Читать книгу The Dominion Astrophysical Observatory, Victoria, B.C онлайн

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It was necessary to know the location of the instrument before the design of the mounting could be completed as the angle of the polar axis depends upon the latitude of the site. When the new telescope was first proposed there was no thought of locating elsewhere than at the seat of government at Ottawa. However, upon further consideration it was decided that the telescope should be located where, in Canada, the best observing conditions prevailed. To determine this location preliminary selection of five likely stations was made by the aid of Sir Frederic Stupart, chief of the Meteorological Service from the meteorological records. These stations, at Ottawa, at Medicine Hat, at Banff, at Penticton, and at Victoria were occupied by Mr. W. E. Harper, astronomer at Ottawa and the astronomical conditions were observed by means of a 4.5-inch telescope. Victoria was unmistakably superior in “seeing” or defining power, in low diurnal and seasonal range of temperature and about equal so far as quantity of clear sky is concerned. For such a large telescope as a 72-inch there could be no question of the marked astronomical advantages of such a location, and it was therefore decided to locate the telescope at Victoria. While the observatory should not be in the city itself it should not be too far away, not only on account of accessibility and facility in obtaining supplies, but also the advantageous conditions of good seeing, low diurnal range of temperature and small rainfall were confined to a relatively small area near Victoria. An isolated monadnock called locally Little Saanich Mountain but now named Observatory Hill, was selected. This hill is about 7 miles north of Victoria and has a main road and an interurban railway passing its base. It has an elevation of 730 feet, sufficient area around the summit for all necessary buildings and was by far the most suitable site available.