : «Pour coloniser l'Ouest». Les arpenteurs sur le terrain devaient comparer le signal horaire de l'Observatoire fédéral avec l'heure locale où ils se trouvaient, déterminée par des observations astronomiques, soit la différence correspondant à l'écart de longitude entre le méridien origine au Canada (l'Observatoire fédéral) et leur emplacement. La construction de l'édifice débuta en juillet 1902 et fut achevée en 1905.


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