XIII. 



N. AMERICA. LAKE ATHABASCA. Lat. 59 N. Long. 111 W. Greenw. 



Corrections to be applied to the Means of the Hours of Observation to obtain the true 

 Mean Temperatures of the respective Days, Months, and of the Year. LEFROY. 



The corrections for April and May are derived from observations made at Fort Simpson, Lat. 62o N. 

 Degrees of Fahrenheit. 



The numbers without sign must be added ; those with the sign must be subtracted. 



25 



