no 



H. MOHN. METEOROLOGY. [2nd. arc. EXP. fram 



November. 



December. 



Mean | — 09J 



Dark Season. 



-07I -l-oi| +os| +03I +03I] +04I — 02| — 05I +02I +o6| — 02 [ 



The last column gives the number of days in each month, from 

 which bi-hourly observations have been available for the determination 

 of the daily period. It will be seen that all the months from November 

 to June are represented by four years, while the other months — parti- 

 cularly August — or the months in which the Fram was under way, 

 are less frequently represented in this respect. The means for these 

 later months have been computed, giving the numbers a weight pro- 

 portional to the number of observing days. They are designated 

 Weighted means. 



By plotting the means and drawing a free-hand curve, I obtain 

 the numbers headed "Smoothed". In these as well as in the "Means" 

 the sum of the negative numbers is equal to the sum of the positive 

 numbers. In some months, April, July and August, no smoothing of 

 the numbers has been judged necessary. The smoothed numbers may 

 be taken as the best expression for the daily period. 



The minima and maxima of the smoothed curves have been calcu- 

 lated by a parabolic formula ^ The following Table gives the hour and 

 amount of the minima and maxima, their difference or the daily peri- 

 odic range, and the "Mean ordinate", or the mean of the 12 positive 

 and negative numbers in the row "Smoothed". 



Norw. N. Pol. Exp. 1893-96, p. 469. 



