Description

Geographical position 

Dominion Observatory, 1 Observatory Crescent, Ottawa, ON K1Y 4X2, 
Central Experimental Farm, Carling Avenue, Ottawa, Canada
See also:
- Dominion Astrophysical Observatory, Victoria, British Columbia, Canada (1918)

- Please do not confuse this with this observatory:
Dominion / Carter Observatory, Wellington, New Zealand

Location 

Latitude 45.393687 N, Longitude 75.714261 W, Elevation ...m above mean sea level.

IAU observatory code 

790

Description of (scientific/cultural/natural) heritage 

Observatories in the 19th century in Canada: Cliff Street Observatory

(https://astro-canada.ca)

In Ottawa, Ontario, an observatory on Cliff Street (*1890) near Ottawa River was  constructed by astronomers William Frederick King (1854--1916), Édouard-Gaston Daniel Deville (1849--1924), a surveyor and astronomer in Quebec 1875, Surveyor General of Canada 1885, and Otto Julius Klotz (1852--1923), astronomer in the Dominion of Canada 1885. A transit instrument was used for timekeeping, and the observatory was used as a primary reference point for surveyors. The Geological Survey of Canada was founded in 1841, the Hydrographic Survey (1880s), the Topographic Survey (1880s), and the Geodetic Survey of Canada (1909). 

• 1. Dome of the 15-inch (38-cm) Brashear Refracting Telescope (Ingenium no. 1974.0488)
• 2. Transit room (with two "shutters" for the meridian instrument and the Cooke transit)
• 3. Brashear Coelostat (Ingenium no. 1966.0402), the white shed. 
  Note the anemograph tower on the roof of the Observatory building.
• 4. The south meridian mark for the meridian instrument; 
  the north meridian mark was removed when Carling Avenue - at top - was constructed.
• 5. Photo Equatorial Building for the Brashear Astrograph (installed in 1915), (Ingenium no. 1966.0401)
• 6. Gravity and standards testing building
• 7. Observatory House -- home for the Director / Dominion Astronomer
• 8. Building for the Photographic Zenith Tube (PZT), installed in 1951.
• 9. Mirror transit building; it had a roll-off roof like the coelostat shed and PZT shed..
• 10. The floral sundial-a centrepiece of the approach to the Observatory since its founding.
  11. Geophysical laboratory.
  12. Seismology building.

Since the photo was taken in 1966, the buildings 3, 8 and 9 have been disassembled.
Copyright of all Photos: historic images: Canada Science and Technology Museum (CSTM) Archives.

Dominion Observatory in Ottawa

In 1902, it was decided to build a larger Government Observatory. 
The architect David Ewart (1841--1921) designed the Dominion Observatory in Ottawa in Baronial style (Romanesque Revival style, historical architecture of Scotland in the Late Middle Ages, Gothic Revival, and in the Renaissance) from 1902 to 1905.

Because of the meridian instruments, the orientation of building is on an east-west line. The main building is dominated by a four-storey tower with a copper dome. 

Later the South Azimuth building (1912) and the Photo Equatorial Building (1914) were added in the same style. The star-shaped flower beds exist no longer.

It was the first government observatory and provider of official time in Canada. In addition, surveying and cartography were an important tasks (Geological Survey of Canada). 

William Frederick King (1854--1916) studied at the University of Toronto (Bachelor of Arts degree in mathematics in 1874). His duties were Dominion land / topographical surveyor (1876) and first chief astronomer (1890), became the founding director (1905) of the Dominion Observatory in Ottawa, and president of the Royal Society of Canada from 1911 to 1912. 

In addition, Otto Julius Klotz (1852--1923), an important land surveyor from 1880 to 1892, became Assistant Chief Astronomer (1908), and Dominion Astronomer (1916), cf. Ackerman 1995.

King recognized also the importance of the emerging field of astrophysics, and asked his mechanical superintendent, John Stanley Plaskett (1865--1941), to develop new instrumentation for this research. Some astrophysical measurements were made (photography, spectroscopy, and photometry). Especially John S. Plaskett measured radial velocities and studied spectroscopic binaries from 1903 to 1918. In addition, one can mention the Belgian / Canadian astronomer François Charles Pierre Henroteau (1889--1951), head of the physical astronomy department at the Dominion Observatory from 1920 to 1945.

