THE DOMINION OBSERVATORY - OBSERVATOIRE FÉDÉRAL

The Dominion Observatory is located in Ottawa, a few hundred metres from Dow's Lake and the Central Experimental Farm. It was founded in 1905 at the instigation of the Geological Survey of Canada, which urgently needed to create a service that could provide accurate geographic and time measurement data for its topographic and cartographic surveys. It was William Frederick King, chief astronomer of the Department of the Interior, who was chosen to establish it, and equipped it with a 35 cm diameter telescope, small by today's standards and yet the largest ever installed in Canada at that time! The most essential role of this observatory was the measurement of time. King entrusted this task to Robert Meldrum Stewart, an astronomer and future director of the department, because this measurement was made from the position of the stars once they passed the south meridian, that is, the point where they were at their highest in the sky. Thanks to this fundamental work and the acquisition of a high-precision clock in 1929, Stewart succeeded in setting up a real network of clocks in the city's federal government buildings. In 1930, no fewer than 700 clocks displayed the time synchronously in Ottawa! Such a high level of efficiency that this system was then extended to the whole country. The other work of the observatory was to accurately measure the position of the stars, so that geographical coordinates, latitudes and longitudes could then be determined across Canada. Finally, the Federal Observatory's objective was to centralize all geophysical, seismic, gravimetric and magnetic data throughout the country. From the 1970s, Canadian scientific institutions were reorganized and the services related to the observatory were transferred to the National Research Council of Canada. Then the observatory ceased its activities and the building became the headquarters of this council. In 1974, the telescope was transferred to the Canada Science and Technology Museum, where it is still located today.

To our knowledge, the interior of the observatory is not accessible to the public. On the other hand, it is possible to discover its exterior façade and domes, especially since the park in which it is located is rather pleasant. Part of the building can be seen from Carling Avenue. Designed by David Ewart in 1902, this two-storey stone building is quite imposing, with a central tower topped by a dome using copper for its construction. Other buildings are visible, the South Azimuth Building, built to house part of the astronomical equipment, and the Photo Equatorial Building, which had a retractable copper roof and was also used to house the precious equipment.