304 



H. MOHN. METEOROLOGY. 



[nOEW. POL. EXP. 



below and above 4"5 metres per second for each month. The numbers 

 used for the pressure are the mean values of the pressure for each day 

 given in the next chapter. The results of this calculation are given in the 

 following tables. 



Mean 

 velocity. 



m. p. s. 



Mean 

 pressure 



Mean 

 velocity. 



m. p. s. 



Mean 

 pressure. 



Diffe- 

 rence in 

 pressure. 



m.m. 



January 1894-96 

 February — i — 

 March — » — 

 April _ » — 



May — » — 



June — J — 



July -.- 



August 1894-95 

 September — > — 

 October 1893-95 

 November — »- 

 December — » — 



Year 



3-06 

 3-03 

 313 

 2-98 

 3-03 

 3-15 

 3-64 

 3-02 

 3-24 

 2-93 

 2-85 

 2-79 



761-4 

 64'4 

 60-6 

 64-5 

 638 

 59-7 

 57-4 

 64'0 

 57-3 

 64-8 

 60-1 

 66-0 



6-30 

 6-90 

 6-03 

 5-95 

 6-30 

 6-49 

 5-57 

 6-67 

 5-96 

 6-75 

 6-56 

 6-27 



757-5 

 50-7 

 55-2 

 60-3 

 59-8 

 57-0 

 53-4 

 560 

 53-1 

 57-8 

 57-4 

 55-1 



3-9 

 13-7 

 5-4 

 4-2 

 4-0 

 2-8 

 4-0 

 8-0 

 4-2 

 7-0 

 2-7 

 10-9 



3-10 



762-0 



6-27 



756-1 



5-9 



The table shows that the weaker winds correspond to a pressure above 

 760 m.m., and the stronger winds to a pressure below 760 m.m. We know 

 that anticyclonic winds are as a rule the weaker, and cyclonic winds the 

 stronger. 



The remarkable magnitude of the range of the diurnal period of the 

 velocity of the wind in the dark season, has induced me to calculate the 

 relative frequency of the different wind-directions in this season, separately 

 for weaker and for stronger winds. The result is given in the following 

 Table. Frequency per cent. 



