248 METEOROLOGY. 



from the Irish Sea and the Atlantic Ocean, When their contents 

 reach the colder air of the mountainous distiicts, they are con- 

 densed and are deposited on the sitles of the eminences which 

 arrest their progress, and thus occasion the extraordinary amounts 

 of rain in these particular localities. The difference in the tem- 

 perature of different portions of a no very extended district in a 

 mountainous country is often considerable. In the process of 

 restoring the equilibrium thus temporally destroyed, currents 

 and eddies of wind are propagated, and are often the causes of 

 sudden and strong gusts which rush down the sides of the moun- 

 tains, and agitate the surface of the adjoining lakes, to the risk of 

 the slight sailing-vessels that are kept on most of the larger sheets 

 of water in this district. This agitation of the surface is often 

 attributed by the natives to wliat are termed " bottom winds," or 

 violent currents of air rising from the bottoms of the lakes, and 

 thus causing these agitations of the surface. The various direc- 

 tions of the winds among the masses of the mountains, at no great 

 distance from each other, may be ascribed to the various deflections 

 of the aerial currents, occasioned by the different positions of the 

 flanks of the hills, turning the direction of the current from its 

 original course, so that a wind from the west, for instance, may be 

 deflected by the flank of a mountain and become a north-west or 

 south-west wind at another part near to the same place, according 

 as the face of the hill may tend in one direction or the other. But 

 little dependence on the probable changes of the weather can be 

 placed in the direction of the winds near the surface, as these 

 conformations of the eminences must often and sometimes very 

 materially alter the original course of the currents in the air. 



S. M. 



