PROCEEDINGS OF THE CANADIAN INSTITUTE. 



The Toronto Magnetic Observatory. By R. F. Stupart, Director. 



(Read January 14th, iSqq.) 



On the recommendatiou of the Royal Society aud the British Associatiou the 

 British Government determined in 1840 to establish a fixed Magnetic Observatory 

 in Canada, and it was decided that it should be placed under the general super- 

 vision of the Ordnance Department of the Army. Arrangements having been 

 completed, Lieutenant Charles James Buchanan Riddell, R.A., was selected for 

 duty in Canada. Leaving his detachment, consisting of four non-commissioned 

 oificei's of the artillery to embark with the instruments on a vessel bound direct 

 to Quebec, he proceeded himself to Canada by the more expeditious route of the 

 United States. Having waited on the Governor-General at Montreal to present a 

 letter of introduction with which he had been furnished by the Master-Geileral of 

 Ordnance, and having communicated with the commanding engineer, to whom 

 he was the bearer of instructions and authority to build an Observatory, he pro- 

 ceeded to examine different localities which were suggested as convenient sites. 

 The preference was finally given to Toronto, where a grant of two and a half acres 

 of land belonging to the University of King's College was offered by the Council 

 of the LTuiversity. The first Observatory building was^of logs, rough cast ou the 

 outside and i^lastered on the inside ; it was completed during the summer of 1840, 

 and the observations were begun in September. The operation of the Observatory 

 as an Imperial establishment was brought to a close in the early part of the year 

 1853, and was resumed under the authority of the Provincial Government in July 

 of the same year. 



In the autumn of 1853 the present Observatory was commenced, to take the 

 place of the old building. Very great care was taken during construction to 

 insure freedom from magnetism in all the stone used, and all nails and fiistenings 

 were of either copper or zinc. For twenty-three years the position of the Ob.^er- 

 vatory was, as far as known, faultless ; observations were carried on systematically 

 and carefully, and results were given to the scientific world which, with those 

 obtained under the old military regime, have made the Toronto Observatory 

 famous in the history of Terrestrial Magnetism. 



In 1876. however, trouble began with the erection of buildings close to the 

 Observatory, causing some very small changes in zero values. Then followed a few 

 years later electric light circuits, which produced a change in the force instruments 

 whenever the currents were turned on and oft" ; this difficulty was in part over- 

 come by the Light Company courteously agreeing to arrange their Avires in the vicin- 

 ity of the Observatory in such a manner that the currents would counteract each 

 other. The next difficulty occurred when a large addition was made to the neigh- 

 bouring buildings before mentioned, tons of iron were used in construction in all too 



