84 LOCAL CAUSES. 



formerly an atmospheric chaos, an evidence of design 

 and system, which is not, indeed, absolutely clear, 

 but which is nevertheless abundantly perceptible to 

 minds that cannot hope in this life to see otherwise 

 than "through a glass, darkly." 



The causes which modify the action of the winds 

 are, as we have said, various. Local causes pro- 

 duce local currents. A clear sky in one region 

 allows the sun's rays to pour upon, let us say, the 

 ocean, producing great heat ; the result of which is 

 evaporation. Aqueous vapour is very light, there- 

 fore it rises ; and in doing so the aqueous particles 

 carry the air up with them, and the wind necessarily 

 rushes in below to supply its place. The falling of 

 heavy rain, in certain conditions of the atmosphere, 

 has the effect of raising wind. Electricity has also, 

 in all probability, something to do with the creation 

 of motion in the atmosphere. Now, as these are 

 all local causes, they produce local or what, in regard 

 to the whole atmosphere, may be termed irregular 

 effects. And as these causes or agents are in cease- 

 less operation at all times, so their disturbing influ- 

 ence is endless ; and hence the apparent irregularity 

 in the winds. 



But these causes are themselves, not less than 

 their results, dependent on other causes or laws, the 

 workings of which are steady and unvarying ; and the 

 little irregularities that appear to us in the form of 

 fluctuating and changing winds and calms may be 

 compared to the varying ripples and shifting eddies 



