METEOROLOGY. 



XXV. 



The heavy rainfall at Glenlee is probably due to its situation on 

 the eastern side of a hilly region where many of the summits are over 

 2000 feet in altitude. 



The westerly and south-westerly winds laden with moisture from the 

 Atlantic meet these hills, and are forced up into a higher stratum of the 

 atmosphere, where they expand under the lower pressure there existing. 

 Consequently the aqueous vapour is condensed, and heavy rain falls on 

 the hills, and particularly their eastern slopes. There was a good example 

 of this on a smaller scale in 1888 at Drumpark, where 47*20 inches fell, 

 as compared with only 37 inches at Dumfries. 



It is also commonly observed that across the watershed of the Nith 

 valley, for example at Colvend, there is frequently no rain, while there 

 is continuous wet weather about Dumfries. 



The direction of the wind seems to be chiefly westerly. Thus the 

 mean of nine years gives as below : 



S.W. 

 Days, 89 



W. 



62 



N.W. 



42 



N.E. 

 39 



E. 



S. 

 32 



S.E. 

 26 



N. 

 23 



Calm or Variable. 

 17 



The following table is also interesting : 



WIND. 



Cyclones passing over the county almost invariably pass from S.W. 

 or S.S.W., to N.W. and N. The wind veers from the former to the 

 latter direction as the depression passes. It is possible this may account 

 for the curious difference betwixt the wind observations, Dumfries 

 having 71 south-westerly wind days, Drumlanrig 57, and Wanlockhead 

 only 8. 



* No reports of wind at Wanlockhead for months of April, July, August, and September. 



