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V. On the Periodic and Non-periodic V ariations of the Temperature at Toronto in 
Canada, from 1841 to 1852 inclusive. By CoZo/ze/ Edward Sabine, of the Royal 
Artillery, Treas. and P.P.R.S. 
Received January 20, — Read February 10, 1853. 
IHE interest with which the comparison of the contemporaneous non-periodic 
variations of the temperature in Europe and America is regarded by meteorologists 
of great reputation, leads me to hope that the present communication may not be 
unacceptable to the Royal Society. The geographical situation of Toronto, both as 
respects latitude and inland position, renders it a very suitable locality for such com- 
parison with stations in the middle parts of Europe, where similar observations have 
been made and where the conclusions to be derived from them are the subjects of 
active investigation. The years over which the observations at Toronto extended, 
1841 to 1852 inclusive, were years of unusual meteorological activity in Europe ; and 
the period of twelve years embraced by them is one of sufScient duration to supply 
a fair basis for generalisation on many of the problems which are now receiving the 
attention of meteorologists. 
The observations at Toronto were made at the Magnetical and Meteorological 
Observatory at that station, by the detachment of the Royal Artillery by whom the 
duties of the observatory were carried on, and were under the direction of Captain 
Riddell, R.A., at the commencement of the observations, of Captain Younghusband, 
R.A., from February 1841 to the end of 1844, and of Captain Lefroy, R.A., from 
1845 to 1852 inclusive. The latitude of the observatory is 43° 39'-6 N., and its 
longitude 79° 21''5 west of Greenwich ; the height above the surface of Lake Ontario 
is 108 feet, and above the Ocean about 342 feet. 
From 1841 to 1844 inclusive, the thermometer was stationed beneath a roof on 
the outside of the north wall of the observatory. The height of the roof above the 
ground was about 7 feet, and three of the sides of the space which it covered (the 
observatory wall being the fouith side) were closed in by venetian-blind shutters 
descending from the roof to within 4 feet of the ground. The slope of the blinds of 
the shutters was such as to admit a free current of air whilst it completely screened 
the thermometer from rain. The shutters and the wall were coloured green, and 
the ground beneath was a grass-plat. The thermometer was fastened to two narrow 
strips of wood running horizontally from side to side of the thermometer shed, the 
ball being perfectly free, and about 6 inches higher than the bottom of the Venetian 
blinds. The thermometer was read from the inside of the observatory through a 
MDCCCLIII. TT 
