RECORD AND DISCUSSION OF TEMPERATURES. 27 



rn r~~r 



rig. 3 



\ 



\ 



I i 



CQ O 



S P=H 



SCS BELOW THE HORIZON. 



bo 

 O 

 &quot;t 



SUN ABOVE THE HORIZON. 



The absolute maximum value of the amplitude was observed in April (9. 09), 

 and the absolute minimum in November (1.00); the diurnal variation never dis 

 appearing altogether, although the sun remained for 2i months below the horizon. 

 A secondary minimum was reached in July (3. 37), somewhat later than the 

 middle of the time the sun made his circuit round the points of the compass with 

 out setting. 1 The mean amplitude of the diurnal variation during the whole year 

 is 4.20 the maximum rising 4. 9 above, and the minimum falling 3. 2 below. 

 The daily range of the effect of the thermal wave propagated northward during 

 the long arctic darkness, may be set down to 1.6 on the average. 



For the purpose of comparing with similar results at other stations, I add a table 

 of the mean daily variation during the year. Each figure is simply the mean of 

 the twelve values corresponding to the same hour, and was taken from the preced 

 ing table. No attention was paid to the small anomalies noticed in three winter 

 months, which cannot sensibly affect the means. The second column contains the 

 mean values, and the third the same after the general mean has been subtracted 

 from each of them, and, consequently shows the mean variation proper, + indicat 

 ing a &amp;lt; , &amp;gt; value than the mean. The fourth column exhibits the hourly 

 ( lower j 



differences of the variation. 



1 A more complete understanding of the diurnal variation can only be had in connection with hygro- 

 metric observations. 



