NO. 17.] 



PRECIPITATION. 



531 



The Table and the diagrams on PL IX (1 mm. = 10 per cent. 1 ) show that 

 the greatest probability of precipitation belongs generally to winds from the 

 south-eastern quadrant, but without any regular distribution in the different 

 months. The least probability is found with winds from the north-eastern 

 and north-western quadrants. All winds may be attended by precipitation. 

 Calms are very seldom accompanied by precipitation. The formation of rain 

 and snow goes on more easily and frequently with wind than in calm weather. 

 The following Table sums up the results: 



NUMBER OF DAYS WITH PRECIPITATION. 



The following Tables show the number of days on which rain, snow, 

 or both rain and snow have been observed. 



1 On PI. IX is written 1 per cent, indstead of 10 per cent. 