But for astrophysics; the new Dominion Astrophysical Observatory, Victoria, B.C., was opened in 1918.

Dominion Observatory in Ottawa -- Robert Meldrum Stewart and Timekeeing

Dominion Observatory in Ottawa was not only active in astronomy, but also in surveying, and later in geosciences like geophysics, geomagnetism, seismology and gravimetry. 

But the emphasis of the work was mainly on timekeeping -- Robert Meldrum Stewart (1878--1954) was appointed Superintendent of the Time Service in 1905: it was responsible for Canada's official time signal -- the time signals were distributed via telegraph wires around Ottawa, to the railways and to other government observatories from Saint John to Victoria. Radio broadcasting short wave frequencies was used since 1927. For the time service, the meridian circle was used until 1935, then the Cooke transit, much later with a Photographic Zenith Telescope (PZT). He also had the idea for the construction of a Time Signal Machine (1938), first combined with a Shortt pendulum clock, then since 1942, with a crystal clock. The time was broadcasted over the Canadian Broadcasting Corporation network, first with a Talking Clock since the 1930s, replaced by the Ateliers Brillié Frères machine (1955). 

Stewart became a pioneer by using of wireless time signals, later he extended the programme to stations remote from telegraphic communications, The first station was in the province of Quebec in 1914. After he became director in 1923, he participated for Canada in world longitude programmes in 1933. 
Apart from Time Service and Positional Astronomy, he was also interested in Terrestrial Magnetism, Gravity, Seismology, Stellar Physics. He established the Dominion Radio Astrophysical Observatory, near Penticton, British Columbia. In addition, he studied meteorite impact craters in the Canadian shield.

Dominion Observatory in Ottawa 1950s to 1970

The successor of Stewart was Carlyle Smith Beals (1899--1979), who received at University of Toronto his master's degree in Physics in 1923, and a PhD in 1926 at Imperial College London. He became Assistant Astronomer at the Dominion Astrophysical Observatory (DAO), Victoria from 1927 until 1946, becoming Assistant Director of the DAO in 1940. He studied spectra of hot stars and gas clouds in the interstellar medium and emission lines seen in Wolf-Rayet and P Cygni-type stars caused by strong stellar winds. In 1946, he moved to Dominion Observatory, and was appointed director from 1847 to 1964. 

Peter Mackenzie Millman (1906--1990) joined the staff of Dominion Observatory in 1946; in 1955, he transferred to the National Research Council as head of upper atmospheric research.

The seismologist John H. Hodgson (1913--2011) was appointed as last director of Dominion Observatory from 1964 to 1970. 

The Dominion Observatory in Ottawa had continued the work only until 1970. At that time the National Research Council of Canada (NRC) was founded, and took over the responsibilities of the Dominion Observatory. 

In 1974, the Brashear refractor was moved from the Dominion Observatory to the Helen Sawyer Hogg Observatory (named in 1988 in honour of Canada's leading female astronomer) at the Canada Science and Technology Museum (CSTM), used until 2016.

Since 2008, the historical observatory building is used by the Office of Energy Efficiency. 

History 

Instruments of Dominion Observatory Ottawa

(preserved in the Collection and Research Division,
Canada Science and Technology Museum,
P.O. Box 9724, Station T, Ottawa, Ontario  K1G 5A3, CANADA)

• 3-inch broken-type Transit instrument, made by Cooke & Sons of London (1890), 
  used both at the Cliff Street Observatory since 1890, and since 1905 at Dominion Observatory (CSTM 1976.0300)
• Zenith telescope, Troughton & Simms of London (1872), (CSTM 1972.0376), aperture: 2 1/2-inches, focal length: 28-inches. Inscriptions: "T.S. 394" and on the baseplate, "Fo. 1".
  used for the Dominion Lands Survey in Western Canada.
  With the Zenith telescope, one was able to determine latitude of the site and, if one had in addition a chronometer, one could also determine longitude. 
• 6-inch-Meridian Circle, made by .... (1907), (destroyed in 1970)
• Precision Sideral Pendulum Clock with vacuum, Sigmund Riefler of Munich (1902),  (CSTM 1966.0545) - precision of 0.015 second per day
• Sidereal and solar clocks, Paris (1902)
  
