162 



THE ROYAL SOCIETY OF CANADA 



This cable was larger, and embodied improvements which our previous 

 experience had found necessary. 



In the Autumn of 1912 the observations were resumed. The same 

 thermometers have been used, but a new Recorder, built by the Cam- 

 bridge Scientific Instrument Co., has replaced the old Callendar 

 instrument. 



The records have proved unusually good, and we trust that a new 

 series of curves will now be obtained, which will enable us to continue 

 our study of the changes in the monthly differences. 



The observations so far reduced are those for the months of Decem- 

 ber, 1912, January, March, and April, 1913. These are given in the 

 following table. 



Table of Monthly Differences between the summit and base of Mount 



Royal. 



In the last column we give the deviation of the average temperature 

 for each month from the average for the same month during the past 

 38 years taken from the observatory records. It is of interest to notice 

 that all the five months, except one, show high temperatures. January 

 is as much as 10 degrees above the average, and this must be regarded 

 as abnormal. Associated with these high temperatures, we find that 

 the differences between the summit and base of the Mountain are 

 adnormally small. Comparison with the values we previously obtained 

 shows that the average for December is the smallest monthly difference 

 we have ever observed. This is associated with abnormally high 

 temperature conditions for this and the succeeding month, as shown 

 by the readings at the observatory. Only a few records were obtained 

 during the month of February owing to a defective contact, which 

 resulted from the drying out of the wood on the recorder. It was some 

 time before the trouble was located owing to its gradual appearance, 

 and difficulty of location. 



