The nation’s timekeeper: McGill and the Dominion Observatory
The Department of Atmospheric and Oceanic Sciences marks its 50th anniversary this year, but meteorological work at McGill began about 150 years ago inside a stone tower built by the Dominion of Canada to track the north star and keep time for the freight trains. Known locally as the McGill Observatory, this tower enclosed a 7-foot telescope and stood on the bluff just behind what is today the Leacock Building. “The nation’s timekeeper” was housed inside this tower, and most of Canada’s clocks in the last century were set by McGill’s time!
By 1863, the wires from the Montreal Telegraph office had been laid into the Observatory to connect it with the principal places in the United States because the President of Grand Trunk Railway had proposed that there be an observatory in Montreal, and that the University might offer a ‘sight’. All the American railways were recommending astronomical observatories to provide reliable time-keeping. Dr. Clement Henry McLeod, or “Bunty” had already started working in the Observatory while he was an undergrad Engineer and he had been allowed to room in the McGill College Building beside the observatory so he could take observations at the required times.
This 7-foot telescope was used by Bunty to take daily measurement of astronomical readings lined up with the North Star. As Supervisor of the Observatory, Dr. McLeod calculated McGill’s longitude relative to the continental reference point at Harvard College. In 1892, while working on a follow-up reading relative to the zero meridian at Greenwich, England, McLeod revised the longitude figure for Harvard. As a result, McLeod was responsible for more accurately positioning every city, town, hamlet and farm in North America. In his honour, a plaque made from the housing of this telescope is mounted on the Radar Station at Ste. Anne-de-Bellevue and reads “Henry McLeod, B.A. Sc., F.R.S.C. THE NATION’S TIMEKEEPER”.
In the late 1800s, the Canadian Meteorological service started a ‘new’ comprehensive system of observing the weather and reporting it by telegraph to a central forecast office in Ottawa. In 1874 the McGill Observatory became “chief station” in the new network connected directly to the telegraph system so observations could be reported without delay every 3 hours. Thus, the timekeeping grew out of the astronomical observations. All of Canada set their watches by McGill’s time for many years and the railways were still using the signal in the 1960s.
C.H. McLeod Achievements
In 1882, McLeod was one of the observers in an international effort to watch and record the transit of Venus. By observing (from various locations) the rare event of Venus passing in front of the sun, it was an opportunity to get a better estimate of the size of the solar system. McLeod went to Winnipeg to observe the event, while another observer at McGill also attempted observations but there were some problems with clouds over Montreal and the readings were not accurate enough. In 1886, McLeod and Howard Barnes (Macdonald Professor of Physics) measured the temperature differences between the observatory and the top of Mount Royal. They found changes in temperature at the Observatory that were anticipated by corresponding changes at the top of the mountain, varying from 4-24 hours. This work was ahead of its time, detecting the passage of cold-fronts and warm-fronts before such things had been discovered or conceived. In 1889 he was made Fellow of the Royal Society of Canada (RSC) and his work was published in the Transactions of RSC. McLeod died in 1917. His legacy was that he made McGill a centre for research in meteorology and geodesy for over 60 years.
An untimely end…
McGill Observatory became the outstanding time-keeping observatory in Canada, providing time signals to the railways and to government services in Ottawa, including the signal that fired the noon gun on Nepean point. This supremacy continued for ten years after McLeod’s death, until the late 1920s when the Dominion Observatory in Ottawa appropriately took over the task of being the country’s time-keeper, but for another forty years McGill’s time signals continued to go out to the railways.
The Observatory was destroyed in 1962 to make way for construction of the Leacock Building. A brass marker embedded into the floor slate outside Leacock Room 132 marks the spot where the telescope was mounted in the Observatory.