  
• 15-inch (38-cm) Refracting Telescope (f=5.7-m, f/15),
  the largest refractor ever erected in Canada, 
  John Brashear of Pittsburgh, Pennsylvania (optics) and
  Warner & Swasey of Cleveland, Ohio (mounting and dome), 1901-1905, (CSTM refractor 1974.0488) 
  The original mechanical clock drive (CSTM 1974.0488) of the telescope for tracking the stars, driven by falling weights, controlled by a fly-weight governor (like that invented by James Watt for the steam engines) was replaced by a synchronous electrical motor in the 1950s in order to take photographs.
  Filar micrometer, made by Brashear of Pittsburgh (CSTM 1970.0212).
  In 1958, the 15-inch (38-cm) Brashear achromatic lens (CSTM 1975.1087) was replaced by a three-component (triple) apochromat, made by Perkin-Elmer Corporation of Norwalk, Connecticut. 
  
  
• Prism spectrograph (1930) for studying binary or multiple star systems to measure radial velocities.
• Measuring instruments for stellar spectra, made by Otto Toepfer of Potsdam (CSTM 1970.0214, CSTM 1970.0221) and by Carl Zeiss of Jena (CSTM 1970.0222).
  
  
• Coelostat for tracking the Sun and its spectrum (CSTM 1966.0402),
  used first in 1905 for the total solar eclipse expedition to Labrador  (CSTM 1974.0754). 
  This solar telescope for photographing and spectroscopically studying the Sun was installed in a shed with roll-off roof.
  
  
• Double Astrograph, made by John Brashear of Pittsburgh, Pennsylvania (1915), (CSTM 1966.0401) with two main cameras plus a patrol camera, located in a small dome (Photo Equatorial building, 1914) near the main building. 
  It was used for photographing the sky and to measure the brightness of the stars on the photographs with a photometer.
  One camera has an wedge-shaped objective lens prism to get the spectra of the stars in the field.
  
  
• Glass Wedge Photometer, made by Brashear of Pittsburgh, Ohio, 1903 (CSTM 1970.1516).
  This wedge-shaped objective lens prism on one camera lens was used to get the spectra of the stars in the field. Cluster variable stars were discovered, and used for getting the distance of the cluster nebulae.
• Photometer with a photosensitive cell using light and electrical signals, made by Kipp & Zonen of Delft, Netherlands, 1930s (CSTM 1970.0213). Stars to approximately 7.5mag could be measured.
  
  
• First Talking clock (time signal broadcast on CBC Radio from the 1930s), replaced by an Ateliers Brillié Frères machine, 1955 (CSTM 1966.0791).

Directors of Dominion Observatory Ottawa

• 1905 to 1916 -- William Frederick King (1854--1916), Time Service, Surveyor and Astronomer 
• 1916 to 1923 -- Otto Julius Klotz (1852--1923), Dominion Astronomer since 1916, Surveying
• 1923 to 1946 -- Robert Meldrum Stewart (1878--1954), Time Service, Geophysics
• 1947 to 1964 -- Carlyle Smith Beals (1899--1979), Astrophysics
• 1964 to 1970 -- John H. Hodgson (1913--2011), Seismology

State of preservation 

The Dominion Observatory in Ottawa (1905), Romanesque Revival and Edwardian Classicist styles, is well preserved.
Treasury Board Policy on Management of Real Property
Designation Date: 1992-12-10, FHBRO Report Reference: 92-035, 92-41 and 92-42, DFRP Number: 0862500

Most of the historical instruments can be found in the the Canadian Museum of Science and Technology (CMST). 

