292 



H. MOHN. METEOROLOGY. 



[NORW. POL. EXP. 



have deduced the numbers contained in the following Table, viz. for each 

 month the hours (h), and values (D) of the daily minimum and maximum, 

 the diurnal range or amplitude, and the mean of the hourly values with- 

 out respect to the sign, or what we call the mean ordinate (M. Or.). The hours, 

 or epochs, are given to the nearest tenth of an hour. 



The velocity of the wind is lowest in the morning hours, and strongest 

 in the hours about and after noon: this is the usual rule. The range has 

 an annual period ; it has its highest maximum in May, and a second maxi- 

 mum in September and October, and minima in December and July. The 

 mean ordinate has an annual period of exactly the same character. 



Taking the means for the meteorological seasons, and for the dark season, 

 the sunny season, the equinoctial months, and the year, we get 



