272 



EEPORT — 1886. 



is understood to mean that the bank was not much more than 6 feet 

 high, and was hard frozen at that depth ; the depth to which the frost 

 extended is therefore unknown. 



5. Lat. 64° 20' N., long. 124° 15' W.— On Mackenzie Hirer.— The 

 face of a cliff from which a recent, land-slide had occurred was measured 

 by the present reporter in June 1844. The soil was frozen to a depth 

 of 45 feet from the surface (see 'Magnetic Survey,' p. 161). 



6. Lat. 62° 39' N., long. 115° 44' W.— At Fort Rae, on Great Slave 

 Lake. — Captain Dawson, B.A., observed the temperature of the soil 

 monthly at his station of circumpolar observation, 1882-3. The follow- 

 ing table contains his results : — 



The mean temperature of the air at 5 feet 10 inches above the surface, 

 in the same months, was as follows : — 

 1882. 



September 

 October . 

 November 

 December 



January 



1883. 



1883. 



We learn from this table that the soil is frozen at a depth of 4 feet 

 from November to June inclusive, and is at the lowest temperature at 

 that depth in March. It further shows that, like the waters of the 

 Scottish lakes, as proved by the observations of Mr. J. Y. Buchanan and 

 Mr. J. F. Morrison in Loch Lomond and Loch Katrine last winter, the 

 mean temperature of the soil reaches its minimum about the time of the 

 vernal equinox. The rise of earth temperature in February above that 

 recorded in either January or March is remarkable. It does not appear 

 from the convergence of the lines when projected that temperatures below 

 32° F. extend lower than 11 or 12 feet. Captain Dawson writes : ' There 

 are two reasons why these earth temperatures are above what is probably 

 the average in that latitude. (1) The ground had a slope of ^ to the 

 S.W. ; and (2) it was fully exposed to the rays of the sun ; now in most 