The 15-inch-refracting telescope was moved to the Helen Sawyer Hogg Observatory in the CMST for public star gazing (1984 to 2014). It is now also preserved in the Ingenium -- Canada Science and Technology Museum Collections Conservation Centre.

Comparison with related/similar sites 

The Dominion Observatory in Ottawa is a very large one-dome observatory building, arranged in an astronomy park.

Threats or potential threats 

no threats

Present use 

The Dominion Observatory in Ottawa was transferred to the National Research Council of Canada (NRC) in 1970.
The former Dominion Observatory is now used for geophysics, for the gravity program of Natural Resources Canada. 

Astronomical relevance today 

The Dominion Observatory in Ottawa is no longer an astronomical observatory.

References

Bibliography (books and published articles) 

• Ackerman, Brenda: Marking the line: The surveying career (1872--1892) of Otto Julius Klotz. The professionalization of dominion land surveyers and patronage in the federal civil service. Wilfrid Laurier University, Department of History (M.A. thesis) 1995, (https://scholars.wlu.ca/etd/19).
• Basham, Peter William & Larry Newitt: A historical summary of Geological Survey of Canada studies of earthquake seismology and geomagnetism. In: Canadian Journal of Earth Sciences 30 (1993), 2, p. 372-390.
• Brooks, Randall & Calvin Klatt: The Dominion Observatory - 100th Anniversary. Ottawa 2005, (https://www.casca.ca/ecass/issues/2005-me/features/brooks/e-Cassi_DomObsV4.htm).
• Burland, Miriam S.: Obituary notices: Robert Meldrum Stewart. In: Journal of the Royal Astronomical Society of Canada 116 (1956), No. 2, p. 160-161.
• Covington, Arthur: A Zenith Telescope of Historical Interest. In: Journal of the Royal Astronomical Society of Canada 55 (1961), No. 6.
• Fortier, Rénald: "Did astronomers at the Dominion Observatory discover a new planet? Read all about it!" François Charles Pierre Henroteau, Miriam Seymour Burland and Planet 'X' - or was it Planet 'Y', part 3. Ottawa, Ingenium Channel, Apr 13, 2025, (https://ingeniumcanada.org/channel/articles/did-astronomers-at-the-dominion-observatory-discover-a-new-planet-read-all-about-1).
• Hodgson, John: The History of the Dominion Observatories: I 1905--1946; II 1946 -- the present. Ottawa 1965.
• Hodgson, John H.: The Heavens Above and the Earth Beneath: A History of the Dominion Observatories, Energy, Mines and Resources Canada 1989.
• Jarrell, Richard A.: The Cold Light of Dawn: A History of Canadian Astronomy. Toronto: University of Toronto Press 1988.
  
• Jarrell, Richard A.: The Cold Light of Dawn: A History of Canadian Astronomy. Toronto: University of Toronto Press 1988.
• King, William Frederick.  In: Dictionary of Canadian Biography (online ed.). Toronto: University of Toronto Press 1979-2016.
• Klotz, Otto: The Dominion Astronomical Observatory at Ottawa. In: Journal of the Royal Astronomical Society of Canada 13 (1919), No. 1.
• Locke, J.L.: Obituary -- Beals, Carlyle-Smith 1899--1979. In: Journal of the Royal Astronomical Society of Canada 73 (1979), p. 325, (1979JRASC..73..325L).

Links to external sites 

• Dominion Observatory, Ottawa, Ontario
• Observatories in the second half of the 19th century in Canada -- The first astronomical observatory in North America was Canadian (Jesuit priest Joseph-Pierre de Bonnécamps, College of Quebec from 1750 to 1759)
• Dominion Observatory - Classified Federal Heritage Building
• Dominion Observatory, Ottawa (Wikipedia)
• William Frederick King (1854--1916)
• The Dominion Observatory's Historic Telescope, part 1 (Ingenium channel)
• The Dominion Observatory's Historic Telescope, part 2 (Ingenium channel).
• Carlyle S. Beals (Wikipedia).
• John H. Hodgson (Wikipedia).

Links to external on-line pictures 

no information available