504 



H. MOHN. METEOROLOGY. 



[NORW. POL. EXP. 



As a rule the southerly to westerly winds bring most vapour into the 

 atmosphere, and the northerly winds less. March, June, August and Sep- 

 tember exhibit a smaller maximum with north-easterly winds. PL VI. (1 cm. 

 = 1 mm.) 



The vapour-tension with calms, for each month, is generally of the same 

 amount as the mean value, and shows an analogous annual range. Its maxi- 

 mum falls in July and August, the maximum of the monthly tension in July. 

 PL VI. (1 mm. = 1 mm.) 



The tension of vapour with calms is less than the mean tension with 

 winds in each of the four meteorological seasons. It is greater than the mean 

 tension with wind in the sunny season and in the equinoctial months, but the 

 difference is inconsiderable. 



