The Dominion Observatory was an astronomical observatory in Ottawa, Canada that operated from 1905 to 1970. The observatory grew out of the Geological Survey of Canada'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 by the Agriculture Department's Central Experimental Farm . This building was completed in 1905. Its main instrument was a 15 inch refracting telescope, the largest refracting telescope ever installed in Canada. The building was more than a astronomical observatory. In the basement the Survey maintained Canada's top seismic observatory. The facility did important work, but Canadian astronomers quickly demanded a large facility. In 1917 the Dominion Astrophysical Observatory was opened in Victoria, B.C. and it supplanted the Dominion Observatory as Canada's foremost astronomical observatory. The Dominion Observatory remained an important facility. For many years it was best known to Canadians as the source of Canada's official time signal.

The observatory continued in operation until 1970 when Canada's science institutions were reorganized and the observatory was transferred from the Geological Survey to the National Research Council. The NRC ceased conducting astronomical observations from the building and it became home to NRC offices. The telescope was opened to the public for educational astronomy in partnership with the Canadian Museum of Science and Technology. In 1974 the telescope was moved from the Dominion Observatory to the Helen Sawyer Hogg Observatory just outside the museum where it remains to this day.

External links

• The Dominion Observatory – 100th Anniversary