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Dominion Observatory

Ottawa, Ontario, Canada

Formally Recognized: 1992/12/10

Exterior photo; (Department of Energy, Mines and Resources, 1992.)
Exterior photo
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Other Name(s)


Links and documents

Construction Date(s)

1902/01/01 to 1904/01/01

Listed on the Canadian Register: 2006/01/23

Statement of Significance

Description of Historic Place

The Dominion Observatory is a symmetrical, two-storey, stone building that features a central, four-storey octagonal tower flanked by two “T”-shaped flat-roofed wings, which are oriented at a 15º angle away from the tower. In 1905, the one-storey transit house was added to the western wing and housed the meridian circle telescope and transit instruments used to determine time, longitude and star positions. The tower, which is capped by a retractable copper dome and serves as the main entrance to the building, formerly housed the observatory’s equatorial telescope. Located at the north edge of the Central Experimental Farm on a campus-like site bounded by Carling Avenue and Observatory Drive, the Dominion Observatory forms a picturesque ensemble with the South Azimuth building (1912) and the Photo Equatorial building (1914) which formerly played supporting roles in the Observatory’s scientific endeavours. The designation is confined to the footprint of the building.

Heritage Value

The Dominion Observatory is a Classified Federal Heritage Building because of its historical associations, and its architectural and environmental values.

Historical value:
The Dominion Observatory is one of the best examples of the important historic theme of the advancement of pure and applied scientific research at the national level in Canada. Established to aid and improve the survey work of western Canada through the investigation and application of positional astronomy, the Observatory also served as a world-class centre for astronomical and geophysical research, and developed a national profile as the source of Dominion Observatory Official Time. The Dominion Observatory is one of four major public buildings constructed in Ottawa during the expansionist years of the Wilfrid Laurier government as part of Laurier’s efforts to turn Ottawa into the –Washington of the north-, and heralded Ottawa’s transformation from a lumber town to a capital city. Scientists of national standing directly associated with the observatory include its co-founders William Frederick King and Otto Julius Klotz, along with John Stanley Plaskett.

Architectural value:
The Dominion Observatory is an excellent example of an eclectic blend of Romanesque Revival and Edwardian Classicist styles. Carefully planned by the founding scientists, the functional design of the building’s research facilities originally accommodated the requirements of a small scientific department and has proven to be adaptable to new uses. A very good example of David Ewart’s work, the building successfully combined aesthetics with the original functional requirements, making it well-suited to both the scientific activities it housed, as well as fulfilling the government’s desire for a building that would express the federal and national importance of the institution.

The Dominion Observatory has a principal public façade which features most of the decorative detailing, and a more functional façade which features the photographic laboratory’s skylight and the curved projecting wall of the stairs which are direct expression of the building’s functions. Constructed of the highest quality materials and craftsmanship, the public and functional facades of the building are unified by the masonry work, which is characterized by a rich and vibrant palette of colours and textures.

Environmental value:
Visually prominent by virtue of its distinctive design, massing, materials and location, the Dominion Observatory forms part of a harmonious ensemble that includes the South Azimuth building and the Photo Equatorial building, which together reinforce the picturesque character of the Central Experimental Farm. The Dominion Observatory is one Ottawa’s most well-known and easily recognizable public buildings.

Jacqueline Hucker, Dominion Observatory, South Azimuth and Photo Equatorial buildings, Ottawa, Ontario. Federal Heritage Buildings Review Office Report 92-35, 92-41, 92-42; Dominion Observatory, South Azimuth and Photo Equatorial buildings, Ottawa, Ontario, Heritage Character Statement 92-35, 92-41, 92-42.

Character-Defining Elements

The character-defining elements of the Dominion Observatory should be respected:

Its masterful, eclectic blend of the Romanesque Revival and Edwardian Classicist styles, excellent functional design, and exceptionally high quality materials and craftsmanship as manifested in:
-the symmetrical composition of the building which consists of the central, four-storey tower and two “T”-shaped wings, one of which also features the one-storey former transit house addition;
-the formal treatment of the principal south façade including the decorative detailing, which expresses the federal and national importance of the institution, in contrast to;
-the simpler, less elaborate treatment of the north façade which is a direct expression of the building’s interior functions;
-the distinctive and vibrant exterior treatment which unifies the public and functional sides of the building and is characterized by a rusticated limestone base, rock-faced variegated Nepean sandstone walls, and contrasting smooth, red Sackville sandstone string courses and window and door surrounds;
-the tower’s decorative, stone detailing including the foliated capitals which flank the main entrance and separate the windows of the tower’s drum, the incised lettering and carved royal coat of arms above the main entrance, the stone brackets supporting the drum’s balcony;
-the hemispherical copper dome which caps the tower;
-the decorative ironwork including the drum’s balustrade;
-the large clock face at the center of the tower’s drum which recalls the Observatory’s former timekeeping function;
-the interior features that define the building’s early federal government office character such as the pressed yellow brick, ceramic tile floors, moulded baseboards and paneled wood office doors with transom lights, as well as the original light fixtures.

The manner in which the building reinforces the picturesque character of the observatory’s campus-like setting within the Central Experimental Farm, as evidenced in:
-its visual prominence owing to its distinctive design, massing, materials and location;
-its harmonious relationship with the South Azimuth and the Photo Equatorial buildings, which together form a picturesque ensemble.




Recognition Authority

Government of Canada

Recognition Statute

Treasury Board Heritage Buildings Policy

Recognition Type

Classified Federal Heritage Building

Recognition Date


Historical Information

Significant Date(s)


Theme - Category and Type

Function - Category and Type



Health and Research
Research Facility

Architect / Designer

David Ewart, Chief Architect of the Department of Public Works



Additional Information

Location of Supporting Documentation

National Historic Sites Directorate, Documentation Centre, 5th Floor, Room 89, 25 Eddy Street, Gatineau, Quebec

Cross-Reference to Collection

Fed/Prov/Terr Identifier




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Central Experimental Farm National Historic Site of Canada

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