page_title: David Dunlap Observatory
section_title: Genesis
hierarchical_section_title: David Dunlap Observatory / History / Genesis
caption_attribution_description: Concept sketch of David Dunlap Observatory
context_page_description: The David Dunlap Observatory is an astronomical observatory site just north of Toronto, in Richmond Hill, Ontario, housed on a 189-acre estate. Formerly owned and operated by the University of Toronto, from its establishment in 1935 until 2008; the observatory is now managed by the Royal Astronomical Society of Canada, Toronto Centre, and the David Dunlap Observatory Defenders. Its primary instrument is a 74-inch reflector telescope, at one time the second-largest telescope in the world, and still the largest in Canada. Several other telescopes are also located at the site, which formerly also included a small radio telescope. The legacy of the David Dunlap Observatory continues in the Dunlap Institute for Astronomy & Astrophysics, a research institute at the University of Toronto established in 2008.
  The DDO is the site of a number of important studies, including pioneering measurements of the distance to globular clusters, providing the first direct evidence that Cygnus X-1 was a black hole, and the discovery that Polaris was stabilizing and appeared to be "falling out" of the Cepheid variable category.
context_section_description: The DDO owes its existence almost entirely to the efforts of one man, Clarence Chant. Chant had not shown an early interest in astronomy, but while attending University College, University of Toronto he became interested in mathematics and physics, eventually joining the university as a lecturer in physics in 1892. Over the next several years he worked as a schoolteacher and civil servant. During a later leave of absence he earned his PhD from Harvard University and did postdoctoral work in Germany.
  Chant joined the Astronomical and Physical Society of Toronto in December 1892; it was eventually renamed the Royal Astronomical Society of Canada in 1902. Chant became president of the Society, serving between 1904 and 1907. Throughout the 1890s, Chant was concerned about how little the University did for astronomy, and in 1904 he proposed adding several undergraduate courses for fourth-year students, and six such courses were added to the 1905 calendar.
  With courses now officially on the books, Chant started looking for a proper telescope. Previously the university had hosted the Toronto Magnetic and Meteorological Observatory, which had been run by the Meteorological Office of the Ministry of Marine and Fisheries. The observatory, built in 1840, had contained the high-quality 6-inch (150 mm) Cooke Refractor, but the Observatory was now surrounded by new university buildings, rendering it useless for astronomy. The Meteorological Office had already decided to abandon the site and turn the building over to the university, but they were taking the telescope with them to their new location at 315 Bloor Street West. Even if the university had been able to secure time on the instrument, which was highly likely, it was at this time quite a small instrument in comparison to those being built around the world.
  The same problem of encroachment that had led to the observatory falling into disuse led Chant to conclude that there was no suitable location on the university grounds for a new observatory, and he started looking for off-campus sites. While looking, he started getting quotes for a new instrument from Warner & Swasey in Cleveland, Ohio, who had provided the mount for the recently opened Dominion Observatory in Ottawa. In 1910 Chant finally found the perfect location, a 10-acre (40,000 m²) plot of land near what is today Bathurst Street and St. Clair Avenue. The land had originally been set aside by the city for the Isolation Hospital, but this was never constructed and it now lay empty. Chant convinced the city to become involved in the Royal Astronomical Observatory, but the outbreak of World War I put the project on hold, and in 1919 it was cancelled outright.
caption: Concept sketch of David Dunlap Observatory
exif: {"Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop 7.0", "Image DateTime": "2008:01:29 16:07:24", "Image ExifOffset": "156", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "294", "Thumbnail JPEGInterchangeFormatLength": "3163", "EXIF ColorSpace": "Uncalibrated", "EXIF ExifImageWidth": "460", "EXIF ExifImageLength": "322"}